METHOD AND SYSTEM FOR GEOTHERMAL DESIGN, ANALYSIS AND INSTALLATION CERTIFICATION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority under 35USC§119(e) of US provisional patent application 61/411153, filed on November 8, 2010.

BACKGROUND

(a) Field

[0002] The subject matter disclosed generally relates to geothermal technology. More specifically, it relates to the design and analysis of geothermal installations.

(b) Related Prior Art

[0003] How GeoExchange Systems Work?

[0004] The heat energy taken from the ground by a GXS (or GeoExchange Systems) is considered low-grade heat. In other words, it is not warm enough to heat your home without being concentrated or upgraded somehow. However, there is plenty of it - the average temperature of the ground just a few meters below the surface is similar to (or even higher than) the average annual outdoor air temperature. For example, in Toronto, the average annual air temperature is about 8.9°C, but the average ground temperature is 10.1 °C. It is important to note that this ground temperature is 10.1°C on the hottest day of summer as well as on the coldest day of winter. That is why some of the first humans lived in caves - the caves would protect them from the temperature extremes of winter and summer. That is also why a GXS works so efficiently - it uses a constant, relatively warm source (ground or water) from which to draw energy. [0005] Basic Components of a GXS

[0006] Generally speaking, a GXS is made up of three main parts: a loop, the heat pump and the distribution system. The following section describes some of the various loop designs, heat pumps and distribution systems commonly used in a Canadian GXS.

[0007] The loop is built from polyethylene pipe which is buried in the ground outside your home either in a horizontal trench (horizontal loop) or through holes drilled in the earth (vertical loop). The loop may also be laid on the bottom of a nearby lake or pond (lake loop or pond loop). The GXS circulates liquid (the heat transfer fluid) through the loop and to the heat pump located inside the home. The heat pump extracts heat from the ground and distributes the heat collected from it throughout the home. The chilled liquid is pumped back into the loop and, because it is colder than the ground, is able to draw more heat from the surrounding soil. These loops are often referred to collectively as a closed loop, as the same liquid circulates through the closed system over and over again.

[0008] Each of the ground-coupling systems already described utilizes an intermediate fluid to transfer heat between the ground and the refrigerant. Use of an intermediate heat-transfer fluid necessitates a higher compression ratio in the heat pump in order to achieve sufficient temperature differences in the heat- transfer chain (refrigerant to fluid to earth). Each also requires a pump to circulate water between the heat pump and the ground loop. Direct-expansion systems remove the need for an intermediate heat-transfer fluid, the fluid- refrigerant heat exchanger and the circulation pump. Copper coils are installed underground for a direct exchange of heat between refrigerant and ground. The result is improved heat-transfer characteristics and thermodynamic performance. However, the systems require a large amount of refrigerant and, because the ground is subject to larger temperature extremes from the direct expansion system, there are additional design considerations. In winter heating operation, the lower ground-coil temperature may cause the ground moisture to freeze. Expansion of the ice buildup may cause the ground to buckle. Also, because of the freezing potential, the ground coil should not be located near water lines. In the summer cooling operation, the higher coil temperatures may drive moisture from the soil.

[0009] Another way is to pump ground water or well water directly through the heat pump. A GXS that uses ground water is often referred to as an open- loop system. The heat pump extracts heat from the well water, which is usually returned to the ground in a return well. To run an open-loop GXS, it needs two reliable wells with water that contains few dissolved minerals that can cause scale build-up or rust over the long term, as it is pumped through the heat pump's heat exchanger.

[0010] In both cases, a pump circulates liquid through the loop and the heat pump. The heat pump chills (or collects the heat stored in) the liquid when it is being used as a source of heat, and circulates it back through the loop to pick up more heat. A system for a large home will require a larger heat pump and ground loop, with a circulation pump to match.

[0011] After the GXS has taken the heat energy from the ground loop and upgraded it to a temperature usable in the home, it delivers the heat evenly to all parts of the building through a distribution system. It can use either air or water to move the heat from the heat pump into the home. Forced air is the most common distribution system in most parts of Canada, although a hot-water or hydronic system can also be used. [0012] Forced-Air Systems

[0013] A heat pump in a forced-air GXS uses a heat exchanger to take the heat energy from the refrigerant to heat the air that is blown over it. The air is directed through ducts to the different rooms in the home, as with any forced air fossil fuel or electric furnace. The advantages of a forced-air GXS are as follows: it can distribute fresh, outside air throughout the home if it's coupled with a heat recovery air exchanger; it can air-condition the home (by taking the heat from the air in your home and transferring it to the ground loop) as well as heat it; and it can filter the air in your home as it circulates through the system

[0014] Generally, a GXS is designed to raise the heat of the air flowing through the heat pump by between 10 and 15°C; fossil fuel or electric furnaces are designed to raise it by 20 to 30°C. That difference means a GXS must move more air through the home to distribute the same amount of heat as a conventional furnace. So to design an efficient, quiet forced-air GXS, the contractor designing the ductwork must take into account the larger amount of air to be moved. The ductwork should also have acoustic insulation installed inside the plenum and the first few meters of duct, as well as a flexible connection between the heat pump and the main duct to ensure quiet operation.

[0015] Hydronic (Hot-Water) Heating Systems

[0016] As described earlier, a heat pump can heat either air or water. The latter type distributes the heat by means of a hydronic (or hot-water) heating system. If you choose it for your home, keep in mind that currently available heat pumps can heat water to no more than about 50°C.

[0017] This limits the choices for equipment to distribute the heat to your home. Hot-water baseboard radiators are designed to operate with water heated to at least 65 to 70°C; they are less effective when the water is not as warm. As a result, larger radiators will be needed - or more of them - to distribute the same amount of heat. Or it is possible to reduce the heat loss from the home by installing more insulation, so less heat will be needed. It is also possible to install radiant floor, or in-floor, heating systems. These are becoming more common because they can increase comfort and improve system efficiency. Again, it is a need to make sure that the radiant floor heating system is designed to operate within the temperature capabilities of the GXS.

[0018] The temperature difference between the ground loop and the hot water distribution system depends on the efficiency of the GXS; the greater the difference, the less efficient the system. Typically, a GXS will extract heat from the earth at about 0°C. If a radiant floor heating system requires a temperature of 50°C to heat the home, the heat pump will produce about 2.5 units of heat for every unit of electricity used to operate the system. If the system can be designed to operate with water at 40°C, it will produce 3.1units of heat for every unit of electricity used to operate it. In other words, it will be about 25 percent more efficient.

[0019] For instance, if hot spring water is available to heat the home, a heat pump is not required. The hot spring is a totally free, 100 percent efficient source of energy. But if the temperature of the water from the well needs to be raised 5°C to be high enough to heat the home, some additional energy is needed. If it has to be raised 20°C, even more energy is needed. The greater the temperature difference, the greater the additional energy need. If thinking of installing a radiant floor heating system in the home, the person designing should know that it is planned to use a GXS. The following factors should be taken into account: placing the floor pipe 20 cm (rather than 30 cm) apart reduces the water temperature required to heat the home by 4 to 5°C and increases the efficiency of the GXS by about 10 percent; laying the floor heating pipe in concrete rather than using aluminum reflective plates with the pipe reduces the required temperature by 12 to 15°C, increasing the efficiency of the GXS by 25 to 30 percent; suspending pipe in the joist space under a floor means that y temperatures higher than what the GXS can produce is needed, unless the heat loss in the space is very low; placing insulation under a slab-on-grade floor or under a basement floor reduces heat loss to the ground below; and installing a control system that lowers the water temperature pumped through the floor as the outdoor temperature rises increases the efficiency of the GXS. This type of control is commonly called an outdoor reset control.

[0020] GXS, by definition, use the earth as their energy source. As noted earlier, there are basically two ways to move energy from the ground and into the home - an open loop or well-water system, or a closed loop.

[0021] In a closed loop system, a loop is buried in the earth around the home, or laid in a nearby lake or pond. Virtually all loops built today use high- density polyethylene (HDPE) pipe. This type of pipe is specifically designed to be buried in the ground and is marked "geotherma or "geo". It cannot be marked "potable". Joints are made by fusing or melting the pipe and fittings together, which makes a nearly leak-proof connection. Mechanical joints are not used in the ground. A loop made out of HDPE can last 50 years or more.

[0022] For instance, a mixture of antifreeze and water is circulated continuously through the loop and heat pump, transferring heat from or to the soil respectively, as heating or air conditioning is needed. In a closed-loop system, the fluid never comes in contact with the soil. It is sealed inside the loop and heat pump.

[0023] In an open-loop system, ground water is drawn up from a well and through the heat pump, then typically pumped back into a return well. New water is always being pumped through the system when it is in operation. It is called an open-loop system because the ground water is open to the environment.

[0024] Closed Loops [0025] Closed loops can have many configurations. There are three basic types: vertical, horizontal and lake (or pond). The loop type and configuration most suitable for the home depend on the size of the property, the future plans for it, its soil, and even the contractor's excavation equipment. Most often, the loop configuration is selected on the basis of cost. If the loop is designed and installed properly, by taking into account the heating and cooling requirements of the home, one type of loop will operate with the same efficiency as another, and provide years of free, renewable energy.

[0026] Over the years, the industry has developed standards for GXS installation. The best known standard is CSA C448.2-02 Design and Installation of GeoExchange Systems for Residential and Other Small Buildings. In addition, most heat pump manufacturers have developed guidelines or proprietary software for their products to ensure that GXS using them are designed and installed according to their specifications. As a homeowner considering the installation of a GXS, it is important to ask the contractor for proof of training, experience and competence of its staff in loop design and installation. Since 2007, the Canadian GeoExchange Coalition trains and accredits industry professionals. The best way to ensure the installation contractor's competence is to verify whether he/she is CGC accredited.

[0027] Horizontal Loops

[0028] As the name implies, these loops are buried horizontally, usually at a depth of about 2 to 2.5 m, although it can vary from 1.5 to 3 m or more. Usually trenches are excavated with a backhoe; a chain trencher can be used in some soil types. Fill can sometimes be used to cover a loop in a low-lying area of the property. The trench can be from 1 to 3 m wide. Four or even six pipes can be laid at the bottom of a wide trench, while some loop designs allow two layers of pipe to be stacked in a trench at different levels. Loop configurations may even use a "slinky" or coiled configuration that concentrates additional pipe in a trench. Many different configurations have been tested and approved. It is important to ask the contractor for references in those types of GXS installations. Contractors can often show photographs of loops they have installed.

[0029] The area needed to install an horizontal loop depends on the heating and cooling loads of the home, the depth at which the loop is to be buried, the soil and how much moisture it contains, the climate, the efficiency of the heat pump and the configuration of the loop. The average 150-m ² home needs an area of between 300 and 700 m ² . The contractor will use computer software or loop design guidelines provided by the heat pump manufacturer to determine the size and configuration of the earth loop.

[0030] Vertical Loops

[0031] Vertical loops are usually made out of HDPE pipe, which is inserted into holes drilled in the soil. Taking in to account different Canadian geological conditions and drilling equipment used, these boreholes are 15-150 m deep, and 10-15 cm around. Generally, two lengths of pipe are fused into a "U-bend" (two 90° elbows) and inserted into the borehole. The size of pipe used for the loop varies, depending on the cost of drilling and the depth of the borehole; 32 mm pipe is common in some areas, 19 or 25 mm pipe in others. After the pipe has been placed in the borehole, it must be grouted to prevent potentially polluted surface water infiltration into lithostratis graphic units and aquifers. A bentonite grout is normally used. This is to ensure good contact with the soil and prevent surface water from contaminating the ground water. CSA standards specify that the borehole around the pipe is to be filled by means of a tremie line, or a pipe inserted to the bottom of the borehole and retracted as it is filled with grout. This process is designed to eliminate air pockets around the pipe and ensure good contact with the soil. [0032] The main advantage of a vertical loop is that it can be installed in a much smaller area than a horizontal loop. Four boreholes drilled in an area of 9 m ² - which fits easily into an average city backyard - can provide all the renewable energy needed to heat an average 150-m ² home.

[0033] The cost of installing a vertical loop can vary greatly, with soil conditions the single most important factor. Drilling into granite requires much heavier, more costly equipment, and is much more time-consuming than drilling into soft clay. It is even more time-consuming when the soil contains a mix of materials, such as layers of boulders, gravel and sand.

[0034] The installation of a vertical loop in this type of soil is three to four times more costly than that of a horizontal one. In areas like southern Manitoba and Saskatchewan, however, where glacial Lake Agassiz has left 15-50 m of soft clay deposits, a vertical loop can be installed for about the same cost as a horizontal one.

[0035] The depth of borehole needed for a vertical loop depends on the same factors that determine the land area required for a horizontal one. The land area needed for the vertical loop, however, depends on the depth to which the boreholes can be drilled cost-effectively. For example, if a GXS requires 180 m of borehole in total, and is to be installed where bedrock is found at 20 m, it would usually be cheaper to drill nine boreholes to a depth of 20 m than three to a depth of 60 m. Nine boreholes would require an area of about 150 m ² , and three, an area of about 60 m ² .

[0036] Lake or Pond Loops

[0037] These types of loops can be installed very cost-effectively for a home located near a lake or pond. Many homes in northern Ontario, for example, are within meters of a lake that soaks up the sun's energy all summer. The water temperature at the bottom of an ice-covered lake is about 4 to 5°C even during the coldest blizzard. And in the summer, the lake water can easily absorb the heat you are trying to expel to cool the home. All is needed is a year-round minimum depth of 2-2.5 m of water in which the loop can be protected from wave action and ice pile-ups.

[0038] Unless the lake is owned by someone, however, a permission is needed from the provincial government, and in some cases from the Government of Canada, to install a lake loop. Some jurisdictions do not allow them. Destruction of fish spawning grounds, shoreline erosion, obstruction of traffic on navigable waters and potential damage to the environment concern several government departments. In some jurisdictions, enough lake loops have been installed that permission is simply a matter of filling out forms. Some GXS contractors who specialize in lake loop installations handle all the permission paperwork for their clients.

[0039] In the Prairies for instance, farm ponds are often excavated to provide water for irrigation or livestock. A 750- 1000-m ² pond with a constant depth of 2.5 m can do double duty as a clean source of energy. The oceans can also supply vast amounts of energy, but care must be taken to protect an ocean loop from tide and wave damage. Many homes on the West Coast already benefit from free, renewable ocean energy.

[0040] Open Loops

[0041] Open loops, or ground water GXS, take heat from well water that is pumped directly through the heat exchanger in a heat pump. The required flow of well water is determined by the capacity of the heat pump. In the coldest part of the winter, heating a typical 150-m ² new home takes 20 000-30 000 L of water per day, or a flow rate of 0.4-0.5 L per second (a typical backyard pool contains about 60 000- 70 000 L). A larger home will need proportionally more water. A reliable well is needed to supply this volume of water. Typically, a second or return well will be needed to dispose of the water by pumping it back into the ground. Most provinces regulate the use of wells, and can advise on the use of well water for GXS applications. For example, avoid affecting the neighbors' wells when pumping continuously is an important issue to take care off. Regulations on the use of well water as a heat source for a GXS vary with each province. The department with jurisdiction over ground water resources should be contacted to be informed of the regulations in each province.

[0042] To ensure that the well is capable of supplying the water on a sustainable basis, and that the return well has the capacity to accept the water after it has circulated through the heat pump, a pump test needs to be carried on the wells. In some locations, the capacity of the aquifer is well known, and it is possible to find out the capacity of the new well within a few hours. In other areas, it will be necessary to perform a test by measuring the drop in water levels at specified intervals while the well is pumped at a known rate for as long as 24 hours.

[0043] As well water circulates through the heat pump, corrosive water can damage the heat exchanger over time; additionally, water with a high mineral content can cause scale buildup. Most manufacturers can supply heat pumps made out of resistant materials like cupronickel or stainless steel that are more suitable for use in open-loop systems. Manufacturers will specify the quality of water that is acceptable for their equipment. Again, water may need to be tested to ensure it falls within the guidelines. The department that regulates the water resources in each province may be able to advise on where the water can be tested.

[0044] Mechanical equipment lasts longer if it does not have to start and stop repeatedly. Well pumps are no exception. The contractor installing the well pump and pressure system must be told that it will be used to supply water for a GXS. For efficient operation, the pump design and horsepower must be chosen to supply the correct amount of water. Bigger is not better. The water requirements for the system, the height the water is lifted from the well and the piping from the well to the house and to the return well must be taken into account. To prevent the well pump from short-cycling, a larger pressure tank may need to be installed. These details can affect the overall efficiency of the GXS by as much as 25-30 percent.

[0045] The temperature of ground water is very constant, ranging between 5 and 12°C across Canada. The temperature of the fluid pumped through a closed loop used in a home normally drops to a value slightly below freezing during the winter. When well water is used as the energy source during the winter, the heat pump produces more heat and will be more efficient. However, since the water must actually be lifted from the ground, sometimes as much as 15-30 m, a more powerful pump than the one required for a closed-loop system will be needed. In addition, the same pump often supplies water for both the heat pump and general household use. The cost of operating the larger well pump often offsets the efficiency of running the GXS with well water. Questions need to be asked to GXS contractors in each area about their experience with open-loop systems when deciding on the best option for the home.

[0046] Many types of software exist in the GeoExchange market and they are provided by different editors (e.g., government institutions, manufacturers, software editors).

[0047] However, CGC has observed over the years that stakeholders are complaining about the bogginess and the non-accuracy of these software and the unwillingness of the editors to correct these problems. [0048] There is therefore a need to further provide a computer- implemented method for determining design parameters for a geothermal installation.

SUMMARY

[0049] According to an embodiment, there is provided a computer- implemented method for determining seasonal performance coefficient for a geothermal installation at a specific location, the geothermal installation comprising a heat pump, the method comprising: providing to a computing device: installation parameters and weather data representative of the weather at the specific location; or building energy consumption data for heating and cooling; the computing device calculating maximum power requirements for given time intervals using at least part of: the installation parameters and the weather data; or the building energy consumption data for heating and cooling; obtaining from a database the coefficients of performance of the heat pump for each of the given time intervals; calculating by the computing device heat to be extracted or dissipated in the soil; for a horizontal heat exchanger configuration, providing a total trench length, and for a vertical heat exchanger configuration, providing a total drilling depth; from the heat to be extracted or dissipated in the soil, and the total trench length or total drilling depth, calculating by the computing device the temperature at the entrance of the heat pump for each of the given time intervals, wherein the temperature at the entrance of the heat pump for each of the given time intervals is representative of the seasonal performance coefficient for the geothermal installation.

[0050] According to an aspect, the installation parameters comprise at least one of: ground properties; heat pump specifications; antifreeze selection; pipe specifications; and a calculation period. [0051] According to an aspect, the ground properties comprise at least one of: a ground layers listing, global thermal diffusivity of the ground and conductivity of the ground.

[0052] According to an aspect, the heat pump specifications comprises at least one of: a total antifreeze flow rate through the loop in heating mode, a total antifreeze flow rate through the loop in cooling mode, a heating capacity, a heating COP, a cooling capacity, a cooling energy efficiency rating and a unit size.

[0053] According to an aspect, the antifreeze selection comprises at least one of: a descriptive name, a percentage of antifreeze used in the solution, a solution's freezing point, a specific heat capacity and a dynamic viscosity.

[0054] According to an aspect, the pipe specification comprises at least one of: a pipe material, an outer diameter, an internal diameter, a resistance, a wall thickness and an equivalent diameter.

[0055] According to an aspect, the building energy consumption data for heating and cooling comprise at least one of: a building heat loss, a building heat gain, a set point in heating mode, a set point in cooling mode, a coefficient of degradation factor, a number of persons in the building and a building size.

[0056] According to an aspect, the heat exchanger configuration further comprises at least one of: a number of boreholes inside one of the heat exchanger, a number of boreholes inside two of the heat exchangers, a distance between each borehole, a distance below surface of top of U-tubes, a diameter of bore holes, a grout conductivity, configuration and number of serial bore holes.

[0057] According to an aspect, using at least part of the installation parameters and at least part of the location data to calculate maximum power requirements is performed for given temperature for at least one of: the warmest month of the year, the coldest month of the year, and annually.

[0058] According to an aspect, the performance of the geothermal installation is representative of a ratio temperature released by the geothermal installation/temperature released by a heat pump.

[0059] According to another embodiment, there is provided a computer- implemented method for determining design parameters for a geothermal installation at a specific location, the method comprising: providing installation parameters to a computing device; obtaining weather data representative of the weather at the specific location and forwarding the weather data to the computing device; the computing device using at least part of the installation parameters and at least part of the weather data to calculate maximum power requirements; selecting a heat exchanger configuration comprising at least a selection of a vertical loop installation and a horizontal loop installation and providing the selected heat exchanger configuration to the computing device; for a vertical loop installation, the computing device calculating a total drilling depth of the heat exchanger installation; and for a horizontal loop installation, the computing device calculating a total trench length of the heat exchanger installation.

[0060] According to an aspect, the total drilling depth and the total trench length constitute design parameters and wherein the method further comprises inputting existing design parameters from and existing design to the computing device and, using the computing device, comparing the design parameters for the geothermal installation with existing design parameters.

[0061] According to an aspect, when the result from the comparing is that the existing design parameters are comprised within a given threshold of the design parameters, the method further comprising approving the existing design parameters. [0062] According to an aspect, the method further comprises, for a vertical loop installation, calculating a number of holes and dividing the total drilling depth by the number of holes to obtain a depth of each hole of the vertical loop installation.

[0063] According to an aspect, the method further comprises calculating, by the computer, a depth heating value (depthHeating) representative of the drilling depth necessary to meet the power requirements for the coldest period of the year and a depth cooling value (depthCooling) representative of the drilling depth necessary to meet the power requirements for the hottest period of the year, wherein the total drilling depth of the vertical loop installation is the highest value between the depth heating value and the depth cooling value.

[0064] According to an aspect, the depth heating value and the depth cooling value are calculated using factors comprising at least one of:

- mean heat transfer to the underground loop (qa) representative of yearly cooling load;

- annual resistance (rgAnnual) representative of thermal conductivity of the soil;

- maximum heatpump capacity or building load in heating mode (ql Heating);

- monthly load ratio (plfmonthly);

- monthly resistance (rgMonthly) representative of thermal conductivity;

- daily resistance (rgDaily) representative of thermal conductivity;

- FSC value (fscHeating) representative of the number of GPM per ton;

- ground temperature for chosen city (Tground);

- entering heatpump temperature in heating (twiHeating);

- maximum heatpump capacity or building load in cooling mode (qlCooling); - entering heatpump temperature in cooling (twiCooling); and

- penality temperature (tp).

[0065] According to an aspect, the depth heating value and the depth cooling value are calculated using the formulas:

depthHeating =

[0066] According to an aspect, the method further comprises, for a horizontal loop installation, calculating a number of holes and dividing the total trench length by the number of holes to obtain a length of each hole of the horizontal loop installation.

[0067] According to an aspect, the method further comprises calculating, by the computer, a the total pipe length in heating mode (IHPipe) representative of the trench length necessary to meet the power requirements for the coldest period of the year and a total pipe length in cooling mode (ICPipe) representative of the trench length necessary to meet the power requirements for the hottest period of the year, wherein the length of the horizontal loop installation is the highest value between the total pipe length in heating mode and the total pipe length in cooling mode. [0068] According to an aspect, the total pipe length in heating mode and the total pipe length in cooling mode are calculated using factors comprising at least one of:

- Heating capacity (H_heatC);

- Heating COP (H_cOP);

- Resistance (P_rp);

- entering heatpump temperature in heating (twiHeating);

- entering heatpump temperature in cooling (twiCooling); and

- cooling capacity (H_coolC).

[0069] According to an aspect, the total pipe length in heating mode and the total pipe length in cooling mode are calculated using the formulas:

[0070] According to an aspect, the installation parameters comprise at least one of: ground properties; building specifications, heat pump specifications; antifreeze selection; pipe specifications; and a calculation period

[0071] According to an aspect, the ground properties comprise at least one of: a ground layers listing, global thermal diffusivity of the ground and conductivity of the ground. [0072] According to an aspect, the building specifications comprise at least one of: a building heat loss, a building heat gain, a set point in heating mode, a set point in cooling mode, a coefficient of degradation factor, a number of persons in the building and a building size.

[0073] According to an aspect, the heat pump specifications comprises at least one of: a total antifreeze flow rate through the loop in heating mode, a total antifreeze flow rate through the loop in cooling mode, a heating capacity, a heating COP, a cooling capacity, a cooling energy efficiency rating and a unit size.

[0074] According to an aspect, the antifreeze selection comprises at least one of: a descriptive name, a percentage of antifreeze used in the solution, a solution's freezing point, a specific heat capacity and a dynamic viscosity.

[0075] According to an aspect, the pipe specification comprises at least one of: a pipe material, a outer diameter, an internal diameter, a resistance, a wall thickness and an equivalent diameter.

[0076] According to an aspect, the heat exchanger configuration comprises at least one of: a number of boreholes inside one of the heat exchanger, a number of boreholes inside two of the heat exchangers, a distance between each borehole, a distance below surface of top of U-tubes, a diameter of bore holes, a grout conductivity, configuration and number of serial bore holes.

[0077] According to an aspect, using at least part of the installation parameters and at least part of the location data to calculate maximum power requirements is performed for given temperature for at least one of: the warmest month of the year, the coldest month of the year, and annually.

[0078] The following terms are defined below. [0079] The term "calculating" is intended to mean using building specifications, heat pump specifications, antifreeze selection, pipe specification and calculation period to calculate a number of holes and depth/length for each hole according to industry standards.

[0080] The term "total drilling depth" is intended to mean the necessary drilling depth for a vertical loop installation according to design parameters. For instance, the vertical loop installation may require 3 bore holes each having a drilling depth of 20 meters for providing a total drilling depth of 60 meters.

[0081] The term "total trench length" is intended to mean the necessary trench length for a horizontal loop installation according to design parameters. For instance, the horizontal loop installation may require 3 bore holes each having a trench length of 20 meters for providing a total trench length of 60 meters.

[0082] Features and advantages of the subject matter hereof will become more apparent in light of the following detailed description of selected embodiments, as illustrated in the accompanying figures. As will be realized, the subject matter disclosed and claimed is capable of modifications in various respects, all without departing from the scope of the claims. Accordingly, the drawings and the description are to be regarded as illustrative in nature, and not as restrictive and the full scope of the subject matter is set forth in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Further features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which:

[0084] Fig. 1 is a schematic diagram which illustrates a Residential GeoExchange System in the Heating Mode; [0085] Fig. 2 is a schematic diagram which illustrates a Residential GeoExchange System in the Cooling Mode;

[0086] Fig. 3 is a schematic diagram which illustrates a Closed Vertical Loop Installation;

[0087] Fig. 4 is a schematic diagram which illustrates a Closed Horizontal Loop Installation;

[0088] Fig. 5 is a computer-implemented method for determining design parameters for a geothermal installation;

[0089] Fig. 6 is a computer-implemented method for determining seasonal performance coefficient for a geothermal installation at a specific location; and

[0090] Fig. 7 is an exemplary hardware and operating environment.

[0091] It will be noted that throughout the appended drawings, like features are identified by like reference numerals.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0092] A step-by-step program schematic from training and accreditation of individuals, qualification of firms and system certification for geoexchange systems is detailed below. Usually, the objective is to tie incentive programs (financial assistance programs normally in the form of money from the government or tax reduction) to those geoexchange installations which are designed and installed by accredited individuals and/or qualified corporations/companies.

[0093] STEP 1— TRAINING FOR INDIVIDUALS

[0094] Training is required for all individuals directly involved in the design or installation of a geoexchange system. [0095] There are four distinct training course modules currently available in Canada: Training for system installers: Canadian GeoExchange™ Coalition Installers' Course®; Training for residential designers: Canadian GeoExchange™ Coalition Residential Designers' Course®; Training for commercial designers: Canadian GeoExchange™ Coalition Commercial Designers' Course®; Training for municipal inspectors: Canadian GeoExchange™ Coalition Municipal Inspector's Course®; And one additional course available in 2009, Training for vertical loop installers: Canadian GeoExchange™ Coalition Drilling, Well Construction and Loop Installation Course®

[0096] STEP 2— APPLICATION FOR INDIVIDUAL ACCREDITATION

[0097] CGC training certificates or equivalent are required to apply for each and any individual's accreditation.

[0098] STEP 3— APPLICATION FOR COMPANY QUALIFICATION

[0099] Companies (including sole proprietorships) hiring CGC accredited individuals for vertical loop installation, system installation or design, either as full time employees or as subcontractors, must be qualified under the CGC Global Quality GeoExchange™ Program®. For most companies, this will only be a simple formality. However, company qualification is an important step to ensure quality installation and consumer protection: It allows the CGC to verify the credentials of the companies/contractors who will ultimately provide the consumers with a guarantee on their geoexchange system. It will allow the CGC to screen out of the CGC Global Quality GeoExchange™ Program® companies/contractors that have been found guilty of various professional malpractices and/or breached CGC's Code of Conduct. Qualification of companies will allow CGC to recognize the highest quality workmanship, and highest ethical standard and screen out companies only interested in short terms gains and benefits. Company/contractor qualification is also an important step in the CGC management of the consumer complaint mechanism.

[00100] STEP 4— APPLICATION FOR SYSTEM CERTIFICATION

[00101] A CGC Certified GeoExchange™ System is a geoexchange system on which CGC accredited system installers and designers have been involved. A CGC Certified GeoExchange™ System is a geoexchange system that follows CAN/CSA C-448-02 at a minimum. A CGC Certified GeoExchange™ System is a geoexchange system that fully satisfies all relevant municipal, provincial and federal regulations. A CGC Certified GeoExchange™ System is a geoexchange system that meets CGC Certification Guidelines. A CGC Certified GeoExchange™ System is the condition to access many utility incentive programs, as well as provincial and federal grants programs if and where available.

[00102] Definition of terms. The different terms all form part of the Global Quality GeoExchange™ Program®. There are four major steps within this national Initiative:

[00103] Training for individuals means that individuals may register and attend one or more of the national training courses (choosing according to their area of specialty and requirements), and take the examination. Four CGC courses - for system installers, residential system designers, commercial system designers, and Municipal Inspectors - are currently available.

[00104] Accreditation of individuals is achieved by those who successfully complete training with a passing mark on the examination, and apply for accreditation. A different accreditation is available for system installers and designers. No accreditation can be given by CGC for provincially regulated Municipal Inspectors. Accreditation requires: a passing mark on the relevant CGC examination satisfactory work on up to five previous geoexchange systems credit references if and where appropriate proof of adequate insurance and liability coverage if and where appropriate assent to the CGC Code of Conduct, etc. and is valid for two years.

[00105] Company Qualification means that companies hiring CGC accredited individuals for vertical loop installation, system installation or design, either as full time employees or as subcontractors, have had their credentials verified and offer the highest quality of workmanship, at the highest ethical standards. Qualification allows CGC to screen out flyby- night firms and firms interested in making sales rather than executing quality work. Certification of systems is completed once an application for certification has been approved by CGC.

[00106] Certification means that the system has been designed by an accredited designer, installed by an accredited installer, and any borehole work has involved a CGC Qualified company. For a system to be certified it must follow all guidelines within CSA Standard C-448-02, use ISO/CSA-approved equipment, and engage such best practices as delivering an 'As built' book to the project owner, clearly labelling all piping and valves, be verified and inspected as necessary to ensure the system is in compliance with all provincial regulations, etc. Much of this is covered in initial training phase.

[00107] Vertical loop installers, system installers, and system designers are the three main components of the workforce in the geoexchange industry. Very often, these three functions will be performed by three different individuals, although it is not rare that one individual will carry forward two or even the three functions. For the CGC, it was important that the training program put in place reflect this market reality. Until the CGC training program was deployed, only one basic introductory training course was available. Ranging from half day to three days, none of those, either in Canada or in the United States had the scope or the depth to support a growing industry in a meaningful and sustainable manner. The quality program is a comprehensive effort to ensure better trained professionals deliver quality work more consistently.

[00108] CGC has developed its courses as part of a national quality initiative. This initiative is the CGC's response to over a decade of stakeholder requests to "raise the bar" in available training and in the consistency of quality of work delivered by geoexchange practitioners. These four CGC courses - for system installers, residential system designers, commercial system designers and municipal inspectors respectively, as well as the course for loop installers to be finalised, are part of the first national training and quality initiative based on Canadian climate, geology, and CSA Standards (C-448-02, principally). The course training materials are the product of over eighteen months of effort from CGC staff, with contributions from about fifty of the industry's top professionals and critical ongoing support from the federal and many provincial governments. The courses went through six drafts before release in 2007, and are thoroughly revised at least once a year. The CGC Municipal Inspector s Course was likewise developed in partnership with City of Calgary and is taught by Municipal Inspectors, to help form the basis for consistent and fair enforcement of code.

[00109] Financial assistance programs are put in place by utilities and government to help grow a renewable energy industry or increase energy efficiency. These programs are built around a variety of economic and performance criteria with the objective of transforming markets. They are generally meant to reduce customer energy bills while providing some form of economic value to energy distributor and governments. Over the years, these programs have been tightly connected to the availability of qualified work forces and reputable firms / companies. Despite efforts to run those programs as smoothly as possible, it takes little effort to document horror stories of customers being fooled by unscrupulous firms and serious companies being forced into bankruptcies because of aggressive marketing campaign by competitors more interested in selling subsidies than selling quality and reliable work.

[00110] In the geoexchange industry, this happened in many European countries during the 1970s. Unfortunately, no lessons were learned and it happened again in the 1980s. Every time subsidies were available, it seemed that the geoexchange industry would live a golden age. Every time subsidies disappeared, so did dozens of fly by night, unqualified companies that left behind hundreds of poor installations. Every time this happens, the concerned technology goes into oblivion, only kept alive by a handful of serious companies who pick up the pieces and keep the industry alive until the next subsidy round. It happened in Canada in the early 1990s. And it has happened in the United States as well.

[00111] The goal of the Global Quality GeoExchange™ Program® is to ensure that these fly by night companies are kept out of the geoexchange industry. At the same time, those who are serious about their endeavour will be welcomed as well-trained and accredited professionals working for trustworthy companies. To play with Global Quality GeoExchange™ Program®, both companies and individuals have to show their professional intent, before and during their participation in the program.

[00112] CGC's courses are about providing quality assurance to the consumer and about describing and delivering industry best practices when designing, installing vertical loops or installing geoexchange systems. CGC members and partners understand that for the geoexchange industry to continue growing rapidly, consistently high quality of training, and system design & installation, is a top industry priority.

[00113] Further, Canadian incentive programmes increasingly refer to and require Canadian accreditation as developed by the CGC. Several levels of government have examined the CGC training materials and accreditation mechanisms and have decided to refer to this new Canadian industry standard as a way to ensure best practice and/or code compliance. Those already engaged in quality assurance measures - such as the well developed regional or national distributor - understand that provincial governments, banks, insurance companies, and international partners all desire to work with one national quality framework for Canada. Taking the CGC course and supporting the CGC Global Quality GeoExchange™ Program® will in the longer term lead to higher quality field work in Canada, and is therefore crucial to the long term growth of the industry.

[00114] Given the variety of training initiatives available in the market and the wide variance in their content and quality control mechanism, the CGC announced in December 2006 that in future it would only recognize trainings which are harmonized with CGC training. Several manufacturers and organisations have since expressed their desire to harmonize their training with CGC training. It is the responsibility of organisations to inform their potential registrants of this policy. It is also the responsibility of those other organisations to contact the CGC to discuss partial or full harmonization. Recognizing that experienced and knowledgeable professionals have been successfully working in the industry, and that elements of currently available training have merit, CG has developed training upgrade seminars for those who have successfully passed other installer trainings and/or have significant current experience in the field. These upgrade seminars are developed and adapted as needed and on a case by case basis. Having equivalent training is the first step in earning CGC accreditation. Therefore, those who have taken non-CGC courses before January 1st, 2007, and who want to become accredited, may be eligible to take one of the upgrade seminars in their specialty - installation, drilling, or design. All those seeking equivalency with CGC training must at a minimum take and pass the CGC examination. It is important for the CGC that field work is performed by well-trained professionals. A three day introductory training, whether CGC's or training from another organisation, is not by itself sufficient to be awarded any CGC accreditation. To be awarded CGC accreditation, loop installers, system installers and residential designers have to prove they have received the appropriate training (either CGC courses or recognised equivalents) and also prove they have positive field experience backed by customer references and manufacturer's or distributor's favourable recommendations. There has never been and there is currently no other geoexchange accreditation program anywhere in North America that has such diversified and high level training requirements while verifying industry-relevant professional experience.

[00115] A CGC-trained individual does not receive automatic installer accreditation. CGC accreditation is based on real life experience and verification of licences authorizing an individual to perform professional work on a geoexchange system in the province / territory concerned. Simple affiliation or accreditation with other national / international organization is deemed insufficient in Canada for the Global Quality GeoExchange™ Program®. CGC's full programme goes well beyond the basic introductory training for installers offered by other organizations. CGC offers extensive quality-controlled training for system installers as well as designers.

[00116] Firms, whether registered as individuals or sole proprietor, partnership or corporation are, in the normal course of a business transaction involving a geoexchange system, the responsible legal entity that will provide the supervision of professional employees or subcontractors, warranties, quality assurance. Firms are also expected to carry professional liability insurance as well as have a positive business practices record. Customers want their geoexchange system designed and installed by professionals. They also want quality service, not for a month, not for a year, but for the next 10 and 20 years. They are looking for quality service and reliability which is unsurpassed in the industry. CGC Qualified companies demonstrate they stand above the rest. They employ and subcontract work to CGC Accredited professionals. They want a strong national geoexchange industry, and they provide customers the quality service customers want and deserve. Though a hole drilled for geothermal heat shares many characteristics with other types of wells, drilling, grouting and/or trenching properly is not the same job as water, oil, or other types of well drilling. Many conventional groundwater protection practises are followed, and CGC recognises that many drilling companies are competent to follow provincial regulations regulating geoexchange. CGC is working with partners in 2009 to develop specialised training and accreditation modules for all types of loop installation.

[00117] Currently under the quality program, drilling companies must be CGC Qualified® to complete a CGC Certified System®. Qualification ensures that ethical drilling firms, which hold proper verified provincial qualifications, are involved in the quality work required. CGC's Global Quality GeoExchange Program® requires CGC Accredited Installers to verify boreholes and to ensure that borehole reporting forms and records are properly completed.

[00 18] Referring now to the drawings, and more particularly to Fig. 1 , there is shown a schematic diagram which illustrates a Residential GeoExchange System in the Heating Mode. Referring now to Fig. 2, there is shown a schematic diagram which illustrates a Residential GeoExchange System in the Cooling Mode. Referring now to Fig. 3, there is shown a schematic diagram which illustrates a Closed Vertical Loop Installation. Referring now to Fig. 4, there is shown a schematic diagram which illustrates a Closed Horizontal Loop Installation. [00119] According to an embodiment and referring now to Fig. 5, there is provided a computer-implemented method 10 for determining design parameters for a geothermal installation. The computer-implemented method 10 for determining design parameters for a geothermal installation comprises the step 12 of providing installation parameters to a computing device, the installation parameters comprising without limitations, ground properties, building specifications, heat pump specifications, antifreeze selection, pipe specifications, a calculation period and the like. The computer-implemented method 10 for determining design parameters for a geothermal installation further comprises the step 14 of obtaining weather data representative of the weather at the specific location and forwarding the weather data to the computing device. The location data may comprise, without limitations, the country, the province, the city and the like.

[00120] According to another embodiment, the computer-implemented method 10 for determining design parameters for a geothermal installation also comprises the step 16 of using at least part of the installation parameters and at least part of the location data to calculate a maximum power requirements at a given temperature for at least one of: the warmest month of the year, the coldest month of the year, and annually.

[00121] According to another embodiment, the computer-implemented method 10 for determining design parameters for a geothermal installation also comprises the step 18 of selecting a heat exchanger configuration. The heat exchanger configuration may be, without limitations, the selection of a vertical loop installation, the selection of a horizontal loop installation, and the like.

[00122] According to another embodiment, it is to be noted that for a vertical loop installation, the computer-implemented method 10 for determining design parameters for a geothermal installation includes the step 20 of calculating a number of holes and a drilling depth for each hole of the heat exchanger using heat exchanger configuration, installation parameters, location data and power requirements.

[00123] According to another embodiment, for a horizontal loop installation, the computer-implemented method 10 for determining design parameters for a geothermal installation further comprises the step 22 of calculating a number of holes and a drilling depth for each hole of the heat exchanger using heat exchanger configuration, installation parameters, location data and power requirements.

[00124] According to another embodiment, the computer-implemented method 10 for determining design parameters for a geothermal installation may be an online software.

[00125] According to a further embodiment, the computer-implemented method 10 must comply with many rules and standards established by the geothermal installation industry in order to be efficient. The computer- implemented method 10 may help geothermal systems Designers to perform all the geothermal systems calculations in compliance with the industry standards, and more particularly with the CSA-448 standards.

[00126] According to another embodiment, the computer-implemented method 10's intended objective is to offer reliable unique software to perform all geothermal system related calculations and may be evolving on a permanent basis in response to stakeholder's present and future needs.

[00127] According to another embodiment, there is provided a computer- implemented method 80 for determining seasonal performance coefficient for a geothermal installation at a specific location and where the geothermal installation comprises a heat pump. The method 80 comprises the steps 82 or 83 of providing to a computing device: installation parameters and weather data representative of the weather at the specific location (step 82); or building energy consumption data for heating and cooling (step 83).

[00128] In the method 80, there is also provided the step 84 where the computing device calculates the maximum power requirements for given time intervals using at least part of: the installation parameters and the weather data; or the building energy consumption data for heating and cooling.

[00129] The method 80 also includes the step 86 of obtaining from a database the coefficients of performance of the heat pump for each of the given time intervals and the step 88 of calculating heat to be extracted or dissipated in the soil.

[00130] For a horizontal heat exchanger configuration, the method 80 includes the step 90 of providing a total trench length, and for a vertical heat exchanger configuration, of providing a total drilling depth.

[00131] From the heat to be extracted or dissipated in the soil, and the total trench length or total drilling depth, the method 80 includes the step 92 of calculating the temperature at the entrance of the heat pump for each of the given time intervals, wherein the entrance of the heat pump for each of the given time intervals is representative of the seasonal performance coefficient for the geothermal installation.

[00132] According to another embodiment, in the method 80, the report may provide a user of at least one of: a graph of the seasonal performance coefficient per year, a graph of the seasonal performance coefficient per month, a graph of the seasonal performance coefficient per season, a graph of the seasonal performance coefficient per day and a graph of the seasonal performance coefficient per day. [00133] According to another embodiment, in the method 80, the seasonal performance coefficient may constitute design parameters and the method 80 further comprises inputting an existing seasonal performance coefficient from and existing design to the computing device and, using the computing device, comparing the design parameters for the geothermal installation with existing design parameters.

[00134] According to another embodiment, in the method 80, when the result from the comparing is that the existing design parameters are comprised within a given threshold of the design parameters, the method 80 further comprising approving the existing design parameters.

[00135] According to another embodiment, in the method 80, the installation parameters comprise at least one of: ground properties; heat pump specifications; antifreeze selection; pipe specifications; and a calculation period. The ground properties may comprise at least one of, without limitations, a ground layers listing, global thermal diffusivity of the ground and conductivity of the ground. The building specifications may comprise at least one of, without limitations, a building heat loss, a building heat gain, a set point in heating mode, a set point in cooling mode, a coefficient of degradation factor, a number of persons in the building and a building size. The heat pump specifications may comprises at least one of, without limitations, a total antifreeze flow rate through the loop in heating mode, a total antifreeze flow rate through the loop in cooling mode, a heating capacity, a heating COP, a cooling capacity, a cooling energy efficiency rating and a unit size. The antifreeze selection may comprise at least one of: a descriptive name, a percentage of antifreeze used in the solution, a solution's freezing point, a specific heat capacity and a dynamic viscosity. The pipe specification may comprise at least one of, without limitations, a pipe material, a outer diameter, an internal diameter, a resistance, a wall thickness and an equivalent diameter. The heat exchanger configuration may further comprise at least one of, without limitations, a number of boreholes inside one of the heat exchanger, a number of boreholes inside two of the heat exchangers, a distance between each borehole, a distance below surface of top of U-tubes, a diameter of bore holes, a grout conductivity, configuration and number of serial bore holes.

[00136] In the method 80, using at least part of the installation parameters and at least part of the location data to calculate maximum power requirements may be performed for given temperature for at least one of: the warmest month of the year, the coldest month of the year, and annually. Also, in the method 80, the performance of the geothermal installation is representative of a ratio temperature released by the geothermal installation/temperature released by a heat pump.

[00137] Now referring to Fig. 7, there is shown a diagram of the hardware and operating environment in conjunction with which embodiments of the invention may be practiced. The description of Fig. 7 is intended to provide a brief, general description of suitable computer hardware and a suitable computing environment in conjunction with which the invention may be implemented. Although not required, the invention is described in the general context of computer-executable instructions, such as program modules, being executed by a computer, such as a personal computer, a hand-held or palm-size computer, or an embedded system such as a computer in a consumer device or specialized industrial controller. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types.

[00138] Moreover, those skilled in the art will appreciate that the invention may be practiced with other computer system configurations, including hand-held devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCS, minicomputers, mainframe computers, and the like. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.

[00139] The exemplary hardware and operating environment of Fig. 7 for implementing the invention includes a general purpose computing device in the form of a computer 120, including a processing unit 21 , a system memory 122, and a system bus 23 that operatively couples various system components including the system memory to the processing unit 21. There may be only one or there may be more than one processing unit 21 , such that the processor of computer 120 comprises a single central-processing unit (CPU), or a plurality of processing units, commonly referred to as a parallel processing environment. The computer 120 may be a conventional computer, a distributed computer, or any other type of computer; the invention is not so limited.

[00140] The system bus 23 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory may also be referred to as simply the memory, and includes read only memory (ROM) 24 and random access memory (RAM) 25. A basic input/output system (BIOS) 26, containing the basic routines that help to transfer information between elements within the computer 120, such as during start-up, is stored in ROM 24. In one embodiment of the invention, the computer 120 further includes a hard disk drive

27 for reading from and writing to a hard disk, not shown, a magnetic disk drive

28 for reading from or writing to a removable magnetic disk 29, and an optical disk drive 30 for reading from or writing to a removable optical disk 31 such as a CD ROM or other optical media. In alternative embodiments of the invention, the functionality provided by the hard disk drive 27, magnetic disk 29 and optical disk drive 30 is emulated using volatile or non-volatile RAM in order to conserve power and reduce the size of the system. In these alternative embodiments, the RAM may be fixed in the computer system, or it may be a removable RAM device, such as a Compact Flash memory card.

[00141] In an embodiment of the invention, the hard disk drive 27, magnetic disk drive 28, and optical disk drive 30 are connected to the system bus 23 by a hard disk drive interface 32, a magnetic disk drive interface 33, and an optical disk drive interface 34, respectively. The drives and their associated computer- readable media provide nonvolatile storage of computer-readable instructions, data structures, program modules and other data for the computer 120. It should be appreciated by those skilled in the art that any type of computer-readable media which can store data that is accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, random access memories (RAMs), read only memories (ROMs), and the like, may be used in the exemplary operating environment.

[00142] A number of program modules may be stored on the hard disk, magnetic disk 29, optical disk 31 , ROM 24, or RAM 2S, including an operating system 3S, one or more application programs 36, other program modules 37, and program data 38. A user may enter commands and information into the personal computer 120 through input devices such as a keyboard 40 and pointing device 42. Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, touch sensitive pad, or the like. These and other input devices are often connected to the processing unit 21 through a serial port interface 46 that is coupled to the system bus, but may be connected by other interfaces, such as a parallel port, game port, or a universal serial bus (USB). In addition, input to the system may be provided by a microphone to receive audio input. [00143] A monitor 47 or other type of display device is also connected to the system bus 23 via an interface, such as a video adapter 48. In one embodiment of the invention, the monitor comprises a Liquid Crystal Display (LCD). In addition to the monitor, computers typically include other peripheral output devices (not shown), such as speakers and printers.

[00144] The computer 120 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 49. These logical connections are achieved by a communication device coupled to or a part of the computer 120; the invention is not limited to a particular type of communications device. The remote computer 49 may be another computer, a server, a router, a network PC, a client, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer 120, although only a memory storage device 50 has been illustrated. The logical connections depicted in Fig. 7 include a local-area network (LAN) 51 and a wide-area network (WAN) 52. Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet.

[00145] When used in a LAN-networking environment, the computer 120 is connected to the local network 51 through a network interface or adapter 53, which is one type of communications device. When used in a WAN-networking environment, the computer 120 typically includes a modem 54, a type of communications device, or any other type of communications device for establishing communications over the wide area network 52, such as the Internet. The modem 54, which may be internal or external, is connected to the system bus 23 via the serial port interface 46. In a networked environment, program modules depicted relative to the personal computer 120, or portions thereof, may be stored in the remote memory storage device. It is appreciated that the network connections shown are exemplary and other means of and communications devices for establishing a communications link between the computers may be used.

[00146] The hardware and operating environment in conjunction with which embodiments of the invention may be practiced has been described. The computer in conjunction with which embodiments of the invention may be practiced may be a conventional computer an hand-held or palm-size computer, a computer in an embedded system, a distributed computer, or any other type of computer; the invention is not so limited. Such a computer typically includes one or more processing units as its processor, and a computer-readable medium such as a memory. The computer may also include a communications device such as a network adapter or a modem, so that it is able to communicatively couple other computers.

[00147] The present invention will be more readily understood by referring to the following examples which are given to illustrate the invention rather than to limit its scope.

EXAMPLE 1

Software implementation- The GeoAnalyser

[00148] 1. Introduction

[00149] Within this description, it will be established the main objectives of the GeoAnalyser, or the computer-implemented method for determining design parameters for a geothermal installation, and its intended purposes. Then, the main modules that will be implemented will be enumerated. Each module will be described in details as for the calculation algorithm and the different data variables used to perform the calculation.

[00150] 2. Project Objectives [00151] The GeoAnalyser, or the computer-implemented method for determining design parameters for a geothermal installation, is an online software intended to GeoExchange professionals in order to help them achieve different design calculations related to a GeoExchange installation. It comes as a response to the GeoExchange market to:

[00152] 2.1 Provide a thorough and reliable tool in order to help professionals design more efficient and compliant GeoExchange Systems (GS)

[00153] A GS system must comply with many rules and standards established by the GS industry in order to be efficient. GeoAnalyser, or the computer-implemented method, will help GS Designers to perform all the GS calculations in compliance with the industry standards (CSA-448)

[00154] 2.2 Fill a demand for such a software

[00155] Many types of software exist in the GeoExchange market and they are provided by different editors (e.g., government institutions, manufacturers, software editors).

[00156] However, CGC has observed over the years that stakeholders are complaining about the bogginess and the non-accuracy of these software and the unwillingness of the editors to correct these problems.

[00157] GeoAnalyser's intended objective is to offer reliable unique software to perform all GS related calculations and will be evolving on a permanent basis in response to stakeholder's present and future needs.

[00158] 2.3 Provide stakeholders with designing reports to be used to file grants and certification request

[00159] As GS are part of the sustainable development plans of almost all governments, they are willing to award grants in order to expand the GeoExchange market. These grants are conditional to the GS meeting the industry standards and requirements. GeoAnalyser, or the computer- implemented method, produces reports usable by homeowners or professionals in order to file for government and institutional grants.

[00160] 3. Conventions and Nomenclature

[00161] 3.1 Variable naming

[00162] Internal variables:

[00163] Internal variables (as opposed to user entry variables) are named in mixed case with a lowercase first letter. Internal words start with capital letters. If the variable name is an acronym (ex.: EER), it must start with a lower case first letter (i.e. : eER).

[00164] User entry variables:

[00165] These are the parameters entered by the user in order to perform the calculations. Each variable name should have the following pattern: S_xxxxXxx where:

- S: is a reference to the section in the form (ex.: H for heat exchanger specifications);

- xxxXxxx: is the name of the variable following the same naming conventions as internal variables.

[00166] 4. GeoAnalyser Modules

[00167] 4.1 Project Settings (S)

[00168] This helper module lets the user set the general settings that will be used to:

- Identify the project - Define some general parameters that will be used by other modules' calculations.

[00169] 4.1.1 Variables

Table 1 : Project settings

[00170] 4.1.2 Comments

[00171] The user will choose from a pre-defined list of cities checked against the country and province he has previously chosen. It is possible that not all existing cities will appear in this field. The user will have to select the closest city to the project installation.

[00172] The following calculation modules will use the bin data of the selected city in order to perform the calculations (c.f. Annex 2: Soil Types).

[00173] 4.2 Ground Loop Design (Vertical closed loop) [00174] The objective of this module is to help sizing a ground heat exchanger to be used by a GS in a vertical closed loop (non DX GS). The main output of this module is the length of the heat exchanger from which an be deducted the height of each bored hole.

[00175] 4.2.1 Variables

[00176] 4.2.1.1 Ground Properties (G)

[00177] The user will have two methods of setting the ground properties:

[00178] a. By listing the ground layers on his field:

[00179] Variable Type Unit

Variable Type Unit Comments

GJayers Array of (soil N/A Ground layers. User can add multiple type, height) layers entering the height for each.

(C.f. Annex 2: Soil Types)

Table 2: Ground Layers

[00180] b. By entering the global thermal diffusivity and conductivity of the ground:

Variable Type Unit Comments

GJhermalDiffusivity Float None

G_thermalConductivity Float None

Table 3: Ground specifications

[00181] If the user chooses option (a), the system will compute the global thermal diffusivity and conductivity (Table 3: Ground specifications) depending on the selected layers.

[00182] 4.2.1.2 Building specifications (B)

B_cdFactor Float Coefficient of degradation factor.

Defaults to 0.25.

B_nbPersons Integer Number of persons living in the building (minimum 2).

B dimHouse Float ft* Building size

Table 4: Building specification variables

[00183] 4.2.1.3 Heat pump(s) specifications (H)

[00184] User will be able to select one heat pump from a pre-defined heat pump database. The heat pump list is provided as a commodity to prevent the user from entering the full specifications. If the heat pump is not present within the predefined list, the user should be able to enter a new heat pump manually by specifying the following information:

Table 5: Heat pump specifications

[00185] Once a user adds manually a heat pump, the specifications will be saved in his profile for future re-use. Internally, the manually entered heat pumps will be screened within all the projects and establish statistics to determine if new manufacturers or new models should be added to the heat pumps database.

[00186] 4.2.1.4 Antifreeze Selection (A)

[00187] User will be able to select from a pre-defined antifreeze database (Ex.: Methanol - 25%). Each antifreeze solution will have the following specifications: Variable T e Unit Comments

Table 6: Antifreeze specifications

[00188] See Table 16: Anti-freeze solutions for a list of available anti-freeze solutions. The user should be able to select the antifreeze based on one of the following criteria:

[00189] The antifreeze solution (%solute) as describer in 4.2.1.4;

[00190] The freezing point. The antifreeze freezing point must be 5°F below the minimum loop temperature (ie. 32°F - 5 = 27°F).

[00191] 4.2.1.5 Heat Exchanger Configuration (X)

Table 7: Vertical heat exchanger specifications

[00192] The heat exchange configuration may be one of the three following options:

[00193] The number of serial bore holes must have a value between 1 and

3:

[00194] 4.2.1.6 Pipe Specifications (P)

[00195] User will be able to choose from a pre-defined pipe types list (c.f. Annex 3: Pipe types) or enter manually a user-defined pipe by specifying the following values: Variable Type Unit Comments

P_material String None Pipe material (descriptive)

P_pressureRating Enum SDR

P_outterDiam Float Inches Outter diameter

PjnternalDiam Float Inches Internal diameter

P_rp Float hr-ft-°F/BTU Resistance

PJhikness Float Inches [AUTO] Wall thikness:

= (ODiam - IDiam) / 2

PjiominalDiameter Float Inches Ex.: ¾, 1, 1 ¼ , ...

P_eqDiameter Float ft Equivalent diameter

Table 8: Pipe Specifications

[00196] 4.2.1.7 General settings (S)

Variable Type Unit Comments

S_calciilationPeriod Integer Year Calculation period in years.

Defaults to 10.

[00197] 4.2.2 Algorithm: Heat Exchanger Depth (vertical closed loop)

S_heatingTemp

¾¾> Heating temperature as defined in the chosen city (°F)

S_coolingTemp

~& Cooling temperature as defined in the chosen city (°F) heatingTempDiff - B setPointHeating - S heatingTemp

¾. Heating temperature difference (°F) coolingTempDiff = S coolingTemp - B setPointCooling

¾s. Cooling temperature difference (°F) kTot = B heatLoss / heatingTempDiff

^Puissance / Degretemperature inGain =532 + .77 ^* B dimHouse + 116 ^* B nbPersons ~& Internal gain (ASHREA page 29.10 equation 30 + equation 31) | tBal = B_setPointHeating - (inGain / kTot)

¾¾. Balancing temperature heatLossRate = (B_heatLoss - inGain ) / heatingTempDiff

¾¾. Heat loss rate heatGainRate = (B_heatGain - inGain) / coolingTempDiff

Heat gain rate

[00198] Bin Data Table:

[00199] The table is based on the city bin data and the heat pump specifications:

ColA: Tbin from city bin data.

ColB: Average loop temperature from city data.

ColC:GeoCapacity from GS heat pump data.

ColD:

- If ColA<tBal: = (tBal - ColA). heatLossRate

- Else If ColA>B_setPointCooling:

= (B setPointCooling - ColA) ^* heatGainRate + inGain

ColE: = Closest value to 0 between ColC and ColD

ColF:Nb hours per temperature in January (from city bin data)

ColG: = ColE * ColF ColH:Nb hours per temperature in July (from city bin data)

Coll: = ColE * ColH

ColJ: Number of hours per temperature in a year (from the city BIN data).

ColK:

[00200] Some of the bin data could also be obtained by studying and aggregating climate data to extract therefrom the data applicable to geothermal calculation. Average climate data can be calculated from historical information. This makes it possible to make calculations based on observations but also to identify climate trends using significant annul variations. Also, the coldest and the hottest 30-day periods in a year can be calculated instead of using January for the coldest and July for the hottest months specifically. This data is used in determining the peak demand for heating (winter) and air-conditioning (summer).

[00201] Another feature could be to standardize a universal specifications standard model for geothermal equipment. The standard model could be populated using the manufacturer's product specifications. This enables comparison charts for heat pumps and puts the different technologies together. 2011/001244

qJanuary = SUM(ColG)

¾¾. Total geo load in January (coldest month) qJuly = SUM(Coll)

·¾. Total geo load in January (hottest month) qHeating = SUM(ColK)

¾¾. Yearly heating load qCooling = SUM(ColL)

¾. Yearly cooling load qlHeating = greatest positive value from ColE hours available

¾¾. Maximum heatpump capacity or building load (heating mode) qlCooling = minor negative value from ColE hours available

¾. Maximum heatpump capacity or building load (cooling mode) plfJanuary = qJanuary / (qlHeating * 24 ^* 31)

¾- Monthly load ratio (January) plfJuly = qJuly / (qlCooling ^* 24 *31)

¾¾. Monthly load ratio (July) qa = ( qCooling * (H_eER + 3.41) / H_eER + qHeating * (H_cOP-1) / H_cOP ) /

8760

Mean heat transfer to the underground loop tGround

aground temperature for chosen city (constant) twiHeating = 32°F

~& Entering heatpump temperature (heating) - Constant value (CSA448) (°F)

twiCooling = 77°F

Entering heatpump temperature (cooling) - Constant value (CSA448) (°F)

pulseAnnual = S_calculationPeriod ^* 365 pulseMonthly = pulseAnnual + 30 pulseSixHours = pulseMonthly + 0.167 fof = 4 ^* GJhermalDiffusivity * pulseSixHours / P_eqDiameter ^!

¾kFourrier number fo1 = 4 * GJhermalDiffusivity * (pulseSixHours - pulseAnnual)/ P_eqDiameter ^; ^-Fourrier number fo2 = 4 ^* GJhermalDiffusivity ^* (pulseSixHours - pulseMonthly)/ P_eqDiameter ^z ¾s.Fourrier number gf = G-Factor(fof)

¾. G factor interpolation matched against the Fourrier table for fof (see Annex 5: Fourrier table and G-Factor interpolation) g1 = G-Factor(fol)

G factor interpolation matched against the Fourrier table for fo1 (see Annex 5: Fourrier table and G-Factor interpolation) g2 = G-Factor(fo2)

G factor interpolation matched against the Fourrier table for fo2 (see Annex 5: Fourrier table and G-Factor interpolation) rgAnnual = (gf - g1) / GJhermalConductivity

·& Resistance (annual) rgMonthly = (g1 - g2) / GJhermalConductivity

¾k Resistance (monthly) rgDaily = g2 / G thermalConductivity

¾. Resistance (daily) rbb

¾s.B value from Annex 6: Rb resistance table depending on the X_configuration user variable. rbbl

¾d31 value from Annex 6: Rb resistance table depending on the X_configuration user variable. boreHoleShape = rbb ^* (X_boreHoleDiameter / P_outterDiam)' rgi = (

(GJhermalConductivity - XjjroutConductivity) / (GJhermalConductivity * X jjroutConductivit ) ) / boreHoleShape

^-Incremental grout resistance φρ = Ρ_φ / 2

¾-Half pipe resistance rb = rpp + rgi

¾s.Borehore resistance gpmPerTonHeating = round(H_heatFIR / H_size)

¾¾-Nb GPM per ton (heat pump) in heating mode gpmPerTonCooling = round(H_coolFIR / H_size)

¾s.Nb GPM per ton (heat pump) in heating mode fscHeating

¾s.FSC value from Annex 7: FSC Table corresponding to gpmPerTonHeating and X nbSerial fscCooling

^• 2S.FSC value from Annex 7: FSC Table corresponding to gpmPerTonCooling and X nbSerial wc = I qlCooling / H_eER

^Operating power in cooling mode (in Watts) wh = qlHeating / ( H cOP ^* 3.412)

¾,Operating power in heating mode (in Watts) facFormW

. If (X_nbHolesSide1=1 And X_nbHolesSide2>1) OR (X_nbHolesSide2=1

And X_nbHolesSide1>1)

facFormW=2

• Else facFormW = 0

¾. Form factor rounded by 1 bore hole facFormX

• If (X_nbHolesSide1 >1 And X_nbHolesSide2>1 )

facFormX=4

. Else if (X_nbHolesSide1 =1 And X_nbHolesSide2>2)

facFormeX=X_nbHolesSide2 - 2

• Else if (X_nbHolesSide1>2 And X_nbHolesSide1=1)

facFormeX=X_nbHolesSide1 - 2

• Else facFormX = 0

¾¾. Form factor rounded by 2 bore holes facFormZ

• If (X_nbHolesSide1 - 2 > 0 And X_nbHolesSide2 - 2 > 0)

facFormZ = (X_nbHolesSide1 - 2) ^* (X_nbHolesSide2 - 2)

• Else facFormZ = 0

· Form factor rounded by 4 bore holes facFormY

• If (X_nbHolesSide1 =1 And X_nbHolesSide2 =1 )

facFormY = 0

• Else facFormY = (X_nbHolesSide1 * X_nbHolesSide2) - facFormX - facFormZ - facFormW Form factor rounded by 3 bore holes J

X _ nbHolesSidel x X _ nbHolesSide2

·¾¾. System's form factor

[00202] Hole depth calculation:

[00203] To compute the depth of bore holes (for both heating and cooling mode), an iterative function that iterates until the penalty temperature (ip) becomes constant must be defined. For the first iteration, assumed to be tp=3.

^Penalty temperature. Changes on each iteration until it becomes constant; at which the iteration is stopped. The first value is 3°F.

Once the depthHeating and depthCooling variable (below) are calculated, a new

value of tp is computed (tpNew) and repeated until tpNew=tp.

For details about tp calculation, refer to "Annex 8: Interference table and penalty

temperature calculation .".

qa x rgAnnual + {qlCooling - 3.412 x wc)x (rb + plf July x rgMonthly + rgDaily x fscCooling) depthCooling =

{twiCooling + twoCooling)

tGround - - tp ¾¾ otal depth of bore holes needed in cooling mode. requiredTotalDepth = max(depthHeating, depthCooling)

¾sTotal drilling depth required for all holes combined in order to be sufficient.

[00204] 4.3 Ground Loop Design (Horizontal loop)

[00205] This module should compute the length of the heat exchanger for a horizontal loop project. The main output is the length of the heat exchanger from which could be deducted the length of each trench (the depth and the width of the trenches being set by the user).

[00206] 4.3.1 Variables

[00207] 4.3.1.1 Ground Properties

[00208] The user will have two methods of setting the ground properties:

[00209] a. By choosing the ground layers on his field:

Table 10: Ground Layers

[00210] b. By entering the global thermal diffusivity and conductivity of the ground

Variable Type Unit Comments

GJhermalDiffusivity Float None

GJhermalConductivity Float None

Table 11 : Ground specifications [00211] If the user chooses option (a), the system will retrieve the thermal diffusivity and conductivity (Table 3: Ground specifications) depending on the selected layer.

[00212] 4.3.1.2 Building specifications (B)

[00213] c.f. 4.2.1.2 Building specifications (B)

[00214] 4.3.1.3 Heat pump(s) specifications (H)

[00215] c.f. 4.2.1.3 Heat pump(s) specifications (H)

[00216] 4.3.1.4 Antifreeze Selection (A)

[00217] c.f. 4.2.1.4 Antifreeze Selection (A)

[00218] 4.3.1.5 Heat Exchanger Configuration (X)

Table 12 : Horizontal heat exchanger specifications

[00219] Note:

- The X_depth value must be at least :

X_depth >= 3 ft + X_nbLevels*P_outterDiam + (X_nbi_evels-1) *X_level Height

- The X_width value must be at least: X_width >= P_outterDiam ^* $this->X_nbPipes

[00220] 4.3.1.6 Pipe Specifications (P)

[00221 ] c.f . 4.2.1.6 Pipe Specifications (P)

[00222] 4.3.2 Algorithm: Heat Exchanger Length (horizontal loop)

S_meanAnnuaITemp

¾¾. Mean annual temperature as defined in the chosen weather station (°F)

S_meanCoolestMonthTemp

¾*. Mean temperature of the coolest month as defined in the chosen weather station (°F)

S_meanHottestMonthTemp

Mean temperature of the hottest month as defined in the chosen weather station (°F)

¾¾. Annual surface soil temperature swing (°F) xs = 2 ^* X_depth - X_levelHeight ^* (X_nbLevels-1)

^Meat soil depth (ft) tGround

aground temperature for chosen city (constant) tl = tGround - annualSwing * exp(-xs * /(365 * G _ thermalDiffusivity)))

¾. Minimum annual soil temperature @ depth xs th = tGround + annualSwing * exp(-xs * ^(π /(365 * G _ thermalDiffusivity)))

¾¾. Maximum annual soil temperature @ depth xs twiHeating = 32°F

¾k Entering heatpump temperature (heating) - Constant value (CSA448) (°F) twiCooling = 77°F

-a. Entering heatpump temperature (heating) - Constant value (CSA448) (°F)

S_heatingTemp

·& Heating temperature as defined in the chosen city (°F)

S_coolingTemp

¾k Cooling temperature as defined in the chosen city (°F)

heatingTempDiff = B setPointHeating - S heatingTemp

¾. Heating temperature difference (°F)

coolingTempDiff = S coolingTemp - B setPointCooling

Cooling temperature difference (°F) kTot - B_heatLoss / heatingTempDiff

^.Puissance / Degretemperature inGain =532 + .77 *B_dimHouse + 116 ^* B_nbPersons

¾¾. Internal gain (ASHREA page 29.10 equation 30 + equation 31) tBal = B_setPointHeating - (inGain / kTot)

¾¾. Balancing temperature heatLossRate = (B _. _ heatLoss - inGain ) / heatingTempDiff

¾¾. Heat loss rate heatGainRate - (B heatGain - inGain) / coolingTempDiff

Heat gain rate

[00223] Bin Data Table:

[00224] The table is based on the city bin data and the heat pump specifications:

ColA: Tbin from city bin data.

ColB: Average loop temperature from city data.

ColC:GeoCapacity from GS heat pump data.

ColD:

- If ColA<tBal: = (tBal - ColA).heatLossRate

- Else If ColA>B_setPointCooling:

= (B_setPointCooling - ColA) * heatGainRate + inGain I - Else: =0 ColE: = Closest value to 0 between ColC and ColD

ColF:Nb hours per temperature in January (from city bin data)

ColG: = ColE * ColF

ColH:Nb hours per temperature in July (from city bin data)

Coll: = ColE * Col H

ColJ: Number of hours per temperature in a year (from the city BIN data). ColK:

- If ColE>0 : = ColE ^* ColJ

- Else: =0

ColL:

- If ColE<0 : = ColE * ColJ

- Else: =0

¾. Heat run fraction

·& Cooling run fraction

¾. Total pipe length in heating mode f H eER + 3.412

H coolC. rp + rs * fc)

H eER

lCPipe = - twiCooling + twoCooling

^■ th

¾. Total pipe length in cooling mode

IHTrench =■ IHPipe

X _ nbPipes * X _ nbLevels * X _ nbTrenches -& Pipe length on one level of a trench in heating mode.

ICPipe

ICTrench

nbPipes * X _ nbLevels * X _ nbTrenches

¾¾. Pipe length on one level of a trench in heating mode.

[00225] Final result

trenchLength = maxQHTrench, ICTrench)

¾. Trench length auxiliaryHeatingMinimumCapacity = (heatLossRate - GeoCapacity)/3.412

¾. Auxiliary heating minimum capacity - The heat loss rate and geocapacity values must be taken from the latest bin line (lowest temperature for heat loss rate).

¾¾- Total heating energy covered by geothermal auxHeatEnergy = ^ \HeatLossRa te - GeoCapacity^annnalHours

outdoorTemp<TBAL&G oCapacit <HeatLossRate

<¾. Total heating energy covered by the auxiliary heating.

[00226] Annex 1 : City Bin Data Sample

[00227] The following table illustrates a sample bin data table for a specific city:

S tGround = 48°F

¾s.Ground Temperature

S_heatingTemp = -10°F

¾kHeating temperature S_coolingTemp = 105°F ^• a-Cooling temperature [00228] Annex 2: Soil Types

[00229] This table is an export as-is from GS2000 software.

Table 14: Soil types

[00230] Annex 3: Pipe types

40 8

Schedule 0,1054367

24 HDPE 3408/3608 40 1,9 1,61 1,5 0,25 8

HDPE 0,93 0,2074824

25 4710/PE100 SDR 7 1,315 9 1 0,18 7

HDPE 1,18 0,2071466

26 4710/PE100 SDR 7 1,66 6 1,25 0,22 1

HDPE 1,35 0,2069060

27 4710/PE100 SDR 7 1,9 8 1,5 0,25 6

HDPE 1,02 0,1546968

28 4710/PE100 SDR 9 1,315 3 1 0,18 7

HDPE 1,29

29 4710/PE100 SDR 9 1,66 2 1,25 0,22 0,1544067

HDPE 1,47 0,1547380

30 4710/PE100 SDR 9 1,9 8 1,5 0,25 7

HDPE 0,1229783

31 4710/PE100 SDR 11.0 1,05 0,86 0,75 0,15 4

HDPE 1,07 0,1241507

32 4710/PE100 SDR 11.0 1,315 5 1 0,18 2

HDPE 1,35 0,1237124

33 4710/PE100 SDR 11.0 1,66 8 1,25 0,22 1

HDPE 1,55 0,1238461

34 4710/PE100 SDR 11.0 1,9 4 1,5 0,25 4

HDPE 0,89 0,0990906

35 4710/PE100 SDR 13.5 1,05 4 0,75 0,15 9

HDPE 1,12 0,0983365

36 4710/PE100 SDR 13.5 1,315 1 1 0,18 1

HDPE 1,41 0,0988167

37 4710/PE100 SDR 13.5 1,66 4 1,25 0,22 6

HDPE 1,61 0,0989818

38 4710/PE100 SDR 13.5 1,9 8 1,5 0,25 9

HDPE 1,14 0,0842105

39 4710/PE100 SDR 15.5 1,315 7 1 0,18 2

HDPE 1,44

40 4710/PE100 SDR 15.5 1,66 6 1,25 0,22 0,0850297

HDPE 1,65 0,0854244

41 4710/PE100 SDR 15.5 1,9 4 1,5 0,25 9

HDPE 1,16 0,0767362

42 4710/PE100 SDR 17 1,315 1 1 0,18 8

HDPE 1,46 0,0774079

43 4710/PE100 SDR 17 1,66 4 1,25 0,22 5

HDPE 1,67 0,0772839

44 4710/PE100 SDR 17 1,9 6 1,5 0,25 3

HDPE Schedule 0,82 0,1493232

45 4710/PE100 40 1,05 4 0,75 0,15 2

HDPE Schedule 1,04

46 4710/PE100 40 1,315 9 1 0,18 0,1392345

HDPE Schedule 0,1138116

47 4710/PE100 40 1,66 1,38 1,25 0,22 6 HDPE Schedule 0,1020355

48 4710/PE100 40 1 ,9 1 ,61 1 ,5 0,25 9

Table 15: Pipe type (pre-defined values)

[00231 ] Annex 4: Anti-freeze solutions and specific heats

Table 16: Anti-freeze solutions [00232] Annex 5 :Fourier table and G-Factor interpolation

able 17: Fourier table and G-Factor interpolation

[00233] G-Factor() function for a given Fourier number f (interpolation):

- If f is present in the table : G-Factor = the corresponding value;

- If f < 1 , G-Factor = G-Factor ( 1 )

- If f >1000000, G-Factor = G-Factor (1000000)

- Else,

Let f1 = the closest minor Fourier number in the table.

Let f2 = the closest greater Fourier number in the table.

Let gl = G-Factor(f1)

Let g2 = G-Factor(f2)

Let gap = (f - f1) / (f2 - f1) G-Factor(f) = (g2 - g1) ^* gap + g1

00234] Annex 6 :Rb resistance table

a e : res stance ta e

[00235] Annex 7 : FSC Table

Nb Serial bore GPM/ton

holes

Table 19: FSC Table

[00236] Annex 8: Interference table and penalty temperature calculation

Table 20: Sample interference table calcula ion

rlnternal, rExtemal, rMean: Constants xFactor: • If X_distBoreHoles + 2.6 <= rMean;

xFactor - 0

• Else

„ rMean

xr actor =

iX: Interpolated l(xFactor) as described in "Annex 9: l(X) table and calculation" deltaTHeating:

deltaTHeating - ^q ° ^{l X)}

2π x S _ tGroung x depthHeating qHeating:

G thermalConductivity , , „ , _{2 l2} , , , _™T . qHeating =— = — x depthHeating x π x (rExtemal - rlnternal ) x delta 1 Heating

G _ thermalDiff sivity qTotallnterference = SU (qHeating)

qTotalln terference

G _ thermalConductivity

x distBoreHoles x depthHeating

thermalDiffusivity

qTotallnterfer

3¾ = G thermalConductivitx . „

x distBoreHoles x depthCoolmg

G _ thetmalDiffusivity

tp _x x facForm [00239] Annex 9: l(X) table and calculation.

Table 21: l(X) table

l(X) function for a given xFactor X (interpolation):

- If X is present in the table :I(X) = the corresponding value;

- If X=0, l(X) = 0

- If X>0 and X<0.01 , l(X) = 1(0.01)

- If X >1 , l(X) = I (1)

- Else,

Let X1 = the closest minor xFactor number in the table. Let X2 = the closest greater xFactor number in the table. Let 11 = l(X1)

Let I2 = l(X2)

Let gap = (X- X1) / (X1 - X2) l(X) = (I2 - I1 )*gap + 11

[00240] Annex 10: RS soil resistance calculation (Horizontal loop)

[00241] a. Setup the field map and compute coordinates, X Factor, IX and

RS for each pipe: [00242] Diagram 1 shows an example of a field map with the following parameters:

X_nbPipes = 3 X_nbLevels = 3 X_nbTrenches = 2

SOIL

/ / / / / / / ^' // / / / / / ///, ^y // /' / '// // // /./

X_depth

[00243] Diagram 1 : Example of a field map

[00244] The trenches' images are a projection of each trench having the soil as a projection axis. Given that X_depth=8ft, X_levelHeight=0.75ft and X_distTrenches=10ft, the pipes would have the following coordinates (pipe 1 represents the origin of the coordinates):

Table 22 : Coordinates of the example field map

[00245] Using the coordinates, the distances are computed between each pipe in the real field (as opposed to the image field) using the regular plan distance formula: [00246] ^{d =} ^-^ + ^ ² -^ ¹⁾²

[00247] Formula 1 : Distance between Pipel (x1 ,y1 ) and Pipe2(x2,y2)

[00248] The distance between the same pipe will be assumed to be d' rather than being null:

P _ outterDiam

[00249] 2 * 12

[00250] Formula 2 : Fictive distance between the same pipe

[00251] The distances for each pipe is computed in the image field from the origin pipe (Pipe 1 in the figure) using Formula 1.

[00252] The XFactor and IXFactor for each couple of pipes are computed in both the real field and the image field using this formula ¹ :

XFactor = , ^

[00253] 2 * ^G _ thermalDiffiisivity * time

[00254] Formula 3 : Pipe's X factor value

[00255] The time variable used in the XFactor formula is a constant value normally set to 1000. This value would be subject to tweaking in order to obtain more realistic RS values.

[00256] If XFactor have a value between 0 and 0.54 (exclusively), the IXFactor is computed using Formula 4:

1 ^" \ XFactor ² XFactor*

IXFactor = 2.303 * logl d + 0.2886

[00257] XFactor) 2 8

[00258] Formula 4 : IXFactor for XFactor values between 0 and 0.54

[00259] For all other XFactor values, the IXFactor must computed using Formula 5: o = XFactor ⁸ +8.5733287 *XFactor ^s + 18.059017 *XFactor ⁴ + 8.637609* XFactor ² + 0.2677737

[00260] fc = XFactor ⁸ + 9.5733223 *XFactor ⁶ + 25.6329561 *XFactor ⁴ + 21.0996531 * XFactor ² + 3.9684969

1

IXFactor - -

2* XFactor ¹ * _e ^XFactor' b

[00261] Formula 5 : IXFactor for XFactor values NOT between 0 and

0.54

[00262] Finally, the RS value is computed for each pipe couple (Formula 6)

IXFactor

RS = -

[00263] 2π * G _ thermalConductivity [00264] Formula 6 : RS formula for a couple of pipes

[00265] The following tables are excerpts of the previous formulas applied

to the example above

Table 23 : Distance, XFactor, IXFactor and RS values of the real field pipes ' d=15.25 d=14.5 d=13.75 d=15.3235929207

XFactor=0.292405401998 XFactor=0.278024808457 XFactor=0.263644214916 XFactor=0.293816481839 lXFactor=0.983072301656 IXFactor=1.02957761229 IXFactor=1.07894519016 IXFactor=0.978653111262 S=0.208614421634 RS=0.2 8483155056 RS=0.228959280453 RS=0.207676640306

' d=14.5 d= 3.75 d=13 d=14.5773797371

XFactor=0.278024808457 XFactor=0.263644214916 XFactor=0.249263621375 XFactor=0.279508497187 IXFactor=1.02957761229 IXFactor=1.07894519016 lXFactor=1.13147817544 !XFactor=1.0246518406 RS=0.218483155056 RS=0.228959280453 RS=0.240107126163 RS=0.217437873839

' d=16.07015868 d=15.3235929207 d=14.5773797371 d=16

XFactor=0.308131226819 XFactor=0.293816481839 XFactor=0.279508497187 XFactor=0.306785995539 )XFactor=0.935187263613 IXFactor=0.978653111262 IXFactor=1.0246518406 IXFactor=0.939169330032 RS=0.198452900961 RS=0.207676640306 RS=0.217437873839 RS=0.1992979217

Table 24 : Distance, XFactor, IXFactor and RS values of the image field pipes

[00266] b. Compute the global soil resistance (RS) per pipe

[00267} The total trenches soil resistance is computed by summing up all the RS values in the real field table (Table 23) minus the sum of RS values in the image field table (Table 24): totalRS =∑ RS _ Re alField -∑ RS _ Im ageField

[00268]

[00269] Formula 7 : Total soil resistance

[00270] Finally, the soil resistance is computed per pipe (RS):

_{D t} , totalRS

X _ nbLevels * X __ nbPipes * X _ nbTrenches

[00272] Formula 8 : Soil resistance per pipe

[00273] While preferred embodiments have been described above and illustrated in the accompanying drawings, it will be evident to those skilled in the art that modifications may be made without departing from this disclosure. Such modifications are considered as possible variants comprised in the scope of the disclosure.