IMPROVEMENTS IN AND RELATING TO MODULAR HEATING,

VENTILATING AND AIR CONDITIONING SYSTEMS

The present invention concerns improvements in and relating to modular heating, ventilating and air conditioning systems and particularly, the present invention relates to a modular heating, ventilating, air conditioning and heat recovery system.

United States Patent Specification No. US 5 277 036 discloses a modular air conditioning system with adjustable capacity which includes a cooling module, a heating module, and a blower module which can be assembled in any of a plurality of configurations, including a vertical downflow configuration, a vertical upflow configuration, or a horizontal configuration, using the same set of modules. The same set of modules can be operated over a range of cooling capacities by employing a condensing unit of the required capacity connected to the cooling module and by adjusting the airflow volume rate of air transported through the system. A movable restrictor plate is disclosed as being positioned in partial covering relation to a discharge opening of the blower module and is adjusted to achieve the required airflow volume rate.

Known heating, ventilating and air conditioning (HVAC) systems exemplified by the system disclosed in US 5 277 036 have the following disadvantages associated with them:

1. The system of US 5 277 036 is not able to carry out heat recovery. In an age when recycling and recovery of energy is of paramount importance, the lack of such capability is a significant disadvantage;

2. In the system of US 5 277 036, (column 2, lines 37 to 54) the airflow volume rate is adjusted by a variable restrictor plate according to the cooling capacity of the condensing unit employed to result in a constant airflow volume rate per unit of cooling capacity, such as 200 cubic feet per minute (CFM) (94.4 liters/second) per ton (3.514

KW cooling). The variable restrictor plate is slidably mounted across the discharge opening of the blower module to vary the area according to the airflow volume rate required for the cooling capacity desired. A control handle of the restrictor plate extends through a slot in a plenum connection of the blower module. An index mark on the control handle is matched with one of a number of graduation marks on a label on the wall above the discharge opening to indicate the proper setting of the restrictor plate for the cooling capacity desired. The restrictor plate is described in US 5 277 036 as being fixed at the desired setting by means such as a screw or similar fastener extending through a slot in the control handle.

The disadvantages of the blower module in the system of US 5 277 036 is that it includes a metal guillotine (i.e. the restrictor plate 29 in Figure 5 of US 5 277 036) as a very crude device to regulate air flow. The air flow is pre-set by the position of this metal guillotine at the time of commissioning of the system. This does not enable adjustability after commissioning. One of the differences between the system of the present invention and any prior art system is that the airflow is controlled by the supply duct static pressure. In the system of US 5,277,036, the static pressure and air flow are set by the restrictor plate. There is back pressure put on the supply fan when the airflow is throttled down the airflow leading to inefficiencies.

In a single zone system in accordance with US 5,277,036, with a single speed fan, the static pressure and airflow do not change, they are not required to change the system of US 5,277,036 is limited to two or three zones. In a multizone system in accordance with US 5,277,036, with a single speed fan, the static pressure would increase as each zone damper shuts off. This increases the back pressure on the supply fan and decreases the efficiency of the fan motor. A high static pressure increases the air flow and corresponding air noise of the opened zone (s).

Bypass dampers have been added to alleviate the excessive supply duct pressure in a system based on the disclosure of US 5,277,036. Using a barometric when excessive pressure is reached in the supply duct, the damper opens and takes some supply air and puts it directly into the return air. This can lead to short cycling of the condensing unit on heating or cooling. In cooling mode, it can cause the condensing unit to have a return air which is too cold (some of the cold supply air is being delivered into the return air stream on by pass) and switch off on freeze prevention or low pressure. This in an extremely inefficient method of zoning and capacity control. In heating mode, too warm return air onto the heat pump coil (caused by bypassing some hot supply air into the return air) can cause the condensing unit to trip off on high pressure. This is an extremely inefficient method of zoning and capacity control. With the system of the present invention, the static pressure is controlled by

Programmable Logic Controller (PLC) by checking the supply duct pressure and modulating the fan speed to regulate the pressure. The EC fan motor, included in the system of the present invention, is directly controlled by the PLC and only uses the necessary amount of electricity to achieve the required static pressure. As the duct sizes are fixed, an increase in supply duct static pressure will have a direct effect on the air volume. This is an efficient method of zoning and capacity control and is a significant advantage of the system of the present invention.

The inherent problems with a fixed speed supply fan (whether single or multi speed) are eliminated by the system of the present invention, by inter alia, comprising an infinitely variable speed EC fan motor and therefore infinitely variable and controllable air flow (within the physical limits of the fan motor and fan pressure curve). In conjunction with variable speed condensing units allowing the capacity of the condensing units (for heating and cooling) to vary in proportion to the supply air volume, the need for bypass dampers is eliminated. Furthermore, in the system of the present invention, the limitation on the number of zones is eliminated. The system of the present invention provides significant advantages in controllability and efficiency of the modular style air conditioning and heating system as electrical consumption is directly related to the amount of supply air required and the amount of cooling and heating capacity required. The portion and ratio of these (supply fan airflow versus heating/cooling capacity) can be linked via the PLC software. No other compact modular air conditioning/heating system offers this. This is a further novel feature of the system of the present invention. The necessity to have this restrictor plate (indicated by reference numeral 29 in Figure

5 of US 5 277 036) is awkward and inefficient because of difficulties in sealing the air gap at the restrictor plate. There is trial and error adjustment needed in getting the correct static pressure. There is additional noise associated with air turbulence at restrictor plate and additional resistance against the fan motor decreasing its efficiency. The fan motor is an A/C single speed centrifugal type fan motor with a front discharge. The system of US 5 277 036 includes a hot water coil module having a slide in coil which is slideable from one side only. The air conditioning module in US 5 277 036 has a fixed air conditioning or heat pump coil.

3. The modules in the system of US 5 277 036 are connected together using a hook and latch connection referred to as a "suitcase" latching connection. This type of connection between modules has been found to be less than satisfactory because the latch requires room to open close (i.e. the metal casing of the system of US 5,277,036 cannot be tight to the ceiling structure).

4. The weight of the metal used in the walls of the modules in the system of US 5 277 036 is relatively light.

5. Another problem with known small duct high velocity air conditioning systems is that they are generally designed for use with fixed speed condensers. Such known systems are not built or tested to European standards. There is no independent and certified testing of the hot water coil ratings, heat pump coil ratings or chilled water coil ratings to European standards. There is no certified test of air flow or acoustic performance to European standards.

6. Furthermore, the control systems in known HVAC systems are basic and lack the facility to drive variable capacity inverter driven condensing units. These condensing units are provided to operate with but are external of the system of the present invention however the PLC of the system of the present invention with the custom software controls the modulation (capacity) of the condensing unit.

The present invention seeks to alleviate the disadvantages associated with known heating, ventilating and air conditioning (HVAC) systems.

Summary of the Invention

The present invention provides a heating, ventilating, air conditioning and heat recovery system comprising various combinations of the following modules: fan module (also referred to as the blower module);

hot water/chilled water module;

mixing box module;

heat recovery (HRV) EC fan module;

heat recovery (HRV) core module (heat recovery core module including heat exchanger);

heat pump coil module;

PLC controller housed in a control panel together with transformer, circuit breakers, relays and wiring;

heat pump coils; and

optionally wherein the hot water/chilled water module, the HRV core, the mixing box and/or the heat pump coil are adapted to be accessed from more than one side of the module, thereby providing at least dual sided access to the interior of said modules.

The system of the present invention is capable of variable airflow and is capable of performing as a Small Duct High Velocity system as defined by the United States Department of Environment. The United States Department of the Environment (US DOE) has a specific definition of small duct, high velocity (SDHV) systems which is as follows:

The term "small duct, high velocity (SDHV) system" indicates a blower and indoor coil combination that:

(1 ) is designed for, and produces, at least 1.2 inches of external static pressure when operated at the certified air volume rate of 220-350 CFM (103.83

L/s - 165.18 L/s) per rated ton (3.514 KW) of cooling; and

(2) when applied in the field, uses high velocity room outlets generally greater than I OOOfpm (5.08 M/s) which have less than 6.0 square inches (38.71 square Centimeters) of free area.

In one aspect, the present invention provides a modular heating, ventilating, air conditioning and heat recovery system comprising:

(a) a supply fan module including a fan and a fan motor; preferably a variable speed fan motor;

(b) a mixing box module; and (c) means for controlling the supply fan thereby providing a system for circulating air and for controlling the manner in which the air is circulated.

The mixing box module preferably comprises a filter and a filter sealing plate and also including connection means to enable the mixing module to be connected to other modules.

The hot water coil module advantageously includes a hot water coil for extracting heat from hot water thereby providing heated air (when the hot water coil is supplied with hot water of temperature between 30 ⁰ C and 80 ⁰ C) to the premises in which the system of the present invention is installed.

The hot water coil module also includes connection means for connecting the hot water coil module securely to another module in the system.

Advantageously, in the system of the present invention, each module is provided with connection means for removably connecting the module to another module in the system.

The heat pump coil module includes a heat pump coil for heating or cooling air depending on whether the condensing unit which is connected to the heat pump coil is in heating mode or cooling mode respectively. The heat pump coil module also includes connection means for connecting it securely to another module in the system.

The heat pump module is advantageously adapted to receive the heat pump coil from two sides thereby providing double sided access.

The heat pump module is preferably adapted by including a channel for receiving the heat pump coil which can be inserted in the channel from either side of the heat pump module. Preferably, the heat recovery (HRV) core module includes a heat exchanger, and further including a heat recovery (HRV) exhaust fan module so as to provide means for heat recovery in the system.

The HRV core module and the HRV exhaust fan module preferably also include connection means for connecting the modules securely to other modules. A heat pump coil module and a hot water coil module may also be included. The heat pump coil can carry heated water or cooled/chilled water depending on whether air heating or air cooling respectively is needed.

A heat recovery (HRV) exhaust fan module and a heat recovery (HRV) core module may also be included, thereby providing a water heating, heat pump and HRV system.

Preferably, the connection means comprises male and female latches which enable the modules to be interconnected together securely.

Preferably, the male and female latches comprise cam latches.

Thus, the present invention provides a modular heating, ventilating, air conditioning and heat recovery system with variable air flow capacity including a supply fan module incorporating a variable speed fan; and

further including a heat pump coil module, a hot water coil module, a chilled water coil module, a heat recovery module and a heat recovery (HRV) exhaust fan module incorporating a variable speed fan, the modules being adapted to be assembled in numerous configurations and means for controlling operation of the said modules, in use.

Advantageously, the fan module is positioned near to the heating coil/cooling coil module.

Preferably, in the modular heating, ventilating, air conditioning and heat recovery system of the present invention, the configurations in which the modules can be assembled include a horizontal configuration, a vertical upflow configuration, or a vertical downflow configuration, using the same set of modules. The HRV core module may be mountable horizontally and the chilled water module may be mountable horizontally. The supply fan module includes an air tight seal; and preferably the seal is provided by a gasket.

Advantageously, the means for controlling operation of the modules comprises a programmable logic controller (PLC), and is adapted to take account of water temperatures, refrigerant coil temperatures, air discharge temperature, return air temperature or humidity and CO ₂ (optional).

Ideally, the heating, ventilating, air conditioning and heat recovery system of the present invention is for use as a Small Duct High Velocity System (SDHV) (sometimes also referred to as a "mini-duct") which is of a size that can be easily accommodated in structures such as residences and commercial buildings.

In the system of the present invention, the air flow is controlled by a programmable logic controller (PLC) which allows for an infinitely variable supply duct pressure and numerous modes of operation such as supply fan only; Heat recovery (HRV) only; cooling only; heating only; cooling and heat recovery (HRV); heating and heat recovery (HRV) wherein the respective modes of operation are controlled by the PLC (computer implemented) and in turn controlled by algorithms adapted to control the system of the present invention

Ideally, the modules are removably connected together using connection means comprising a cam-locking latch thereby providing a completely secure connection without risk of one or more modules becoming disconnected from an abutting or adjacent module during movement or relocation of the heating, ventilating, air conditioning and heat recovery system.

Accordingly, the present invention relates to a modular heating, ventilating, air conditioning and heat recovery system with variable air flow capacity utilizing a supply fan module incorporating a variable speed fan and including a heat pump coil module, a hot water coil module, a chilled water coil module, a heat recovery module and a heat recovery (HRV) exhaust fan module incorporating a variable speed fan which can be assembled in numerous configurations.

Conveniently, the possible configurations of the modules include a horizontal configuration, a vertical upflow configuration, or a vertical downflow configuration, using the same set of modules. (The HRV core module itself can be mounted one way only (horizontal) and the chilled water module itself can only go one way (horizontal)).

The system of the present invention includes a gasket to provide an air tight seal between modules. The control system in the modular heating, ventilating, air conditioning and heat recovery system of the present invention includes a programmable logic controller (PLC), and is adapted to take account of water temperatures, refrigerant coil temperatures, air discharge temperature, return air temperature or humidity and CO ₂ (optional).

Particularly, the present invention provides a heating, ventilating, air conditioning and heat recovery system for use as a Small Duct High Velocity System (SDHV) (sometimes also referred to as a "mini-duct") which is of a size that can be easily accommodated in structures such as residences and commercial buildings. In the United States of America, this type of system is officially classed a Small Duct High Velocity (SDHV) system.

The improved heating, ventilating, air conditioning and heat recovery system of the present invention has the advantage, inter alia, that it does not rely on nor require a restrictor plate to control the air flow. Instead, in the system of the present invention, air flow is controlled by a programmable logic controller (PLC). It allows for an infinitely variable supply duct pressure and numerous modes of operation such as fan only, HRV only, cooling only, heating only, cooling and HRV, heating and HRV. The modes of operation are controlled by the PLC (computer implemented) and in turn controlled by algorithms specifically prepared to control the system of the present invention.

The PLC also advantageously increases the zoning capabilities of the system (refer to page 3, lines 10 to 35 hereinabove). Ideally, the modules are removably connected together using connection means comprising a cam-locking latch. The inclusion of this cam-locking latch as the connection means on the modules of the system of the present invention has the advantage that it provides a completely secure connection without risk of one or more modules becoming disconnected from an abutting or adjacent module during movement or relocation of the heating, ventilating, air conditioning and heat recovery system of the present invention. The system of the present invention also allows fitting of empty modules and adding the appropriate hot water/chilled water coil or heat pump coil at a later date. Since all modules are of equal size, this makes packaging, shipping and installation easier. Ideally, the heating, ventilating, air conditioning and heat recovery system of the present invention includes an air tight and water tight gasket provided on the fan module. Throughout this specification, the term "fan module" is interchangeable with the term, "blower module" and "supply fan module".

Preferably, the heating, ventilating, air conditioning and heat recovery system of the present invention includes heat recovery means comprising a heat recovery core module including a heat exchanger. Preferably, the heat recovery means also includes a fan. It is believed that including heat recovery means in a small duct HVAC (SDHV) Heating and air conditioning system is previously unknown. Specifically, including a heat recovery module adapted to interact with the other modules of the system is believed to be novel. The heat recovery capability in the small duct heating, ventilating, air conditioning and heat recovery system of the present invention has the significant advantage of providing an extremely efficient system which enables cost-savings to be made and reduces the carbon footprint associated with the users of the building structure in which the heating, ventilating, air conditioning and heat recovery system of the present invention is installed.

The heating, ventilating, air conditioning and heat recovery system of the present invention has the further advantage that it is specifically designed for use with inverter driven variable capacity condensing units. The heat pump coil volume is matched with the condenser manufacturer's specifications to a given condensing unit capacity. This gives a matched system (indoor coil volume matches the manufacturer's outdoor condensing units correctly) for maximum efficiency and reliability. The variable speed condensing units allowing the capacity of the condensing units (for heating and cooling) to vary in proportion to the supply air volume. The system of the present invention provides significant improvements in controllability and efficiency of the modular style air conditioning and heating system as electrical consumption is directly related to the amount of supply air required and the amount of cooling and heating capacity required. The portion and ratio of these (supply fan airflow versus heating/cooling capacity) can be linked via the PLC. There is no other known compact modular air conditioning/heating system which provides this control. The system of the present invention has the advantage of providing a modular system with optional integrated heat recovery and no prior art high velocity mini duct modular system includes this feature. In the system of the present invention, airflow volume rate is controlled by static pressure instead of requiring a restrictor plate as required in the prior art thereby leading to greater controllability, flexibility and efficiency in the system of the present invention.

Furthermore, the airflow volume rate can be easily changed even after commissioning of the system thereby reducing inefficiencies.

The present system also has the advantage that the airflow rate will remain constant even as filters in the system accumulate dust particles because the supply fan will ramp up to compensate for restrictions caused by dust particles on air filters. This ramping up of the fan is controlled by the PLC to which is transferred, information from a static pressure sensor provided in the ducting in accordance with the present invention.

In the prior art, an increase in static pressure increases air flow and increases corresponding air noise of the opened zone as in US 5277036. However, the system of the present invention has the advantage that an increase in air flow does not result in a corresponding increase in noise.

In the system of the present invention, the static pressure is controlled by PLC thereby providing an extremely efficient method of zoning since only the energy required to provide the airflow; and heating/cooling to the required zone/s is used.

The variable speed fan motors included in the system of the present invention eliminate the inherent problems associated with the prior art fixed speed supply fans. The zoning capabilities are increased with the present system due to the control provided by the PLC, (refer to pg 3 lines 10 - 35 hereinabove).

The supply fan module is pressurized by the fan/fan motor. This pressurization of the supply fan module allows the ducting to be attached to any position on the supply fan module. This provides huge versatility to a person installing the system of the present invention especially in tight restricted spaces.

Advangateously, the supply fan is a radial fan which pulls the air through the centre of the fan and exits along the propeller blades to pressurize the supply fan box, thereby enabling ducting to be attached on either top, bottom or front panels of the supply fan module.

The supply fan module, mixing box module and heating/cooling coil modules have dual sided access which allows versatility for the person installing the system of the present invention.

The gasket arrangement and latch system used on the modular small duct high velocity system of the present invention is unique. The latch system allows for the modules to be fitted tight to the ceiling unlike other modular high velocity mini duct systems. The latches are extremely strong and this allows the modules to be cantilevered so that the additional supports which are required by prior art systems need not be provided for the modules of the present invention to connect them to the ceiling of a building in which the system of the present invention is installed. Advantageously, the variable speed radial fan is controlled with a 0 - 10 volt signal which is unique in a modular small duct high velocity system.

Advantageously, a static pressure sensor is located in the supply fan module to measure static pressure. This is connected to the static pressure sensor and converted to a 0 - 10 volt signal.

The fan is positioned in front of the heating and cooling coils and the air is pulled through the heating and cooling coils and into the fan and then discharged into the supply module fan which is then pressurized. This is unique to the system of the present invention and is not available in any prior art modular high velocity mini duct system.

The system of the present invention also has the following advantages:

It is compatible with the inverter driven condensing units heat pump which controls the modulation (capacity) of the condensing unit; carbon footprint reduction through extremely efficient heat recovery system; full control of the heat recovery exhaust fan, fresh air dampers and mixing box; gauge/strength of metal used in the modules as compared to other systems; the quality will last many years; slide-in cooling coil and heating coils are unique to a small modular high velocity mini duct system.

The Summer by-pass feature (as shown in Figure 22) has the advantage of providing "free" cooling (i.e. at no cost) since it relies on introducing cooler air from outside the building. This feature is not available on any prior art high velocity mini duct system.

The present invention will now be described more particularly, by way of example only, with reference to the accompanying drawings in which are shown several embodiments of the improved heating, ventilating, air conditioning and heat recovery system of the present invention.

In the drawings:

Figure 1 is a perspective view of the assembled modules of the heating, ventilating, air conditioning and heat recovery system of the present invention;

Figure 2 is a perspective view of the modules of the heating, ventilating, air conditioning and heat recovery system of the present invention shown spaced from each other to show the disassembled modules (in partial section with module lids removed); Figure 3 is a perspective view of the fan module;

Figure 3a is a further perspective view of the fan module;

Figure 3b is a view of the fan module disassembled and showing the component parts; Figure 3c is a front view of the fan module with the front panel of the module cabinet removed to view the fan;

Figure 3d is a side sectional view of the fan module;

Figure 3e is a plan view from above, of the fan module with the lid of the module cabinet removed;

Figure 4 is a perspective view of the hot water and chilled water module;

Figure 4a is a perspective view of the hot water and chilled water module with the slide-in coil shown partially removed from the module;

Figure 5 is a perspective view of the mixing box module;

Figure 5a is a further perspective view of the mixing box module;

Figure 5b is a view of the mixing box module, disassembled and showing the component parts;

Figure 5c is a plan view from above, of the mixing module with the lid of the module cabinet removed;

Figure 5d is a front view of the mixing module;

Figure 5e is a side sectional view of the mixing module;

Figure 6 is a perspective view of the heat recovery EC fan module; Figure 7 is a perspective view of the heat recovery (HRV) core module;

Figure 7a is a perspective view of the heat recovery module comprising the heat recovery EC fan module and the heat recovery (HRV) core module; Figure 7b is a view of the heat recovery module disassembled and showing the component parts;

Figure 7c is a side view of the heat recovery module, with the lids removed;

Figure 7d is a front view of the heat recovery module;

Figure 7e is a plan view, from above, of the heat recovery module, with the lids removed; Figure 7f is a perspective view of the heat exchanger that is included in the heat recovery module with one of the plates of the heat exchanger shown pulled out, for clarity;

Figure 8 is a perspective view of the heat pump coil module; Figure 8a is a further perspective view of the heat pump coil module;

Figure 8b is a view of the heat pump coil module disassembled and showing the component parts; Figure 8c is a plan view; Figure 8d is a front view;

Figure 8e is a side sectional view;

Figure 9 is a perspective view of the heat pumps;

Figure 10 is a schematic diagram of the modules of the heating, ventilating, air conditioning and heat recovery system of the present invention in one embodiment, with the heat recovery module, hot water/chilled water module and heat pump module together with the mixing box module and the EC fan module arranged in a horizontal configuration;

Figure 11 is a schematic diagram of the modules of the heating, ventilating, air conditioning and heat recovery system of the present invention, in another embodiment, with the heat recovery module, hot water/chilled water module and heat pump module together with the mixing box module and the EC fan module, arranged in a compact horizontal configuration;

Figure 1 1a is a perspective view of the modules arranged in the compact horizontal configuration, as in Figure 1 1 ;

Figure 12 is a schematic diagram of an alternative embodiment of the system of the present invention with the hot water module and heat pump module together with the mixing box module and the EC fan module, in a generally L-shaped configuration . Figure 12 refers to hot water module - this is the same as the hot water/chilled water module except that only one side panel is different. This is due to the arrangement of the coil inlet/outlet pipe (connections). It is another novel feature of the system of the present invention that the one module can be used for the heat pump coil and the hot water/chilled water coil just by changing this one panel;

Figure 13 is a schematic diagram of an alternative embodiment of the system of the present invention with the heat pump module and the hot water/chilled water module together with the mixing box module and the EC fan module, arranged in a generally L- shaped configuration;

Figure 14 is a schematic diagram of an alternative embodiment of the assembled modules of the present invention which in this embodiment, includes only the hot water/chilled water module together with the mixing box module and the EC fan module, in a horizontal configuration;

Figure 15 is a schematic diagram of an alternative embodiment in which the heat recovery module is together with the heat recovery EC fan module, the mixing box module and the supply fan; for heat recovery only, function; Figure 15a is an isometic view of the heat recovery combination of modules shown in Figure 15;

Figure 16 is a schematic diagram of the airflow through the modules connected together in the horizontal configuration of Figure 10; Figure 17 is a schematic diagram of the airflow through the modules connected together in the compact horizontal configuration of Figure 1 1 ;

Figure 18 is a schematic diagram of the airflow through the modules connected together in the configuration as shown in Figure 12;

Figure 19 is a schematic diagram of the airflow through the modules connected together in the configuration as shown in Figure 13; Figure 20 is a schematic diagram of the airflow through the modules connected together in the configuration as shown in Figure 14;

Figure 21 is a schematic diagram of the airflow through the modules connected together in the configuration (modified version of Figure 14);

Figure 22 is a schematic diagram of the airflow through the modules connected together in the configuration as shown in Figure 15 and Figure 15a;

Figure 23 is a flow chart indicating the control steps to be taken by the programmable logic controller (PLC) in certain operating mode(s) indicated in the flow chart;

Figure 24 is a flow chart indicating the control steps to be taken by the programmable logic controller (PLC) in certain operating mode(s) indicated in the flow chart; Figure 25 is a flow chart indicating the control steps to be taken by the programmable logic controller (PLC) in certain operating mode(s) indicated in the flow chart;

Figure 26 is a flow chart indicating the control steps to be taken by the programmable logic controller (PLC) in certain operating mode(s) indicated in the flow chart; and

Figure 27 is a flow chart indicating the control steps to be taken by the programmable logic controller (PLC) in certain operating mode(s) indicated in the flow chart.

The system of the present invention will now be described with reference to the accompanying drawings. Referring initially to Figures 1 and 2, the system comprises a number of the following modules in any one of several possible arrangements/configurations: 1. fan module (also referred to as the blower module) (reference numeral 300);

2. hot water/chilled water module (reference numeral 400);

3. mixing box module (reference numeral 500);

4. heat recovery (HRV) EC fan module (reference numeral 600);

5. heat recovery (HRV) core module (reference numeral 700) (heat recovery core module including heat exchanger);

6. heat pump coil module (reference numeral 800);

7. heat pumps module (reference numeral 900); and

8. PLC controller. The operation of the system of the present invention, including the control of the air flows of the combined modules is controlled by a programmable logic controller (PLC).

Each of the modules will firstly be described individually in terms of its construction and technical features. Subsequently, the operation of the modules, in use, when combined in a number of alternative configurations will then be described.

1. Fan module (also known as blower module)

Referring to Figures 3, 3a, 3b, 3c, 3d and 3e, the fan module (also known in the art as a "blower" module) included in the system of the present invention is indicated generally by reference numeral 300. The blower module 300 comprises an electrically commutated (EC) fan motor which is supported by a housing and is encased in a cabinet.

Referring now particularly to Figure 3b, the fan module 300 comprises a duct end panel 301 , a fan motor mounting plate 302, an inlet end panel 303, two female latch brackets

304 and two male latch brackets 308, a top panel (lid) 305a, a bottom panel (base) 305b and two side panels 307. The fan module 300 also includes a fan motor mounting rail 306 comprising an upper mounting rail 306a and lower mounting rail 306b. The fan module

300 is connectable to other modules using a connection means which is a locking mechanism comprising a cam latch 309 which is engageable in a latch receptacle of same construction as latch receptacle 310 e.g. latch receptacle 512 on mixing module 500 thereby enabling the fan module to be securely connected to the mixing module 500. The fan module 300 also includes cable glands 311 , 313 and gland nuts 312 and 314. The fan module 300 also includes an inlet ring 315 and a fan motor 316. The fan motor 316 is a variable speed fan motor so that the fan motor 316 can be set at any speed that is desirable for operating efficiently. Thus, the air flow through the system is not limited to any pre-determined value which must be pre-set at the commissioning stage as is the case with the prior art. The fan motor 316 operates quietly and hence, with the system of the present invention, the assembled modules can be located in a dwelling house, for instance and there will be no noise pollution resulting for the house holders.

The fan 316 pressurizes the fan module 300. The fan motor 316 is located spaced from the side panels 307 and the inlet end panel 303 thereby enabling the supply duct to be attached at any point on the panels defining the module walls. Hence, a person installing the system can attach a duct at any point on the side walls of fan module 300. The fan module is capable of receiving various sizes of take off ducting which can be installed in any area/location of the fan module.

The EC fan motor 316 (a DC variable speed fan motor with inbuilt inverter and electronics) supplies the positive pressure in the fan module 300. Basic DC motors rely on carbon brushes and a commutation ring to switch the current direction, and therefore the magnetic field polarity, in a rotating armature. The interaction between this internal rotor and fixed permanent magnets induces its rotation. In an EC motor, the mechanical commutation has been replaced by electronic circuitry which supplies the right amount of armature current in the right direction at precisely the right time for accurate motor control. Furthermore, a compact external rotor design with stationary windings is used. The permanent magnets are mounted inside the rotor with the fan impellar attached. An EC motor under speed control is virtually silent. Doubling the speed of a motor increases its power input by a factor of eight so it is very wasteful to run a fan faster than is required. By tailoring the fan speed to match the demand, the potential for energy saving is huge. Even when compared to on/off operation, EC speed modulation is much more efficient. The EC fan motor 316 includes an inlet ring 315 for increased performance and efficiency. The fan motor 316 and fan wheel itself can be accessed from two sides (i.e. by removing either one of the two side panels 307) for ease of replacement and to aid design and installation flexibility. The fan motor is held in place by four nuts 312 and 314 for ease of removal. The fan motor 316 is mounted on a motor mounting plate 302 and upper and lower mounting rails 306a, 306b which provide a rigid assembly to minimize vibration.

The fan motor 316 is controlled by a Programmable Logic Controller (PLC) with a custom written software specifically for the operation of the system in whole or in part housed in a separate control panel (see description of control panel below). The fan motor 316 is lined with 19mm acoustic open cell foam for superior sound reduction and to prevent condensation and enhance the efficiency of the heat pump coil by reducing heat loss through the cabinet defined by the duct end panel 301 , side panels 307, top and bottom panels 305a, 305b and inlet end panel 303. The seals between each module comprise an 8mm heavy duty compressible seal.

The connection means (also referred to herein as the locking mechanism), for removably connecting the modules together provides an extremely strong interlocking of modules together and also ensures tight compression of the gasket to ensure a leak proof seal. The locking mechanism is activated using an Allen wrench. The locking mechanism comprises a male member 309 and a female member 310 and the locking mechanism is encased in metal to prevent air leakage.

The access doors are held on four bolts on each door. The access door has a gasket seal to prevent air leakage.

2. Hot water/chilled water module

Referring now to Figure 4 and Figure 4a, the hot water/chilled water module is indicated generally by reference numeral 400. The hot water/chilled water module comprises the following features:

• High performance slide in hot water and chilled water coil 401 ;

• Dual side access and multi position options;

• 1.2mm galvanized steel construction; • Strong cam latch and heavy duty gasket provide air tight seal;

• 19mm high performance insulation; and

• Low pressure drop coils on air flow and water flow. The hot water and chilled water coil can be slided in from both sides of the module. This is a significant advantage when installing the system of the present invention as it gives greater flexibility when installing, especially in tight spaces.

3. Mixing box module (reference numeral 500)

The mixing box module is adapted to enable mixing of return and fresh air.

The mixing box module is indicated generally by reference numeral 500 and includes the following features:

• 50mm heavy duty air filter;

• Dual side access and multi position options;

• 1.2mm galvanized steel construction;

• Strong cam latch and heavy duty gasket provide air tight seal; and

• 19mm high performance insulation.

Referring now to Figures 5, 5a, 5b, 5c, 5d and 5e, the mixing box module will be described in detail. The mixing box module is indicated generally by reference numeral 500 and includes four female latch brackets 501 , four male latch brackets 502 and a top panel (lid) 503a and a bottom panel (base) 503b. The mixing box module 500 also includes a left end panel 504, a right end panel 505 and two side panels 508.

The mixing box module 500 also includes a filter 513 as well as a filter sealing plate 506 and a rectangular shaped filter bracket comprising long bracket sides 507 and short bracket sides 509; and filter bracket holding arms 510. The mixing box module 500 is connectable to other modules such as the fan module 300 by connection means which is a locking mechanism comprising a latch 511 (male member) which is engageable in a latch receptacle of the same configuration as latch receptacle 512 (female member) on another module e.g. the female member latch receptacle 310 on fan module 300 to enable connection of the mixing box module to the fan module 300. 4. Heat recovery (HRV) fan module (600)

The heat recovery (HRV) fan module is indicated generally by reference numeral 600 and includes the following features:

• an EC fan motor technology for optimal energy efficiency;

• Dual side access and multi position options;

• Super quiet infinitely variable speed fan motor;

• 1.2mm galvanized steel construction;

• Strong cam latch and heavy duty gasket provide air tight seal;

• 19mm high performance insulation; and

• Programmable Logic Controller (PLC). 5. Heat recovery Module (HRV)

The Heat recovery module includes a heat recovery core module 700 and is available as an add on module to the system of the present invention. The heat recovery (HRV) fan module 600 includes an exhaust fan. Air is exhausted from within the building through the HRV core module 700 via a fan built into the heat recovery module. Fresh air enters the heat recovery module and is pulled across the heat recovery module into the mixing box and across the respective coil modules and then supplied into the duct distribution system via the fan module 600. Referring now to Figures 7, 7a, 7b, 7c, 7d and 7e, the heat recovery module will be described in detail. The heat recovery module includes a heat recovery (HRV) core module 700 and the HRV EC fan module 600.

Heat recovery (core) module (700)

The heat recovery core module 700 includes the following features:

• High efficient Aluminum core heat exchanger;

• Dual side access and multi position options;

• Up to 2000 M3/Hr supply air, Up to 2000 M3/Hr exhaust air; • Up to 94% thermal efficiency;

• 1.2mm galvanized steel construction;

• Strong cam latch and heavy duty gasket provide air tight seal; and

• 19mm high performance insulation.

The heat recovery core module 700 includes female latch brackets 701 and male latch brackets 702 as well as top and bottom panels 703 of the heat recovery module 700 together with end panels 704 and an end panel 705 and side panels 708. The heat recovery module includes a core mounting bracket 707 on which the core heat exchanger 717 is mounted. The heat exchanger 717 comprises a plurality of plates 717a which are manufactured of Aluminium/Epoxy coated aluminium. The frame of the heat exchanger 717 is formed of corner profiles in aluminum and endplates in aluminium or aluzinc. It is of course to be understood that other materials can also be used for the manufacture of the HRV core module 700 such as a plastic material, for instance. The heat exchanger is characterised by the fact that the plates, made of raw or epoxy coated aluminium, are corrugated. Heat transfer is improved by the surface creating turbulence. The increased turbulence occurs without any filth erecting stagnation points and speed changes. In this way, the entire exchanger is utilized to the maximum. The heat exchanger allows a differential pressure up to 1800 Pa. A single pass exchanger can provide an efficiency of 65-70%. The expected efficiency is 86% on the supply air.

The heat recovery core module 700 comprises two block off plates 709 to prevent air leakage between the supply and extract air.

The heat recovery module also includes the heat recovery EC fan module 600. The heat recovery fan module 600 includes a fan inlet panel 606 and a fan 624.

There are also two fan support plates 610 included for supporting the fan 624 and a fan mounting plate 611 on which the fan 624 is mounted. The heat recovery core module 700 also includes two drain block off members 712e and a drain pan weld assembly 713.

The heat recovery module is connectable to other modules such as the fan module 300 and/or the mixing box module 500 using a connection means which is a locking mechanism comprising a latch 715 (male member) which is engageable in a latch receptacle of same construction as latch receptacle 716 (female member) e.g. latch receptacle 512 on the mixing module 500 or latch receptacle 310 on the fan module 300.

There are a number of gland nuts 619, 621 and cable glands 618, 620 included to secure the panels together thereby defining the cabinet in which the fan 624 and the heat exchanger core 717 are encased.

The heat recovery unit also includes a lint screen 722 which functions as an air filter and protects the HRV from dust.

There is an inlet ring 623 placed into the inlet on the inlet panel and the fan 624 is located on the inlet ring 623.

6. Heat pump coil module (800)

The heat pump coil module is indicated generally by reference numeral 800.

The heat pump coil module 800 is lined with 19mm acoustic open cell foam for superior sound reduction and to prevent condensation and enhance the efficiency of the heat pump coil by reducing heat loss through the cabinet.

The heat pump coil module 800 includes the following features:

• High performance slide in hydrophilic coated heat pump coil;

• Dual side access;

• 1.2mm galvanised steel construction;

• Strong cam latch and heavy duty gasket provide air tight seal;

• 19mm high performance insulation; and

• Low pressure drop coils specifically designed for inverter driven modulating capacity heat pumps.

The heat pump coil module is manufactured from galvanized steel and has hanging brackets to aid in suspending the module. Referring now to Figures 8, 8a, 8b, 8c, 8d and 8e, the heat pump module 800 will now be described in detail.

The heat pump coil module is indicated generally by reference numeral 800 and includes four female latch brackets 801 , four male latch brackets 809 and a side panel 804 and top and bottom panel 808. Also included is an evaporator coil 814, coil rails 802, coil side supports 803, a coil inlet panel 805, a coil exhaust panel 806, coil clamp brackets for holding the evaporator coil 814 in position. There is also a blank side panel 810 and a hot water (HW) side panel 81 1. The heat pump module 800 also includes connection means which is a locking mechanism comprising a latch 812 which is engageable in a latch receptacle of the same configuration as latch receptacle 813 e.g. latch receptacle 512 on the mixing module 500 and/or latch receptacle 310 on the fan module 300 so as to enable a secure connection between the heat pump coil module 800 and the mixing module 500 or fan module 300 for instance.

The heat pump module 800 has double sided access for the heat pump coil 814 and features a channel to receive the slide-in heat pump coil 814. The heat pump coil 814 can slided in from either side to aid design and installation flexibility. This is a significant advantage over the prior art.

7. Heat pump coil module (900)

The heat pumps are indicated generally by reference numeral 900 and include the following features:

• Modulating inverter driven variable capacity as demanded by the programmable logic controller (PLC);

• Heat pump coils specifically designed to match up with Daikin™ heat pumps; and

• Daikin™ interface box controlled by the PLC.

Heat Pump Coil

The heat pump coil is designed to be connected to any third party condensing unit and features a hydrophilic coated coil surface, an angled center draining condensate drain pan and cased coil fins. It also features a large suction header and a oversized distributor for low pressure drop and maximum coil efficiency.

These coils are specifically engineered to work with inverter driven variable speed and variable capacity condensing units from leading manufacturer's such as Daikin™ and Mitsubishi™.

The heat pump coil is exclusively designed and built to fit into the heat pump module 900. 8. Control Module

The control module is mounted externally to the blower module 300. The control module comprises a Programmable Logic Controller (PLC), terminal connector and transformer. A custom written software program controls the PLC.

The control module include the following features:

• PLC controller with specially designed software;

• Building Management Systems compatible;

• Can interface with: BacNet™, LonWorks™, Modbus™, JCI's N2 Open™,

Trend/Novar, Carel protocol on modem and TCP/IP EthernetTM (FTP, HTTP, SNMP);

• Modulating capacity signal to control capacity of compatible inverter driven heat pumps;

• Heat Pump, Chilled Water, Hot Water and HRV functions; and

• Wide ranges of sensors and inputs available.

The PLC uses various inputs to control the fan motor speed and controls the external third party heat and cooling sources.

On hot water modules, the control box utilizes temperature probes to measure the entering and exiting hot water temperature. The fan will ramp up slowly and is prevented from operating at full speed through the PLC software program until the temperature of the hot water being delivered reaches a predefined (field changeable) set point. On chilled water modules, the control box utilizes temperature probes to measure the entering and exiting hot water temperature. The fan will ramp up slowly and is prevented from operating at full speed through the PLC software program until the chilled water temperature being delivered reaches a predefined (field changeable) set point.

On heat pump modules, the control box utilizes temperature probes to measure the entering and exiting refrigerant temperatures. The fan will ramp up slowly and is prevented from operating at full speed through the PLC software program until the temperature being delivered reaches a predefined (field changeable) set point (in both heating and cooling).

Also on heat pump modules, a humidity sensor will limit through the PLC software program, the maximum fan speed to prevent any water carryover on startup in high humidity environments.

A pressure sensor will measure the fan pressure and connect to the PLC. On a zoned system, the PLC software program will allow the installer to select an appropriate duct pressure. The PLC software program will modulate the fan motor RPM to maintain the selected static pressure. As zones dampers open or close, the fan speed and airflow across the coils will increase or decrease. The PLC software program is responsible for maintaining the supply static pressure.

On a heat pump system with variable speed inverter driven condensing units, an output from the PLC to vary the capacity of the condensing unit will be provided by the PLC software program. This will provide energy savings as on a multi zoned system, the fan power and condensing unit capacity can be matched exactly to the needs of the zone. This feature is field selectable and adjustable on the PLC software program.

The PLC controller has a four line LCD display which displays a custom written menu offering the installer various parameters and settings for commissioning the system. Air flows through the system

Referring now to Figures 16 to 22, the air flows through the system, in use, in some of the several configurations/arrangements of assembled modules will be described by way of example only.

Referring initially to Figure 16, the air flow will be described for the horizontal configuration of modules (shown in Figure 10), in use, including the heat recovery (HRV) fan module 600, the heat recovery (HRV) core module 700, the mixing box module 500, the hot/chilled water coils module 400, the heat pump module 800 and the supply EC fan module 300 for supplying air.

It should be noted that the duct attachments on the supply EC fan module 300 and on the heat recovery (HRV) fan module 600 can be positioned in any one of several locations on the modules 300, 600 themselves.

The system of the present invention also includes motorised dampers 200 provided in the duct(s) leading to the assembled modules. In Figure 18, two motorized dampers 200 are included.

In use, fresh air can be drawn in from outside the dwelling house/commercial premises in which the system of the present invention is located. This fresh air is drawn through a motorised damper 200 and through the heat recovery module. This fresh air exchanges heat from exhaust air from within the building which is also drawn through the heat recovery module. After passing through the heat exchanger (i.e. in the heat recovery core module 700) in the heat recovery module, the exhaust air from within the building is then passed through the heat recovery fan module 600 and is exhausted to the outside.

The now warmed fresh air (indicated by arrow A) emerging from the heat recovery module is fed through to the mixing box module 500 in which the warmed fresh air is mixed with return air circulated from within the building and then the combined air streams are pumped through the hot water/chilled water module, the heat pump module and the supply fan module (i.e. the blower module) 300. Referring now to Figure 17, the air flows through the assembled modules in the compact horizontal configuration (shown in Figure 11 ) including the mixing box module 500, heat recovery (HRV) fan module 600, heat recovery (HRV) core module 700, hot water/chilled water coils module 400, heat pump module 800 and supply EC fan module 300.

It should be noted that the duct attachments on the supply EC fan module 300 and on the heat recovery (HRV) fan module 600 can be positioned in any one of several locations on the modules 300, 600 themselves. As shown in Figure 17, fresh air from outside is drawn through the ducting and is passed through the motorised damper 200 through the heat recovery core module 700 including heat exchanger 717 and exhaust air from within the building is also drawn through the heat exchanger 717 in the heat recovery core module 700. Waste air emerging from the heat recovery core module 700 is pumped to the outside by heat recovery fan module 600.

The now heated fresh air emerging at arrow B from the heat recovery core module 700 and is pumped into the mixing box module 500 where it is mixed with return air from within the building indicated by arrow C. The mixed air streams emerge from the mixing box module 500 at arrow D and are pumped through the hot water/chilled water module 400, the heat pump module 800 and the supply fan 300.

It should be noted that for all of the configurations described herein, the duct attachments can be made in any position on the supply EC fan module 300 and the heat recovery fan module 600.

Referring now to Figure 18, the air flows through the assembled modules in the L-shaped configuration (shown in Figure 12) including the heat recovery fan module 600, the heat recovery module 700, the mixing box module 500, the heat pump module 800, the hot water/chilled water module 400 and the supply fan module 300. Fresh air from outside is pumped through the heat recovery core module 700 where there is exchange of heat across the heat exchanger 717 (shown in Figure 7b). The now warmed fresh air supply (indicated by arrow E is pumped under the action of the EC fan module 300 through the mixing box module 500 where this stream is mixed with return air (indicated by arrow F) from within the building. The combined air streams emerging from the mixing box module 500 are pumped through the heat pump module 800, the hot water/chilled water module 400 and the supply EC fan module 300.

Referring now to Figure 19, the air flows for the L-shaped configuration (shown in Figure 13) including the mixing box module 500, hot water/chilled water module 400, heat supply pump module 800 and the supply fan module 300. In use, return air from within the building is pumped through the mixing box module 500, the hot water/chilled water module, the heat pump module 800 and the supply fan module 300.

Referring now to Figure 20, the air flow will be described for the horizontal configuration (shown in Figure 14) including the mixing box module 500, the hot water/chilled water module 400 and the supply fan module 300.

In this configuration in use, air flow is through the mixing box module 500, the hot water/chilled water module 400 and the supply fan module 300.

Referring now to Figure 21 , the air flow for a modification of horizontal configuration shown in Figure 14 will be described, including air flow through the mixing box module 500, the hot water/chilled water module 400, the heat pump module 800 and the supply fan module 300.

In use, return air from within the building is pumped through mixing box module 500, the hot water/chilled water module 400, the heat pump module 800 and the supply fan module 300. Referring now to Figure 22, the air flow diagram for heat recovery configuration (shown in Figure 15) will be described.

In this configuration of modules, the heat recovery (HRV) fan module 600, the heat recovery module 700 including heat exchanger 717; the mixing box module 500 and the supply fan module 300 are included. In use, fresh air from outside is drawn in through a motorised damper under action of the fan motor in the supply fan module 300. The fresh air is pumped in the direction of arrow G through the heat exchanger 717 in the heat recovery module 700 while exhaust air from within the building is pumped in to the heat exchanger 717 in the direction of arrow H. The fresh air becomes heated through the heat exchange process with the exhaust air and heated fresh air is pumped through the mixing box module 500 and the supply fan module 300 in the direction of arrow J. The exhaust air is pumped to the outside in the direction of arrow K under action of the heat recovery (HRV) fan module 600.

Furthermore, in Summer time mode, fresh air from outside or return air from within the building can be drawn in through respective motorized dampers 200 and directed (in the direction of arrow M) to the mixing box module 500. This can provide "free" cooling (i.e. at no cost) by using the cooler air from outside be mixed with warmer air inside the building thereby providing the cool air conditioning.

Referring now to Figures 23 to 27, the flow charts for the programmable logic controller (PLC) are shown and the control logic steps are described in the following pages. The PLC is adapted to control each of the modules included in any of the configurations described by way of example above. Various modes of operation are indicated in the Figures 23 to 27 and are described in the following pages.

Mode input Operation Supply Fan on

Fan Only Check input from supply duct air pressure sensor

if < supply duct fan only pressure setpoint, increase control signal voltage value to supply fan

If = supply duct fan only pressure setpoint, maintain control signal voltage value to supply fan Maintain supply fan control signal voltage if supply air pressure within field settable deadband

If > Supply duct fan only pressure setpoint, reduce control signal voltage value to supply fan

Maintain supply fan control signal voltage if supply air pressure within field settable deadband

Mode input Operation Supply Fan on, Compressor on

Heat Pump - Supply Fan

Cooling Check input from supply duct air pressure sensor

If < supply duct cooling pressure setpoint, increase control signal voltage value to supply fan

If = supply duct cooling pressure setpoint, maintain control signal voltage value to supply fan Maintain supply fan control signal voltage if supply air pressure within field settable deadband

If > Supply duct cooling pressure setpoint, reduce control signal voltage value to supply fan

Maintain supply fan control signal voltage if supply air pressure within field settable deadband

Compressor

Check humidity sensor value If humidity > humidity setpoint, then subtract value from supply duct target pressure to decrease air flow by field adjustable value

On compressor run request (input), Compressor run relay energised (output)

If input, check duct supply temperature and duct return temperature Check fan operating percentage Output variable control voltage signal to drive compressor capacity in relation to field adjustable matrix of fan operating percentage & control signal voltage

Mode Input Operation Supply Fan on, Compressor on, Reversing valve on

Heat Pump - Supply Fan

Heating Check input from supply duct air pressure sensor

If < supply duct heating pressure setpoint, increase control signal voltage value to supply fan

If = supply duct heating pressure setpoint, maintain control signal voltage value to supply fan

Maintain supply fan control signal voltage if supply air pressure within field settable deadband

If > Supply duct heating pressure setpoint, reduce control signal voltage value to supply fan

Maintain supply fan control signal voltage if supply air pressure within field settable deadband

Compressor

On compressor run request (input), Compressor relay energised (output)

On reversing valve request (input), reversing valve relay energised (output)

If input on compressor nun and reversing valve, check duct supply temperature and duct return temperature Check fan operating percentage Output variable control voltage signal to drive compressor capacity in relation to field adjustable matrix of fan operating percentage & control signal voltage Mode Input Operation Supply Fan on, Auxiliary heat on

Auxiliary Heating Supply Fan

Check Input from supply duct air pressure sensor

If < supply duct auxiliary heating pressure setpoint, increase control signal voltage value to supply fan

If = supply duct auxiliary heating pressure setpoint, maintain control signal voltage value to supply fan Maintain supply fan control signal voltage if supply air pressure within field settable deadband

If > Supply duct auxiliary heating pressure setpoint, reduce control signal voltage value to supply fan Maintain supply fan control signal voltage if supply air pressure within field settable deadband

Auxiliary heat

On auxiliary heat request (input), auxiliary heat relay energised (output)

If input on auxiliary heat, check duct supply temperature Run fan at fan only duct pressure setting until supply duct temperature starts to Increase above field settable temperature and/or field settable time out value

Auxiliary heat relay energised (output)

Mode input Operation Supply Fan on, HRV Fan on

HRV only Check input from supply duct air pressure sensor

(Heat Recovery If supply duct pressure < fan only pressure setpoint, increase control signal voltage Only)

value to supply fan

If supply duct pressure = fan only setpoint, maintain control signal voltage value to supply fan Maintain supply fan control signal voltage if supply air pressure within (laid settable deadband

If supply duct pressure setpoint > fan only setpoint, reduce control signal voltage value to supply fan Maintain supply fan control signal voltage If supply air pressure within field settable deadband

HRV Fan

Send control signal voltage to run HRV fan at field settable level

Dampers

Open fresh air damper

Close return air damper

HRV Defrost Function

Check incoming fresh air temperature If temperature is below a field settable level (-

8C for example) and the HRV has run for a field settable length (20mιns for example) then perform a defrost for field settable duration (2 5 minutes for example)

On HRV defrost

Fresh air damper closed

HRV fan controller signal voltage to field settable maximum value to run HRV fan

Return air damper to field settable level (100% open for example) Mode input Operation Supply Fan on, HRV Fan on Compressor On

HRV & Heat Supply Fan

Pump - Cooling Check input from supply duct air pressure sensor

If < supply duct cooling pressure setpoint, Increase control signal voltage value to supply fan

If = supply duct cooling pressure setpoint, maintain control signal voltage value to supply fan Maintain supply fan control signal voltage if supply air pressure within field settable deadband

If > Supply duct cooling pressure setpoint, reduce control signal voltage value to supply fan Maintain supply fan control signal voltage if supply air pressure within field settable deadband

Compressor

On compressor run request (input), Compressor relay energised (output)

If input, check duct supply temperature and duct return temperature Check fan operating percentage Output variable control voltage signal to drive compressor capacity in relation to field adjustable matrix of fan operating percentage & control signal voltage

Check humidity sensor value If humidity > humidity setpoint then subtract value from supply duct target pressure to increase air flow by field adjustable value

HRV Fan

Send control signal voltage to run HRV fan at field settable percentage level

Dampers

Energise fresh air damper relay (output) to open fresh air damper

Open return air damper (output) to field settable percentage for cooling

Mode input Operation Supply Fan on, HRV Fan on Compressor On reversing Valve on

HRV & Heat Auxiliary Heat On

Pump - Heating Supply Fan

Check input from supply duct air pressure sensor

If < supply duct heating pressure setpoint, increase control signal voltage value to supply fan

If = supply duct heating pressure setpoint, maintain control signal voltage value to supply fan Maintain supply fan control signal voltage if supply air pressure within field settable deadband

If > Supply duct heating pressure setpoint, reduce control signal voltage value to supply fan Maintain supply fan control signal voltage if supply air pressure within field satiable deadband

On compressor run request (input), Compressor relay energised (output)

On reversing valve request (input), reversing valve relay energised (output)

If input on compressor run and reversing valve, check duct supply temperature and duct return temperature Check fan operating percentage Output variable control voltage signal to drive compressor capacity in relation to field adjustable matrix of fan operating percentage & control signal voltage

HRV Fan

Send control signal voltage to run HRV fan at field settable percentage level

Dampers

Open fresh air damper

Open return air damper to field settable percentage for heating Mode Input Operation Supply Fan on, HRV Fan on Compressor On reversing Valve on

HRV & Heat Pump Supply Fan

Heating & Auxiliary Check input from supply duct air pressure sensor

Heating If < supply duct heating pressure setpoint, increase control signal voltage value to supply fan

If = supply duct heating pressure setpoint, maintain control signal voltage value to supply fan Maintain supply fan control signal voltage if supply air pressure within field settable deadband

If > Supply duct heating pressure setpoint, reduce control signal voltage value to supply fan Maintain supply fan control signal voltage if supply air pressure within field settable deadband

Compressor

On compressor run request (input), Compressor relay energised (output)

On reversing valve request (input), reversing valve relay energised (output) if input on compressor run and reversing valve, check duct supply temperature and duct return temperature Check fan operating percentage Output variable control voltage signal to drive compressor capacity in relation to field adjustable matrix of fan operating percentage & control signal voltage

HRV Fan

Send control signal voltage to run HRV fan at field settable percentage level

Dampers

Open fresh air damper

Open return air damper to field settable percentage for heating

Auxiliary heat relay energised (output)

Mode input Operation Supply Fan on, HRV Fan on

All HRV Modes Check input from supply duct air pressure sensor

Carbon Dioxide If supply duct pressure < fan only pressure setpoint, increase control signal

Sensing voltage value to supply fan

If supply duct pressure = fan only setpoint, increase control signal voltage value to supply fan Maintain supply fan control signal voltage if supply air pressure within field settable deadband

If supply duct pressure setpoint > fan only setpoint, reduce control signal voltage value to supply fan Maintain supply fan control signal voltage if supply air pressure within field settable deadband

HRV Fan

Send control signal voltage to run HRV fan at field settable level

Dampers

Open fresh air damper

Close return air damper

HRV Defrost Function

Check incoming fresh air temperature If temperature is below a field settable level (-8C for example) and the HRV has run for a field settable length (20mιns for example) then perform a defrost for field settable duration (2 5 minutes for example)

On HRV defrost

Fresh air damper dosed

HRV fan controller signal voltage to field settable maximum value to run HRV fan

Return air damper to field settable level (100% open for example)

When carbon dioxide level > a field settable setpoint then increase the supply fan and the exhaust fan rates up to the maximum allowed by the field setting value for each fan The supply and exhaust fans are linked by a scaling matrix to vary the operating percentages of the fans in proportion to one another

Summary and Advantages of present system

In summary, the present invention provides a small duct high velocity (SDHV), warm air heating and air conditioning and heat recovery (HRV system. The system of the present invention has the advantage of including the following features:

• Warm air heating from hot water or heat pumps;

• Air conditioning from chilled water or heat pumps;

• Heat Recovery Ventilation (HRV);

• Suitable for passive buildings, new construction and retrofits;

• Provides air filtration and fresh air;

• Space saving, modular construction fits into all buildings;

• an EC variable speed fan motors for optimal energy efficiency; and

• BMS (Building Management System) compatible.

It will of course be understood that the invention is not limited to the specific details described herein which are given by way of example only and that various modifications and alterations are possible without departing from the scope of the invention as defined in the appended claims.