Field of the invention The present invention relates to the field of condenser units for an air conditioning system. In particular, embodiments of the invention relate to a condenser unit for an air conditioning system for use in hot and dusty environments.

Background

A condenser is part of a cooling system, for example an air conditioning system, that cools air. In use, dirt and debris can accumulate in some of the operating parts of the condenser, in particular those parts exposed to ambient. Cleaning of the condenser is therefore required to maintain performance of the cooling system.

In hot and dusty environments, such as an underground rail network, a condenser unit can be challenging to maintain, and can necessitate regular services to maintain performance. High working temperatures and a build-up of dust and dirt can hamper performance of the condenser unit by using more power to cool the relevant parts of the machinery.

Regular cleaning and services required to remove the accumulated debris can be expensive and time consuming, so there is a need for condenser unit that is both easy to maintain and that can withstand particularly dusty or dirty conditions.

Summary

Aspects of the invention are set out in the independent claims and preferred features are set out in the dependent claims.

According to a first aspect there is provided a condenser unit for an air conditioning system comprising: a condenser coil for containing a refrigerant; an airflow entrance and an airflow exit defining an airflow pathway therebetween, the airflow pathway arranged to provide a route for an airflow through the condenser unit such that the airflow at least in part passes the condenser coil; a condenser blower for directing the airflow along the airflow pathway; a filter for filtering the airflow through the airflow pathway; and a controller configured to control the condenser blower to control a direction of the airflow along the airflow pathway in a first direction to cool the condenser coil and a second reverse direction to clean the filter. Wherein the second reverse direction is opposite to the first direction. Advantageously, reversing the first airflow direction, from the first direction, to the second reverse direction may help to self-clean the condenser unit. Reversing the airflow helps to remove accumulated dust on the airflow pathway of the condenser unit through which the airflow passes when the airflow acts in the first direction. In particular, the airflow in the second direction helps to clean the filter configured to filter the airflow along the airflow pathway, where a there is greater deposit of dirt. Maintaining a cleaner filter by using the self-cleaning condenser unit can help to reduce the number of services required to maintain performance of the condenser unit. In particularly dirty or dusty environments, the filters can very quickly become clogged with dirt and debris carried by an ambient airflow. Reversing the airflow for even a short period of time can improve the condition of the filter, and in turn the condenser unit, without intervention requiring the manipulation or removal of parts by a human operator or servicer, which may be both tricky to do and costly to perform on a regular basis. Servicing may still be required, however, the ability to self-clean helps to prolong the time interval between services. The act of self-cleaning, namely controlling the airflow to flow in the second direction, beneficially can be performed based on the condition of the environment of the condenser unit and can adapt to a change of environment on a daily, even hourly, basis by controlling the direction of airflow along the airflow pathway. The condenser unit may comprise the condenser coil being positioned along the airflow pathway between the filter and the condenser blower. In the first direction, the airflow may pass through the filter first, before passing through the condenser coil and the condenser blowers. The condenser blower can be located along the airflow pathway such that the airflow passes through the condenser blowers. Preferably, the first direction is a default or normal operating direction of the airflow, and the condenser only operates with the airflow in the second direction for a short period of time compared to the first direction. The airflow direction preferably returns to the first airflow direction after being reversed. For example, the second operating condition is a temporary condition of the condenser unit.

The condenser coil optionally comprises a non-flammable refrigerant, such as R407H refrigerant.

Optionally, the condenser unit further comprises a first sensor configured to monitor a parameter of at least one of the condenser unit and the airflow; and wherein the controller controls the condenser blower based on the parameter; optionally wherein the condenser unit further comprises a second sensor configured to monitor the parameter. For example, the sensors may be distributed on respective first and second sides of the filter and/or the condenser blowers.

Monitoring a parameter of the condenser unit allows the condenser unit to be controlled based on the measured parameter, such that it can dynamically respond to changes in operation performance.

Advantageously, monitoring the parameter with a temperature transducer, or two sensors provides means for determining a differential in the parameter. This may help to indicate that there is a blockage caused by a build-up of dirt, and the extent of it.

In some examples, the airflow passes from the first sensor to the second sensor in normal airflow conditions via the first airflow direction; and the airflow passes from the second sensor to the first sensor in the second reversed airflow direction. The first sensor may be inside or outside of the condensing unit, for example to measure ambient conditions. Preferably the first sensor is proximate the airflow entrance when the airflow is directed in a first airflow direction. In examples, the sensors may be positioned along the airflow pathway. In other examples, the sensors are not so limited and may be configured to measure general conditions of the condenser unit, from which it may be inferred that there is an issue with the airflow pathway being blocked.

Optionally, the parameter comprises one or more of: temperature, pressure, airflow rate, condenser unit power consumption and condenser blower rotation speed. The first and/or second sensors may comprise one or more transducers. Reduced condenser blower speed may be caused by lack of airflow along the airflow pathway, which may be caused by debris on the filter. In contrast, high speed of the condenser blower rotation may indicate that the condenser unit is struggling, for example that it is operating at full capacity to achieve an airflow sufficient to cool the condenser coil, and needs cleaning or servicing.

Optionally, the controller is configured to determine an airflow rate and/or duration for the airflow in the second direction; and control the condenser blower based on the determination. The airflow rate may be based on condenser blower speed and/or monitored by the sensor(s). Determining the airflow rate may comprise the controller determining the volume of airflow per second passing through the condenser blower.

Optionally, the airflow rate and/or duration is based on one or more threshold values of the parameter. A greater speed of the condenser blower can create a more powerful airflow to remove a greater amount of dirt and debris whilst a slower speed saves power. These parameters may be determined based on the measurements of the parameter by the sensor(s). Beneficially, the condenser unit may act to clean the filter with the airflow in the second direction with an airflow rate and duration determined by a condition of the condenser unit as indicated by the parameter. For example, higher airflow rates with longer durations may be required when the filter is particularly clogged or dirty compared to when it is relatively cleaner. Greater airflow rates may have a greater force with which to dislodge dirt and debris. An airflow profile may be determined and executed by the controller, which starts with a larger airflow rate when the airflow direction is first changed to the second direction, and slows down as dirt and debris is removed. The removal may be monitored by the sensors so that the profile may be determined on a per-clean basis.

If there are two sensors, and the sensors measure a differential value of a parameter, the duration may be based on when these sensor measurements equalise. The condenser blower speed, or airflow rate may also be related to this difference in measurements by sensors. A differential can also be measured by a single transducer, for example a biometric transducer. In examples, the airflow rate and/or duration in the second direction may be constant. The airflow rate in the first direction may also be constant.

Optionally, the controller is configured to change the airflow direction from the first direction to the second reverse direction at a predetermined time interval. For example, at 2 am every morning/every Sunday morning/every first day of the month etc.

Optionally, the controller is configured to change the airflow direction from the first direction to the second reverse direction based on the monitored parameter. The controller may determine that the airflow pathway is blocked based on received measurements of the parameter at the controller. The controller may configured to directly prompt the sensor for a measurement from one or more of the sensors, or measurements may be provided at predetermined intervals. In some examples, an alert may be triggered by the controller to notify a user that there is a need for cleaning or service in addition to reversal of the airflow direction.

Optionally, the change in airflow direction is determined by the controller in response to the parameter exceeding a threshold comprising one or more of: a pressure drop below a threshold pressure value; a temperature value that exceeds a threshold temperature value; a condenser blower speed above a threshold speed value; a power consumption that exceeds a threshold power consumption threshold value; or an airflow rate below a threshold airflow rate value. In some examples, the controller is configured to determine whether or not the parameter exceeds the threshold. The threshold may optionally be based on a differential value of the measured parameter. For example, wherein the first sensor and the second sensor measure a value having a difference in value over a threshold value. In an example, the first sensor measures temperature and measures a temperature of 21 degrees Celsius. The second sensor also measures temperature, and measures a temperature of 21 + n degrees Celsius, where n is the differential value of the measured parameter. If n is above the threshold based on the differential value, the controller may be configured to control the condenser blower to change the direction of airflow. Optionally, the controller is configured to change the airflow from the first direction to the second reverse direction for a determined time period. The determined time period may be between a minute and an hour, preferably about 20 minutes. For example, the determined time period is a duration. Preferably the controller changes the airflow direction to the first airflow direction after the determined time period.

Optionally, wherein the controller determines the determined time period based on the parameter. For example, until the condenser unit reaches a stabilised condition. Wherein a stabilised condition may correspond to a measured value of the parameter, or a measured differential value of the parameter. Monitoring of the parameter, for example measuring the differential, may be performed during the determined time period to determine the duration, until the parameter equalises.

Optionally, the condenser unit is configured to start-up via a soft start procedure, wherein a soft-start procedure comprises load balancing to maintain a current drawn by the condenser unit below a current threshold value. This can prevent a current overload, a current surge and/or subsequent failure in both a singular condenser unit and connected system of condenser units.

Optionally, the condenser unit further comprises a second condenser blower for directing the airflow along the airflow pathway; and the controller controls operation of the first and second condenser blowers based on a threshold value of the parameter. Controlling operation of the condenser blower may comprise activating one or both condenser blowers, deactivating one or both condenser blowers, driving the one or both condenser blowers with a determined power, speed, direction etc. A second condenser blower may beneficially provide redundancy. In some examples, the controller is configured to activate the second condenser blower if the parameter exceeds a first condenser blower threshold and deactivates the second condenser blower if the parameter is below the threshold.

Preferably, the condenser blowers are configured to direct the airflow in the same direction as one another.

According to a second aspect there is provided a method of operating a controller of a condenser unit for an air conditioning system, the method comprising: directing an airflow along an airflow pathway defined between an airflow entrance and an airflow exit, the airflow pathway arranged to provide a route for an airflow through the condenser unit such that the airflow at least in part passes through a filter for filtering the airflow through the airflow pathway and a condenser coil for containing a refrigerant; controlling the direction of the airflow by controlling a condenser blower; controlling the condenser blower to control the direction of the airflow along the airflow pathway in a first direction to cool the condenser coil; and controlling the condenser blower to control the direction of the airflow along the airflow pathway in a second reverse direction to clean the filter.

Optionally, the method further comprises monitoring a parameter of the condenser unit via a first sensor and/or a second sensor configured to monitor a parameter at least one of the condenser unit and the airflow; and controlling the condenser blower based on the parameter. The parameter optionally comprises one or more of: temperature, pressure, airflow rate, condenser unit power consumption and/or condenser blower rotation speed.

Optionally, the method further comprises determining an airflow rate and/or duration for the airflow in the second direction; and controlling the condenser blower based on the determination. The airflow rate can be achieved using first and or second condenser blower. Optionally, the airflow rate and/or duration is based on one or more threshold values of the parameter.

Optionally, the method further comprises changing the airflow direction from the first direction to the second reverse direction at a predetermined time interval.

Optionally, the method further comprises changing the airflow direction from the first direction to the second reverse direction based on the monitored parameter. In some examples, the changing in direction of airflow is optionally controlled in response to a determination at the controller that the parameter exceeds a threshold comprising one or more of: a pressure drop below a threshold pressure value; a temperature value that exceeds a threshold temperature value; a condenser blower speed above a threshold speed value; a power consumption that exceeds a threshold condenser unit power consumption threshold value; or an airflow rate below a threshold airflow rate value. Optionally, the threshold is based on a differential value of the measured parameter.

Optionally, the method further comprises changing the airflow from the first direction to the second reverse direction for a determined time period. The controller optionally determines the determined time period based on the parameter.

Optionally, the method further comprises starting-up the condenser unit via a soft start procedure comprising load balancing to maintain a current drawn by the condenser unit below a current threshold.

Optionally, the condenser unit further comprises a second condenser blower; and the method further comprises operating the first and second condenser blowers based on a threshold value of the parameter.

According to a third aspect there is provided a system comprising: the condenser unit according to the first aspect; an evaporator unit; and a controller for controlling the condenser unit according to the second aspect.

According to a fourth aspect there is provided a computer program product comprising instructions which, when the program is executed by a computer, cause the computer to carry out any of the steps of the method as laid out above.

Brief Description of the Drawinqs

Example embodiments are illustrated in the accompanying figures in which: Figure 1 illustrates a perspective view of an example condenser unit according to an embodiment;

Figure 2 illustrates a perspective view of an example condenser unit according to an embodiment; Figure 3 illustrates a perspective view of an example condenser unit according to an embodiment;

Figure 4 illustrates a schematic diagram of information transfer to and from a controller configured to control one or more condenser blowers;

Figure 5 illustrates a flow diagram of an example method for controlling a condenser unit by a controller according to an embodiment.

In the drawings, like reference numerals are used to indicate like elements.

Detailed Description Figures 1, 2 and 3 illustrate perspective views of an example condenser unit 100 according to an embodiment and are described together below.

The condenser unit 100 comprises a unit having a top side, a bottom side, a back side a front side, a left side and a right side. The condenser unit comprises a front plate 104 disposed on the front side, a back plate disposed on the back side, a bottom plate 106 disposed on the bottom side, a top plate 108 disposed on the top side and along a portion of the front side and two side plates 110, 110’ disposed on the left and right sides. The top plate 108, along the top side, and bottom plate 104 are positioned in a plane parallel to one another. The side plates 110, 110’ are positioned in a plane parallel to one another and perpendicular to the plane of the top and bottom plates 108, 106. The front plate 104 and back plate are positioned in a plane parallel to each other and perpendicular to the planes of the top and bottom plates 108, 106 and the side plates 110, 110’ such that the unit comprises a generally cuboidal structure. The top plate 108 comprises a portion that extends along the front side of the condenser unit 100 and comprises a ventilation panel 102 that is parallel to and lies flush with the front plate 104. The ventilation panel 102 of the top plate 108 is located above an angled blower plate 122 positioned inside the condenser unit 100 and as seen in Figure 3. The condenser unit 100 comprises two openings 102 along one or more of the front and bottom sides defining an airflow entrance and an airflow exit. The openings may comprise a perforated wall, for example a ventilation panel 102. In Figures 1 , 2 and 3 a ventilation panel 102 is disposed on the portion of the top plate 108 that extends along the front side and on the bottom plate 106 (not shown). The openings of the condenser unit 100 may comprise perforated sheets of material (e.g. sheet metal comprising perforations).

The openings 102 comprising the airflow entrance and airflow exit determine an airflow pathway therebetween. Whether the opening is an entrance or an exit depends on the direction of an airflow therethrough. A filter 121 is disposed along the airflow pathway, preferably wherein the filter 121 is proximate the bottom plate 106. In examples, the bottom plate comprises the filter 121 itself. In some examples, the filter 121 is positioned proximate the bottom plate 106.

The condenser unit 100 comprises attachment means 116. Figures 1 to 3 illustrate an embodiment of the attachment means 116 comprising a series of attachment holes along an extended portion of the back plate. The condenser unit 100 internally comprises condenser blowers 124, 124’ mounted on a blower plate 122, a compressor unit 120 section, and electrical panel 118 as illustrated in Figures 2 and 3.

The condenser blowers 124, 124’ may be provided in a linear arrangement, for example in a blower plane. In examples, the condenser blowers 124, 124’ may be fans comprising blades which rotate about a rotational axis. The condenser blowers 124, 124’ may be arranged so that their rotational axes are at an angle relative to the top plate 108 of the condenser unit 110. The blower plate 122, defining an axis of rotation of the condenser blowers 124, 124’ perpendicular to the blower plate 122, may be angled relative to the top plate 108 at an angle of around 45 degrees as illustrated in Figure 3.

The compressor unit 120 comprises a circuit for a refrigerant that is completed and closed when the condenser unit 100 is connected to an evaporator unit. The condenser unit optionally comprises a non-flammable refrigerant, preferably R407H refrigerant. The compressor unit circuit comprises refrigerant inlet 112, the compressor unit 120 comprising at least a condenser coil, and refrigerant outlet 114. A flat surface heat exchanger may also be provided in the compressor unit 120. The compressor unit 120 may comprise a planar array of microchannels disposed obliquely to the blower plane and to the top side 301 of the condenser unit 100.

Refrigerant inlet 112 and refrigerant outlet 114 extend through the side plates 110, 110’ and into the interior of the condenser unit 100, and connect to the compressor unit 120. The refrigerant inlet 112, compressor unit 120 and refrigerant outlet 114 are connected together to form a closed loop refrigerant flow path. The refrigerant flow path is configured to receive a refrigerant, for example an R407H Refrigerant.

The refrigerant inlet 112 and outlet 114 are connectable to an evaporator. The evaporator forms part of an air conditioning unit including the condenser unit 100 and a closed loop through which refrigerant may flow is created when the two units are connected.

The air conditioning unit 100 may further comprise monitoring apparatus comprising one or more of: a temperature transducer, a temperature probe, pressure sensors and/or other sensing equipment (not illustrated). The monitoring apparatus may be disposed within the condenser unit, for example, but may also be disposed on the surface of the condenser unit 100.

The condenser unit 100 comprises an exterior having a mixture of solid and mesh plates arranged to direct an airflow along an airflow pathway therein, the airflow comprising ambient air that is drawn into and through the condenser unit 100 to cool a refrigerant that circulates through the compressor unit 120. When the airflow flows in a first direction as illustrated by arrows Ai in Figure 1, cold air is drawn into the condenser unit 100 via a ventilation panel and a filter 121 at the bottom of the condenser unit 100. Hot air that has been heated by the energy stored in the refrigerant is released back to ambient through the ventilation panel 102 proximate the top plate 108 when the airflow is in the first direction Ai.

The top plate 108 can be removed so as to expose the condenser blowers 124, 124’. The blower plate 122 on which the condenser blowers 124, 124’ are mounted can be lifted to access the compressor unit 120 and the condenser blowers 124, 124’ themselves. A handle may be mounted on the blower plate 122 for this purpose, and the blower plate 122 may be hinged. Easy access to the condenser blowers 124, 124’ can be provided by the blower plate 122 being hinged and having a handle mounted thereon. Easy access may improve servicing of the condenser unit, for example, by reducing the time taken to perform a service.

Alternatively, and/or additionally, the front plate 104 can be removed or attached to the condenser unit 100 by a hinged connection so as to provide ease of access for servicing. The ventilation panel(s) 102 are configured to permit flow of a fluid (e.g. gas) through the openings of the condenser unit 100. An airflow can flow along the airflow pathway defined between the ventilation panel(s) 102 in a first direction Ai or a second direction, wherein the second direction is an opposite direction to the first direction. In examples, the openings and/or the top plate 108 and front plate 104 may be attached to the condensing unit 100 by a hinge or the like in order to provide easy access to the internal features of the condenser unit 100 for maintenance. The condenser unit 100 may comprise at least one plate attached to the unit by a hinge such that it can be opened, for example the top plate 108 or front plate 104. The condenser unit 100 can be mounted and attached to a wall via the attachment means 116, for example wherein the attachment means comprise screws. The condenser unit 110, when mounted on a wall, is positioned a distance above the ground and is configured to receive an airflow in the first direction Ai through the bottom plate 106 comprising a ventilation panel. The airflow pathway is created by air drawn into the condenser unit 100 from the bottom plate 106, which flows through the condenser unit 100 and is released via the ventilation panel 102 of the top plate 108. In the second direction, the airflow flows out of the bottom plate 106 when the condenser unit is mounted on a wall.

The condenser blowers 124, 124’ are arranged to provide a flow of air incident on the condenser coil unit 120. The blowers 124, 124’ are configured to provide airflow along an airflow pathway. The airflow pathway is defined between ventilation panels 102 of the top and bottom plates. For example, the airflow provided by the condenser blowers 124, 124’ in the first direction Ai may increase the rate of cooling (e.g. heat exchange) of the refrigerant passing through the first compressor unit 120 comprising the condenser coil. The airflow provided by the condenser blowers 124, 124’ in the second direction may remove some built up dirt and debris from the condenser unit 100, in particular dirt and debris caught by the filter 121 , which may help to maintain performance of the condenser unit 100 and delay the need for repair or servicing. A controller is configured to control the condenser blowers 124, 124’, for example the direction of rotation and speed of rotation, to provide the airflow to the condenser unit 100.

The condenser blowers 124, 124’ act to control the rate of the airflow through the airflow pathway. A controller may be configured to control the condenser blowers 124, 124’, for example the speed of rotation of the fans of the condenser blowers 124, 124’, by sending signals to the condenser blowers 124, 124’ that are connected to the electrical panel 118. The condenser blowers 124, 124’ are further configured to control the direction of the airflow along the airflow pathway. The controller may be configured to control the condenser blowers 124, 124’, for example the direction of rotation of the fans of the condenser blowers 124, 124’, by sending signals to the condenser blowers 124, 124’.

In the example shown, the condenser blowers 124, 124’ comprise fans having blades which rotate about a rotational axis. For example, the condenser blowers 124, 124’ may be arranged such that fluid (e.g. gas) is drawn into and out of the condenser unit 100. Condenser blowers 124, 124’ provides airflow through the compressor unit 120 which increases the rate of cooling (e.g. heat exchange) between the refrigerant inside the condenser coil and the exterior of the condenser coil.

The electrical panel 118 comprises a controller for controlling the electrically driven elements of the condenser 100, such as the condenser blowers 124, 124’. The controller controls the operation of the condenser 100 and varies the condenser blowers speed so as to provide an airflow along the airflow pathway that is sufficient to cool the condenser coil and the refrigerant therein such that it condenses the refrigerant to liquid phase. Access to the electronics unit may be restricted, for example, by providing the unit with restricted access means such as a lock.

Optional features such as sensing means may also be controlled and/or monitored by the controller. In examples, the controller may prompt and/or receive measurements from the sensing means. The condenser unit 100 acts to cool refrigerant as it passes through a condenser coil located in the compressor unit 120. Heated refrigerant contained in conductive tubing enters the compressor unit 120 to be cooled. Condenser blowers 124, 124’ blow air through the compressor unit 120 passages to disperse the heat energy stored by the refrigerant such that the energy is released, resulting in condensation of the refrigerant. High-pressure liquid refrigerant that has been condensed in the compressor unit 120 leaves the compressor unit 120 via the refrigerant outlet 114 to flow back to an evaporator coil in use in an air conditioning system.

The refrigerant inlet 112 is configured to receive vapourised refrigerant from an evaporator. The inlet 112 may comprise a pipe suitable for receiving refrigerants in vapour phase. The inlet 112 is configured to provide vapourised refrigerant to the compressor unit 120 comprising the condenser coil. A pump may be used to pump the refrigerant through the system. The refrigerant outlet 114 is configured to receive liquified refrigerant from the condenser coil to be transferred back to an evaporator connected to the condenser unit 100. The outlet 114 may comprise a pipe suitable for receiving refrigerants in liquid phase. The outlet 114 is configured to provide liquified refrigerant to the evaporator. An evaporator, condenser pair together act in an air conditioning system in operation. Heat from hot air is extracted by the evaporator at a location of the evaporator and transferred to the condenser unit 100, which may be located separately to the evaporator, for example in a different room to the evaporator. Heat energy is transferred through the system by the refrigerant that circulates through a closed system of pipes between the two units. When the heated refrigerant reaches the condenser unit 100 from the evaporator, the compressor unit 120 comprising a condenser coil cools and releases the heat transferred thereto by the refrigerant.

From the evaporator, the refrigerant flows through the system via an insulated conduit to the condenser unit 100 housing a compressor and a condenser coil in the compressor unit 120. Heated refrigerant entering the compressor via the inlet 112 is cooled via the condenser coil such that the heat energy acquired at the evaporator is released from the refrigerant. An airflow flowing in a first direction Ai, under default operation of the condenser unit 100, is guided along the airflow pathway by the condenser blowers 124, 124’ which draw cold air into the condenser unit 100 and then directs subsequently heated air out of the condenser unit 100. In a second direction, the condenser blowers 124, 124’ operate in reverse direction such that the airflow flows in the opposite direction along the airflow pathway.

The airflow in the first direction Ai cools the compressor unit 120 comprising the condenser coil and the refrigerant therein. The airflow in the second reverse direction cleans the filter 121 by blowing debris off the filter 121. Removing debris and dirt can improve the operation of the condenser unit 100 operating with the airflow flowing in the first direction Ai by clearing the airflow pathway and making it easier for the condenser blowers 124, 124’ to draw enough air into the condenser unit 100 to cool the condenser coil.

In a cooling configuration, cold air is drawn in through the bottom plate 106 and a filter 121 proximate the bottom plate 106, passes through the condenser coil unit 120 where the air is heated by energy released from the refrigerant, and then passes through the condenser blowers 124, 124’ and out of the ventilation panel 102.

In a cleaning configuration, air flows along the pathway in the opposite direction. Air is drawn into the condenser unit 100 at the ventilation panel 102, passes through the condenser blowers 124, 124’, the compressor unit 120, and through the filter 121 proximate the bottom plate 106. The airflow through the filter 121 acts to remove built up debris incident on the filter 121 by blowing it off.

In some examples, the condenser unit 100 is designed to run at 60% of fan air volume capacity, allowing for 40% overspeed potential to maintain performance as the filter 121 and heat exchanger are being fouled with dust. Although it will be understood in other examples it is designed to run at 70%, 80% etc. up to 100%.

At the compressor unit 120, the vaporised refrigerant is received from the refrigerant inlet 112 and is compressed. The increased pressure of the compressed refrigerant relative to the vaporised refrigerant drives the refrigerant through a refrigerant flow path in a direction from the inlet 112 to the outlet 114. A soft start procedure may be used to start the condenser unit 100. A soft-start procedure may comprise load balancing to maintain a current drawn by the condenser unit 100 below a current threshold value. This can prevent current overload, current surges and failure of the condenser unit 100. There may be provided any number of condenser blowers 124, 124’, for example, there may be provided one first condenser blower or two first condenser blowers. The condenser blowers may alternatively comprise more than two condenser blowers.

In other embodiments, the blower plate 122 may be parallel to the top plate 108, rather than angled. The blower plate 122 is optionally provided with a handle.

In other embodiments, the condenser unit 100 may be freestanding. In this instance, the condenser unit may comprise legs for supporting the unit on a surface, for example a floor.

In another embodiment, the front panel 104 may comprise a second ventilation panel, located below the ventilation panel 102 and below the condenser blowers 124, 124’. The condenser blower plate 122 and the bottom plate 106 may comprise a solid panel, preventing ventilation therethrough in this embodiment.

The heat exchanger of the compression unit 120 can be flat; designed to limit dirt penetration to the condenser unit 100, in particular the apparatus exposed to the airflow along the airflow pathway.

Optionally, the filter 121 is mounted on a detachable filter 121 panel to allow for manual cleaning or replacement of the filter 121. It may be made easily accessible, for example, by mounting in a location that can easily be reached when the removable or hinged panels are removed or opened.

The condenser unit 100 can help to substantially reduce servicing hours and has been found to achieve around a 50% reduction. It has shown to be significantly more robust technology to prior art devices, having designed out common failure modes. Service focused design such as ease of access via hinged panels and intuitive interior design helps to reduce service time. The condenser unit 100 is configured to withstand operation in hot, dusty environments, for example with 55 degrees Celsius temperatures.

Figure 4 illustrates a schematic diagram of information transfer to and from a controller configured to control one or more condenser blowers 224, 224’. For example, wherein the condenser blowers 224, 224’ are equivalent to the condenser blowers 124, 124’ of Figures 1 to 3.

A controller 216 comprises inputs and/or outputs from one or more of: one or more sensors 210, a memory 212, a user input 214 and a remote monitoring system 218. Outputs from the controller 216 comprise one or more condenser blowers 224, 224’ and optionally a pump 220.

The sensor 210 may comprise one or more sensors and be configured to monitor one or more parameters. For example, the sensor 210 may comprise one or more of: a temperature transducer, a pressure sensor, a temperature probe, a tachometer, an ammeter, a voltmeter, and/or any other sensors suitable for measuring one or more parameters of the condenser unit. In particular, the sensors are configured to measure parameters of the condenser unit that indicate one or more issues related to the performance of the condenser unit, for example parameters indicating that the condenser requires cleaning. For example, the condenser unit 100 may be operated to respond to a measured rise in filter 121 pressure drop caused by a clogged filter. Optionally, the condenser unit comprises an alert, for example a notification, notifying the controller 216 of a need for cleaning when a determined pressure drop is reached, for example when a pressure drop threshold is exceeded.

The controller 216 may prompt or poll the sensor(s) 210 for a reading or measurement of the parameter that the sensor is configured to measure. This measurement could be used to determine how to control the condenser blowers 224, 224’. In examples, the controller 216 may prompt the one or more sensor(s) 210 before and/or after reversing the direction of the airflow along the airflow pathway. In other examples, the sensor(s) 210 may be configured to transmit information to the controller 216 at determined intervals. Optionally, the determined intervals are between once a second and once every 12 hours, preferably once a minute. The memory 212 may comprise one or more stored profiles for controlling the condenser blowers 224, 224’. For example, a profile may instruct the controller 216 to control the condenser blowers 224, 224’ according to a predetermined schedule. A profile may comprise a pre-determined schedule for instructing the controller 216 comprising: which of the available condenser blower(s) 224, 224’ to operate, how many times per day, at what time of day, on which date or which days of the week, and for how long to reverse the airflow from the first to the second airflow direction. For example, a first example profile may instruct the controller 216 to control the condenser blowers 224, 224’ to reverse the direction of the airflow from a first direction Ai to a second direction at 2 am every morning for a period of 20 minutes. A second example profile may instruct the controller 216 to control condenser blower 224 to reverse the direction of the airflow from a first direction Ai to a second direction at 2 am, 10.30 am, 4 pm, and 7 pm on Monday to Friday for 5 minutes each time. It will be appreciated that a number of other profiles are available and that those detailed above are merely examples. In examples, the memory 212 may store data, such as values of one or more parameters measured by the sensor(s) 210. In some examples, the values may be aggregated or average values so as to reduce storage space required by the memory 212. From this stored data, one or more profiles can be determined for future control of the condenser unit. In examples, the controller 216 may be configured to determine, via machine learning techniques for example, a profile based on the measured parameter measured by the sensor 210 and/or user inputs 214. Such profiles may be stored in the memory 212.

The user input 214 may be, for example, a command or instruction from a user of the condenser unit to control the condenser blowers 224, 224’, for example at a user interface. A user interface for inputting a user input 214 maybe located a distance away from the condenser unit, for example in another room. It may be provided on a computer screen or the like. In other examples, the condenser unit comprises a user interface on the condenser unit itself.

In an example, the user input 214 may comprise a “one-off’ or “manual override” instruction to the controller 216 to control the condenser blowers 224, 224’, for example, to manually override any other instructions received by the controller 216. In another example, the user may input instructions via a user input 214 if the user has determined that the filter 121 is particularly blocked with dirt and debris, even after the controller 216 has reversed the direction of the airflow along the pathway for a predetermined period.

In examples, the controller 216 may be connected to a remote monitoring system 218. The connection may be wired or wireless. Information may be transmitted between the controller 216 and the remote monitoring system 218. In some examples, the controller 216 is configured to simply execute instructions to control the condenser blowers 224, 224’ according to instructions sent to the controller 216 from the remote monitoring system 218, wherein the remote monitoring system 218 determines how to operate the condenser blowers 224, 224’ and instructs the controller 216 accordingly. The controller 216 is configured to control the condenser blowers 224, 224’. The condenser blowers 224, 224’ may be controlled together or separately. The condenser blowers 224, 224’ may be controlled by the controller 216 to be activated at a determined rotational speed and in a specified direction. The controller 216 may control both of the condenser blowers 224, 224’ to have the same or different parameters. In examples, only one condenser blower is activated until a measured parameter exceeds a threshold, after which both condenser blowers 224, 224’ may be activated together. In other examples, one condenser blower 224’ may provide redundancy for the other condenser blower 224. For example, if the condenser blower 224’ fails and/or needs to be serviced or repaired. The controller 216 may receive an input or an instruction from one or more of the sensor(s) 210, the memory 212, the user input 214, or the remote monitoring system 218 which may be used to determine how to control the condenser blowers 224, 224’.

In examples, the controller 216 may be configured to interpret the information it receives from the sensor(s) 210, memory 212 and user input 214. For example, the controller 216 may determine whether a parameter measured by the sensor(s) 210 and transmitted to the controller 216 exceeds a first threshold value for that parameter. The controller 216 may be further configured to determine the extent to which the parameter is exceeded, for example whether the parameter exceeds a second threshold value. The condenser blowers 224, 224’ can then be controlled according to the determination. The condenser blowers 224, 224’ are configured to direct an airflow through the condenser unit along an airflow pathway therein as described in relation to Figures 1 to 3. Optionally, the controller 216 may be connected to a pump 220 configured to pump the refrigerant round the compressor system. For example, if the controller 216 operates the condenser blowers 224, 224’ in the second airflow direction, it may simultaneously turn the pump 220 off so as to temporarily pause cooling of refrigerant. Figure 5 illustrates a flow diagram of an example method 300 for controlling a condenser unit by a controller according to an embodiment.

A first step 310 comprises receiving sensor feedback at the controller from one or more sensors configured to monitor a parameter of a condenser unit.

A second step 320 comprises determining that a measured value of the monitored parameter exceeds a first threshold value for the parameter. Wherein the first threshold value is determined based on the condenser unit having an airflow in a direction to cool the condenser coil, e.g. in a first direction.

A third step 330 comprises determining whether a measured value of the parameter exceeds a second threshold value for that parameter. Wherein the second threshold value is determined based on the condenser unit having an airflow in a direction to cool the condenser coil, e.g. in a first direction.

In examples, the threshold values may be determined using machine learning techniques. In other examples, the threshold values may be determined by a user, for example an operator, of the condenser unit. A fourth step 340 comprises, measuring the parameter having a value between the first threshold value and the second threshold value, and in response controlling the condenser blower(s) to maintain an airflow rate in a first direction of the airflow.

If the parameter measurement is below the first threshold value, operation is within normal operating conditions and it can be determined that operation is satisfactory, for example that the condenser unit is operating at a green level.

If the parameter is measured to have a value between the first and second threshold values, the condenser unit may be operating at a tolerant level. For example, an amber level. An amber level may indicate that the condenser unit is operating at a reduced performance level, for example having increased power consumption, compared to a green level. In amber level conditions, the condenser blowers may be required to work harder to maintain a constant airflow input to effectively cool the condenser coil. Monitoring of the parameter may be increased during the amber level. In some embodiments, the second condenser blower may be activated when the condenser unit is operating at an amber level. A fifth step 350 comprises, measuring the parameter having a value above the second threshold value, and in response controlling the condenser blower(s) to direct the airflow in a second reverse direction.

If the parameter is measured to have a value above the second threshold value, the condenser unit may be operating at a maximum level, for example a red level. A red level may indicate that the condenser unit is operating at or close to full power and is not achieving a desired airflow input such that the condenser coil is not being cooled to a desired level. This could indicate that the filter 121 is blocked. In response to this determination, the airflow may be reversed so as to clean the filter 121.

The above method may be in addition to or in place of a predetermined schedule of airflow reversal.

If the condenser unit is still operating at a red level after the reversal, this may indicate that a service is required.

In an alternative embodiment, there is a first threshold value only. In this example, the controller is configured to reverse the airflow direction to the second airflow direction when a parameter is measured to have a value that exceed the first threshold value.

It will be appreciated from the above description that many features of the different examples are interchangeable and combinable. The disclosure extends to further examples comprising features from different examples combined together in ways not specifically mentioned. Indeed, there are many features presented in the above examples and it will be apparent to the skilled person that these may be advantageously combined with one another.