AU2013101086A4 - Air conditioning system and method of control in heat mode - Google Patents

Abstract

Abstract 5 A method of controlling a heater or air conditioner in heating mode, the method including the steps of: obtaining a room temperature using at least one temperature sensor; determining if the difference between the room temperature and a pre-defined target temperature is greater than a pre-defined difference threshold; and if so, operating in a high speed fan mode for a time period calculated based on the difference between the room 10 temperature and the target temperature. 100 q startingstop -an Yes4 Yesen first star select max diff "emp Fan Boost time = max d iff temp* FanRros1_Rate (in mimita%) start Fa2n with S% FW AAu Ikxie Auto wnMual modo DisableFan BstmodB erable disable? 1 5 140 Enal High Hg!Iif :vL cw citemn,2 deg 144Ye/ 46 152 Fan Doost tirne = 0? .k set High Fan speed set Mid Fan. speed set Low Fan speed set Fan FMlimit set Fan RPMA lim it set Fan RPM limit 150 ve 51 162 163 164 .I ru, ran in Auto mode ReFztum Figure 1

Description

- 1 AIR CONDITIONING SYSTEM AND METHOD OF CONTROL IN HEAT MODE Technical Field 5 [001] The present invention generally relates to ducted air conditioning systems, and in particular to an air conditioning system having a plurality of zones and/or a method of control in heat mode or operation of an air conditioning system. Background 10 [002] Reference to an air conditioning system should be understood to include reference to an air conditioner, a heat pump system and/or a heat pump. As an illustrative example, a heat pump can be considered to be a reverse cycle air conditioner, that is, a type of air conditioning system. It should be noted that reference to 'outdoor unit' need not necessarily require the unit to be physically located completely external to a home or 15 building, rather the unit need only be separated from the air conditioned areas/zones. [003] Presently there exists a major focus on the energy consumed by air conditioning systems and the need for highly energy efficient systems is more important than ever before. There is a need to allow energy consumed by ducted air conditioning systems to be 20 dramatically lowered compared to current systems available on the market today. Users, owners and operators of ducted air conditioning systems desire to be able to control the temperature of each zone (for example a room or office) and to be able to turn on or off any zone they desire, no matter how large or small, to help reduce energy usage and reduce running costs. However, being able to turn any zone on or off is desired to be achieved 25 without sacrificing comfort in other zones or wasting energy by air conditioning unoccupied areas. So in essence, consumers typically want a ducted air conditioning system that can air condition an entire home or office area, but also be able to air condition only a small room/zone or office. Currently, this has not been possible with typical ducted air conditioning systems. 30 -2 [004] Presently known conventional ducted air conditioning systems need to have major components all matching in capacity whenever the system is operating. This requires that the compressor capacity has to match the maximum thermal load of the space to be conditioned, the outdoor and indoor heat exchangers have to match the compressors 5 performance, the indoor fan has to have a corresponding amount of airflow over the indoor heat exchanger, and the number of zones and outlets need to have corresponding airflow characteristics. Furthermore, the compressor only has ON and OFF operation modes, so has to cycle on with 100% capacity when cooling or heating is required, and cycle completely off with 0% capacity when the air conditioned space target temperature is 10 reached. This type of cycling system can cause large temperature and humidity swings, and also large changes in noise levels in the air conditioned space, when the thermal load is below the maximum design conditions. [005] A conventional indoor unit typically contains a heat exchanger (i.e. coil), a fan 15 motor and a blower, and sometimes a control module. The typical indoor unit delivers a relatively constant airflow to the contained space when the ductwork remains constant. Whether the system has zones or no zones, a standard Permanent Split Capacitor (PSC) Alternating Current (AC) induction fan motor operates by delivering an airflow quantity equal to the system profile and fan curve intersection points. Some systems offer a small 20 range of speeds, so the operator can select between high airflow and a slightly reduced airflow when maximum capacity is not required or quieter operation is required. The motor speed is typically limited by the motor design. Typically, the airflow would only change about 10 to 15% depending on the static pressure in the ductwork. 25 [006] Zoning the air conditioned space into separate zones (typically 2 to 8 zones) that can be manually turned on or off, has now become a popular method to offer energy savings; but only offers limited improvement in reducing temperature swings in the conditioned space. For example, temperature swings sometimes can be made worse as too much refrigerating or heating and airflow capacity is directed into a smaller air conditioned 30 space. This is because the compressor still only operates at a single level of 100% and the -3 indoor fan cannot adjust its airflow rate low enough, so the operator would usually resort to opening outlets at all the zones to regain comfort at the expense of more energy use. [007] With conventional systems, an operator must be very careful when adding zones to 5 the ducting system, as closing off too many zones by the operator increases the static pressure in the duct work. It is known that an increase in static pressure on an conventional indoor fan causes a lower total airflow volume and this effects the thermal load on the heat exchanger / compressor combination, which can cause the system to malfunction. This is similar to a heat exchanger freeze-up in a cooling operation or refrigerant over-pressure in 10 a heating operation. [008] One known way to allow the operator to make more use of zoning and to attempt to save energy and also improve comfort is by adding a Variable Air Volume (VAV) zone system. A typical VAV system has individual thermostats controlling the zone dampers 15 and providing cooling or heating calls to a main controller. A VAV system may also include a bypass damper between the supply and return air ducts. This type of system overcomes the previously mentioned problem of too many zones closing and the airflow being reduced over the indoor heat exchanger. By adding a bypass duct installed between the return air and supply air ducts, the airflow can be kept more constant over the indoor 20 heat exchanger. In this type of design, the bypass damper is controlled by how much static pressure is present in the supply duct, so when zones are closing, the static pressure of the installed duct work will increase and open the bypass damper. This allows the fan to keep forcing a relatively constant air volume over the indoor heat exchanger and not blowing too much air into the zones that are still on. 25 [009] One problem with this type of system/method is when the bypass damper opens then the heated or cooled supply air enters the bypass damper. The supply air is then passed into the return air, where it mixes with the return air from the conditioned space, sometimes making the air at the indoor heat exchanger too cold for a cooling mode, and 30 too hot for a heating mode. This type of system typically attempts to monitor this by having a temperature sensor that is either measuring the air passed onto the indoor heat -4 exchanger or the air coming off the indoor heat exchanger. Then, if these temperatures fall outside predefined safety limits, the compressor is shut down. This method is an improvement over a non-zoned system, but still does not provide optimal comfort or efficiency. 5 [010] Indoor fan motor technologies have been developed that keep a constant volume of air over the heat exchanger. So when a zone is closed, the fan will sense the change in static pressure and increase power to the motor, thus keeping a relatively constant volume of total airflow. This operation can be reversed when zones are opened. However, this 10 arrangement does not always satisfy a user. As more zones are turned off, the total airflow rate will remain the same; so the excess pre-conditioned airflow will now recycle through the bypass damper and duct, thus sometimes making the air passing onto the indoor heat exchanger either too cold or too hot. 15 [011] There are also known systems with two stage compressors that give two capacity steps. Step one would be 100% and step two normally would be between 50% and 70%. This gives better temperature control, but is still limited to only two compressor capacity settings that cannot always match the required thermal load of multiple zone demands. 20 [012] Another type of ducted system is provided with an inverter controlled compressor in the outdoor unit. These inverter controlled compressor systems offer more capacity steps than a two-stage compressor, but none of these types of system provide for any sort of integrated VAV zoning that can interact with the outdoor compressor unit. 25 [013] An additional problem with existing systems relates to the automatic control of fan speeds and/or air flow rates to particular zones when systems are initially turned on or when a particular zone is activated. In such situations there may be a large difference between the current temperature and the desired temperature. The Applicant has recognised this problem and that it is in the interest of the user to be able to reduce this 30 difference as fast as possible, while at the same time preventing accidental heating or -5 cooling beyond the desired temperature and limiting the time at which air flow rates are at high levels. [014] There is a need for an air conditioning system and method of operation or control 5 which addresses or at least ameliorates one or more problems inherent in the prior art. [015] The reference in this specification to any prior publication (or information derived from the prior publication), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that the prior 10 publication (or information derived from the prior publication) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. Brief Summary 15 [016] According to example forms, the present invention provides a method and/or a system of controlling a heater or air conditioner in heating mode. The method can be implemented by a control system, for example at start up in a heating mode. [017] According to another aspect, there is provided a method of controlling a heater or 20 air conditioner in heating mode, the method including the steps of: obtaining a room temperature using at least one temperature sensor; determining if the difference between the room temperature and a pre-defined target temperature is greater than a pre-defined difference threshold; and if so, operating in a high speed fan mode for a time period calculated based on the difference between the room temperature and the target 25 temperature. [018] According to another aspect, the room temperature is periodically or continuously monitored by the temperature sensor and the high speed fan mode is ended prior to the end of the time period if the room temperature reaches the target temperature. 30 -6 [019] In other particular, but non-limiting, forms the control panel provides an interface through which the user may set one or more of the target temperature; the difference threshold; and/or a duration factor used to calculate the time period. 5 [020] According to another optional aspect, the method is employed separately in each zone of a multiple zone heating or air conditioning system. [021] In another form there is further provided an air conditioning system including a control system, wherein the control system is configured to: receive a room temperature 10 using at least one temperature sensor; determine if the difference between the room temperature and a pre-defined target temperature is greater than a pre-defined difference threshold; and if so, operate in a high speed fan mode for a time period calculated based on the difference between the room temperature and the target temperature. 15 [022] In another example, the room temperature is periodically or continuously monitored by the at least one temperature sensor and the high speed fan mode is ended prior to the end of the time period if the room temperature reaches the target temperature. [023] In various forms aspects of the invention can be embodied as a method, system, 20 computer program product and/or computer readable medium of instructions. Brief Description Of Figures [024] Example embodiments should become apparent from the following description, which is given by way of example only, of at least one preferred but non-limiting 25 embodiment, described in connection with the accompanying figures. [025] FIG. 1 illustrates a flowchart of an example routine that can be utilised by a control system to carry out a method for operating a heater or air conditioner; and 30 [026] FIG. 2 illustrates a functional block diagram of an example processing system that can be utilised to embody or give effect to a particular embodiment.

-7 Preferred Embodiments [027] The following modes, given by way of example only, are described in order to provide a more precise understanding of the subject matter of a preferred embodiment or 5 embodiments. [028] In the figures, incorporated to illustrate features of an example embodiment, like reference numerals are used to identify like parts throughout the figures. 10 [029] An example embodiment of the present invention provides a method of controlling an air conditioner or another form of heat pump. The air conditioner is capable of supplying heated air to at least one room or space and includes a control system, such as or including a processing system, that may be operated by a user via a control panel or other type of user interface. The control panel allows the user to program various parameters 15 and to turn the air conditioning system off or on in a particular room. The room includes one or more temperature sensors for supplying air temperature information to the control system. [030] The present invention can be implemented by the control system when a user 20 signals start up via a control panel, where the air conditioner is operating in heating mode. The method employed determines if the fan will operate at high speed for a certain time period and calculates what the time period should be. [031] The method begins by obtaining a room temperature using the temperature sensor 25 in the room. This temperature is compared to a target temperature as supplied from the control panel by a user. A difference threshold is also programmed, set or otherwise selected by the user, or can be programmed or set by an installer of the system or left at a factory setting. If the difference between the target temperature and the room temperature is greater than the difference threshold then the fan operates at high speed for a certain 30 time period. In an alternative embodiment the difference threshold may be fixed, rather than being variable if, for example, input by the user.

-8 [032] The time period at which the fan operates at high speed is calculated by the control system. To perform this calculation the control system uses a duration factor that is programmed by the user, or alternatively is a fixed value. The duration factor indicates the 5 number of minutes (or equally seconds or hours) the fan will operate at high speed for every degree difference between the target and room temperatures. Therefore, in a particular example, the time period is calculated by multiplying the duration factor by the temperature difference. There are a variety of other ways for determining the duration factor, for example by using a reference curve or equation, which may be linear or non 10 linear, or a table of corresponding data, to obtain a time period for a given temperature difference. [033] In a preferred embodiment, the temperature sensors continue to monitor the room temperature and supply this data to the control system. The control system can then 15 monitor this value and reduce the fan speed before the end of the time period if the room temperature reaches the target temperature. [034] A particular embodiment of the present invention can be realised using a method that is implemented in a processing system, an example of which is shown in FIG. 1. The 20 flowchart of FIG. 1 illustrates the preferred series of steps and decisions made by the control system each time the air conditioner is turned on in heating mode to determine the speed at which the fan should run and for how long it will run at that speed. [035] The method 100 of FIG. 1 begins at start 110, which would generally occur after a 25 user signals the air conditioner to start up via the control panel, a pre-programmed timer, or some other form of switch. A decision 112 determines if the fan requires starting. As this routine is designed for a system being turned on, the fan will generally be required. Occasionally this will not be the case, however, such as if the room temperature is already above the target temperature, for example. In this case the fan would be stopped 114 and 30 the rest of the routine 100 is not required.

-9 [036] The next decision 120 determines if the fan is being started for the first time. If this is the case, a calculation 122 is performed to determine the time period that the high speed fan will operate if certain other criteria are also met. An example of a situation where the fan would be not starting for the first time is if the air conditioner had already been on for 5 some time, but the fan had not been operating because the target temperature had already been reached. [037] The next decision 130 determines if the system is in automatic or manual mode. In manual mode the fan speed is chosen by the user and the fan will not automatically go into 10 high speed mode. If the system is in manual mode the program moves to the manual setting 160 which is determined from input at the control panel, where the fan will go into one of high speed 162, middle speed 163 or low speed 164. After any of these three options the program ends 190. 15 [038] The alternative at the decision 130 is that the system is in automatic mode. The decision 140 then determines if the "Turbo Mode" is enabled. Enabling this mode means the fan will automatically go to high speed if all other necessary criteria are met. If it is enabled 142 the program queries 144 if the temperature difference is greater than the difference threshold. If this is the case (step 146) the program then checks that the time 20 period as calculated 122 earlier is not equal to zero. If it is not (step 152) the program then moves to set the fan to high speed mode 162. [039] If the "Turbo Mode" is disabled 141, the temperature difference is below the threshold 145, or the time period calculated at step 122 is equal to zero (step 151), then the 25 routine moves to run in automatic mode 155. This automatic mode involves a separate routine that does not form part of the present invention. [040] If the "Turbo Mode" is activated and the fan goes into high speed, another routine will be required to determine when the time period has ended and to return the fan speed to 30 the control of the automatic mode 155.

- 10 [041] The following description is a particular example of a preferred embodiment in operation, provided by way of illustration only, and should not be read as limiting the scope of the invention. 5 [042] The control panel will previously be set up with chosen parameters stored. These include: - "Turbo Mode" Enabled - Difference Parameter: 2.0'C - Duration Parameter: 5 min/ 0 C 10 - Fan Setting on wall control: "Automatic" - Target temperature: 22 0 C [043] The values determined by the control system include: - Room temperature: 18 0 C 15 [044] The unit is set to heating mode and is turned on, for example by pressing "ON" on the wall control. The temperature difference is then calculated by the control system: - Difference = Target temperature - Room temperature = 22 0 C - 18 0 C 20 = 4 0 C. [045] The difference of 4 0 C is greater than the difference parameter of 2 0 C. Because the difference is greater than the difference parameter the high speed fan is activated. The high speed fan will be activated for 20min, according to the following calculation: 25 - Time = Difference x Duration parameter = 4 0 C x 5 min/C = 20 min. [046] However, the temperature sensor in the room continuously or periodically monitors 30 the room temperature and if during this time period the temperature in the room reaches the target temperature, the high speed fan mode will be ended early. For example, if after - 11 15 minutes the room temperature is 22'C, the same as the target temperature, the fan speed will be reduced even though the time period of 20 minutes has not elapsed. [047] When either the target temperature or time period are reached, the fan speed 5 decreases to a value determined by the normal operating mode of the air conditioner. [048] This method is only employed when the air conditioner is first turned on. When the procedure has completed, a flag in the control system is set to prevent the high speed fan mode being activated again until sometime after the system has been turned off and 10 back on again, unless of course the high speed fan is required for another reason. Preferably, the method only operates once on Off to On cycle. [049] The following description is an example of how a control panel may be configured in a particular embodiment of the invention. To enable the initial high speed fan mode, or 15 "Turbo Mode", and to set the appropriate parameters the user would follow the steps of: 1) Enter the set-up menu by pressing "FAN CONTROL" and "TIMER" keys; 2) Scroll through the wall control (Using the "TIMER" key) until the "HIGH", 20 "MID", "LOW" and "AUTO" LEDs are on; If the "OFF" LED is blinking it means "Turbo Mode" is "Disabled". If the "ON" LED is blinking means "Turbo Mode" is "Enabled". The default is "Disabled"; 25 "Turbo Mode" is toggled between "ON" and "OFF" by pressing the "Set Temp" up and down arrows. 3) After enabling "Turbo Mode" press the "TIMER" key to enter the next set-up menu to set the difference threshold, or "Turbo Start Temperature". 30 The default value is 2.0'C. The "RUN" LED should be blinking.

- 12 The "Turbo Start Temperature" may be adjusted using the "Set Temp" up and down arrows; 4) Press the "TIMER" key to enter the next set-up menu to set the duration factor, or 5 "Turbo Duration". The default is "050" which means 5 min/ 0 C. "100"= 10 min/ 0 C. The "TIMER" LED should be blinking; [050] The present invention may be used as part of the control for a system for a single 10 space, or as part of a system that includes multiple rooms or zones cooled by a single system. In such a multiple zone system, the control system may operate on only one zone, causing the high speed fan mode to operate when that particular zone is started, even if other zones are already in operation. Each room or zone would have its own control panel and one or more temperature sensors. The air conditioning system would have the ability 15 to alter the air flow to the particular room or zone independently of the other rooms or zones. Turbo mode works at system level irrespective of which zone is operational and airflow of all the zones are affected. [051] References throughout the specification to fan speed may be an actual fan, or may 20 refer to some other control method of varying the flow rate of air to a particular zone. For example, a fan may be operating in the air conditioning system to supply air to a different zone. The "fan speed" of another zone may then be altered by opening some form of valve, increasing air flow to the zone even though an equivalent change in the speed of the fan may not have occurred. 25 [052] In another example there is provided a method of controlling or operating an air conditioning system where signals, data or commands are received from individual zone thermostats and a priority is provided to a highest demand zone / thermostat. For example, the priority thermostat can be used to control a variable capacity compressor. Control can 30 be direct and via an indoor controller and outdoor controller as typically the variable capacity compressor is part of an outdoor unit.

- 13 [053] In another example there is provided a method of controlling an air conditioning system, the air conditioning system including a plurality of individual zone thermostats, an outdoor unit including a variable capacity compressor, and at least one controller, the 5 method including the steps of: receiving, at the at least one controller, signals from the plurality of individual zone thermostats; determining a heating or cooling demand based on the signals; and, using the determined demand to control operation of the variable capacity compressor. 10 [054] In another example there is provided an air conditioning system for supplying conditioned air to a plurality of zones, each zone provided with an individual zone thermostat, each zone also provided with a zone damper, the system including at least one controller able to communicate with the individual zone thermostats and able to control operation of the zone dampers. 15 [055] In another example there is provided a method for controlling residential or commercial air conditioning systems. For example, the method can be utilised in the control of a ducted air conditioning system that includes a compressor unit (also known as a condenser), an indoor unit (also known as an evaporator or indoor fan coil unit), zone 20 dampers, and zone thermostats or sensors. In one form, the method analyses a plurality of individual zone thermostats and provides for control of an outdoor unit, for example including a variable capacity compressor, a multi-speed outdoor fan(s), and a reversing valve. Control of an indoor unit also can be provided, the indoor unit including, for example, a variable speed indoor fan (e.g. an electronically commutated (ECM) fan), an 25 electronic expansion valve (EXV), and modulating zone dampers to improve comfort and reduce energy usage. [056] The method can be applied in residential and commercial air conditioning and/or heat pump systems having individual zone thermostats or temperature sensors. An air 30 conditioning system is also provided that may include digital proportional feedback control from one or more zones, or variable duct work paths. In another form, an indoor unit can - 14 be provided that is installed in ducted / central heating / cooling / heat pump systems that have zones or variable duct work paths and require a fan that can deliver a variable volume of air to match a changing thermal and airflow load depending on how many zones are turned on or off. In yet another form, an outdoor unit can be provided that includes a 5 variable capacity refrigeration compressor that can also adapt to the changing thermal load. [057] In another example there is provided an air conditioning system, and method of control thereof, in which selected components have variable capacity control, speed control or modulation control. This allows the air conditioning system to air condition an entire 10 house or office area, or air condition only a small room/zone or office, without recycling air through a bypass damper, or dumping conditioned air in unoccupied zones. This also eliminates any need for multiple separate systems to be installed. [058] In another example the method/system can directly and proportionally control a 15 variable capacity compressor resulting from sensing performed at any of the individual zone thermostats. An indoor fan speed can be automatically slowed when any zone is closed, and increased when any zone is opened. For example, the system can operate between about 10% and 100% of full load thermal capacity. 20 [059] Generally, in relation to control of the system, the system can be part of a networked information or data communications system, where a user has access to one or more terminals (e.g. fixed control panels or remote control systems) which are capable of requesting and/or receiving information or data from the air conditioning system or local or remote information sources. In such a communications system, a user terminal or interface 25 may be a type of processing system, computer or computerised device, mobile or cellular telephone, smart phone, Personal Digital Assistant (PDA), thin client, or any other similar type of digital electronic device. The capability of such a terminal to request and/or receive information or data can be provided by software, hardware and/or firmware. A terminal may include or be associated with other devices, for example a local data storage 30 device such as a hard disk drive or solid state drive.

- 15 [060] An information source can include a server, or any type of terminal, that may be associated with one or more storage devices that are able to store information or data, for example in one or more databases residing on a storage device. The exchange of information (i.e., the request and/or receipt of information or data) between a terminal and 5 an information source, or other terminal(s), is facilitated by a communication means. The communication means can be realised by physical cables and/or electromagnetic (i.e. wireless) signals. [061] A further particular embodiment of the present invention can be realised using an 10 example processing system, which can be provided as, or as at least part of, an indoor controller, outdoor controller, or thermostat or humidity sensor, an example of which is shown in FIG. 2. In particular, the processing system 200 generally includes at least one processor 202, or processing unit or plurality of processors, memory 204, at least one input device 206 and at least one output device 208, coupled together via a bus or group of buses 15 or communication pathways 210. In certain embodiments, input device 206 and output device 208 could be the same device, port or interface. An interface 212 might also be provided for coupling the processing system 200 to one or more peripheral devices. At least one storage device or memory 214 which houses at least one database 216, or at least data, might also be provided. The memory 204 can be any form of memory device, for 20 example, volatile or non-volatile memory, solid state storage devices, magnetic devices, etc. The processor 202 could include more than one distinct processing device, for example to handle different functions within the processing system 200. [062] Input device 206 receives input data 218, for example temperature or humidity 25 signals, and could be an interface, port, data receiver, antenna or wireless data adaptor, data acquisition card, etc. Input data 218 could come from different sources. Output device 208 produces or generates output data 220, for example component control signals, user visual display, etc. Output data 220 could be derived from different output devices and might include data transmitted to a network. In one form, a user or technician could 30 view data output, or an interpretation of the data output, on, for example, a display, monitor or via a network.

- 16 [063] In use, the processing system 200 is adapted to allow data or information to be stored in and/or retrieved from, via wired or wireless communication means, the at least one database 216 or memory. The interface 212, if provided, may allow wired and/or 5 wireless communication between the processing unit 202 and peripheral components that may serve a specialised purpose. It should be appreciated that the processing system 200 may be any form of specialised hardware or the like. The processing system 200 may be a part of a networked communications system. Processing system 200 could connect to network, for example the Internet, WAN or LAN. Input data 218 and output data 220 10 could be communicated to other devices via a network. For example, a telecommunications network could facilitate the transfer of data between processing system 200 and a smartphone or mobile or cellular telephone, by utilising wireless communication means. 15 [064] Optional embodiments may also be said to broadly include the parts, elements, steps and/or features referred to or indicated herein, individually or in any combination of two or more of the parts, elements, steps and/or features, and wherein specific integers are mentioned which have known equivalents in the art to which the invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth. 20 [065] Although a preferred embodiment has been described in detail, it should be understood that many modifications, changes, substitutions or alterations will be apparent to those skilled in the art without departing from the scope of the present invention. 25 [066] The present invention in various embodiments may take the form of a processor or computer-implemented method, an air conditioning system, a processing system or processor, hardware, software or a computer program product, firmware, or a combination of software and hardware aspects. 30 [067] It should be appreciated that throughout the description, discussions utilizing terms such as "processing" or "computing" or "calculating" or "determining" or "displaying" or - 17 the like, refer to the action and processes of a computer, computer system, processor or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's processors, memories or registers or other such information storage, transmission or display devices. 5

Claims (5)

1. A method of controlling a heater or air conditioner in heating mode, the method including the steps of: 5 obtaining a room temperature using at least one temperature sensor; determining if the difference between the room temperature and a pre-defined target temperature is greater than a pre-defined difference threshold; and if so, operating in a high speed fan mode for a time period calculated based on the difference between the room temperature and the target temperature. 10

2. The method according to claim 1, wherein the room temperature is periodically or continuously monitored by the at least one temperature sensor and the high speed fan mode is ended prior to the end of the time period if the room temperature reaches the target temperature. 15

3. The method according to claim 1 or 2, wherein a control panel provides an interface through which the user may set one or more of: the target temperature; the difference threshold; and/or 20 a duration factor used to calculate the time period.

4. The method according to any one of claims 1 to 3, wherein the method is employed separately in each zone of a multiple zone heating or air conditioning system. 25

5. An air conditioning system including a control system, wherein the control system is configured to: receive a room temperature using at least one temperature sensor; determine if the difference between the room temperature and a pre-defined target temperature is greater than a pre-defined difference threshold; and if so, 30 operate in a high speed fan mode for a time period calculated based on the difference between the room temperature and the target temperature.