AU2002301054B2

AU2002301054B2 - Operator control systems for an air conditioning installation

Info

Publication number: AU2002301054B2
Application number: AU2002301054A
Authority: AU
Inventors: Jimmy Adamlu; Walter Kimble
Original assignee: Air Advantage Pty Ltd; Advantage Air Australia Pty Ltd
Current assignee: Advantage Air Australia Pty Ltd
Priority date: 2001-09-18
Filing date: 2002-09-18
Publication date: 2008-02-28
Anticipated expiration: 2022-09-18

Description

P/00/011 2815/91 Regulaton 3.2(2)

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: OPERATOR CONTROL SYSTEMS FOR AN AIR CONDITIONING

INSTALLATION

The following statement is a full description of this invention, including the best method of performing it known to us OPERATOR CONTROL SYSTEMS FOR AN AIR-CONDITIONING

INSTALLATION

Field of the Invention The invention relates to air-conditioning systems, including systems for heating, cooling and ventilation. In particular, to control systems for controlling air flow for said systems from an air-conditioning unit to a plurality of zones.

Background of the Invention For an air-conditioning installation within a house, air is generally drawn into the air-conditioning unit via a return air grille which is located centrally within the house. Adjacent or within the return air grille will be located a temperature transducer from which will be received data relating to the "average" temperature within the house. The unit control system reads this average temperature and set point and uses this data to determine the fan speed and operation of the compressor.

In elaborate installations there can be multiple zones serviced by the airconditioning unit, the zones being notionally divided between the rooms, such as for bedrooms, family room, kitchen, study, and infrequently used areas, such as for formal entertaining. As air-conditioning units are frequently designed to service a limited combination of zones, in certain circumstances the unit will have to provide for either larger or smaller zone combinations than the unit was selected for.

To provide a sufficient volume of air in most circumstances, the airconditioning unit will be designed to service a pre-determined combination of zones. Thus, when the air-conditioning unit is switched to servicing a combination of zones requiring a lower capacity than the designated zone combination, said zone will be over cooled or heated. Nothing within such a conventional system provides for selectively varying the volume of air going to a particular zone, and so the possibility that one or more zones may never be adequately serviced exists for conventional installations. To overcome such problems air flow based control systems may be used, whereby temperature is controlled through varying the air flow into a zone.

00 A consideration in such a system is the balance between the supplied volume of air to the zones and the capacity to deliver that air based upon the size and number of zones within the system.

For a system having a temperature and air flow control system, the closure of zones will lead to a detected temperature change of the return air. It will also reduce the capacity of the system to deliver the air flow from the air-conditioning C unit. Together, these factors may reduce the air flow passing over the heat transfer coils of the unit. In an extreme case, this may lead to the coils suffering c-i an ice build up.

O 10 Thus, a problem exists in the combination of an air flow control system and a temperature control system whereby any conflict between the requirements of an operator manipulating the air flow control system and the requirements of the air-conditioning unit to provide a volume of air flow based upon a temperature setting of the thermostat.

It would therefore be advantageous if there was a means by which this conflict could be minimized.

STATEMENT OF INVENTION It is therefore an object of the invention to provide a means of limiting the ability of an operator to provide an instruction to the air flow control system which may be in conflict with the requirements of the temperature control system and thus, the air-conditioning unit.

Therefore, in one aspect the invention provides for a sub-control system for an air conditioning system adapted to activate and de-activate zones in the air conditioning system, including a receiving means for receiving operator instructions, communication means between the receiving means and a master control system for communicating the instructions to the master control system and over-riding means wherein the over-riding means selectively over-rides the operator instructions to maintain a pre-determined number of zones activated, and thereby maintain a volume of air flow.

If an operator exercises a degree of control over the air flow control system through a sub-control system and thus, provides instructions to the master control system, it is possible that said instructions may deactivate too many zones and thus reduce the ability of the air-conditioning system to deliver an air flow which 00 O may be based upon the requirements of the temperature controlled system.

SConsequently, a condition exists where an operator may damage the system t when seeking to control temperature through a control of zones rather than through control of the thermostat. By providing an over-riding means within the sub-control system whereby the volume of air to be delivered and the capacity of the zones to deliver said air may be balanced and if the operator instructions are in conflict with this balance, said over-riding means can over-ride these and preventing the loss of functionality of the air-conditioning system.

(Another aspect of the invention provides a method for activating and de- 0 10 activating zones in an air conditioning system, including the steps of receiving operator instructions, communicating the instructions to a master control system and selectively over-riding the operator instructions to maintain a pre-determined number of zones activated and thereby maintain a volume of air flow.

In delivering the instructions the operator will enter his preference as to the activation or de-activation of a zone through the receiving means, preferably an input panel, which may be of the form of a simple switch for each zone, which will turn a zone on or off. The instructions input by the operator are then communicated to the master control system to activate or de-activate a zone, and thus the functioning of the air-conditioning system will vary based upon the operator instructions. The over-riding means may be a separate instruction within the sub-control system, or other means to compare the requirements of the temperature control system and the air flow control system.

The over-riding means may effect the over-riding of the instructions by automatically opening the predetermined number of zones. In determining which zones should be open the over-riding means may sequence through a predetermined list of zones. Thus, having determined that further capacity is required and that at least one zone needs to be opened, the over-riding means may sequence through the list of zones until a closed zone is encountered and consequently open said zone.

In a preferred embodiment, over-riding may be restricted to a partial opening, relating to an incremental positional change of the motor. Alternatively, over-riding may be the zone being fully opened.

The over-riding means may be limited to the opening of a predetermined number of zones and not be capable of opening an indeterminate number of zones. The predetermined number of zones may be set at two zones, or alternatively one zone. The over-riding means may also be de-activated and in effect, the predetermined number of zones may be set to zero.

Description of Preferred Embodiment It will be convenient to further describe the present invention with respect to the accompanying drawings, which illustrate possible arrangements of the invention. Other arrangements of the invention are possible and consequently the particularity of the accompanying drawings is not to be understood as superceding the generality of the preceding description of the invention.

Figure 1 shows an input pad of one aspect of the present invention; Figure 2 shows a schematic view of an air-conditioning system in communication with an input device of the present invention.

Figure 1 shows an input pad used to receive instructions from an operator to be communicated to an air flow control system for an air-conditioning system. The input pad provides for the operator to designate whether individual zones are to be on or off simply by engaging button with LED (4) providing a visual indication as to the status of that zone. In this embodiment of the present invention the input pad provides for five zones listed in sequential order from bedroom 1, bedroom 2, bedroom 3, lounge and dining. It will be understood that the number of zones under control can be substantially greater than the five zones cited in this embodiment.

Figure 2 shows the air-conditioning system in schematic form wherein the input pad is in communication with the air flow control system which in turn provides control over dampers (7a to 7e) which determine the air flow to the respective zones (8a to 8e).

The air flow is generated by air-conditioning unit which is fed from return air grille The temperature control system (11) which is integral with the air-conditioning unit is typically placed adjacent the return air grille, and thus the temperature control over the air-conditioning unit is based upon an average temperature of return air.

The occupants of the building for which the air-conditioning system services will set a certain temperature based level through temperature control system (11) which functions through air-conditioning unit For individual control of individual zones (8a to 8e) and also to balance the air-conditioning requirements of the building, an operator will use the air flow control system in a manner analogous to a fine tuning with the temperature control acting as a coarse adjustment. The person skilled in the art will of course recognize that in the absence of a temperature control an air-conditioning unit may be subject to discrete fan settings which may be activated by an operator. The difference between these two alternatives is that under a temperature control the fan will react to variations in the temperature of the return air, whereas for a direct fan control, the operator will make the determination as to temperature and control the fan directly in accordance with the operator's perception of the return air temperature.

A conflict arises therefore, when having determined the fan speed in terms of temperature, an operator wishes to control temperature through the air flow control system by switching zones on and off through the opening and closure of dampers (7a to 7e). Because of the flexibility and ease of use as well as its response time characteristic, it is likely an operator will choose to control temperature in individual zones using the air flow control system rather than the temperature control system Should the operator choose to close several or all of zones (8a to 8e), the flow of air to the zones (8a to 8e) will all but stop.

Correspondingly, the fan speed, which is unaffected by the temperature control system, will not diminish, leading to a substantial pressure increase and air flow decrease. It follows that the back pressure increase can lead to structural damage to the ductwork, and the reduced airflow across the coils of the air conditioning unit can lead to damage to the unit. It is here that the core feature of the present invention is enacted wherein a portion of the sub-control system, having determined the flow of air has dropped below the predetermined minimum and so will over-ride the operator instructions to close the zones (8a to 8e). In over-riding these instructions the sub-control system will test the state of each zone in sequence to determine whether it is open or closed. The first non-critical "off "zone will then be turned "on" and a further test as to the number of "on" 6 zones made. If the balance is met the control system will end its over-riding condition, however if the number of "on" zones is still less than required the control system will continue to test in a sequential manner, turning on zones and retesting until the number of minimum "on" zones reaches the desired level.

In a preferred embodiment of the present invention, the sub-control system will be limited to a predetermined number of zones for which it can over-ride the operator instructions with the preferred alternatives being a limit on the sub-control system in over-riding the operator instructions by turning on a maximum of one or two zones.

In a further preferred embodiment the present invention may provide a means to selectively turn off the means to over-ride the operators instructions, and thus effectively including a third predetermined limit of zero.

Claims

1. A sub-control system for an air conditioning system adapted to activate _and de-activate zones in the air conditioning system, including a receiving means for receiving operator instructions, communication means between the receiving means and a master control system for communicating the instructions to the Smaster control system and over-riding means wherein the over-riding means selectively over-rides the operator instructions to maintain a pre-determined number of zones activated and thereby maintain a volume of air flow.

S2. The sub-control system according to claim 1 wherein the over-riding means maintain the pre-determined number of zones by activating de-activated zones.

3. The sub-control system according to claim 2 wherein activating de- activated zones includes fully opening the zones.

4. The sub-control system according to claim 2 wherein activating de- activated zones includes incremental re-positioning of the zones towards a partially open position.

The sub-control system according to any one of claims 2 to 4 wherein the over-riding means determines which zones to activate by testing each zone and activating de-activated zones in a pre-determined sequence.

6. The sub-control system according to any one of claims 2 to 4 wherein the over-riding means determines which zones to activate by testing a discrete number of zones and activating de-activated zones in a pre-determined sequence.

7. The sub-control system according to claim 3 or 4 wherein testing includes measurement of the position of each zone and calculating the cumulative opening total of all activated zones. 00 O

8. The sub-control system according to claim 6 or 7 wherein the discrete Snumber of zones is no more than a pre-designated number of zones to be subject Sto over-riding.

9. The sub-control system according to any one of claims 5 to 8 wherein the pre-determined sequence of zones is a function of either or both occupation rate and operator preference.

The sub-control system according to claim 1 wherein the pre-determined Snumber of zones is a function of a required air flow through the air conditioning system.

11. The sub-control system according to any one of the preceding claims further including means to selectively disable the over-riding means.

12. The sub-control system according to any one of the preceding claims wherein the receiving means includes either or both of a wall mounted panel and a remote control device.

13. A method for activating and de-activating zones in an air conditioning system, including the steps of receiving operator instructions, communicating the instructions to a master control system and selectively over-riding the operator instructions to maintain a pre-determined number of zones activated and thereby maintain a volume of air flow.

14. The method according to claim 13 wherein the over-riding step includes activating de-activated zones.

The method according to claim 14 wherein the activating step includes fully opening the zones.

16. The method according to claim 14 wherein the activating step includes incremental re-positioning of the zones towards a partially open position.

17. The method according to any one of claims 14 to 16 wherein the over- riding step includes determining which zones to activate by testing each zone and activating de-activated zones in a pre-determined sequence.

18. The method according to any one of claims 14 to 16 wherein the over- riding step includes determining which zones to activate by testing a discrete number of zones and activating de-activated zones in a pre-determined sequence.

19. The method according to claim 15 or 16 wherein the testing step includes measuring the position of each zone and calculating the cumulative opening total of all activated zones.

The method according to claim 18 wherein the discrete number of zones is no more than a pre-designated number of zones to be subject to over-riding.

21. The method according to any one of claims 17 to 20 wherein the pre- determined sequence of zones is a function of either or both occupation rate and operator preference.

22. The method according to claim 13 wherein the pre-determined number of zones is a function of a required air flow through the air conditioning system.

23. A sub-control system for an air conditioning system as herein before described and illustrated with reference to the figures.

24. A method for activating and de-activating zones in an air conditioning system as herein before described and illustrated with reference to the figures. DATED this 1 8 th day of September, 2001. ADVANTAGE AIR (AUST) PTY LTD WATERMARK PATENT TRADEMARK ATTORNEYS 2 1 ST FLOOR, "ALLENDALE SQUARE TOWER" 77 ST GEORGE'S TERRACE PERTH WA 6000