GB2099985A - Air conditioning apparatus - Google Patents

Abstract

An outlet arrangement for use with an air-conditioning apparatus, said outlet arrangement including a housing 7 defining two chambers, first inlet means 5 for introducing air from an air conditioning apparatus to a first of said chambers 14 and a first outlet 17 for directing air from the first of said chambers 14 to a space to be air-conditioned, the second of said chambers 18 being associated with a second inlet 23 to permit air to be withdrawn from said space being conditioned to said second chamber and a second outlet 6 for returning air from said second chamber to said air conditioning apparatus, there being controllable means 21 for establishing a flow path for air between said two chambers. <IMAGE>

Description

SPECIFICATION Improvements in or relating to air conditioning apparatus The present invention relates to air conditioning apparatus, more particularly to air conditioning apparatus suitable for use in connection with a small or moderate sized installation.

When a small or moderate size building is to be air-conditioned it is possible to utilize several alternative forms of air-conditioning apparatus. For example, each room may be provided with an individual air-conditioning apparatus. This may be found to be practicable in some situations, but in most cases it may be found pereferable, from the point of view of cost, to provide a central airconditioning plant, this plant being connected by appropriate ducting to the various rooms that are to be air-conditioned. However, there are disadvantages associated with such an arrangement. Firstly, if a single sensor is provided to detect parameters relating to the air present in one of the rooms to control the central air-conditioning plant, all the rooms will receive conditioned air in response to the actuation of the sensor in that one room.If the atmospheric conditions are different in the different rooms this will not result in even conditions being established economically in the various rooms. If, alternatively, adjustable outlets for conditioned air are provided in each room, the total flow of air within the air conditioning plant will fluctuate in response to the demand for conditioning air in the various rooms. This is not desirable since an air conditioning apparatus will operate most satisfactorily when there is a substantially constant flow of air through the apparatus.

According to this invention there is provided an outlet arrangement for use with an air-conditioning apparatus, said outlet arrangement including a housing defining two chambers, first inlet means for introducing airfrom an air conditioning apparatus to a first of said chambers and a first outlet for directing air from the first of said chambers to a space to be air-conditioned, the second of said chambers being associarted with a second inlet to permit air to be withdrawn from said space being conditioned to said second chamber and a second outlet for returning air from said second chamber to said air conditioning apparatus, there being controllable means for establishing a flow path for air between said two chambers.

Preferably means are provided to ensure that, in operation of the arrangement, a predetermined constant volume of air flows, during a unit period of time, into the first chamber, from the air conditioning apparatus and a corresponding constant volume of air flows, in a unit period of time, from the second chamber to the air conditioning apparatus.

Conveniently said means establishing a flow path between the two chambers are variably adjustable so that a flow path can be established to permit a selected proportion of the said constant volume of air to flow from the first chamber to the second chamber.

The means for establishing a flow path between the two chambers may comprise at least one cylindrical damper cooperating with a plate forming a partition between the said chambers and provided with an aperture receiving a portion of the periphery of the damper, the damper having at least one diametrically extending channel formed therein.

Alternatively said means for establishing a flow path between said chambers may comprise an outer tube in which is nested an inner tube or rod, the nested elements having apertures formed therein that can be aligned to establish a flow path between the two chambers, or an iris, or an opposed blade aerofoil damper.

Preferably the first inlet and the second inlet are associated with respective equalising grids, and the first outlet and the second outlet are provided with respective baffles.

Conveniently, ducting is connected to the said first outlet and said second inlet, said ducting communicating with appropriately spaced orifices within a space to be air conditioned.

The invention also relates to an air conditioning apparatus comprising, means for supplying treated air (such as air of predetermined temperature and relative humidity) and a plurality of outlet arrangements as described above, each of the said outlet arrangements being connected thereto by ducts which communicate the first inlet and the second outlet of each outlet arrangement.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described by way of example with reference to the accompanying drawings in which: Figure lisa diagrammatic view of part of a small air-conditioning apparatus, illustrated supplying conditioned air to three rooms; Figure 2 is a sectional diagrammatic view through one of the outlet devices shown in Figure 1; Figure 3 is en enlarged diagrammatic perspective view of part of the outlet device shown in Figure 2.

Referring now to Figure 1, three rooms 1, 2, 3 that are to be air conditioned are shown schematically. A small supply air conditioning plant 4 is provided, which can be located appropriately, and this air conditioning plant4 is connected by an air supply conduit 5 and an air return conduit 6 to air outlet devices 7,8,9 provided in each of the rooms 1,2,3 respectiveiy. The air conditioning plant also has an air inlet 10 for drawing in airfrom the atmosphere, as is appropriate and an air exhaust outlet 11 for discharging air to the atmosphere, as is appropriate.

The air conditioning apparatus 4 is of a conventional design, and is adapted to control the temperature and the humidity of air supplied through the supply conduit 5. Such air conditioning plants are well known per se and thus the plant will not be described in detail herein.

Turning now to Figure 2 the air supply conduit 5 is shown as being connected to a constant volume controller 12 which is only illustrated schematically.

Such a constant volume controller is known per se, and one example of such a device is the device sold under Trade Mark "Volustat" by Sound Attenuators Limited. Such devices can be adjustably operated to ensure that a selected constant volume of air flows through a conduit during a predetermined period of time. The outlet of the constant volume controller is connected to an inlet port of a housing 13, where it is directed into a first plenum chamber 14. The plenum chamber is provided with an equalising grid 15 which is located immediately adjacent the inlet port, so that air passing through the inlet port is directed against the grid 15. The plenum chamber 14 is also provided with a baffle 16 which is located adjacent an outlet port 17 therefor, so that air which is to flow out of the outlet port must flow past the baffle.

Whilst in Figure 3 the outlet port 17 is illustrated as discharging to the atmosphere it is to be appreciated that further ducting may be connected to the outlet port 17 to duct conditioned air to appropriate outlet orifices located within the room that is to be air conditioned at appropriate locations. Such ducting 17' is shown schematically in Figure 1.

The housing 13 defines a second plenum chamber 18 which is separated from the first planar chamber by means of a partition 19. This partition 19 has at least one aperture therein which is dimensioned to accommodate a cylindrical damper 20 is spaced above the plane of the partition 19, so that the partition 19 abuts the damper 20 at point below the level of its axis. The cylindrical damper 20 is shown in perspective in Figure 3 and it can be seen that the damper 20 has at least one channel 21 extending diametrically through it. The damper 20 can be rotated by means of an electric motor 22, schematically illustrated in Figure 2, which may be controlled by an appropriate thermostat arrangement.It will be appreciated that if the damper 20 is rotated to have such a position that both the open ends of the channel 21 are located entirely to one side of the partition 19, the two plenum chambers 14,18 will be effectively sealed from each other. However, if the damper 20 is rotated so that the channel 21 is located with the axis thereof perpendicular to the plane of the partition 19, then the two chambers 14,18 will be in communication with each other. It will be appreciated that the degree of communication between the two chambers will be dependent upon the precise rotational position of the damper 20.

Whilst it is apreciated that one channel 21 has been illustrated in the damper 20 in Figure 3, two or more axially spaced channels could be provided.

Also it is to be appreciated that a plurality of such dampers may be provided located in position between the plenum chambers 14 and 18, and in the preferred embodiment two dampers are provided, the dampers being parallel with each other.

The plenum chamber 18 has an inlet port 23, which is shown as opening directly to the atmosphere with the room to be air conditioned. However, it is to be understood that this inlet port may be connected by appropriate ducting to appropriately located inlet orifices. Such ducting 23' is shown schematically in Figure 1. Immediately adjacent the inlet port 23, with the plenum chamber 18, there is provided an equalising grid 24, such that air flowing through the inlet port will be directed against the grid 24. The plenum chamber 18 also has an outlet port, adjacent which there is provided a baffle 25 so that air flowing through the outlet port must first flow past the baffle. The outlet port is connected directly to a constant volume controller 26 which corresponds with the constant volume controller 12 described above.The outlet of the constant volume controller 26 is connected to the return conduit 6.

Each of the rooms 1,2,3 illustrated schematically in Figure 1 may be provided with appropriate sensors to sense the condition of the ambient air within that room. Typically the sensors would comprise thermostats which effectively call for conditioned air to be supplied to the room when the temperature within the room devriates from a predetermined temperature range. When any of the thermostats in any of the rooms indicates that there is a requirement for conditioned air, the air conditioning plant 4 would operate, thus supplying conditioned air through the conduitS. The air flowing through the conduit 5 is supplied to each outlet device 7,8, 9 through a respective constant volume controller 12.

In each room a predetermined constant volume of conditioned air will flow into the first plenum chamber 14 of the outlet device 7,8 or 9 in that room.

The precise position of the damper will be determined by the thermostat, and thus a predetermined quantity of the air introduced to the plenum chamber 14will leave the plenum chamber 14through the outlet port 17, thus passing into the room to be air conditioned, and the remaining proportion of the air will pass into the second plenum chamber 18. It is to be noted that this remaining proportion of the air can be anything between 0 percent and 100 percent of the air entering the plenum chamber 14 from the constant volume controller 12 depending upon the precise volume of conditioned air needed to maintain the room at a desired temperature.

The constant volume controller 26 will ensure that a volume air is withdrawn from the plenum chamber 18 which corresponds precisely to the volume of air entering the plenum chamber 14. This air then passes through the conduit 6, to be returned to the air conditioning plant. Thus, at all times equal volumes of air will flow through the conduits 5 and 6, regardless of the precise quantities of air needed to maintain the rooms at a desired temperature. This allows the air conditioning plantto operate with a substantially constant through flow of air at a constant pressure. Any fluctuations of temperature within any one of the rooms to be conditioned, will merely result in operation of the appropriate damper which will alter the proportion of air that enters the plenum chamber 14 of the respective outlet device that is diverted directly to plenum chamber 18, thus controlling the quantity of conditioned air that is supplied to the room.

The described system has the advantage that the apparatus operates at constant pressure and at constant volume. However the volume of treated air supplied to each room can readily be controlled. Any volumes of treated air that are not supplied to a room are returned to the air conditioning plant, thus minimising the treatment that will have to be effected by that plant.

Whilst the invention has been described with reference to one specific embodiment it is to be noted that many modifications may be effected. For example, whilst a cylindrical damper has been described, the damper between the plenum chambers may comprise an iris, an opposed blade aerofoil damper, or may even comprise two nested tubes (or a tube with a nested central rod therein), the two nested elements being provided with holes or slots formed along the length thereof which can be brought into alignment when the two elements have an appropriate relative rotational position to form channels establishing communication between the two plenum chambers. It is to be appreciated that the position of the damper may be adjusted by utilising a pneumatic actuator operated in response to a room thermostat, instead of the above described electric motor.

Of course, an air conditioning apparatus in accordance with the invention may be used to air condition any building, regardless of whether it is divided into separate rooms.

Claims (14)

1. An outlet arrangement for use with an airconditioning apparatus, said outlet arrangement including a housing defining two chambers, first inlet means for introducing airfrom an air conditioning apparatus to a first of said chambers and a first outlet for directing air from the first of said chambers to a space to be air-conditioned, the second of said chambers being associated with a second inlet to permit air to be withdrawn from said space being conditioned to said second chamber and a second outlet for returning air from said second chamber to said air conditioning apparatus, there being controllable means for establishing a flow path for air between said two chambers.

2. An arrangement according to Claim 1, wherein means are provided to ensure that, in operation of the arrangement, a predetermined constant volume of air flows, during a unit period of time, into the first chamber, from the air conditioning apparatus and a corresponding constant volume of airflows, in a unit period of time, from the second chamber to the air conditioning apparatus.

3. An arrangement according to Claim 1 or Claim 2 wherein said means establishing a flow path between the two chambers are variably adjustable so that a flow path can be established to permit a selected proportion of the said constant volume of air to flow from the first chamber to the second chamber.

4. An arrangement according to any one of the preceding claims wherein the means for establishing a flow path between the two chambers comprise at least one cylindrical damper cooperating with a plate forming a partition between the said chambers and provided with an aperture receiving a portion of the periphery of the damper, the damper having at least one diametrically extending channel formed therein.

5. An arrangement according to any one of Claims 1 to 3 wherein said means for establishing a flow path between said chambers comprise an outer tube in which is nested an inner tube or rod, the nested elements having apertures formed therein that can be aligned to establish a flow path between the two chambers.

6. An arrangement according to any one of Claims 1 to 3 wherein said means for establishing a flow path between said chambers comprise an iris.

7. An arrangement according to any one of Claims 1 to 3 wherein said means for establishing a flow path between said chambers comprise an opposed blade aerofoil damper.

8. An arrangement according to any one of the preceding claims wherein the first inlet and the second inlet are associated with respective equal is ing grids.

9. An arrangement according to any one of the preceding claims wherein the first outlet and the second outlet are provided with respective baffles.

10. An arrangement according to any one of the preceding claims wherein ducting is connected to the said first outlet and said second inlet, said ducting communicating with appropriately spaced orifices within a space to be air conditioned.

11. An air conditioning apparatus comprising, means for supplying treated air and a plurality of outlet arrangements according to any one of the preceding claims, each of the said outlet arrangements being connected thereto by ducts which communicate the first inlet and the second outlet of each outlet arrangement.

12. An outlet arrangement for use with an air conditioning apparatus substantially as herein described and as shown in the accompanying drawings.

13. An air conditioning apparatus substantially as herein described and as shown in the accompanying drawings.

14. Any novel feature or combination of features disclosed herein.