GB2333355A

GB2333355A - Air conditioning unit

Info

Publication number: GB2333355A
Application number: GB9801052A
Authority: GB
Inventors: Paul Anthony Eastope; Roger Leonard Woodcock
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-01-20
Filing date: 1998-01-20
Publication date: 1999-07-21
Anticipated expiration: 2018-01-20
Also published as: GB2333355B; GB9801052D0

Abstract

An air conditioning unit for adjusting the temperature of air passing through the units, comprising first 17 and second 19 air channels between an inlet and an outlet, a fan 40 for causing air flow through the channels, a heat exchange 20 in the first air channel, and a rotatable drum 30 having an air flow passage 34 therethrough such that rotation of the drum enables selection of the relative amount of air flow through the first and second air channels. The second channel may also contain a heat exchange. A third by-pass channel 18 is provided.

Description

AIR CONDITIONING UNIT The invention relates to an air conditioning unit in particular such a unit which is able to moderate the temperature of air by both heating and cooling incoming air to the unit.

It is known to provide such an air conditioning unit which comprises an inlet having an air filter through which air passes to a heater and a cooler due to suction of an upstream fan which causes the air to be pulled through the heater and the cooler before passing through an outlet. In order to moderate the temperature of the air passing through the unit, a sensor is used to determine the temperature of the incoming air and then to actuate either of the heater or cooler within the units. The heater and cooler are basically heat exchangers comprising a large surface area for contact with the air and a series of pipeways through which heated or cooled water, or other fluid, can pass. Water for the cooler is refrigerated using a separate refrigeration unit whilst water for the heater is heated up using a separate heating unit. The system controls the flow of fluid to the respective cooler or heater using valves in the feedpipes thereto. Accordingly, by varying the period of time for which either the heater or the cooler is on, the temperature of air in a room can be controlled by the unit.

However, such known systems can be prone to leakage at the valves for example.

The invention seeks to provide an improved air conditioning unit. An object of the invention is to overcome the problems of the prior art and to provide a valveless air conditioning unit.

According to one aspect of the invention there is provided an air conditioning unit for adjusting the temperature of air passing through the units, comprising first and second air channels between an inlet and an outlet, a fan for causing air flow through the channels, a heat exchanger in the first air channel, and a rotatable drum having an air flow passage there through such that rotation of the drum enables selection of the relative amount of air flow through the first and second air channels. A second heat exchanger can also be provided in the second channel. The unit can also comprise a third channel which can bypass the or both heat exchangers. The heat exchanger or exchangers can be a cooler or a heater.

In one form, the rotatable drum is upstream of the fan thereby to provide acoustical attenuation between the fan and the inlet. Beneficially the drum can act as an acoustic attenuator and can for example comprise a large volume of sound attenuating materials such as mineral wool. Also, the drum can insulate the air passing through the system from the redundant heat exchanger. e.g. on the downstream side of the heat exchanger.

In another form, the units comprises two rotatable drums, one on the downstream and one on the upstream ends of the heat exchanger. Beneficially this arrangement segregates the heat exchanger paths to optimum heat exchange.

Preferably an apertured plate is positioned adjacent a cylindrical outer surface of the drum thereby to enable selection of the relative amounts of air flow through the apertures in the plate and the drum passageway. Preferably brushes or other air flow constraining means are provided between the drum and the plate to ensure efficient transfer of air therebetween.

The rotatable drum preferably comprises a large cavity substantially filled with sound attenuating material such as mineral wool. The large cavity can comprise two sections in two components which substantially form the drum. Preferably, an apertured wall or grating is provided along the passageway through the drum in order to enable sound attenuation due to contact of the air with the sound attenuating material.

Another aspect of the invention provides a rotatable drum for channelling air in an conditioning unit.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side elevation view of a first embodiment of an air conditioning unit according to the invention; Figure 2 is a plan view of part of the unit shown in Figure 1; Figure 3 is a side elevation view of a second embodiment of a unit according to the invention; Figure 4 is a perspective view of a rotatable drum according to the invention; and Figure 5 is a schematic perspective view of a component of the drum shown in Figure 4.

Referring to Figures 1 and 2, there is shown an air conditioning unit 10 comprising a body 12 having an air inlet 14 which can comprise a filter F. Unit 10 further comprises a cooler 16, a bypass channel 18 defined by plates 17 and 19, and a heater 20. Downstream of these heat exchangers is a plate 22 comprising apertures 24, 26, and 28 which respectively provide air outlets from the cooler, bypass and heater to drum 30 comprising a through passageway 34.

Drum 30 comprises an outer wall 32 which is positioned proximal to plates 22 and for example nylon brushes or other air channelling devices can be provided adjacent the apertures 24,26 and 28 in order to provide efficient transfer of air from these outlets to the drum passageway 34. The drum passage 34 allows air to flow radially through the drum. Brushes can be provided adjacent the inlet of passageway 34 on outer wall 32 as well as or instead of on plate 22. Drum 30 further comprises end plates 36 having spindles 38 enabling rotation of the drum about a longitudinal axis.

Units 10 further comprises a fan 40 for drawing air through the unit to an outlet 42 which passes the air to a plenum 44.

Referring to Figure 2, it can be seen that the unit further comprises a controller 46 for example comprising a programmable logic control or microprocessor, which is connected to a temperature sensor 48. Controller 46 is also connected to a motor 50 which enables rotation of drum 30 by a drive shaft 52. The drum can be mounted on bearings 54.

The motor can be limited for example to a 90" rotation provided that it enables a full heating and full cooling mode.

Accordingly, in use a user sets on the controller a desired temperature for a room. The air temperature of the room is detected by sensor 48 and fed to controller 46 which compares the selected temperature with the actual temperature. Controller 46 then causes motor 50 to drive rotatable drum 30 to a desired orientation wherein passageway 34 is partially or wholly aligned with one or other of outlets 24,26 or 28 in plate 22. Fan 40 causes air from the room to be drawn into the unit and the selected position of drum 30 enables air flow along a selected route. For example, if passageway 34 is wholly with outlet 28 then fan 40 will cause air to be drawn through heater 20, through outlet 28 and then passageway 34 to fan 40. Such a configuration will cause heating of the incoming air.

In another configuration, passageway 34 can be wholly aligned with outlet 26 thereby to cause incoming air to bypass both the heater 20 and cooler 16 thereby substantially to maintain the current air temperature. In a further configuration, passageway 34 can be aligned with outlet 24 thereby to cause all air to pass through cooler 16. By overlapping parts of apertures 24 and 26 simultaneously, the extent of cooling of the air, due to the relative amount of flow of the air through cooler 16 and bypass 18, can be controlled. Similarly, by allowing passageway 34 to partially overlap both apertures 26 and 28, selected amount of heating of the air can be achieved due to the relative amount of flow of the air through heater 20 and bypass 18.

In a preferred form cooler 16 and heater 20 are maintained at approximately constant temperatures due to the regulated flow of constant temperature controlled fluid such as water through inlet and outlet pipes 21 to the respective heat exchangers.

Preferably the apertures such as 24,26 and 28 in plate 22 have seals or brushes B adjacent their defining rims which press against the drum 30 thereby to prevent cross contamination between the different airflow channels. The brushes or seals can for example comprise nylon brushes which are spring loaded to engage the drum resiliently.

In a further embodiment of the invention, a unit 110 comprises two rotatable drums. One drum 30 downstream of the heat exchangers as unit in 10, and a second rotatable drum 130 upstream of the heat exchangers. The drums can be substantially identical except that they are orientated to cooperated in the selection of relative air flows down the appropriate channels.

Accordingly, as shown in Figure 3, when drum 30 is aligned with outlet 28 from heater 20, drum 120 is also aligned with an appropriate aperture 128 in plate 122. Accordingly, drums 30 and 130, plates 22 and 122 are substantially a mirror image of one another. In order to ensure that the two drums cooperate in channelling the air, only one drum needs to be driven by a motor.

That drum can be connected to the other drum in order to transfer the drive. For example, a link 58 such as an arm can pass between spindles or pins on end plates of each of the drums as shown in Figure 3.

In a further embodiment of the invention only drum 130 is used at an upstream location with respect to the fan and heat exchangers. Accordingly, drum 30 is dispensed with.

Referring to Figures 4 and 5, there is shown a drum 30 according to the invention which comprises first and second components 62 and 64, attached to end plates 36 thereby to provide passageway 34 through the drum. Each of components 62 and 64 comprise an outer wall 34 which provides a cylindrical wall of the drum. This wall can for example be formed from a sheet of metal folded to provide side flanges 66 to which a grill or mesh 68 can be attached for example using rivets 70. Additionally, end flanges 74 can be provided to which the end plate 36 can be attached.

Preferably the cavity between wall 34 and grill 68 is filled with a sound attenuating material such as mineral wool.

Preferably the size of upstream air inlet to or downstream outlets from the different channels through the heat exchangers or temperature neutral path, are substantially equal. More preferably, they are as wide as possible within the given dimensions of the overall conduit or apparatus.

It will be appreciated that the invention provides the benefits of selective channelling of air across appropriate heat exchangers.

A preferred embodiment of the drum also provide large acoustic attenuation benefits, for example especially when positioned upstream of the main air conditioning components thereby to minimise sound passing back to a room. Additionally, the drum can provide good thermal stability characteristics due to the fact that it prevents air flow to the other of the two heat exchangers when air flow to only one of the exchangers, the heater or the cooler, is required. Accordingly, the rotatable drum reduces the amount of turbulent flow through the air conditioning unit thus reducing the extent of undesired air flow to unnecessary regions of the unit.

Claims

Claims 1. An air conditioning unit for adjusting the temperature of air passing through the units, comprising first and second air channels between an inlet and an outlet, a fan for causing air flow through the channels, a heat exchanger in the first air channel, and a rotatable drum having an air flow passage therethrough such that rotation of the drum enables selection of the relative amount of air flow through the first and second air channels.
2. A unit according to Claim 1 comprising a second heat exchanger in the second channel.
3. A unit according to Claims 1 or 2 comprising a third channel which bypasses the or both heat exchangers.
4. A unit according to Claims 1, 2 or 3 wherein the heat exchanger or exchangers are a cooler and/or a heater.
5. A unit according to any preceding claim wherein the rotatable drum is upstream of the fan thereby to provide acoustical attenuation between the fan and the inlet.
6. A unit according to any preceding claim wherein the drum is adapted to act as an acoustic attenuator and preferably comprises a large volume of sound attenuating materials such as mineral wool.
7. A unit according to any preceding claim wherein the drum is adapted to insulate the air passing through the system from the unused heat exchanger for example on the downstream side of the heat exchanger(s).
8. A unit according to any preceding claim comprising two rotatable drums, one on the downstream and one on the upstream ends of the heat exchanger.
9. A unit according to any preceding claim wherein an apertured plate is positioned adjacent a cylindrical outer surface of the drum thereby to enable selection of the relative amounts of air flow through the apertures in the plate and the drum passageway.
10. A unit according to Claim 9 wherein brushes or other air flow constraining means are provided between the drum and the plate to ensure efficient transfer of air therebetween.
11. A unit according to any preceding claim wherein the rotatable drum comprises a cavity substantially filled with sound attenuating material such as mineral wool.
12. A unit according to Claim 11 wherein the cavity can comprise two sections each in one of two components which substantially form the drum.
13. A unit according to any preceding claim wherein an apertured wall or grating is provided along the passageway through the drum in order to enable sound attenuation due to contact of the air with the sound attenuating material.
14. A rotatable drum for channelling air in an conditioning unit.
15. An air conditioning unit substantially as described herein and/or as referred to in Figures 1 and 2 or 3.
16. A drum for an air conditioning unit substantially as described herein and/or as referred to in Figures 4 and 5.