GB2459337A

GB2459337A - Reducing noise in an air conditioning unit

Info

Publication number: GB2459337A
Application number: GB0807552A
Authority: GB
Inventors: Philip Gillatt
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-04-25
Filing date: 2008-04-25
Publication date: 2009-10-28
Also published as: GB0807552D0

Abstract

An air conditioning unit 100 comprises a means of reducing the noise 300 of the unit 100 by preventing the dripping of condensate from a cooled heat exchanger 210, 220, and collecting or removing the formed condensate that accumulates in the unit 100. The unit 100 may cool air via natural induction and/or convection and does not require fan. The heat exchanger may comprise of a chilled beam having pipework 210 through which chilled water flows and connected to one or more spaced fins 220. An air deflection plate 230 may direct air between the fins 220. Noise reducing means 300 may comprise of a first inclined guide 310 communicating condensate via gravity to a first drain point 330. The chilled beam may be in contact with the first guide 310. The first drain point 330 comprises a gap between the first guide 310 and a first wall 322 that permits condensate to flow down by surface tension. First guide 310 may comprise of an extended portion 312 extending to a collector 320. A second guide 350 with an extended portion 352, second drain point 340 and second wall 324 may be provided and permits condensate to flow down when the volume of condensate is too great for the first drain point 330. The unit 100 is of particular use in sound recording or audio booths for conducting hearing tests.

Description

AIR CONDITIONING UNIT

Field of the invention

The present invention relates to an improved air conditioning unit, and in particular to an air conditioning unit with improved noise reduction.

Description of the background art

There is a need for substantially silent air conditioning units, especially in the context of sound recording booths or audio booths used for conducting hearing tests. For the results of hearing tests to be

valid there must be minimal background noise, and

preferably no background noise at all. For this reason the walls of such audio booths are generally very thick and substantially soundproofed, meaning that they can get very hot, especially when a patient undergoing a hearing test remains in such an audio booth for a long period of time, typically in excess of one hour. Such hot conditions may lead to extreme discomfort for the patient, and may furthermore cause excessive sweating which in itself leads to drips causing undesirable background noise which may interfere with the results of the hearing test.

Therefore some form of cooling within the audio booth is essential.

At present, large and complex fan-assisted air conditioning systems are employed where the fan is exterior to the booth along with large silencing baffles within extensive ducting between the fan and the audio booth. A problem with such air conditioning system is that the space required by the ducting and corresponding air handling system to feed "silent air" into the booth is very large due to the long path needed to overcome the significant sonic vibrations caused by the fan.

Furthermore it is necessary to keep the fan as far away from the audio booth as possible. This all leads to an inefficient use of space and also energy inefficient air conditioning since chilled air passing through such a long path is likely to heat up before it reaches the booth.

Chilled beam air conditioning units are used in a number of buildings, particularly passive chilled beam units which use a laminar air flow to induce cooling by convection in a non-fan assisted way. A "chilled beam" is similar to a radiator, but with coolant (water) passing through rather than hot fluids. Such units enjoy a significantly reduced space requirement since the need for extensive ducting and large silencing baffles is reduced.

However, a problem with such chilled beam air conditioning units is that the minimum temperature for water circulated within the chilled beams is 16°C, as anything below 14°C results in significant condensation upon the cooling components of the chilled beam units. The nature of audio booths clearly means that water flow temperatures of below 14°C would be required to maintain a comfortable temperature therein, especially as chilled beams are significantly less powerful than standard fan-assisted air conditioning systems. However, the condensation thereby produced would cause a significant drop in the cooling efficiency within the audio booths, and furthermore may lead to dripping of the condensate which is particularly undesirable in view of the noise such drips create.

Therefore, these chilled beams are not at present suitable for use in audio booths.

In this specification, "dripping" refers to where a liquid, particularly a droplet, is forced to break contact with a first surface (whether a solid or liquid surface) so as to be temporarily airborne before making contact with a second surface (whether solid or liquid) . The sound created on impact with the second surface is the noise caused by "dripping".

It is an object of the present invention to overcome

at least one of the problems of the prior art.

Disclosure of the invention

In accordance with a first aspect of the present invention there is provided an air conditioning unit for cooling a room or booth, comprising: an air cooler; and a noise reducer; wherein the noise reducer substantially prevents dripping of a condensate from the noise reducer, which condensate in use accumulates within the unit, through providing a path for the condensate to drain such that the condensate substantially remains in contact with the noise reducer as said condensate is either removed from the unit or collected within the unit.

Preferably the noise reducer substantially prevents dripping of a condensate within the noise reducer.

Providing such a path for the condensate to drain quietly (preferably below 20 Db, most preferably below 15 Db) and steadily is a significant advantage in terms of noise reduction. Clearly the condensate may be drained to a point outside the unit or even outside the building, via such as a drainpipe or exterior mechanical pump. However, the condensate can be collected within the unit itself so that the bulk condensate can be disposed of at a convenient time.

In use, the air cooler preferably cools air via non-fan assisted natural induction and/or convection. This is advantageous because an air cooler without a fan can be placed in the room to be cooled itself, since the amount of noise generated by the air cooler in use is negligible.

This reduces the space requirement outside the room or booth to be cooled, since extensive ducting and silencing is no longer required.

The air cooler preferably comprises a chilled beam.

In use, such chilled beams typically allow pre-chilled water to flow therethrough, which in turn provides cooling to the immediate atmosphere.

The chilled beam preferably comprises pipework, and preferably pipework which connects to one or more fins, wherein the one or more fins are thermally conductive.

The fins themselves are preferably not hollow and do not receive water from the pipework. The advantage of such fins is that they increase the surface area of cooled components exposed to the air, which in turn improves the rate of cooling (cooling power) within the room or booth.

Preferably the pipework connects to each of the one or more fins in more than one place, and preferably more than two places, thus improving the delivery of a cooling effect from the pipework to the fins.

The fins are preferably substantially parallel, and may be of a thickness between 0.1 and 0.2mm, preferably 0.15mm. This provides for efficient laminar air flow between the fins, whilst this narrow gauge of fin allows the cooling effect to be dissipated very efficiently throughout each fin.

The fins are preferably spaced apart by a minimum of 10mm, preferably 11mm and most preferably 12mm.

Preferably the fins are spaced apart at a maximum of 14mm, preferably 13mm, and most preferably 12mm. The most preferred spacing is 12mm. These spacings are particularly advantageous in terms of balancing the rate of air flow through the fins whilst maximising overall fin surface area within the air cooler. Typically in the

prior art the spacing used is 1.5 to 6mm.

Each fin is preferably substantially rectangular, and each fin, preferably all fins, are long side vertical and short side horizontal relative to a floor. Most preferably each fin, preferably all fins, are inclined relative to the floor, preferably at an angle of 1° to 450, more preferably 3° to 15°, most preferably 6°.

The air cooler may further comprise an air deflection plate which directs an inflow of unchilled air between the one or more fins in the direction of an air outlet.

Preferably the inflow of unchilled air enters via an air inlet at the top of the air conditioning unit, whilst chilled air, chilled by the air cooler, exits via an air outlet, typically rotated approximately 90° to the air inlet. The advantage of such air deflection plates is that air may be guided to where the air cooling effect is at a maximum within the air cooler. The profile of the air deflection plate preferably complements the positioning of the air inlet and outlet and helps efficiently direct air between the two. The air deflection plate is preferably curved. This improves air guidance. Preferably the air deflection plate extends across the width of the one or more fins, and preferably the air deflection plate has slots into which the one or more fins fit.

The noise reducer may comprise a first condensate guide which receives condensate directly from the air cooler to guide the condensate to a first drain point.

The first condensate guide is preferably an imperforate planar sheet. The condensate guide is preferably inclined downwards towards the first drain point at an angle from the horizontal, preferably by 1 to 85°, preferably by 1 to 45°, more preferably by 3 to 15°, and most preferably about 6° relative to the floor, and preferably at the same angle of inclination of the fins. Preferably the floor is horizontal. The advantage of such a condensate guide is that it can collect condensate directly from the air cooler, and rather than allowing the condensate to drip through the air into a collector or elsewhere, said condensate is allowed to drain steadily and silently down the condensate guide to the first drain point where the condensate is further processed. If such a drain point is outside the room or booth in question, such as outside a building, the condensate may then be allowed to drip without causing noise in the room or booth itself. It will be understood by those skilled in the art that the first condensate guide may lead either directly or indirectly to the first drain point, and may comprise one or more turns and/or angles of inclination.

The fins preferably rest on the first condensate guide. This again ensures that there is no noise-producing dripping of condensate between the fins and the first condensate guide. Preferably the first condensate guide is a plate which extends across the width of all the one or more fins. The first condensate guide preferably sits below the one or more fins so that the condensate is always allowed to drain under gravity. Preferably the air cooler and the noise reducer are arranged such that there can be no dripping of condensate between them.

Noise is generally not caused by condensation dripping from pipework onto the noise reducer, since the large surface area of the fins relative to any pipework means that condensation generally accumulates on the fins. The fins are preferably arranged so that no dripping occurs between the air cooler and the noise reducer. Albeit unlikely that condensate will form on the underside of the pipework, to eliminate this possibility the body of the air cooler may be slightly raised at one end so that the natural gravitational path of the condensate will run along the pipework or pipes towards a fin. Such condensate may then run down the fin as normal, in accordance with the present invention. The air cooler is preferably slightly raised to give an angle of inclination of between 1° and 2°.

The air conditioning unit preferably further comprises a collector for collecting condensate. Again, the collector preferably lies below the first condensate guide such that condensate may enter the collector via the first drain point. Preferably the condensate is guided from the drain point into the collector substantially without any dripping. An advantage of having the collector within the air conditioning unit and thus within the room or booth itself, is that this reduces the potential complexity and space requirement of having to plumb in drainage to a point exterior to the air conditioning unit. This naturally facilitates installation and effective maintenance. Alternatively, the unit has a facility for an exterior pump to be connected to allow removal of condensate from the collector. The collector may be removable to allow for maintenance or condensate to be emptied periodically as is convenient.

The first drain point preferably has a narrow gap, at one side of which is the first condensate guide, and the other side a first wall. Preferably the wall is part of the collector. Droplets of condensate which pass through the narrow gap may then drain into the collector either via the first wall or via the underside of an extended portion of the first condensate guide which extends downwards and back on itself underneath the original portion of the first condensate guide and into the collector. The size of the gap and the angles of inclination of both the first wall and the extended portion of the first condensate guide are important to ensure that no droplets drip into the collector from the noise reducer. A narrow gap ensures that only droplets of a certain size pass therethrough, and thereafter surface tension ensures that the droplets preferentially flow along the wall or extended portion of the first condensate guide rather than dripping directly off into the collector. Preferably the gap is at least 2, preferably 2.5mm and most preferably at least 3mm. The gap is preferably a maximum of 4mm, preferably 3.5mm, most preferably 3mm.

The first wall and/or the extended portion of the first condensate guide provide surfaces upon which water can flow without dripping. Water flowing down such surfaces preferably does not form beads which may drip.

Preferably the first wall and/or the extended portion of the first condensate guide have a substantially hydrophilic surface, or a wetable surface, at least in respect of the surface along which condensate flows.

Preferably substantially all surfaces within the noise reducer are substantially hydrophilic.

The preferred angle of inclination of the wall relative to the vertical axis is 0 to 85°, more preferably to 45° and most preferably about 3Q0 The internal angle between the first condensate guide and the extended portion of the first condensate guide is preferably 5 to 90°, more preferably 30 to 80°, and most preferably about 60°. Preferably the extended portion of the first condensate guide and the first wall extend to rest on the bottom of the collector. This arrangement ensures that all condensate is drained steadily and quietly into the collector ready to be pumped away or emptied at a convenient time.

It will be understood by those skilled in the art that the roles of the extended portion of the first condensate guide and the first wall may be inverted so that condensate will flow on the underside of the first wall and on the upper side of the extended portion. In this situation the angles would be reversed such that the extended portion did not extend back underneath the first condensate guide, but instead extended downwards underneath the first wall.

Preferably there is a second condensate guide which extends on a downward incline from the top of the first wall to terminate at a second drain point. This ensures that any condensate not passing through the first drain point gap does not accumulate and eventually drip noisily elsewhere. Instead this second drain point also leads into a collector, preferably the same collector to which the first drain point leads. The second condensate guide is preferably an imperforate planar sheet.

The second drain point is similar to the first drain point in that it is characterised by a gap on either side of which are second inclined surfaces which allow droplets of condensate to drain steadily and quietly into the collector. Preferably the gap at the second drain point is between 0.5 and 3mm, most preferably 1 to 2mm. The second inclined surfaces may be a second wall, which may be part of the collector, and a extended portion of the second condensate guide. Preferred features of both the second wall and extended portion of the second condensate guide are the same as for the corresponding first wall and extended portion of the first condensate guide respectively.

Preferably the first condensate guide and first wall are both imperforate planar sheets. Preferably the extended portion of the first condensate guide is an imperforate planar sheet. Preferably all surfaces of the noise reducer upon which condensate can drain are imperforate planar sheets.

The pipework is preferably connectable to pipes or pipework external to the air conditioning unit, and may be removably connectable thereto to enable portability of the air conditioning units of the present invention.

Preferably the pipework is connectable to pipework of one or more adjacent air conditioning units, where the adjacent air conditioning units are preferably in accordance with those of the present invention.

Preferably one or more adaptors is/are provided to allow for the aforementioned connectability.

In accordance with a second aspect of the present invention there is provided a plurality of air conditioning units, according the first aspect, connected together. Preferably each of the plurality of air conditioning units is removably connected to an adjacent air conditioning unit. This allows for a larger cooling surface area which in turn improves overall cooling efficiency. Furthermore, this arrangement allows air conditioning units to be added or subtracted from the plurality of units in accordance with the needs of the room or booth to be cooled. There may be an expanse of pipework between each of the plurality of air conditioning units, allowing a number of rooms to be air conditioned using a single coolant source. Preferably, however, the air conditioning units are close together, preferably no more than im apart.

In accordance with a third aspect of the present invention there is provided a booth comprising an air conditioning unit in accordance with the first aspect or a plurality of air conditioning units in accordance with the second aspect. An advantage of such a booth is that it may be larger than standard air conditioned booths of the prior art, since extensive ducting is no longer required.

Furthermore, such a booth may serve as an audio booth in which hearing tests may be carried out, since air conditioning units of the present invention have the advantage of significant noise reduction, particularly in respect of noise generated from a fan and/or from the dripping of condensate.

In accordance with a fourth aspect of the present invention there is provided a method of reducing noise in an air conditioning unit, comprising: installing within the air conditioning unit a noise reducer that substantially prevents the dripping of a condensate, which in use accumulates within the system, through providing a path for the condensate to drain such that the condensate substantially remains in contact with the noise reducer as said condensate is either removed from the unit or is collected in the unit itself.

Preferred features of any aspect of the present invention are also preferred features of any other aspect of the present invention.

Brief description of the drawings

For a better understanding of the present invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which: Figure 1 is a schematic side view of the prior art; Figure 2 is a top side projection of an embodiment of the present invention; Figure 3 is a cross section of the internal components of the embodiment of Figure 2; Figure 4 shows a top view an air deflector plate in accordance with the present invention; Figure 5 shows a side view of the air deflector plate of Figure 4; Figure 6 shows a side cross section of the internal components of Figure 2; Figure 7 shows a side view of a noise reducer in accordance with the present invention.

Detailed description of the exemplary embodiments of the invention The exemplary embodiments of the present invention will be discussed in detail in relation to an air conditioning unit which solves the problem of inefficient use of space inherent in units of the prior art, whilst also solving the problem of excessive noise. The present invention is particularly applicable for use in audio booths such as those used for conducting hearing tests.

However, the teachings, principles and techniques of the present invention are also equally applicable in other exemplary embodiments, such as air conditioning units for use in office environments, recording studios, and consulting rooms.

Figure 1 is a schematic side view of the prior art, and shows an air conditioning unit as applied to an audio booth A. In such cases a fan B is positioned outside the audio booth along with an air cooler C, and significant ducting D is required to feed cool air into the audio booth B via a large silencer E. Such assemblies as are commonplace in the prior art, and represent an inefficient use of space.

Figure 2 is a top side projection of an embodiment of the present invention, and shows an air conditioning unit with an air inlet 110 and an air outlet 120. To protect the internal components, a grill or mesh is typically fitted to the air inlet 110. In this example therefore air is drawn in from the top of the unit 100 and released from the side.

Figure 3 shows a cross section of the internal components of the embodiment of Figure 2. This shows an air cooler 200, which essentially serves as a heat exchanger for the air flowing therethrough; and a noise reducer 300 which allows a condensate which in use accumulates within the unit to be drained quietly without any dripping.

This embodiment relates to a chilled beam air conditioning unit and cools air using non-fan assisted natural induction and/or convection to cool air in such as an audio booth. The air cooler 200 therefore comprises a chilled beam 205 through which a coolant can flow. In this case the coolant is cold water which in the present embodiment may be cooled to temperatures as low as 1°C, albeit 7°C is the preferred minimum. In this embodiment the chilled beam 205 is connected to a source of chilled water outside the audio booth, and also connected to an outlet which takes heat exchanged water out of the audio booth either to waste or to be recycled through such as a recirculating chilling unit.

In this embodiment the chilled beam 205 comprises pipework 210 consisting of two pipes 212 each of which snakes through the air cooler 200. As can be seen in Figure 3, the pipework 210 connects to several fins 220 which by virtue of their thermal conductivity transmit the cooling effect from the pipework 210 to a much larger surface area via the fins 220. In this example the pipework 210 makes contact with each of the fins 220 in several places, as shown in Figure 6, to increase the rate of cooling in the fins 220.

Each fin 220 is 0.15mm thick and is separated from every adjacent fin by a constant spacing of 12mm.

Naturally the fins are substantially parallel by virtue of this arrangement, which allows for optimum air flow whilst achieving maximum surface area in terms of the air cooler 200.

The air cooler 200 is fixed securely within the air conditioning unit 100, and may be operated by inducing coolant (chilled water) to flow through the pipework 210 which in turn dissipates the cooling effect to the fins 220. In this example the coolant is recirculated water which requires the activation of a pump and a water cooler (both external to the air conditioning unit) to operate the air cooler 200. Alternatively the chilled water supply may be mains water that is chilled prior to its entry into the air conditioning unit 100, and when such water exits the air conditioning unit 100, it is drained to waste or recycled. In the context of the present invention the supply of chilled water is a trivial matter and well known in the art.

In this example the efficiency of the air cooler 200 is further improved by the presence of an air deflection plate 230 around the fins 220 of the chilled beam 205 so that air passing through the air inlet 110 is directed through the fins 220 towards the air outlet 120 in an efficient, aerodynamic manner which substantially maintains a laminar air flow. Such an air flow then maximises the contact between the air and the cool surface of the fins 220.

Figures 4 and 5 provide a more detailed view of the air deflector plate 230, showing the slots 232 for the fins 220 and the curved portion 234, which in this example is positioned toward the rear of the air conditioning unit directing air to the air outlet 120.

Such an air conditioning unit 100 is envisaged for use within audio booths where background noise levels must be below 20 decibels and preferably below 15 decibels. As the air conditioning unit 100 of this example is non-fan assisted, there is no special requirement for noise reduction in respect of the fan. However, when the temperature of the coolant passing through the chilled beam falls below 14°C, condensation will invariably accumulate within the air cooler 200, specifically on the chilled beam 205. Given the large amount of heat generated and trapped within such audio booths during hearing tests, the air cooler 200 is likely to require coolant chilled below this temperature of 14°C. Therefore to satisfy the objective of noise reduction there is a need to prevent any dripping of this condensate, as this will produce noise at a level which cannot be tolerated.

Therefore in this example there is a noise reducer 300 to prevent such dripping.

The noise reducer 300 has a first condensate guide 310 to drain and direct condensate to a collector 320 wherein condensate is collected.

Figure 3 shows the position of the noise reducer 300 below the air cooler 200 within the air conditioning unit 100. Figure 6 shows a side view of the internal components of the air conditioning unit 100 where the first condensate guide 310 is shown directly below the fins 220 inclined from horizontal along with the bottom edge of the fins 220 at an angle of 6°. This slight inclination allows condensate that falls onto the condensate guide 310 to be guided under gravity to a first drain point 330. To prevent the condensate from noisily dripping through the drain point 330 into the collector 320, the drain point 330 has a 3mm gap leading to additional surfaces of the noise reducer 300 which quietly guide the condensate to prevent dripping. At one side of the gap is the first condensate guide 310 and at the other side is a first wall 322 of the collector 320. The size of the gap at the drain point 330 and the angle of inclination of the wall 322 is important since the gap allows condensate to drain through as small droplets as defined by the size of the gap, and due to the size of said droplets the condensate flows down the wall 322 steadily by virtue of surface tension. Protruding backwards from the first condensate guide 310 is an extended portion of the condensate guide 312 which extends away from the wall 322 and downwards into the collector 320. Figure 7 shows this arrangement in more detail where the angle between the condensate guide 310 and the extended portion of the condensate guide 312 is 60°. This extended portion 312 is important since it carries on its underside any droplets passing through the gap which do not pass down the wall 322. Again it is by virtue of surface tension that the droplets do not drip from the extended portion 312 into the collector 320, and to this end the gap and the angle of inclination here are also important.

The volume of condensation, which depends on the temperature of the coolant and humidity of the air in the room or booth in question, may in some circumstances be too large for the noise reducer 300 to cope with. This is due to the flow rate of condensate into the collector 320 being limited by the size of the gap at the drain point 330. Therefore, as shown in Figures 6 and 7, in this example a second drain point 340 has been introduced with a gap of 1 to 2mm, and the second drain point 340 is linked to the first drain point 330 by a second condensate guide 350 extending from the top of the first wall 322 to the second drain point 340. Again this second drain point 340 is characterised by a gap which at one side has a second wall 324, and on the other the second condensate guide 350 with a corresponding extended portion 352 similar to the extended portion of the first condensate guide 312. Both the second wall 324 and the extended portion 352 guide droplets emerging from the second drain point gap 340 into the collector 320 without dripping.

This second drain point 340 essentially deals with the overflow of condensate from the first drain point 330.

Figure 6 shows that within the collector 320 is a condensate removal pipe 360 which connects to an external pump (not shown) to allow condensate to be periodically emptied from the collector 320 as convenient. It will, however, be understood by those skilled in the art that air conditioning units 100 according to the present invention may be produced without such a collector 320, where the condensate guide 310 guides condensate to a drain point 330 external to the air conditioning unit 100 where such condensate may be either collected or expelled, for example outside a building where dripping could not be heard in the audio booth. The essence of the invention is still hereby achieved since the noise reducer 300 performs to prevent the dripping of condensate within the air conditioning unit 100 itself. This is achieved by maintaining the condensate in contact with the noise reducer at all times so that condensate at no point travels through free air space (i.e. dripping) It will also be understood by those skilled in the art that the direction of air flow may be manipulated in a direction other than that shown in Figures 2 and 3. Also the spacing and size of the fins 220 may be varied without departing from the essence of the present invention.

In the present example, the air conditioning unit 100 is fitted within an audio booth used for conducting hearing tests. During a hearing test, when the room would otherwise heat up intolerably, the air conditioning unit is switched on using controls on a panel (not shown) within the booth. These controls activate the supply of an external source of chilled water by initiating the activity of a pump and a water cooler (not shown) . Air then flows naturally through the air conditioning unit 100 as chilled water is passed therethrough, thus cooling the air in the audio booth. The temperature is controlled using a thermostat (not shown) which regulates the instant temperature of chilled water supplied to the air conditioning unit 100 in relation to the overall temperature in the booth. The air temperature in the audio booth is then maintained at a desired temperature with substantially no noise emanating from the air conditioning unit 100. Any condensate arising is drained into the collector 320 during the course of a hearing test. At the end of the hearing test, condensate may be emptied from the collector 320 to waste via the condensate removal pipe 360 using an external pump (not shown) The air conditioning unit 100 of this example requires no special ducting or air handling system, and occupies minimal space. It allows air to be efficiently cooled within severely insulated and soundproofed audio booths with substantially no noise, particularly in relation to the dripping of condensate.

The pipework 210 of this example has adaptors at the ends of the pipes for facile connectivity with the external source of cooled water. This provides the air conditioning units 100 of the present invention with a degree of portability. Such adaptors also allow a plurality of air conditioning units 100 to be connected and run in series, using the same source of cooled water.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification

(including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s) . The invention extends to any novel one, or any novel combination, of the features

disclosed in this specification (including any

accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

Claims 1. An air conditioning unit for cooling a room or booth, comprising: an air cooler; and a noise reducer; wherein the noise reducer substantially prevents dripping of a condensate from the noise reducer, which condensate in use accumulates within the unit, through providing a path for the condensate to drain such that the condensate substantially remains in contact with the noise reducer as said condensate is either removed from the unit or collected within the unit.
2. The air conditioning unit as claimed in claim 1 which cools air via non-fan assisted natural induction and/or convection.
3. An air conditioning unit as claimed in any preceding claim wherein the air cooler comprises a chilled beam.
4. The air conditioning unit as claimed in claim 3 wherein the chilled beam comprises pipework.
5. The air conditioning unit as claimed in claim 4, wherein the pipework connects to one or more thermally conductive fins.
6. The air conditioning unit of claim 5, wherein the spacing between adjacent fins is between 10 and 14 mm, preferably 12mm.
7. The air conditioning unit as claimed in any of claims 5 to 6, wherein the fins have a thickness between 0.1 and 0.2mm, preferably 0.15mm.
8. The air conditioning unit as claimed in any of claims 5 to 7, wherein the air cooler further comprises an air deflection plate which directs air between an air inlet and air outlet via the one or more fins.
9. The air conditioning unit as claimed in any preceding claim wherein the noise reducer comprises a first condensate guide which receives condensate from the air cooler to guide the condensate to a first drain point.
10. The air conditioning unit as claimed in claim 9 wherein the first condensate guide is inclined downwards from the horizontal towards the first drain point to allow condensate to drain thereupon substantially under gravity.
11. The air conditioning unit as claimed in any of claims 9 to 10 wherein at least part of the air cooler is in contact with the first condensate guide.
12. The air conditioning unit as claimed in any preceding claim further comprising a collector for collecting condensate.
13. The air conditioning unit as claimed in claim 12, wherein the condensate is removable from the collector.
14. The air conditioning unit as claimed in any of claims 12 to 13 when dependent on any of claims 9 to 11, wherein the collector is located beneath the first condensate guide.
15. The air conditioning unit as claimed in any of claims 9 to 14, wherein the drain point has a gap, at one side of which is the first condensate guide, and the other side a first wall down which water can flow without dripping.
16. The air conditioning unit as claimed in claim 15 wherein the gap is 2 to 4 mm.
17. The air conditioning unit as claimed in any of claims 9 to 16, wherein the noise reducer comprises an extended portion of the first condensate guide, wherein the extended portion extends on a downward incline.
18. The air conditioning unit as claimed in claim 17 when dependent on claims 12 to 14, wherein the extended portion extends substantially to the bottom of the collector.
19. The air conditioning unit as claimed in any of claims 9 to 18 wherein the noise reducer comprises a second drain point.
20. A plurality of air conditioning units, as claimed in claims 1 to 19, connected together.
21. A booth comprising an air conditioning unit as claimed in any of claims 1 to 19.
22. A method of reducing noise in an air conditioning unit, comprising: installing within the air conditioning unit a noise reducer that substantially prevents the dripping of a condensate, which in use accumulates within the system, through providing a path for the condensate to drain such that the condensate substantially remains in contact with the noise reducer as said condensate is either removed from the unit or is collected in the unit itself.
23. An air conditioning unit, a plurality of air conditioning units, a booth, or a method as substantially hereinbefore described with reference to Figures 2 to 7.