WO2015135025A2 - Air conditioner - Google Patents

Abstract

Disclosed herein is an air conditioner in the form of an active chilled beam. The chilled beam comprises a housing that defines an interior chamber, in the form of induction chamber. The housing includes a heat exchanger for conditioning return air. The chilled beam also includes a restrictor, in the form of a header and nozzles, and a high induction diffuser mounted to the housing.

Description

AIR CONDITIONER

TECHNICAL FIELD

This disclosure relates to air conditioners that can be used to condition a space. The space can include a room within a residential building, commercial high-rise building, hospital, school, aged care facility, hotel, etc.

BACKGROUND ART

Active chilled beams, or induction diffuser units, rely on the introduction of two air streams into the unit and the discharge of a combined air stream from the unit to condition a room within the building. The first stream of air can be pre-conditioned outdoor air, which enters the unit through nozzles as jet streams. The introduction of the first air stream through nozzles decreases the static pressure in the unit, thereby inducing a return air stream from a room within the building through a heat exchanger and into the unit to mix with the first air stream. The return air stream can be received via a grille that connects the unit to the room.

Active chilled beams can reduce the quantity of ducts required to air condition buildings, thereby saving costs, as well as both floor space and ceiling space otherwise required to conceal ducts. Active chilled beams also save on energy consumption in comparison to many commonly installed air conditioning systems, including variable air volume systems. However, the chilled water that is used in the heat exchanger of the active chilled beam to cool the return air has to be run at higher temperatures (typically 15°C in and 18°C out) than conventional chilled water systems (usually 6°C in and 12°C out). If the return air is cooled using a conventional chilled water system, the air supplied by the active chilled beam becomes too dense for stable air distribution and "dumps' into the room (i.e. cold air falls down in a rapid and unstable manner, causing excessive localised cooling at elevated velocities often coupled with higher air temperatures and stagnation further afield, producing thermal discomfort in the space), as well as causing condensation ('sweating') on the heat exchanger. Therefore, if a conventional chilled water system is used in the building, a second chilled water system that runs at a higher temperature is required to service the active chilled beams in addition to that required to pre-condition the outdoor air used for other conventional air conditioning systems in the building. This entails either dedicating a high temperature chiller to the active chilled beam water circuit, which is the more energy efficient option, but extremely costly, or the less costly, but also less efficient option of raising the water temperature from a conventional chiller by means of a secondary water circuit with a dedicated secondary pump and the use of either a heat exchanger or blending of supply and return water into the secondary circuit to raise the water temperature. Either way, the chilled water circuit of elevated temperature adds significantly to the capital costs, and may also increase ongoing costs, of a building's heating ventilation and air conditioning (HVAC) system. If redundancy is required for both the conventional and dedicated active chilled beam chillers, at least four chillers must be installed. Again, this adds significantly to the capital costs associated with installing active chilled beam systems.

The above references to the background art do not constitute an admission that the art forms part of the common general knowledge of a person of ordinary skill in the art. The above references are also not intended to limit the application of the air conditioner as disclosed herein.

SUMMARY

Disclosed herein is an air conditioner for conditioning air in a space. The air conditioner may comprise a body defining an interior chamber, the body having a heat exchanger for conditioning a primary air stream received from the space. The air conditioner may also comprise a restrictor mounted to the body for restricting a flow of a secondary air stream into the chamber into a plurality of small jets discharged by nozzles in the restrictor and arranged such that the secondary air stream induces the primary air stream into the interior chamber and forms a combined air stream together with the primary air stream. The air conditioner may also comprise a high induction diffuser mounted to the body for discharging the combined air stream from the interior chamber so as to cause the air in the space to be induced by and to mix with the combined air stream upon discharge from the diffuser and thereby condition the air in the space with a high level of thermal comfort. In order to induce primary air through a heat exchanger and into an active chilled beam and then discharge it into the space, the air in the induction chamber of the active chilled beam needs to have a negative static pressure relative to the air in the space, and it needs to have a dynamic pressure directed towards the path to the diffuser that is greater than the magnitude of the negative static pressure in the induction chamber plus any pressure losses incurred by the airstream from the induction chamber to the discharge from the diffuser into the space. For a given negative static pressure in the induction chamber, the greater the pressure losses in the airstream path of the primary air from the space into the induction chamber and then to the diffuser discharge, the lower the airflow rate of the primary air and hence the lower the cooling/heating capacity of the heat exchanger. For any given airflow rate of the primary air, the cooling/heating capacity of the heat exchanger is reduced by a reduction in the temperature differential between the room air and the temperature of the primary air downstream of the heat exchanger. The sensible

cooling/heating capacity of the heat exchanger is therefore a balance between the airflow rate and the temperature differential of the primary air, both of which are strongly related to diffuser performance.

In some forms, the heat exchanger comprises piping adapted to be coupled to a chilled water circuit.

In some forms, the piping is arranged to receive chilled water from the chilled water circuit at a temperature of 5 to 10°C and return chilled water to the chilled water circuit at a temperature of 8 to 13°C. Advantageously, this allows for the air conditioner to use a conventional supply of chilled water. In some forms, the secondary air stream is a preconditioned air stream received from outside the space. Preconditioning the secondary air stream allows for the temperature and humidity of the outdoor air introduced to the space to be controlled.

In some forms, the diffuser is configured to have a low pressure drop across a diffuser element, the diffuser element being positioned between the interior chamber and a face of the diffuser. The low pressure drop across the diffuser element ensures that the magnitude of the negative static pressure in the interior is not substantially reduced such that the secondary air stream is able to efficiently induce the primary air stream.

In some forms, the diffuser element is arranged to discharge a high momentum air stream from the face of the diffuser and into the space.

In some forms, the high momentum air stream is a portion of the combined air stream. In some forms, the diffuser element comprises one or more channels able to discharge the high momentum air stream in a direction that is substantially inclined to an axis that is perpendicular to the diffuser face.

In some forms, the diffuser element in manipulable to change the orientation of the one or more channels. Advantageously, this allows for the direction and pattern of the combined air stream discharged from the diffuser to be controlled to further reduce the possibility of cold air dumping.

In some forms, changing the orientation of the one or more channels varies the airflow direction of the high momentum air stream.

In some forms, the diffuser face comprises perforations formed therein, the one or more channels being aligned with at least one of the perforations such that the high momentum air stream is able to be discharged through at least one of the perforations.

In some forms, the diffuser is arranged to discharge a low momentum air stream from the face of the diffuser and in close proximity to the high momentum air stream.

In some forms, the low momentum air stream is another portion of the combined air stream.

In some forms, the low momentum air stream is induced by the high momentum air stream in the space to reform the combined air stream downstream of the diffuser face.

In some forms, the low momentum air stream is discharged by at least one of the perforations in the diffuser face.

In some forms, the discharge direction and/or throw of the combined air stream is largely determined by the discharge direction or throw respectively of the high momentum air stream.

In some forms, the reformed combined air stream induces and thereby mixes with the air in the space such that the stream conditions the air in the space.

In some forms, the diffuser element is a swirl diffuser with a low pressure drop. In some forms, wherein the primary air stream is induced to flow across the heat exchanger and then into the interior chamber, the heat exchanger is arranged in a roof of the body.

In some forms, the heat exchanger is able to abut with a ceiling void and thereby receive the primary air stream directly from the ceiling void. This allows for a ceiling void to be utilised for the primary air stream. As such, a return air grille can be spaced away from the air conditioner.

In some forms, the secondary air stream enters the chamber in a direction that is substantially perpendicular to the direction that the primary air stream is induced through the heat exchanger and thereby received by the chamber. This arrangement allows for the secondary air supply to be ducted to the rear end of the air conditioner, separate to the primary air supply.

In some forms, the combined air stream is received by the diffuser in a direction that is substantially parallel to the direction the secondary air enters the chamber. This allows for the air conditioner to operate as a side-blow air conditioner.

In some forms, a floor of the body is located below the heat exchanger and is configured to drain condensation caused by conditioning the primary air stream. Using the floor of the air conditioner to operate as a tundish saves on material required to manufacture the air conditioner.

In some forms, the floor is sloped to direct condensation to a drain point positioned in the floor.

In some forms, the floor is sealed to prevent condensation draining from the interior chamber at a location other than the drain point.

In some forms, the drain point is connected to a drain pipe. This allows for water to be drained from the air conditioner and also allows for the collection and re-use of condensed water.

In some forms, the restrictor includes at least one nozzle that restricts the flow of the secondary air into the chamber. In some forms, restriction of the secondary air stream by the at least one nozzle decreases the static pressure in the chamber relative to the room such that the primary air stream is induced into the chamber.

In some forms, the heat exchanger comprises piping adapted to be coupled to a refrigerant circuit.

In some forms, the flow of refrigerant through the piping is variable.

In some forms, the air conditioner has the form of a chilled beam.

Also disclosed herein is an air conditioner for conditioning air in a space. The air conditioner may comprise a body defining an interior chamber, the body having a heat exchanger arranged in a roof of the body for conditioning a primary air stream received from the space. The air conditioner may also comprise a restrictor mounted to the body for restricting the flow of a secondary air stream into the chamber and arranged such that the secondary air stream induces the primary air stream into the interior chamber to form a combined air stream. The air conditioner may comprise a diffuser mounted to the body for discharging the combined air stream from the interior chamber and to the space, wherein a floor of the body is located in use below the heat exchanger and is configured to drain condensation caused by conditioning the primary air stream.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments will now be described by way of example only, with reference to the accompanying drawings in which

Figs. 1 shows a side sectional view of an embodiment of the active chilled beam;

Fig. 2 shows a schematic of a chilled water and heating hot water system;

Fig. 3 shows a side sectional view of an embodiment of the high induction diffuser; Figs. 4i-vi show another embodiment of the high induction diffuser;

Fig. 5 shows two discharge element embodiments; Fig. 6 shows details, adjustability and discharge angles of the embodiment shown in Fig. 4;

Fig. 7 shows discharge orientations for the embodiment shown in Fig. 5;

Figs. 8a-i - b-iv show sections and underside views and air distribution patterns of an embodiment of the active chilled beam (a-i to a-vi) and of an active chilled beam of the prior art (b-i to b-iv).

Figs. 9a-d show sections of an embodiment of the active chilled beam with an inlet damper (a-b) and sections of an embodiment of the active chilled beam with plugs (c- d).

Fig. 10 shows a view of a refrigerant system;

Fig. 11 shows a side sectional view of an upward discharge embodiment of the active chilled beam;

Fig. 12 shows a three dimensional image of an embodiment of the active chilled beam; and

Fig. 13 shows a section view of the embodiment of the active chilled beam shown in Fig 1 1.

DETAILED DESCRIPTION

In the following detailed description, reference is made to accompanying drawings which form a part of the detailed description. The illustrative embodiments described in the detailed description, depicted in the drawings and defined in the claims, are not intended to be limiting. Other embodiments may be utilised and other changes may be made without departing from the spirit or scope of the subject matter presented. It will be readily understood that the aspects of the present disclosure, as generally described herein and illustrated in the drawings can be arranged, substituted, combined, separated and designed in a wide variety of different configurations, all of which are contemplated in this disclosure.

Despite the elevated supply air temperature discharged by standard chilled beams in cooling mode, they nevertheless provide poor thermal comfort. This can be a consequence of the performance of the induction nozzle system inside the active chilled beam being extremely sensitive to pressure losses in the path of the return air induced from the room and its supply back into the room. In other words, the induction systems are extremely weak: any resistance to the return air or its reintroduction to the room reduces the airflow across the heat exchanger, and hence results in a reduction in the cooling capacity from the active chilled beam, and such reductions are pronounced. To minimise such capacity reductions, diffusers with very low pressure drop characteristics are used, typically in the form of a simple, non-adjustable sidewall mounted grille or broad ceiling mounted slots that each deliver the supply air largely as a single bundle of air into the space (i.e. with minimal mixing). Sidewall mounted grilles usually discharge the air with a slight incline (typically 15° to the horizontal) and ceiling slots discharge the air horizontally, so as to achieve attachment (called Coanda attachment) of the discharged air stream to an adjacent ceiling surface. Discharge direction adjustability is usually avoided, or severely limited if provided at all, as the adjustable vanes increase pressure drop, and the pressure drop increases the greater the degree by which the discharge direction is adjusted. The air bundles supplied into the space can therefore seldom be properly adjusted to suit the space. Even when limited adjustability is provided, it is in the form of horizontal and/or vertical vanes that may be manually swivelled about vertical and/or horizontal axes. Hence, discharge direction may be manually adjusted in up to two planes - up and down, and left and right (with only the latter applying to ceiling mounted slots) - and horizontal throw may be increased or decreased by arranging vane direction to converge or diverge, thereby concentrating or dispersing the discharged bundle, respectively.

In order for an isothermal air stream to achieve a given axial throw for a fixed terminal velocity, the requisite velocity of the air stream, as it is discharged from a grille, is largely inversely proportional to the volume flow rate of the discharged air stream. Consequently, in order to achieve a given throw from a grille, the effective discharge diameter of the grille needs to be increased roughly in proportion to the increase in volume flow rate to realise the requisite inverse discharge velocity relationship, resulting in increased grille opening discharge size (and hence a "thicker" supply air bundle) and reduced discharge velocity (causing a more "limp" supply air bundle) the larger the airflow rate to be discharged from the grille. These factors, in turn, reduce the stability of the discharged air stream

(increasing uncontrolled air stream trajectory deviations in non-isothermal applications or due to air motion from other sources in the space) and increase temperature and velocity deviations from the average in the space (a tendency towards hot and stuffy, and cold and draughty spots). They afflict active chilled beams in particular, due to the relatively low discharge velocities of comparatively high airflow rates resulting from the elevated supply air temperature and low diffuser pressure drop constraints that typify conventional active chilled beams.

A further disadvantage of grilles is that their vanes often suffer from dirt deposits, called "smudging", that settle onto the visible grille surfaces, including the recessed surfaces of the vanes. Not only is this unsightly, but these surfaces are also difficult to clean, and cleaning generally results in the inadvertent re-adjustment of vanes (if adjustability is provided), thereby compromising airflow to the space, hence causing discomfort and poor performance.

Grilles also tend to suffer from condensation when used in high humidity environments, such as lobbies in the tropics, or in restaurants.

Referring firstly to Fig. 1 , an air conditioner is shown in the form of an active chilled beam 1. The chilled beam comprises a body, in the form of a housing 3, which may be substantially thermally insulated, defining an interior chamber, in the form of induction chamber 5. The housing 3 includes a heat exchanger 7 for conditioning a primary air stream, in the form of return air 9 received from the space, in the form of room 11. The chilled beam also includes a restrictor, in the form of header 13 and nozzles 15, mounted to the housing. The nozzles 15 restrict the flow of a secondary air stream, in the form of preconditioned air 17, into the induction chamber 5 such that the jets of preconditioned air 17 into the induction chamber 5 create a negative static pressure in induction chamber 5 relative to rooml l, thereby inducing return air 9 through a filter 19 and the heat exchanger 7, respectively, and then into the induction chamber 5 to form a combined air stream, in the form of mixed air 21. The heat exchanger 7 may be controlled to cool or heat the return air 9 and hence regulate the temperature of the mixed air 21.

The chilled beam 1 also includes a high induction diffuser 23 mounted to the housing 3 for discharging the mixed air 21 from the induction chamber 5 and to the room 11. Discharge of the mixed air 21 by the diffuser 23 causes the air 25 in the room 11 to be induced by the mixed air 21 to mix with and thereby condition the air 25 in the room 11. The preconditioned air 17 is received from outside the room 11 and is preconditioned by a dedicated outdoor air conditioning system. The temperature and humidity of the preconditioned air 17 can be controlled to achieve the required humidity and temperature of the mixed air 21. Referring now to Fig. 2, the chilled water system will be described in detail. The chilled water system includes a chiller 27 that is connected to heat exchanger 7. Multiple heat exchangers 7a-c can be connected to a single chiller 27. As such, multiple chilled beams 1 can be connected to a single chiller 27. Each heat exchanger 7a-c comprises piping 28 adapted to be coupled to a chilled water circuit, in the form of chiller 27 and associated piping, via inlet 29 and outlet 31. If heating is required, another heat exchanger in each chilled beam 1 can be connected to a heating hot water circuit. The heating hot water circuit includes a boiler 33 and piping to the hot water piping 30 in each chilled beam.

Alternatively, heating may be provided via preconditioned air 17 or hot water may be supplied to piping 28 of each heat exchanger 7a-c via inlet 29, to be discharged through outlet 31 , as may occur if chiller 27 is a reverse cycle chiller capable of supplying chilled or hot water.

The chilled water piping 28 is arranged to receive chilled water from the chilled water circuit at a temperature typically of 6 to 10°C and return chilled water to the chilled water circuit at a temperature of typically 8 to 12°C. This allows the chilled beam to be connected to a conventional chilled water system, which typically produces water at around 6°C.

Depending on how close the chilled beam is to the chiller, the temperature of the chilled water supplied by the chiller may increase slightly before it reaches the chilled beam.

Insulation is used to minimise heat transfer from the environment to the chilled water circuit.

Referring now to Fig. 3, the high induction diffuser 23 of a side-blow embodiment of the air conditioner will be described in further detail (eg for discharge from a wall or bulkhead). The diffuser 23 is configured to have a low pressure drop across a diffuser element 35, the diffuser element 35 being positioned between the induction chamber 5 and a face 37 of the diffuser 23. The diffuser element 35 is arranged to discharge a high momentum air jet 39 from the face 37 of the diffuser 23 and into the room 11. The air jet 39 is a portion of the mixed air 21.

The diffuser element 35 comprises channels 4 leach able to discharge the air jet 39 in a direction that is substantially inclined to an axis (A) that is perpendicular to the diffuser face 37. Some of the plurality of channels 41 may be grouped adjacent to each other and others may be at differing angles or orientations to one another. The diffuser element 35 may be manipulable to change the orientation of the channel 41. Manipulation can either be by hand, such that users can alter the discharge direction, or automated so that the discharge direction can be automatically changed, for example in dependence of the temperature of the discharged air. Changing the orientation of the channel 41 varies the airflow direction of the air jet 39. The airjets 39 of channels 41 that are of similar inclination and orientation and that are grouped abutting or in close proximity to one another (not shown) will combine downstream of diffuser face 37 to form a larger combined jet (not shown) discharging into room 11 of similar orientation to the individual airjets 39 making up a combined jet.

The diffuser face 37 may comprise perforations 43 formed therein such that the air jet 39 is able to be discharged through at least one of the perforations 43; or diffuser face 37 may be otherwise open to the passage of air. The diffuser element 35 may also be arranged to discharge a low momentum air stream

45, via at least one of the perforations 43, if present, in the face 37 of the diffuser 23 and in close proximity to the air jet 39. The low momentum air stream 45 is another portion of the combined air stream 21. The volume flow rate of the plurality of low momentum air streams 45 and airjets 39 when combined is equal to the volume flow rate of the combined air stream 21. The low momentum air stream 45 as well as room air 25 are induced by the air jet 39 (or combined jet) in the room 11 to form room air stream 39a downstream of the diffuser face 37. Multiple room air streams 39a and associated airjets 39 (or combined jets) are substantially discrete. The direction and throw of each room air stream 39a is determined substantially by the discharge direction of the associated air jet 39 (or combined jet). Some of the airjets 39 may be discharged at substantially differing angles and/or orientations to one another to vary coverage and spread of the air streams 39a into the room 11, as well as to maximise induction by each air jet 39 (or combined jet) of the air 25 in the room 11 by minimising the propensity of room air streams 39a to coalesce with one another (ie to ensure that they remain discrete). The high induction of the air 25 in the room 11 by each air jet 39 (or combined jet) strongly dilutes each room air stream 39a and produces rapid discharge velocity decay of the air jet 39 so that, within a short distance downstream of the face 37, the temperature of the room air stream 39a is substantially equalised with the temperature of the air in the room 11 and the velocity at which the room air stream 39a is dispersed into the room 11 is substantially lower than the discharge velocity of the air jet 39 (or combined jet), thereby conditioning the room 11 with substantially low velocity and largely uniform temperature air diffusion. The individual room air streams 39a have minimal propensity to cause cold draughts in the room 11 through dumping of cold air because they are each at a temperature, and hence a density, substantially equal to the temperature and density of the air 25 in the room 11. Draught threat is also reduced because of both the low velocity at which each of the multitude of room air streams 39a is dispersed into the room 11 and because the temperature of each room air stream 39a is substantially equal to the temperature of the air 25 in the room 11. This is in contrast to the mixed air stream 21 being discharged into the room 11 as a bundle with poor mixing characteristics resulting in poor temperature equalisation and limited discharge velocity decay, as would occur if discharged by grilles or slots of the prior art, which would result in inferior temperature distribution in the room and higher velocity air streams of a lower supply air temperature that cause draughts interspersed with zones of higher temperature and stagnation (refer also to Figs. 8 a-vii and 8 b-iv). In the air conditioner, the significantly increased mass flow rate of the room air streams 39a, due to the induction of large quantities of room air 25 by the air jets 39, provides substantial preservation of air stream momentum despite the intense discharge velocity decay of each air jet 39 (or combined jet), thereby achieving substantially penetrating throw and movement of the mixed air stream 21 into the room 11. This combination of high mass flow rate and low velocity air motion of the room air streams 39a diffuses the mixed air 21 into the room 11 in a manner that is suitable for both small spaces and/or short throws, due to the low velocity air motion produced in the room 11, as well as to large spaces and/or long throws, due to the high momentum of the air dispersed into the room 11. These factors combined not only provide the room 11 with enhanced levels of both substantially draught- free and stagnation- free thermal comfort, but also increase the suitability of the air diffusion in accordance with the air conditioner to a wide range of room sizes and shapes.

Figure 4 shows another side-blow embodiment of the active chilled beam high induction diffuser in accordance with the disclosure. Fig 4-1 shows the diffuser face (37), Fig 4-II shows the diffuser discharge chamber inlet face, and Fig 4-III shows side sections of the diffuser as well as diffuser adjustment. The mixed air in the induction chamber (5) flows via perforated inlet plate (13s) into pressure plenum (14s) to a plurality of inclined channels (5s) located in largely hexagonal discharge elements (4a) to discharge as high momentum air jets (39) through perforations (7a) in face (37). Air also passes from pressure plenum (14s) through inlet openings (9s) in hexagonal (4a) and part-hexagonal discharge elements (4b, 4c and 4d) into distribution chamber (10s) to be discharged at low momentum into the room (11) via perforations (1 Is) in the face (37). Locking spring (15s) pushes against perforated inlet plate (13s) and the upstream face of largely hexagonal discharge element (4a) to lock the largely hexagonal discharge element (4a) into place in a sixty degree staggered array of hexagonal discharge elements (4a) so that its hexagonal edges abut the adjacent edges of largely hexagonal discharge elements (4a) and part-hexagonal discharge elements (4b, 4c and 4d). Similar locking springs (not shown for the sake of simplicity) may be used to lock part- hexagonal discharge elements (4b, 4c and 4d) into place. A force applied against compressed locking spring (15s) via a Hex key, screwdriver or similar tool (16s) inserted into a Hex socket, screwdriver slot or similar interface largely centrally located in largely hexagonal discharge element (4a) unlocks largely hexagonal discharge element (4a) from the sixty degree stagger pattern as largely hexagonal discharge elements (4a) moves towards perforated inlet plate (13s) allowing largely hexagonal discharge element (4a) to be subsequently rotated by twisting (17s) the Hex key, screwdriver or similar tool (16s) into any one of six possible orientations that locking spring (15s) will relock largely hexagonal discharge element (4a) into when the Hex key, screwdriver or similar tool (16s) is released.

Figure 5 shows two embodiments of largely hexagonal discharge element (4a) in which locking spring (15) is integrated into largely hexagonal discharge element (4a). Additionally, one embodiment includes locating pin (18) and another embodiment includes locating ring (19) to fix discharge element (4a) into the sixty degree staggered array of largely hexagonal discharge elements (4a) even when largely hexagonal discharge elements (4a) is unlocked from the array and being rotated by twisting (17) the Hex key, screwdriver or similar tool (16). Not shown for the sake of simplicity is a further embodiment of largely hexagonal discharge element (4a) incorporating both locating pin (18) and locating ring (19).

It will be apparent to a person skilled in the art that instead of the perforation hole (7a) centre -points on the face (37) being coincident with the vertices of a regular tessellation of hexagons, regular perforation patterns with perforation hole (7a) centre -points that are coincident with a regular tessellation of squares or triangles may also be used, with the shape of the discharge elements (4a) adjusted to suit, typically to form a substantially regular tessellation, although other tessellation patterns are also possible. The perforation hole (7a) centre -points may even be selected to form an Archemedian tessellation, with a tessellation of discharge elements (4a) to suit. Figure 6 shows, for the embodiment depicted in Figure 4, examples of different high induction diffuser rectangular face dimensions that can be realised by varying the

combination and location of largely hexagonal (4a) and part-hexagonal (4b, 4c and 4d) discharge elements. Also shown are three different sets (A, B and C) of largely hexagonal discharge elements (4a), in which each set has a different angle of inclination (α, β and 0, respectively) of inclined channel (41) and hence of high momentum air jet (39) relative to the perpendicular axis of the face (37). Largely hexagonal discharge elements (4a) with smaller angles of inclination are located closer towards the diffuser centre than those with larger angles of inclination, so as to reduce the likelihood of groups of high momentum air jets (39) from coalescing, thereby maximising induction of room air (25) and low momentum air streams (45) by the high momentum air jets (39). While three different sets of inclination (a, β and 0) have been shown the air conditioner described herein is not restricted to three sets.

Figure 7, showing the front view of two configurations (I and II) of largely hexagonal discharge element (4a), depicts a further embodiment to reduce the propensity for groups of high momentum air jets (39) from coalescing so as to maximise induction of room air (25) and low momentum air streams (45) by the high momentum air jets (39). Figure 7-1 shows inclined discharge channels (41) directed towards hexagonal edge at the 3 o'clock position relative to the central axis of hexagonal discharge element (4a), whereas Fig 7-II shows inclined discharge channels (41) directed towards the hexagonal corner at the two o'clock position relative to the central axis of hexagonal discharge element (4a). The two angles of inclination differ by 30° (or up to 30° in further embodiments not shown for the sake of simplicity). Combining hexagonal discharge elements (4a) as shown in Figure 7-1 with those as shown in Fig 7-II into the same diffuser further reduces the risk of groups of high momentum air jets (39) from coalescing.

Not shown for the sake of simplicity are further diffuser embodiments that include largely hexagonal discharge elements (4a) in which the side-view angles of inclination, as shown in Figure 6, differ from one set of hexagonal discharge elements (4a) to another, and in which the front-view angles of inclination, as shown in Figure 7, differ between sets.

Not shown, is a further embodiment in which a high velocity jet of air, which may be discharged across the entire width of the diffuser, is discharged from the top portion of the diffuser face to attach, by Coanda effect attachment, to a near-by ceiling.

In an alternative embodiment not detailed, the diffuser element is a swirl diffuser with a low pressure drop. Swirl diffusers include substantially radially aligned vanes that break the supply air stream up into a multitude of individual air streams, each one of which is highly inductive to room air, causing mixing of room air with the air discharged by the chilled beam.

Figs. 8a-i to 8a-vi shows an embodiment of the active chilled beam in accordance with the disclosure suitable for installation in a ceiling or suspended above the room (11). Figs. 8b-i to b-iv show an embodiment of a comparable active chilled beam of the prior art (la).

Figures 8a-i to 8a-vi show a plan view section, a bottom view and side-view sections of an active chilled beam embodiment, and figure 8a-vii shows a plan view of the same embodiment installed in the ceiling of a room (11), in which return air stream (9) is drawn from the room (11) through return air grille (19a), filter (19) and heat exchanger (7) into induction chamber (5) as it is induced by preconditioned air stream (17) supplied via a restrictor in the form of header (13) and nozzles (15) to combine and form mixed air stream (21) supplied to a high induction diffuser in the form of a swirl diffuser (23 a), to then be discharged as a multitude of high induction air streams (39i) into the room (11). Condensate tundish (53) collects condensate from heat exchanger (7), which may be drained or pumped to be disposed of elsewhere (not shown). Swirl diffuser (23a) may include a plurality of pilot slots (23d), each between a first vane (23b) and a second vane (23c), configured to discharge pilot air stream (39b), which is adjacent to the high induction air stream (39i) opening bounded by the same first vane (23c) and an adjoining second vane (23c). The pilot air stream (39ii) is of lower momentum than adjacent high induction air stream (39i) and, upon discharge into the room (11), attaches to the trailing edge of the second vane (23c), inducing high induction air stream (39i) into a discharge pattern that is substantially parallel to diffuser face (37). Each first vane (23a) may be adjustable to swivel from a shallow angle to a steep angle relative to the plane of face (37), in which the shallow angle is acute and less than the steep angle, such that pilot slot (23 d) is open at the shallow angle and discharges pilot air stream (39ii), as shown in Fig 8 a-ii, or closed at the steep angle, as shown in Fig 8 a-v, to realise a substantially horizontal discharge pattern (Fig 8 a-iii) or a substantially

perpendicular discharge pattern (Fig 8 a-vi), respectively, of high momentum air streams (39i) relative to the face (37), in which the substantially horizontal discharge provides substantially draught- free air cooling to the room (11), whereas the substantially

perpendicular discharge provides effective penetration of heat from ceiling level into the room (11). Adjustment of the plurality of first vanes (23a) may be manual, by thermal element or electric. Not shown is an embodiment in which the plurality of nozzles (15) are inclined to the vertical to create pre-swirl of the mixed air flowing onto the swirl diffuser (23a).

Fig 8 b-I shows the substantially swirl pattern (39c) formed by the plurality of discrete high momentum air streams (39i) upon discharge into the room (1 1) by the swirl diffuser (23 a). The discrete nature of each high momentum air stream (39i) upon discharge from the diffuser face (37) allows room air (25) to be induced between the individual high momentum air streams (39i), thereby strongly increasing overall induction of air from the room (1 1).

Fig 8 b-ii and 8 b-iii show the substantially four-way blow pattern formed by the high momentum air bundles (39z) discharged by the four discharge slots (23z) of an embodiment of an active chilled beam of the prior art (la). Each high momentum air bundle (39z) is substantially discrete, inducing room air (25) from the room (1 1) between the high momentum air bundles (39z). As there are only four high momentum air bundles (39z), the amount of air (25) induced between them from the room (11) is substantially less than depicted in Fig 8 b-I for a comparable embodiment of the conditioner.

Fig 8 a-iv and b-iii show the increased spacing (Ni, Hi, Gi) in an embodiment of the air conditioner relative to a comparable embodiment of the prior art (Np, Hp, Gp) of the rows of nozzles (15), the heat exchanger elements (7) and the outer edges of the return air grille (19a) due to the orientation of the plurality of vanes (23b, 23c) of the swirl diffuser (23a) to form a swirl discharge pattern that is substantially parallel to the face (37). This orientation allows the plurality of vanes (23b, 23c) to be located closer to the perimeter edge of the active chilled beam (1), in comparison to the four discharge slots (23z) of the embodiment of the active chilled beam of the prior art shown, which need to be located well away from the perimeter of the active chilled beam (la) so as to achieve redirection of each high momentum air bundle (39z) to be substantially parallel to the face (37). Increased dimensions Ni, Hi and Gi of the embodiment of the air conditioner relative to Np, Hp and Gp of the comparable embodiment of the prior art allow the number of nozzles (15) assuming a fixed nozzle pitch, area of the heat exchanger (7), the size of the diffuser (23a) and the area of the filter (19) and return air grille (19a) combination to be increased, thereby increasing the cooling capacity of the embodiment of the air conditioner shown relative to the comparable embodiment of the prior art. Fig 8 a-vii and 8 b-iv show the improved air distribution achieved by the substantially swirl discharge pattern (39c) of the high momentum air streams (39i) discharged by the swirl diffuser (23 a) of the active chilled beam embodiment of the air conditioner and distributed across 360° throughout the room (11), in comparison to the poor air distribution in the room (11) characteristic of a comparable active chilled beam embodiment of the prior art (la) that - in cooling mode - discharges concentrated high momentum air bundles (39z) that typically terminate in zones of cold draught (71) interspersed with warmer zones of stuffiness and stagnation (70). The highly inductive and substantially discrete high momentum air streams (39i) discharged by the air conditioner strongly induce air (not shown) from the room (11), rapidly breaking down the discharge velocity and equalising the air stream temperature of the discharged air with room air temperature, creating uniformly dispersed, draught-free air distribution throughout the room (11). The illustrated embodiment depicts a swirl diffuser (23a) with swirl vanes (23b) arranged in a substantially square pattern with rounded corners. This arrangement allows the high momentum air streams (39i) directed towards each of the four corners of the room (11) to coalesce into a room air stream of extended throw (39e) to reach the far corners of the room (11), whereas the high momentum air streams (39i) directed towards the nearer walls of the room (11) are dispersed so as not to coalesce, thereby increasing their induction of room air and hence reducing their throw.

Fig. 9 shows a side-blow embodiment of the air conditioner in which the header (13) includes an airflow regulation device for the preconditioned air (17i, 17ii) in the form of an open damper (80i) or a throttled damper (80ii) in Figs 9 a and 9 b, respectively, or in the form of a plurality of open plugs (90i) or throttled plugs (90ii) in the nozzles (15) in Figs 9 c and 9 d, respectively. Airflow regulation by means of a damper (80i, 80ii) or plugs (90i, 90ii) allows energy to be saved by activating or modulating airflow of the preconditioned air (17i, 17ii) in response to demand (eg activation by a hotel room key card, or modulation to control

CO₂ levels in a space). A fully open damper (80i) or a plurality of fully open plugs (90i) results in maximum preconditioned airflow (17i) through the nozzles (15), maximising induction of the return air (9i) across the heat exchanger (7), thereby maximising the potential cooling or heating capacity of the heat exchanger (7), as well as maximising airflow rate of the mixed air (21i), and hence maximising the throw and stability of the high momentum jets

(39i) into the room (11). A throttled damper (80ii) reduces both the airflow rate and the velocity of preconditioned air (17ii) discharged by the plurality of nozzles (15), thereby substantially reducing the airflow rate of the return air (9ii) across the heat exchanger (7), with the consequence that the potential cooling or heating capacity potential of the heat exchanger (7) is severely reduced, as well as substantially reducing the airflow rate of the mixed air (21ii) and hence of the high momentum jets (39ii), thereby reducing their throw and potentially compromising their stability into the room (1 1). Alternatively, a plurality of throttled plugs (90ii) in the nozzles (15) reduces the airflow rate of preconditioned air (17iii) discharged by the nozzles (15) but not the discharge velocity from the nozzles (15).

Consequently, for the same throttled airflow rate of the preconditioned air (17i and 7iii) the return airflow rate (9iii) in Fig 9 d is greater than the return airflow rate (9ii) in Fig 9 b. As a result, the maximum cooilng or heating potential of the heat exchanger (7) in Fig 9 d is greater than that in Fig 9 b, and the airflow rate of the mixed air is also greater (21iii > 21i), as are the airflow rate and stability of the high momentum jets (39iii > 39i) into the room (1 1).

In one form, each plug (90i, 90ii) has an air passage extending therethrough that allows for the preconditioned air stream (17i, 17iii) to pass through the plugs (90i, 90ii) when the plug is pressed against the internal walls of the nozzle 15. This embodiment allows for the length of the plug to be shortened and a minimum airflow of the preconditioned air stream (17i, 17iii) to be pre-determined for each nozzle.

Movement of the plugs (90i, 90ii) can be automated by connecting an input on the plugs to an output of a building management system. The position of the plugs is able to be automatically varied in dependence on either the temperature of a room, the C0₂ content of a room or on an occupancy sensor within a room (e.g. an access card for a hotel room). This arrangement also allows for the position of the plugs to be calibrated via a remote station of the building management system during commissioning of a new building, or re- commissioning of an air conditioning system after a change is made within the building (e.g. a new tenancy layout with a different heat load and occupancy profile). This arrangement also allows for significant energy savings to be made. For example, when used in a hotel room and linked to the room access card, the input of pre-conditioned air can be minimised when no occupants are present in the room.

The use of plugs (90i, 90ii) instead of dampers (80i, 80ii) to regulate the pre-conditioned air also allows for the active chilled beams to be standardised. For example, the nozzles 1 within the chilled beams can be the same size for a range of capacities. This arrangement, advantageously, assists with on-site coordination during installation of an air conditioned system (i.e. if an active chilled beam is installed in the incorrect location, another chilled beam can be used to replace the incorrectly installed chilled beam and the plugs can be calibrated to achieve the required capacity).

It will be apparent to a person skilled in the art that many other means exist to reduce the degradation in induction of return air (9i) as a consequence of throttling the airflow rate of the preconditioned air (17i), such as a slide mechanism that throttles the inlet to only some of the nozzles (eg every alternate nozzle) or arranging the damper (80i) to supply a portion of preconditioned air (17i) to a plenum connected to only some of the nozzles (eg every alternate nozzle), whilst the remaining portion of preconditioned air stream (17i) flows unhindered to the remaining nozzles (15).

Referring again to Fig. 1 , the chilled beam will be further described. The heat exchanger 7 is arranged in a roof 47 of the housing 3. The heat exchanger 7 is able to abut with a ceiling void 49 and thereby receive the return air 9 directly from the ceiling void 49. The

preconditioned air 17, supplied from conditioning plant, which for the sake of simplicity is not shown, enters the chamber in a direction that is substantially perpendicular to the direction of the return air 9 induced through the heat exchanger 7 and received into the chamber 5. The mixed air stream 21 is received by the diffuser 23 in a direction that is substantially parallel to the direction of the preconditioned air 17 from the chamber 5.

A floor, in the form of base 51, of the housing 3 is located below the heat exchanger 7 and is configured to drain condensation caused by conditioning the return air 9. The base 51 is sloped to direct condensation to a drain point 53 positioned in the base 51. The base 51 is sealed to prevent condensation draining from the induction chamber 5 at a location other than the drain point 53. The diffuser 23 is also detachably mounted to allow access into the induction chamber 5 to clean the base 51, assembly of nozzles 15 and heat exchanger 7. The drain point 53 can be connected to a drain pipe that can also be concealed in a service space.

The restrictor includes at least one nozzle 15 that restricts the flow of the preconditioned air 17 into the induction chamber 5. A plurality of nozzles 15 can be used to restrict the flow of the preconditioned air 17. Restriction by the nozzle 15 of the preconditioned air 17 discharged into the induction chamber 5 creates a negative static pressure in the induction chamber 5 relative to the air pressure in the room 11 such that the return air 9 is induced into the chamber 5 and replenished with air from the room 11. Referring now to Fig. 10, another alternative embodiment of the chilled beam 1 is shown. The heat exchanger 7 comprises piping adapted to be coupled to a refrigerant circuit 55. Multiple chilled beams 1, or cooling devicessuch as fan-coil units (not shown), are able to be connected to the refrigerant circuit. The refrigerant circuit includes a condenser 57 that is connected via insulated piping to each chilled beam 1. Previously, using refrigerant to cool return air in a chilled beam overly cooled the return air, causing condensation and cold air dumping in the room. The flow or volume of refrigerant through the piping may be variable (VRV or VRF) such that the cooling of the conditioned return air can be controlled independently for each active chilled beam 1. The refrigerant circuit is also able to provide heating to each chilled beam 1 , and may be able to provide cooling to some chilled beams 1 whilst simultaneously providing heating to other chilled beams 1 , as is typical of so-called three-pipe VRV (variable refrigerant volume ) or VRF (variable refrigerant flow) systems (not shown for the sake of simplicity).

As shown in Fig. 11, the chilled beam 1 can be modified to be fitted to the task air workstation system such that it can provide microclimates within such desks. In this arrangement, the return air 9 is received from under a computer desk. Due to the orientation of the arrangement, a portion of the housing may be removable to the induction chamber to access a drain tray (not shown) that may be located beneath the heat exchanger 7.

An active chilled beam 1 that utilises refrigerant to condition the return air can be used to condition spaces where induction unit climate control is desired and where chillers and boilers are not installed. Such examples include aged care facilities, smaller hospitals, hotels and apartments. An active chilled beam 1 that utilises chilled water to condition the return air can be used to condition spaces where a site chiller is already available, or on large sites or in climates where it is advantageous to install a chiller and/or boiler. Another embodiment of the side blow active chilled beam is disclosed in Figs. 12 and 13.

In this embodiment, the preconditioned air 17 enters the induction chamber 5 via rear 59 and/or side 61 entry spigots. The spigots 59, 61 can be connected to ducts that are concealed within a ceiling void. The base 51 of the housing slopes towards the diffuser 23 such that the height of the interior chamber increases towards the diffuser. The tapering of the body by a swing plate 63 forms a venturi 63 a to channel the flow of the preconditioned air 17 into a downstream portion of the chamber 5, thereby increasing the magnitude of the negative static pressure in induction chamber 5 relative to the room 11 so as to increase the flow of the return air 9. The swing plate 63 also allows access to the internal filter 19 from the room after removing the diffuser 23 from the housing. As the heat exchanger can operate at less than the dew point temperature of return air 9 condensation may occur on the fins of the heat exchanger. Therefore, the fins will often be wet, trapping dust particles and the like, which will stick to the fins and ultimately clog the heat exchanger. Filter 19 is included upstream of heat exchanger 7 to prevent such clogging of the heat exchanger.

The sloped base 51 directs condensation towards the drain point 53 such that the condensation can be removed from the chamber via drain pipe 65.

Advantages of the disclosed active chilled beam in comparison to active chilled beams of the prior art include lower maintenance requirements, lower noise levels, elimination of fans and associated wiring, controls, maintenance and noise typical of fan-coil systems to condition air in rooms, lower energy consumption, easier access to clean trays and reduced Legionella risk, simpler systems and reduced building work. Further, it allows for use with and replacement of units within new or existing VRF systems. Advantageous features of the disclosure

Ideally, in order to achieve comfort and efficient operation, uniform temperature distribution with low velocity air motion should be achieved in the space regardless of the airflow rate or the supply air stream temperature. Low induction sidewall diffusers and ceiling slots for active chilled beams of the prior art do not provide air supply approaching this ideal. This is one of the primary reasons that conventional active chilled beams are designed to operate with an elevated primary air temperature of 15°C to 18°C, rather than a typical fan-coil supply air temperature of 12° C to 15°C. However, elevating the supply air temperature to overcome this limitation degrades cooling capacity, as the higher the supply air temperature in cooling mode the lower the temperature differential across the heat exchanger and hence the lower the cooling capacity delivered by the heat exchanger. Low supply air temperatures, however, cannot be used in combination with prior art air diffusion, such as simple grilles and slots, especially when providing low velocity, low pressure drop discharge, as the resultant discharged air stream is limp and will lead to severely

compromised thermal comfort in the space. Active chilled beams of the prior art, therefore, are particularly unsuited to low temperature air discharge, especially for applications for which draught-free performance is increasingly being sought, such as high-end hotel rooms and old-age care facilities.

The minimum permissible mixed (supply) air temperature limitation of approximately 15°C pertaining to active chilled beams of the prior art also prevents such active chilled beams from being suitable for use with direct expansion (so-called "DX") refrigeration systems, including the increasingly popular and highly energy efficient variable refrigerant volume (VRV) and variable refrigerant flow (VRF) systems that have gained a strong international footing, especially in sustainable and energy efficient applications. Depending on the application, DX systems, in particular those incorporating VRV/VRF, offer many advantages in comparison to chilled water systems. For example, for such applications as small-to-medium sized hotels and low-rise commercial office blocks, DX systems usually have a substantially lower capital cost than equivalent chilled water systems, and when combined with VRV/VRF are often far more energy efficient. These advantages, however, cannot currently be combined with the additional potential for capital cost savings (such as eliminating the need for a fan and associated power supply in each and every hotel room) and improved energy efficiency (eg reduced fan energy) that active chilled beams offer. Even further advantages could accrue due to reduced maintenance costs (no multitude of fans to service), reduced maintenance downtime (active chilled beams are extremely simply to maintain) and minimal maintenance disruption to operation (and hotel guests). Advantageous Features of the Embodiments Described Herein

The disclosure allows overall cooling/heating capacity from an active chilled beam to be increased, whilst improving thermal comfort in the space and allowing connection of the active chilled beam to HVAC systems operating with standard chilled water or standard direct expansion of refrigerant (including VRV or VRF systems). By allowing a lower temperature of the combined air supplied by the diffuser into the space, the disclosure helps compensates for reductions in cooling capacity due to reduced airflow across the heat exchanger as a result of any increases in the diffuser pressure drop. These advantages are achieved primarily by forgoing minimal air diffusion pressure loss in favour of high induction air distribution into the space. The combined air stream, upon being discharged from the active chilled beam into the space, is broken up into a multitude of substantially discrete high momentum air jets. Each high momentum air jet becomes a room air stream as it strongly induces and mixes with large quantities of room air, rapidly increasing the mass flow rate of each room air stream whilst simultaneously bringing about intense room air stream velocity decay and rapid temperature equalisation with the air in the room. The resultant low velocity air motion in the space provides substantially draught-free and generally uniform temperature distribution, as each supply air stream is not only of almost equal temperature to the room air, but is also substantially equal in density, preventing draughts. Under-throw and over-throw seldom occur, as the room air streams are low in velocity and are almost at room air temperature, preventing draughts if nearby obstructions deflect them into the occupancy space, whilst their combined high mass flow rate, due to the large quantities of entrained room air, provides them with sufficient momentum - despite their low velocity - to travel over long distances if required. Hence, stable, substantially draught- free operation with uniform temperature distribution and a high level of comfort may be achieved regardless of changes in airflow rate or fluctuations in the temperature of the combined air stream, and for a wide range of room configurations.

Such highly inductive discharge of the combined air stream into the space allows for the supply of much colder air. This in turn allows for chilled water with an inlet temperature of approximately 6°C, or alternatively refrigerant such as R404, to be used in the heat exchanger in lieu of 'warm' chilled water. A multitude of advantages flow from this arrangement, including reduced capital costs otherwise associated with installing multiple chilled water systems and multiple chillers, and energy savings associated with higher efficiencies (eg reduced chilled water reticulation pump power consumption). However, highly inductive discharge of the combined air stream does necessitate a greater pressure requirement than may be achieved with simple grilles or slots used in active chilled beams of the prior art. Even so, the above advantages may more than compensate for the reduced cooling capacity that this increased air diffusion pressure requirement may cause, and, in some embodiments, results in increased cooling capacity. This is because the air temperature of the combined air stream may be reduced to more than offset the reduction in airflow rate without compromising thermal comfort in the space.

An active chilled beam that discharges the combined air in a highly inductive manner, as described herein, also provides potential to enhance the indoor air quality in the space. This is because the highly inductive discharge pattern improves mixing of the fresh air supplied by the by the secondary air stream into the space, thereby improving the removal of pollutants and contaminants by dilution, resulting in improved indoor air quality in comparison to that provided by an active chilled beam of the prior art. The highly inductive discharge pattern of the combined air of the active chilled beam described herein reduces the vertical temperature gradient in the occupancy space in heating mode, thereby improving heating performance, enhancing comfort, and reducing energy consumption in comparison to an active chilled beam of the prior art.

The highly inductive discharge of the disclosure reduces the risk of condensation on the diffuser discharge face in high humidity applications, such as the tropics, in comparison to active chilled beams of the prior art.

The optional adjustable discharge pattern of embodiments of the disclosure described herein allows airflow patterns to be adjusted manually, electrically or thermally to suit the geometry of the occupancy space or changing cooling and heating requirements.

The location of adjustable discharge elements behind a perforated discharge face of embodiments of the disclosure described herein allows discharge direction adjustment without a visible impact on the aesthetics of the diffuser and without inadvertent adjustment via contact with the face (eg by cleaners wiping the diffuser face), especially for embodiments that include the need for a tool to affect discharge direction adjustment.

A side-blow embodiment of the air conditioner includes a hinged or removable diffuser to allow easy access for cleaners to easily wipe clean or sterilise the inside of the active chilled beam, without any other maintenance requirements, thereby reducing maintenance costs and improving hygiene.

The flush and uniformly perforated face of a high induction side-blow embodiment is both aesthetically appealing and easy to clean.

The suitability of the active chilled beam described herein to both short throw and long throw applications without creating draughts or stagnation in the occupancy space improves thermal comfort and reduces installation and commissioning costs.

The suitability of the air conditioner to secondary air streams with a variety of airflow rates (which may be varied in to regulate indoor air quality) without creating draughts or stagnation in the occupancy space allows for improved thermal comfort, enhanced indoor air quality, and increased energy efficiency.

A side-blow embodiment of the air conditioner offers a variety of perforation patterns and/or hole shapes, such as a honeycomb pattern with round or hexagonal holes, or a square pattern with round or square holes, thereby offering a variety of differing designer styles.

The highly inductive discharge pattern of the combined air stream may reduce the rate of dirt accumulation - known as "smudging" - on the visible face of the air conditioner, thereby further improving the aesthetics and reducing cleaning costs. The design of an embodiment of the active chilled beam allows low cost fabrication of the high induction diffuser elements through simplicity and modularity of the components and the ability to achieve economies of scale from mass production, thereby making the air conditioner cost effective for standard side-wall applications, such as hotel rooms.

In the claims which follow and in the preceding summary, except where the context requires otherwise due to express language or necessary implication, the word "comprising" is used in the sense of "including", that is, the features as above may be associated with further features in various embodiments.

Variations and modifications may be made to the parts previously described without departing from the spirit or ambit of the disclosure.

Claims

1. An air conditioner for conditioning air in a space, comprising; a body defining an interior chamber, the body having a heat exchanger for conditioning a primary air stream received from the space; a restrictor mounted to the body for restricting a flow of a secondary air stream into the chamber and arranged such that the secondary air stream induces the primary air stream into the interior chamber and forms a combined air stream together with the primary air stream; and a high induction diffuser mounted to the body for discharging the combined air stream from the interior chamber so as to cause the air in the space to be induced by and to mix with the combined air stream upon discharge from the diffuser to thereby condition the air in the space.

2. An air conditioner in accordance with claim 1, wherein the heat exchanger comprises piping adapted to be coupled to a chilled water circuit.

3. An air conditioner in accordance with claim 1 , wherein the heat exchanger comprises piping adapted to be coupled to a refrigerant circuit.

4. An air conditioner in accordance with claim 2, wherein the piping is arranged to receive chilled water from the chilled water circuit at a temperature of 5 to 10°C and return chilled water to the chilled water circuit at a temperature of 8 to 13°C.

5. An air conditioner in accordance with any one of the preceding claims, wherein the secondary air stream is a preconditioned air stream received from outside the space.

6. An air conditioner in accordance with any one of the preceding claims, wherein the diffuser is configured to have a low pressure drop across a diffuser element, the diffuser element being positioned between the interior chamber and a face of the diffuser.

7. An air conditioner in accordance with claim 6, wherein the diffuser element is arranged to discharge a high momentum air stream from the face of the diffuser and into the space.

8. An air conditioner in accordance with claim 7, wherein the high momentum air stream is a portion of the combined air stream.

9. An air conditioner in accordance with claims 7 or 8, wherein a discharge direction of the high momentum air stream is defined by one or more channels disposed in the diffuser element.

10. An air conditioner in accordance with claim 9, wherein the one or more channels in the element are inclined to an axis that is perpendicular to the diffuser face such that the high momentum air stream is discharged in a direction that is substantially inclined to the axis that is perpendicular to the diffuser face.

11. An air conditioner in accordance with any one of claims 7 to 10, wherein changing the orientation of the discharge element varies the discharge direction of the high momentum air stream.

12. An air conditioner in accordance with any one of claims 7 to 11, wherein the discharge element is one of a plurality of discharge elements that each discharge at least one high momentum air stream into the space.

13. An air conditioner in accordance with claim 12, wherein at least five of the high momentum air streams are discrete.

14. An air conditioner in accordance with claim 12 or 13, wherein two or more adjacent high momentum air streams are discharged into the space at different angles to one another relative to the axis that is perpendicular to the diffuser face.

15. An air conditioner in accordance with any one of claims 12 to 14, wherein two or more adjacent high momentum air streams are discharged at different angles to one another when viewed planar to the diffuser face.

16. An air conditioner in accordance with any one of claims 12 to 15, wherein the difference in orientation of two or more adjacent high momentum air streams is sufficient for each high momentum air stream to be discharged as a discrete airstream.

17. An air conditioner in accordance with any one of claims 7 to 16, wherein the high momentum air stream induces air from the space and thereby mixes with the air in the space with high turbulence such that the combined air stream conditions the air in the space.

18. An air conditioner in accordance with any one of claims 7 to 17, wherein the diffuser element is a portion of a swirl diffuser with a low pressure drop.

19. An air conditioner in accordance with any one of claims 9 to 18, wherein the diffuser face comprises perforations formed therein, the one or more channels being aligned with at least one of the perforations such that the high momentum air stream is able to be discharged through at least one of the perforations.

20. An air conditioner in accordance with any one of claims 7 to 19, wherein the diffuser element is arranged to discharge a low momentum air stream from the face of the diffuser and in close proximity to the high momentum air stream.

21. An air conditioner in accordance with claim 20, wherein the low momentum air stream is another portion of the combined air stream.

22. An air conditioner in accordance with claim 21, wherein the low momentum air stream is induced by the high momentum air stream in the space.

23. An air conditioner in accordance with any one of claims 20 to 22 when dependent on claim 21, wherein the low momentum air stream is discharged via at least one of the perforations in the diffuser face.

24. An air conditioner in accordance with any one of claims 7 to 23, wherein the discharge direction and/or throw of the combined air stream is largely determined by the discharge direction or throw respectively of the high momentum air stream.

25. An air conditioner in accordance with any one of claims 6 to 24, wherein, for a given air diffusion performance index (ADPI) or a given draught rate (DR) in the space, the pressure drop of the high induction diffuser reduces the airflow rate of the combined air stream to a proportion that is greater than the inverse variation of the proportional increase in the maximum sustainable temperature differential between the combined air stream and the air in the space.

26. An air diffuser in accordance with any one of claims 6 to 25, wherein the combined air stream temperature is less than or equal to 13 °C.

27. An air conditioner in accordance with any one of the preceding claims, wherein the primary air stream is induced to flow across the heat exchanger and then into the interior chamber.

28. An air conditioner in accordance with any one of the preceding claims, wherein the heat exchanger is arranged in a roof of the body.

29. An air conditioner in accordance with claim 28, wherein the heat exchanger is able to abut with a ceiling void and thereby receive the primary air stream directly from the ceiling void.

30. An air conditioner in accordance with claim 28 or 29, wherein the secondary air stream enters the chamber in a direction that is substantially perpendicular to the direction that the primary air stream is induced through the heat exchanger and thereby received by the chamber.

31. An air conditioner in accordance with claim 30, wherein the combined air stream is received by the diffuser in a direction that is substantially parallel to the direction the secondary air enters the chamber.

32. An air conditioner in accordance with any one of claims 28 to 31, wherein a floor of the body is located below the heat exchanger and is configured to drain condensation caused by conditioning the primary air stream.

33. An air conditioner in accordance with claim 32, wherein the floor is sloped to direct condensation to a drain point positioned in the floor.

34. An air conditioner in accordance with claim 33, wherein the floor is sealed to prevent condensation draining from the interior chamber at a location other than the drain point.

35. An air conditioner in accordance with claims 33 or 34, wherein the drain point is connected to a drain pipe.

36. An air conditioner in accordance with any one of the preceding claims, wherein the restrictor includes at least one nozzle that restricts the flow of the secondary air into the chamber.

37. An air conditioner in accordance with claim 36, wherein restriction of the secondary air stream by the at least one nozzle decreases the static pressure of the secondary air stream in the interior chamber such that the primary air stream is induced into the chamber.

38. An air conditioner in accordance with any one of the preceding claims, wherein the body further comprises a venturi to channel the flow of the secondary air into a portion of the chamber and thereby induce the primary air stream.

39. An air conditioner in accordance with any one of the preceding claims, the air conditioner having the form of an active chilled beam.

40. An air conditioner in accordance with any one of the preceding claims further comprising at least one regulator that is able to translate relative to the restrictor to vary the airflow rate of the secondary airstream discharged from the nozzle into the interior chamber without substantially varying a discharge velocity of the secondary airstream discharged from the nozzle into the interior chamber.

41. An air conditioner in accordance with claim 40, wherein each regulator is in the form of an elongate plug having a narrow proximal end able to be received within the nozzle and a relatively wide distal end able to engage the nozzle upon translation of the plug.

42. An air conditioner in accordance with claim 41, wherein each plug includes an internal passage extending between the proximal and distal ends of the plug, the passage configured to receive and discharge the secondary air stream.

43. An air conditioner in accordance with claim 41 or 42, wherein each plug is able to translate between a first position, whereby the plug is spaced from the nozzle to maximise the airflow rate of the secondary air stream, and a second position, whereby the plug is closer to or engages the nozzle to reduce the airflow rate of the secondary airstream.

44. An air conditioner in accordance with claim 43, wherein the translation of the plug between the first and second positions is controlled by an automated system, the translation of the plug being dependent on an output of either a carbon dioxide sensor, an occupancy sensor or a temperature sensor.

45. An air conditioner for conditioning air in a space comprising; a body defining an interior chamber, the body having a heat exchanger arranged in a roof of the body for conditioning a primary air stream received from the space; a restrictor mounted to the body for restricting the flow of a secondary air stream into the chamber and arranged such that the secondary air stream induces the primary air stream into the interior chamber to form a combined air stream; a diffuser mounted to the body for discharging the combined air stream from the interior chamber and to the space; wherein a floor of the body is located in use below the heat exchanger and is configured to drain condensation caused by conditioning the primary air stream.

46. An air conditioner for conditioning as defined in claim 45 which is otherwise as defined in any one of claims 1 to 44.

47. A kit for the retrofit of an active chilled beam for conditioning air in a space comprising; a high induction diffuser for connection to a body of the active chilled beam, the diffuser able to discharge an air stream from an interior chamber of the beam so as to cause the air in the space to be induced by and to mix with the combined air stream upon discharge from the diffuser to thereby condition the air in the space.

48. A kit as defined in claim 47 wherein the diffuser is otherwise as defined in any one of claims 1 to 44.

49. An air conditioner for conditioning air in a space, comprising; a body defining an interior chamber, the body having a heat exchanger for

conditioning a primary air stream received from the space; a restrictor mounted to the body for restricting an airflow rate of a secondary air stream into the chamber and arranged such that the secondary air stream induces the primary air stream into the interior chamber and forms a combined air stream together with the primary air stream; at least one regulator that is able to translate relative to the restrictor to vary the airflow rate of the secondary airstream discharged from the restrictor into the interior chamber without substantially varying a discharge velocity of the secondary airstream discharged from the restrictor into the interior chamber, each regulator being able to able to translate between a first position and a second position, translation of the regulator being dependent on an output of either a carbon dioxide sensor, an occupancy senor or a

temperature sensor; and a diffuser mounted to the body for discharging the combined air stream from the interior chamber to thereby condition the air in the space.

50. An air conditioner in accordance with claim 49, wherein each regulator is in the form of an elongate plug having a narrow proximal end able to be received within the restrictor and a relatively wide distal end able to engage the plug upon translation of the plug.

51. An air conditioner in accordance with claim 50, wherein each plug includes an internal passage extending between the proximal and distal ends of the plug, the passage configured to receive and discharge the secondary air stream.

52. An air conditioner in accordance with claims 50 or 51, wherein in the first position, the plug is spaced from the restrictor to maximise the airflow rate of the secondary air stream, and in the second position, the plug engages the restrictor to reduce the airflow rate of the secondary airstream.