GB2095394A - Room ventilating device - Google Patents

Abstract

A room ventilating device has two separate airflow paths 32, 33 respectively intended for the introduction of and removal of air from a room. The apparatus is designed to remove heat from the departing air and to transfer the heat to the fresh air. One radial blower 13 provides a simultaneous air flow through both flow paths, the flow paths then extending through a heat exchanger 27', 27'', 27''', the air subsequently entering outlet chambers 38 and 39 where one flow of air is discharged into the room to be ventilated and the other flow of air is discharged to the atmosphere. The rotor 14 of the blower 13 is located in a chamber that is common to the two flow paths, the chamber having two axially opposed inlets 7 and 9 communicating respectively with the atmosphere and the interior of the room. The chamber is divided longitudinally into portions solely by a partition 15 that is formed integrally with the blower rotor. The heat exchanger, formed from successive stacks of plate shaped elements 27, is such that each flow path comprises an odd number of longitudinal portions arranged consecutively as a zig-zag therebeing a plate or strip-free zone 34, 35 between each adjacent pair of consecutive portions. A longitudinal partition 37 is disposed in the case adjacent the outlet end of the heat exchanger to define the two outlet chambers 38, 39. <IMAGE>

Description

SPECIFICATION Room ventilating device The present invention relates to a room ventilating device, and more particularly the present invention relates to a room ventilating device of the type that has two separate airflow paths, one being forthe introduction of fresh air to a room being ventilated, and the other being for air exhausted from the room being ventilated. The two flow paths are thermally interconnected to facilitate the recovery of heat from the air being discharged from the room, by means of a heat exchanger.

It has been proposed previously to utilise a ventilating system in which fresh air entering a room is heated by use of the enthalpy of exhaust or waste air being discharged from the room. In a ventilating device of this type the incoming fresh air and the outgoing waste airflow past one another in countercurrent air along passages which are solely separated by a thin aluminium sheet or plate. Ventilating devices of this type act as heat recuperators and are adapted to operate in one way in Summer and in a different way in Winter. It has been found in practice that in Winter operation simple ventilators of this type can recover at least 30% of the available heat present in the air being exhausted from the building, this heat being transferred to the incoming fresh air.

In the prior proposed heaters of this type the air is conveyed by two fans driven by a common motor, the fan which conveys the fresh air in Winter operation being a radial fan blower, and the waste air fan being an axial-flow blower. For Summer operation both the fans can be operated to discharge waste air.

The two fans of this prior proposed ventilating device, namely the radial-flow blower and the axialflow blower are each disposed at the end of the respective flow path which is near the room to be ventilated, so that the radial-blower providing the fresh-air intake in Winter operation has a long intake path but a short delivery path, and on the other hand the axial-flow blower for the waste air has a short intake path but a long delivery path. A ventilator of this type is disclosed in Lueger-Lexikon DerTechnik 1966, Volume 11, Page 457.

In another ventilating device, disclosed by Germany Offenlegungsschrift 2,717,462, the rotor and casing of a single radial-flow blower extends into two separate flow paths, and again one flow path is intended for air being drawn into a room being ventilated, and the other flow path is intended for air being exhausted from that room. A physical separation exists between the two flow paths, this separation being constituted both inside and outside the rotor in the blower casing by transverse walls. The rotor, the transverse walls, and the rotor casing are all made of a material which is a good heat conductor, such as sheet or plate metal, and the rotor has vanes which are continuous right along its length, and can therefore act as an additional heat exchanger between the two flow paths.

In this known device, the rotor is provided with two partitions, and only the end portions of the rotor act to cause the required flows of air. The presence of the unavoidable gap between the two partitions prevents the direct exchange of heat from one flow path to the other flow path. Thus, to achieve a reasonable heat exchange between the flow paths, the rotor vanes either have heat tubes or are hollow members containing a liquid refrigerant. A major disadvantage of a ventilating device of this type is that a substantial initial outlay is required. Another disadvantage of this prior device is that a partition formed on the blower casing extends into the gap between the two partitions formed on the rotor to separate the two flow paths from one another, and this inhibits the exchange of humidity between the two air flow paths. This impairs heat recovery.

The radial-flow blower of the ventilator disclosed in German Offenlegungsschrift 2,717,462 cooperates with a main heat exchanger, one half of the blower being connected to the intake side of one flow path through the main heat exchanger, while the other half of the blower is connected to the delivery side of the second flow path through the main heat exchanger. The heat exchanger is designed for counter-current operation. The ventilating device thus shares, with the previously mentioned devices, the disadvantages that the operating conditions of the two halves of the blower relative to the main heat exchanger are the opposite of one another, that is to say one blower part has a short intake path and a long delivery path, whereas the other blower part has a short delivery path and long intake path.Thus the two halves of the blower, if of identical design, provide different rates of air flow in relation to the main heat exchanger.

The present invention seeks to provide a ventilating device generally of the type outlined above, in which the above mentioned disadvantages are obviated or reduced.

According to the broadest aspect of this invention there is provided a device for ventilating a room said device comprising a casing defining therewithin two separate flow paths respectively for the introduction of and removal of air from the room, said two flow paths being thermally interconnected for the transfer of heat from the flow path for air being discharged from the room to the flow path for air being introduced to the room, by way of a heat exchange arrangement located within the casing; a single radial flow blower having its rotor extending into both said flow paths and being adapted to create a forced air flow in both said flow paths, said rotor having a radially extending partition, said two flow paths passing through a common chamber defined within the casing adjacent the radial flow blower, said chamber having two air inlets, said inlets being located on opposite sides of the casing and thus being axially opposite one another relative to the rotor of the blower, said chamber being divided longitudinally into portions solely by said blower rotor partition, the two flow paths being constituted by said heat exchanger in a longitudinal region of the casing adjacent said common chamber, the flow paths within said heat exchanger comprising an odd number of longitudinal portions arranged consecutively as zig-zags in the flow direction, each portion of the zig-zag being at an acute angle to the preceding portion, each portion being forced by a stack of strips or plates, there being a strip-free or plate-free deflecting zone between each two adjacent said portions; the stack of said plates or strips which is adjacent the blower having a corner edge which is at least partially responsible for an initial separation of the two flow paths and which is substantially coplanar with the blower rotor partition; there being a longitudinal partition disposed in the casing longitudinal zone adjacent the end of the heat exchanger remote from the blower, said partition being substantially coplanar with one corner edge of the stack which is most remote from the blower, said partition defining two chambers, each flow path communicating with a separate respective chamber, each chamber having a respective air outlet.

It is known from the Journal "Techno-Tip" Jahrgang 10, No. 6 of June 1980, Page 10, to provide a ventilating system with a heat recovery heat exchanger which is of cross-flow construction and which has longitudinal portions arranged consecutively as a zig-zag in the flow direction, each such portion having, between two exchanger zones which are consecutive, and which are at an acute angle to one another, and which are formed by stacks of appropriate sheet metal channel members, a channelmember-free deflecting zone. However, the inlet flow and the discharge flow pass through the heat exchanger in opposite directions to one another, and to achieve identical rates of airflow in the opposite directions the intake fan and the exhaust fan are associated with opposed ends with the heat exchanger.Thus, the intake fan and the exhaust fan cannot be operated as a secondary heat exchanger.

Thus a ventilating device in accordance with the preferred embodiment of the invention has the substantial advantage over the known ventilating devices outlined above, not only of requiring a reduced outlay, but also of being of compact construction. A further advantage of the preferred embodiment of the invention is that the radialblower acts as an additional heat exchanger which operates in the region of maximum temperature differential between the exhaust air and the fresh air intake. The blower acts in a chamber that is common to both airflows,thus enabling a satisfactory exchange of atmospheric humidity between the air flows, as well as optimum heat exchange, without appreciable impairment of the separation of the two air flows before they enter the main heat exchanger.

Preferably, the volute for the blower is bounded by inserts in the blower-receiving chamber, and preferably the blower has a stator secured, in the casing, to a retaining plate which is independent of said inserts. It is then a simple matter to remove the blower from the casing of the device for servicing and replacing without touching the means defining the volute for the blower. Preferably the inserts are made of a sound-damping material, and convenient lythe inserts are made of a foamed plastics material or sponge rubber. The inserts may be located in the casing by means of the stator retaining plate.

Preferably the blower rotor, and its transverse wall are made of a material which is a good heat conductor, and those surfaces of the inserts which bound the volute for the blower are covered by a foil of a material which is a good heat conductor to form an additional heat exchanger between the two flow paths in the region of the two halves of the radial blower. The rotor may be formed of sheet metal, such as blackened sheet metal, and the sheet metal may be copper. Preferably the foil comprises copper or aluminium foil.

Advantageously the corner edge of the stack adjacent the blower is disposed at a distance from the blower rotor periphery while the corresponding corner edge of the stack remote from the blower is connected directly to the edge of said partition. This facilites the exchange of atmospheric humidity between the air being discharged from the space being ventilated and the inlet air.

In one embodiment of the invention each individual strip or plate in said stacks has a "C" section and those strips or plates which are disposed directly above one another or beside one another in the same layer are arranged alternatively at an offset from one another of 90" around an axis normal to the plane of the strips or plates. Preferably the stacks are so disposed that the corner edges of the adjacent stacks are immediately adjacent one another and said corner edges extend between two side plates and are located in position by means of cross connection bars which engage the corner regions of the stacks adjacent said corner edges.

Conveniently at least a longitudinal portion of the casing which is adjacent the said heat exchanger has on the inside thereof a supporting insert of sounddamping material. The sound-damping material may be a foamed plastics material. The provision of the insert of sound-damping material, together with the previously mentioned inserts, may serve to reduce the noise in the room being ventilated caused by the ventilator. It is envisaged that in a preferred embodiment of the invention the sound-damping coefficient will be 33dB with the grilles open and 39dB with the grilles closed.

Conveniently the longitudinal walls of the casing extending parallel with the axes of the stacks are immediately adjacent the corner edges of the stacks.

Preferably at least one of the longitudinal walls of the casing extending parallel to the longitudinal axes of the stacks is provided with means for varying this distance between an element carried by the lonitudinal wall and the adjacent stack corner edges. This enables the device to operate, for example in the Summer, without any heat recovery between the intake air flow and the exhaust air flow. It is to be appreciated that since the fresh air and the waste air flow through the main heat exchanger in the casing in the same direction as one another, but following flow paths which cross one another, when one of the longitudinal walls of the casing is moved so that there is a distance between the element carried by the longitudinal wall and the adjacent stack corner edges, there is a "short circuit" between the two air flows, so that the air in the two air flows may mix and mingle. Thus the device operates to mix the waste air being exhausted from the room with fresh air being introduced to the room. If the spacing of one longitudinal wall can be very relatively to the corner edges of the stacks the "short circuit" between the two air flows may be such that most of the joint delivery of the two halves of the radial flow blower goes through the fresh air inlet aperture into the room, a smaller proportion of the air issuing through the waste air aperture.

Preferably one or more adjustable plates are associated with the or each casing longitudinal wall extending parallel to the stack longitudinal axes, said adjustable plates being movable transversely of themselves by displacement or pivoting or hinging thus serving to vary the distance relatively to the stack corner edges adjacent to them. Conveniently the relative position between the stacks and the or each said adjustable plate can be varied by one or more actuating elements which are manually or power operated.

In one preferred embodiment of the invention the said longitudinal partition is rigidly secured to the adjacent end of the heat exchanger which is remote from said blower, said partition having a terminal portion which is bent or curved towards one of said air outlets. Preferably said bent or curved portion of the partition engages behind the air outlet. Conve nientlytheretaining plate for the stator of the blower and the heat exchanger end near said blower engage with one another positively and releasably by way of push couplings extending perpendicularly to the length of the heat exchanger and the retaining plate for the stator, each coupling being embodied buy a push pin and means defining a co-operating aperture. The push pin may be on the retaining plate, and the push aperture may be in the heat exchanger.The push pin may be secured by a resilient plug, such as a plug formed of rubber.

Preferably said bent or curved terminal portion of the longitudinal partition has a support projection which engages a support surface disposed near the air outlet and extending transversely of the casing length. Advantageously the total length of the heat exchanger combined with the longitudinal partition and of the retaining plate coupled therewith corresponds with the distance between one end of the casing and the support surface adjacent the air outlet. This facilitates assembly and servicing of the ventilator, since all the operative elements can be easily aligned relatively to one another and to the casing and can be easily secured in position.

Conveniently the sound-damping support insert engaging with the heat exchanger on one side thereo is disposed on the inside of a cover plate which can be releasably and positively connected to the retaining plate and/or heat exchanger by way of push couplings and which, by way of pivoting lugs, is movable transversely of its length within the casing.

In one embodiment of the invention two air grilles are provided associated respectively with one of said inlets and one of said chambers, closure plates being provided for said grilles. Preferably said closure plates form a single integral unit extending over the whole length of the casing, therebeing a longitudinally displaceable sound-damping insert disposed between said unit and the cover plate.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a perspective view of one embodiment of a ventilating device in accordance with the invention, the device being viewed from the side of the device that is normally located within a room to be ventilated; Figure 2 is another perspective view of the device illustrated in Figure 1, but showing the portion of the device that is usually located towards the exterior of the room to be ventilated; Figure 3 is a horizontal section taken on the line Ill-Ill of Figures 1 and 2; Figure 4 is a vertical section taken on the line IV-IV of Figure 3; Figure 5 is a section taken on the line V-V of Figures 3 and 4;; Figure 6 is a section taken on the line VI-VI of Figures 3 and 4; Figure 7 is a sectional view taken on the line VII-VII of Figures 3 and 4; Figure 8 is a perspective view of a stack of strips or plates forming part of the main heat exchanger which is visible in Figures 3 and 4; Figure 9 is a view similarto Figure 8 showing part of another stack of strips or plates for the main heat exchanger, using a variant of the discrete strips or plates; Figure 10 is a horizontal section corresponding to Figure 3, through a modified embodiment of a ventilating device in accordance with the invention; Figure 11 is a section taken on the line XI-XI of Figure 10;; Figure 12 is a view corresponding to Figure 2 and constituting a perspective view, from the side that is normally adjacent the exterior of the room, of a further embodiment of a ventilator in accordance with the invention; Figure 13 is a horizontal sectional view taken on the line XII-XII shown in Figure 12; figure 14 is a vertical sectional taken on the line XIV-XIV of Figure 13; Figure 15 is a cross sectional view taken on the line XV-XV of Figures 13 and 14; Figure 16 is a sectional view taken on the line XVI-XVI of Figures 13 and 14; Figure 17 is a sectional view taken on the line XVII-XVII in Figures 13 and 14; Figure 18 is an exploded front perspective view of the ventilator of Figure 2, the view showing the part of the ventilator that is normally located towards the interior of a room to be ventilated;; Figure 19 is a perspective view, on an enlarged scale, of the part marked XIX in Figure 18, this part being the rear part of the unit formed by the heat exchanger and the longitudinal partition; Figure 20 is a view on a large scale of that portion of the ventilating device which is marked XX in Figures 17 and 18; and Figure 21 is a view on an enlarged scale of that part of the ventilating device which is marked XXI in Figure 13.

Referring initially to Figures 1 to 2 of the accompanying drawings a ventilating device for use in ventilating a room has an elongate substantially parallele pipedic casing 1. The casing 1 is formed from a substantially channel-sectioned member 2 of generally "U" cross section, and a front member 3 which closes the open long side of the member 2, together with two end plates which serve to close the open ends of the channel-sectioned member.

The end plates 4,5 can be secured rigidly to the member 2, or can be connected to the member 2 in such a way that the plates cannot readily be released from the member. However, the front member 3 is preferably releasably secured to the member 2, to facilitate access to the inside of the casing 1 from the room, once the casing has been fixed to a wall or window. The channel-section member 2, and the front member 3, can be made of a light metal, such as aluminium, and the end plates 4,5 are preferably made of a plastics material.

The channel section member 2, in a wall part 6 thereof which extends between the two arms of the "U" sectioned channel, is provided, adjacent the two ends of the channel-sectioned member, with two air passages 7, 8. These air passages are illustrated as being of circular shape, but may be of any other suitable configuration. The front member 3 of the housing 1 has apertures formed therein which define air grilles 9, 10 disposed adjacent the two ends of the front member. Means are provided to enable the grilles 9 and 10 to be opened and closed as required to vary the flow of air through them. These means may comprise a known slider or baffle member arranged to move within the casing 1.

It is to be understood that the air passages 7 and 8 can communicate with the atmosphere through tubular conduits 11, 12, and the conduits may extend through appropriate apertures formed in a wall or window adjacent which the casing 1 is located. Such conduits may be terminated on the exterior of the building containing the room to be ventilated by known terminations for such conduits.

Referring now additionally to Figures 3 to 7 a radial-flow blower 13 is provided which is adapted to intake air axially on both sides. The blower 13 is disposed within the casing 1 in the region where the casing 1 has the air passage 7 and the grille 9. The blower 13 has a single rotor 14 which is provided with a transverse or cross wall 15 subdividing the single rotor 14 into two substantially identical rotor halves 14', 14". The rotor 14' is so located that the intake side 16 thereof is located neår the air passage 7, and the rotor half 14" is located so that the intake side 17 thereof is near the grille 9. This location of the rotor can be seen in Figure 3.As can be seen in Figure 4 the rotor stator 18 is secured by way of plurality, e.g. three, support arms 19 to a retaining plate 20 which extends parallel to the length of the casing 1 and is releasably secured therein. The plate 20 is formed with an aperture 21 therein which is located substantially concentrically with the intake side 17 of the rotor half 14" and which thus provides a through flow connection between the grille 9 and the intake 17 of the rotor half 14". Inserts 22, 23 made of sound-damping material, such as a foamed plastics material or sponge rubber, are located in the casing 1 near the blower 13 and are retained in position by the stator retaining plate 20.The insert 22 forms the outer volute forthe rotor 14, while inserts 23 are linear elements which extend in the discharge direction of the rotor halves 14', 14". The inserts 22,23, in cooperation with the casing wall part 6 and with the plate 20 extending parallel thereto define in the casing 1 a chamber 24 which accommodates the two rotor halves 14', 14". The chamber 24 is undivided lengthwise except near the rotor 14 where it is divided longitudinally by the cross wall 15 of the rotor The rotor 14 is made entirely of a material which is a good heat conductor, for example a thin sheet or plate of metal.Thus the vanes 14"', which are continuous over the entire width of the rotor, the vane and rings of the rotor (not shown) and the cross wall 15 of the rotor are all made of the abovementioned heat conductive material. Also the surfaces of the inserts 22,23 which bound the rotor volute are covered with a thin metal foil which is also in good heat conductor, for example a foil of copper or aluminium.

Thus the rotor 14 and the metal foil on the inserts 22,23 form, in the chamber 24, a heat exchanger between the two air flows conveyed by the rotor halves 14', 14".

Communicating with the chamber 24, but located at a distance 25 from the periphery of the rotor 14, a main heat exchanger 26 is provided. The heat exchanger 26 is of the cross-flow type and has an odd number of strip or plate stacks 27', 27", 27"', clamped between two parallel side walls 28' and 28".

The main heat exchanger 26 is located to receive two streams of air from the rotor 14, when the ventilating device is operating.

When the front member 3 has been removed from the channel section member 2 the main heat exchanger 26 can easily be removed from the casing for servicing, and can easily be replaced in the central longitudinal region within the casing as a single unit.

As can be appreciated by considering Figures 8 and 9 of the accompanying drawings each stack 27', 27",27"', of the main heat exchanger 26 comprises a large number of discrete members in the form of strips or plates 27 each being of substantially C-section and being, in pian, substantially square.

The members 27 are prepared from a relatively thin material which is a good heat conductor, e.g.

aluminium or copper plate. The members 27 are placed immediately above one another in the appropriate layer positions to form the discrete stacks 27', 27", 27"'.

As will be understood from considering Figures 8 and 9, the discrete members 27 of each of the stacks 27', 27", 27"', are arranged alternately at an offset from the previous element in each case, the offset in each case being 90 around an axis normal to the plane of the elements 27 so that the plates bound between them airflow passages which are alternate ly at 90 offset from one another so that the air flows in the flow passages which are consecutive in the layering, and which cross one another.

As can be understood from Figure 3 the stacks 27', 27", 27"', are so retained between the two side walls 28' and 28" that their two diagonally opposite edges 29', i.e. the vertical corner edges of the stacks located at the ends of one diagonal across the stack, are disposed in casing 1 in a plane coinciding with the plane defined by the rotor cross wall 15, while the other two diagonally opposite vertical corner edges 29" are near the wall part 6 and the front member 3 of the casing 1.

The vertical corner edges 29" of the stacks 27', 27", 27"', contact the inside surface of a sound damping insert which is mounted on the rearface ofthefront member 3 and the inner surface of a sound damping insert which is located on the interior face of the wall part 6 of the channel sectioned member 2. Consequently, the stacks 27', 27", 27"', are firmly held in position in the casing 1 between the side walls 28' and 28" and, together with the inserts 30, 31 define two separate airflow paths each having an odd number of sections which are arranged consecutively as a zig-zag in the flow direction. One such flow path is indicated by the solid arrows 32, and the other flow path is indicated by the open arrows 33.

In each said section of the flow paths 32, 33 there is a strip-free or plate-free deflecting zone 34,35 respectively between each two exchanger zones which are consecutive in the flow path. Of course, the axis of the flow of air through a second exchanger zone is at an acute angle to the flow of air through the first exchanger zone. The existence of the deflecting zones ensures that the airflow is distributed uniformly among the various flow channels existing through each stack.

In order to prevent the existence of a "short circuit" between the two flow paths 32, 33 in the exchanger 26, that is to say to prevent air in the flow path 32 passing into the flow path 33, and also to prevent air in the flow path 33 passing into the flow path 32, the adjacent stacks have their adjacent corner edges 29' contiguous or touching, and cross bars or rods are provided in the region of these contiguous or touching corner edges 29', the cross bars or rods 36 serving to interconnect the two side walls 28', 28" and thus locate the same correctly in relation to the stacks 27', 27", 27"', and also serving to provide a substantially air tight seal between the two flow paths.

Located in that longitudinal region of the casing 1 which follows the final stack 27"' when considered in the direction of the flow paths through the heat exchanger is a longitudinal partition 37 which is coplanar with the corner edges 29' of all the stacks 27', 27,27"' and which is substantially contiguous with the corner edge 29' of the final stack 27"'. The partition serves to define, together with the remaining parts of the casing, two end chambers 38 and 39, the end chamber 38 being associated with the above described air passage 8 and the air chamber 39 communicating with the air grille 10.

In operation of the described device the blower rotor 14 is caused to rotate. Two flows of air are thus taken in respectively through the passage 7 and the grille 9. The two flows of air are acted on by the respective rotor halves 14', 14" and are directed, as indicated by the initial arrows 32,33, into the ends of the two flow passages through the main heat exchanger 26. The two air flows follow the above described zig-zag paths through the main heat exchanger 26, whilst advancing generally in the main flow direction, and finally the two flows enter the two separate end chambers 38 and 39 to issue therefrom through the air passage 8 and the grill 10 respectively.Since there are an odd number of longitudinal portions of the main heat exchanger 26, which are arranged to be consecutive in a zig zag manner in the flow direction, the air flow taken in through the passage 7 by the rotor half 14' is eventually expelled through the grille 10, whereas the air flow taken in by the rotor half 14" through the grille 9 is expelled through the passage 8.

It will be understood that if the air flow taken in through the grill 9 is the waste air flow to be discharged from a room, whereas the air flow taken through the passage 7 is fresh air to be introduced to the room, the air issuing from the passage 8 is the discharge flow, while the air issuing from the grille 10 is the inflow or intake air.

As the air passes through the blower 13, as described above the conductivity of the rotor and the conductivity of the foil on the inserts defining the chamber in which the rotor is located serve to exchange heat between the two air flows, the flow of heat serving to commence the process of equalising the temperatures of the two flows of air. As the two streams of air pass through the main heat exchanger 26 this heat exchanging process continues and it has been found that the warm waste air may yield a substantial proportion of its heat, for example at least 70% thereof, to the fresh air flowing in cocurrent through the described apparatus. Consequently the intake air enters the room at a higher temperature than the air on the exterior of the building, whereas the air discharged from the building is at a lower temperature than the air extracted from the room.Consequently the described apparatus can serve to provide adequate ventilation associated with considerable heat recovery, thus minimising the heat requirements for a room provided with the ventilator.

Since the two rotor halves 14', 14" of the blower 13 operate in a common chamber 24, there can be an optimum exchange of atmospheric humidity between the two co-current air flows, with the result that not only is there an adequate transfer of heat from the air being exhausted from the room to the air being introduced to the room, but also there is only a minimum risk of condensation orfrosting and icing due to the temperature of the respective path through the heat exchanger dropping below the dew point of the exhaust stream of air, or to a temperature below freezing point.

The two flows of air do not mix excessively within the common chamber, even though there is no partition in the common chamber between the two flows of air (apart from the transverse wall 15 provided on the rotor) since both the two streams of air are moving at a considerable velocity, and thus they do not mix substantially even in the region between the blower rotary periphery and the main heat exchanger 26. The transverse wall 15 of the rotor and the adjacent stack corner edge 29' act indirectly as air deflectors and provide an imaginary, although effective, separation zone between the two air flows.

Figures 5 to 7 serve to illustrate the very simple and easy-to-easy service construction of ventilating device of the kind hereinbefore described. They show that all the operational elements of the combined ventilator and heat recovery facility are readily accessible from the room side of the ventilating device afterthe front member 3 has been removed.

It is to be appreciated that, as shown in Figure 3, the longitudinal location of all the functional elements in the casing is achieved quite simply. The rotor stator retaining plate 20 and the longitudinal partition 37 located between the two end chambers 38 and 39 both bear, by way of their outer ends, against the casing end plates 5 and 4 respectively, while the inner ends of these two longitudinally extending components are releasably secured, by screws 40, to the main heat exchanger 26. Since the heat exchanger 26 is clamped resiliently between the inserts 30, 31 on the inside of the casing 1, the inside end of the plate 30 and the inside end of the partition 37 are located securely in the required position within the casing 1.It is to be noted that the outer end of the plate 20 is secured in the desired position in the casing 1 by having the said outer end clamped resiliently between an abutment 41 formed on the inner surface of the end plate 51 and the insert 22 of the blower 13. The outer end of the partition 37 is correspondingly clamped resiliently between an abutment 42 formed on the inner face of the end plate 4 and a resilient insert 43 which has one face thereof defining part of the end chamber 38.

Figure 3 also illustrates a closure plate 44 which is adapted to move transversely to the plane of the grille 9 in casing 1 so that the grille 9 can be opened or closed for the passage of air at will. A corresponding closure plate is associated with the grille 10. If desired the two plates 44, 45 can be moved in the same direction by a common driving mechanism.It is to be appreciated that instead of utilising plates 44, 45 intended to move transversely to the plane of the grilles it would be equally possible to utilise sliding plates, each apertured with apertures having a pattern corresponding to the pattern of the apertures of the respective grille, the plates being adapted to slide, whilst in contact with the grille, within a plane that is parallel to the plane of the grille, so that the apertures in the plates can be brought into alignment with the apertures and the grille to open the grille, and can be displaced from such an aligned position to close the grille.

Figure 8 illustrates more clearly the arrangement of the strips or plates 27 which form a stack in the heat exchanger. It is to be understood that the various strips or plates 27 shown have planar edge webs 46 which extend perpendicularly to the main plane of the elements 27. These edge webs 46 act on the oncoming air as impingement surfaces. In contrast, Figure 9 illustrates a modified embodiment of the invention in which the edge webs 47 are replaced by wedge shaped portions which provide an improved distribution of the air, without causing excessive eddying, through the discrete flow passages of the stacks. As can be seen in Figure 9, the discrete strips or plates 27 have, in their corner regions, stepped shoulders or the like 48 which have two edges thereof disposed at right angles to each other.The discrete strips or plates 27, and therefore the stacks formed from such strips or plates 27, can therefore bear as a whole, by way of the shoulders 48, on two adjacent surfaces of a square sectioned bar 36. This facilitates the location of the stacks in the desired position.

A modification of the device shown in Figures 3 to 7 is illustrated in Figures 10 and 11,the principal difference residing in the way in which the main heat exchanger 26 is located in position. The main point of difference in the embodiment shown in Figures 10 and 11 is that the sound-damping insert 30, instead of being secured directly to the inside face of the front member 3, is mounted on an adjustable plate 49 which is located behind the front member 3, and can be moved perpendicularly to the plane of the front member 3 within the casing. The plate 49 can be retained either so as to hinge around its top longitudinal edge or so as to tilt around its bottom longitudinal edge, or may be displaceable transversely of itself.The position of the plate 49 can be adjusted by means of one or more suitable control elements 50 which bear on the front member 3 and which can be either manually or power operated. For the sake of simplicity manually adjustable control elements in the form of adjusting screws 50 are shown in Figures 10 and 11. By means of these elements the adjustable plate 49 can serve to adjust the distance between the insert 30 and stack corner edges 29' near the inser 30, the corner edges 29" either engaging sealingly with the inside of covering 30 or being positioned at varied distances therefrom.

When the insert 30 is in engagement with the corner edges 29", the device shown in Figures 10 and 11 acts in the same way as the device illustrated in Figures 3 to 7, as described above. However, if the insert 30 is retracted so as to be located at a distance from the associated corner edges 29", there is effectively a "short circuit" between the deflecting zones 34 and 35 adjacent the insert 30, and thus the two air streams delivered by the rotor halves 14', 14" converge and mix in the interconnected regions 34, 35, and the result is that most of the air delivered by both the rotor halves 14', flows into the end chamber 39 and therefrom through the grille 10 into the room. Consequently the room is supplied not only with fresh air delivered by the rotor half 14' but also, on a re-circulating basis, with most of the waste air delivered by the rotor half 14".

It is to be appreciated that this embodiment of a ventilating device can therefore operate with "air mixing" and when the device is operated in this mode fresh air is combined with most of the waste air extracted from the room to given an increased quality of room input air which, because of the substantial proportion of fresh air, is of better quality than the waste or outgoing air. This kind of operation may prove to be very advantageous in summer since it is usually unimportant to have heat recovery from the outgoing air at this time of year.

It is to be appreciated that the embodiments shown in Figures 3 to 7 can be modified so that the closing plates 44,45 are of unitary construction and extend over the whole length of the casing 1 behind the front member 3. In such an embodiment, however, the insert 30 must be thinner than shown in Figures 3 and 7 and in the central longitudinal region must be fitted to the back of the unitary plate 44,45. When such a unitary plate 44,45 is in the closed position the inner face of the insert 30 will be spaced away from the stack corner edges 29".

However, when the said unitary plate 44,45 is moved into the open position (corresponding to the position shown in Figures 3, 5 and 6) the inside face of the insert 30 will engage the stack edges 29" so that the deflecting zones 34,35 of the two separate flow paths 32,33 become operative and the main heat exchanger will then, as described, transfer heat from the discharge air flow to the fresh air flow.

Conveniently in such an embodimentoftheventilat- ing device, the main heat exchanger may be secured in position in the casing by means of special bridge members which are independent of the insert 30.

Turning now to Figures 12 to 21 anotherembodi- ment of the invention is illustrated. As will immediately be apparent in certain respects this embodiment closely resembles the embodiments described above and like reference numerals will be used for like parts wherever possible, thus making it unecessary to describe all the illustrated features in detail.

Referring initially to Figures 12 and 18 the described embodiment of a room ventilating device in accordance with the invention has a casing 1 assembled from a substantially "U" sectioned channel member 2 which is formed from two substantially identical L-sectioned members 2', 2" which are disposed in laterally inverted relationship to one another and are held together over their entirely by a clamping or catch action through the agency of a coupling section member 2"'.

The corner edges 29" of the stacks 27', 27", 27"', of the heat exchanger 26 contact the inside surface of a sound-damping insert 30 which is located on the back of a cover plate 51, and the inside surface of a sound damping insert 31 provided on the interior of the wall part 6 of the channel sectioned member 2.

It is to be noted that the longitudinal partition 37 which serves to divide the end chambers 38,39, has an inclined terminal portion 37' which is bent out of the plane containing the partition 37 towards the air outlet 8, and is engaged behind the air outlet 8 as can be seen most clearly in Figure 13. This configuration serves to direct air smoothly from the flow path 32 to the outlet channel 8.

It is to be appreciated that in the presently described embodiment alignment of all the operative elements within the casing is easily achieved.

The heat exchanger 26 may be inserted into the casing 1 as an integral unit with the partition 37, and a bent or curved end portion 3t' of the partition 37 engages, by way of a projection 37" supported thereon, on a support surface 8' disposed near the air passage 8 and extending transversely of the casing length. The surface 8' can be formed, as seen in Figure 13 for example, by an end surface of the coupling section member 21D which interconnects the two L sectioned portions 2', 2" of the channel section member 2.The plate 20 is then introduced into the casing in such a way that its outer end engages between the abutment 41 on the end plate 5 and the resilient insert 22, and the other end of the plate 20 is located adjacent the nearby end of the heat exchanger 26 and carries a resilient plug 52, which is preferably formed of rubber (see Figure 21) in which a push pin is retained in alignment perpendicular to the plane of plate 20. The pin 53 engages in an aperture 54 in a bent part 55 of the side walls 28', 28". The pin 53 and aperture 54 will therefore cooperate to provide a releasable positive push coupling operative perpendicularly to the length of the plate 20 and perpendicularly to the length of the heat exchanger 26, and serving to locate the elements 20, 26 in the required position within the casing 1.The cover plate 51, which carries on its interior surface the sound-damping insert 30, is then introduced into the casing transversely of the main plane of the cover plate so as to engage positively by way of apertures 56 with a push pin 57 projecting from the top of plug 52 in the plate 20 (see Figure 21) whereafter a number (e.g. 4) of pivot tabs 58 mounted on cover plate 51 are moved behind longitudinal webs 59 disposed on the inside of top and bottom longitudinal walls of the casing 1, as can be clearly seen from Figures 17, 18 and 20. The cover plate 51 provides a definitive location within the casing 1 for the elements concerned in the introduction and removal of air and in the heat recovery, and is in turn located thereby against lengthwise movement in the casing 1.

In the presently described embodiment the plates 44 and 45 are formed by parts of an integral aluminium extrusion 61 which extends over the whole length of the casing. This member can be seen most clearly in Figures 13 and 15to 18, and is substantially of channel section. The two plates 44, 45 can thus be moved in the same direction by a single drive.

Located on the rear surface of the member 61 in the central region between the two plates 44 and 45 is a resilient sound-damping insert 62 which, when the plates 44 and 45 are open, engages the outside of plate 51, as can be seen best in Figures 13 and 17.

This obviates any "short circuiting" of the flow between chambers 24 and 39 in the casing 1 when the device is in operation. If the insert 62 can move lengthwise of the casing 1 with the extrusion 61, the flow cross-sections of the grilles 9 and 10, such cross-sections being, for example, determined by the positioning of adjacent orifices 63 on the member 61 adjacent the orifices forming the grilles, can readily be varied thus giving a simple way of controlling the proportioning between the two flows of air through the device.

If required, and as shown in Figure 3, the partition 37 can carry, at least on its bent or curved end portion 37' a sound-damping insert 43 whose free end engages behind the abutment of the end plate 4 to provide an appropriate location.

The total length 64 of the heat exchanger 26 combined with the partition 37 and of the retaining plate 20 coupled with the heat exchanger 26 corresponds to the distance between the inside of the casing and plates 5 and the bearing surface 8' in the air outlet 8 so that the main operative elements are always correctly located longitudinally in the casing 1, thus ensuring that when the device is cleaned and serviced by unskilled labor it can easily be reassembled correctly and in the proper sequence.

Mounting the push pins 53,57 in the resilient plugs 52 of the plate 20 has the advantage that any vibrations occurring when the blower 13 is operating are kept away from the push couplings and are therefore not transmitted to the heat exchanger 26 and cover plate 51.

Claims (33)

1. A device for ventilating a room said device comprising a casing defining therewith in two separate flow paths respectively for the introduction of and removal of air from the room, said two flow paths being thermally interconnected for the transfer of heat from the flow path for air being discharged from the room to the flow path for air being introduced to the room, by way of a heat exchange arrangement located within the casing; a single radial flow blower having its rotor extending into both said flow paths and being adapted to create a forced airflow in both said flow paths, said rotor having a radially extending partition, said two flow paths passing through a common chamber defined within the casing adjacent the radial flow blower, said chamber having two air inlets, said inlets being located on opposite sides of the casing and thus being axially opposite one another relative to the rotor of the blower, said chamber being divided longitudinally into portions solely by said blower rotor partition, the two flow paths being constituted by said heat exchanger in a longitudinal region of the casing adjacent said common chamber, the flow paths within said heat exchanger comprising an odd number of longitudinal portions arranged consecutively as zig-zags in the flow direction, each portion of the zig-zag being at an acute angle to the preceding portion, each portion being formed by a stack of strips or plates, therebeing a strip-free or plate-free deflecting zone between each two adjacent said portions, the stack of said plates or strips which is adjacent the blower having a corner edge which is at least partially responsible for an initial separation of the two flow paths and which is substantially coplanar with the blower rotor partition; there being a longitudinal partition disposed in the casing longitudinal zone adjacent the end of the heat exchanger remote from the blower, said partition being substantially coplanar with one corner edge of the stack which is most remote from the blower, said partition defining two chambers, each flow path communicating with a separate respective chamber, each chamber having a respective air outlet.

2. A device according to claim 1, wherein the volute for the blower is bounded by inserts in the blower-receiving chamber, and wherein the blower has a stator secured, in the casing, to a retaining plate which is independent of said inserts.

3. A device according to claim 2, wherein the inserts are made of a sound-damping material.

4. A device according to claim 3, wherein the inserts are made of a foamed plastics material or sponge rubber.

5. A device according to claim 2,3 or 4, wherein the inserts are located in the casing by means of the stator retaining plate.

6. A device according to any one of the preceding claims wherein the blower rotor, and its transverse wall are made of a material which is a good heat conductor, and those surfaces of the inserts which bound the volute for the blower are covered by a foil of a material which is a good heat conductor to form an additional heat exchanger between the two flow paths in the region of the two halves of the radial blower.

7. A device according to claim 6, wherein said blower rotor is formed of sheet metal.

8. A device according to claim 7 wherein said sheet metal is copper sheet.

9. A device according to any one claims 6 to 8 wherein said foil comprises a copper or aluminium foil.

10. A device according to any one of the preceding claims wherein the corner edge of the stack adjacent the blower is disposed at a distance from the blower rotor periphery while the corresponding corner edge of the stack remote from the blower is connected directly to the edge of said partition.

11. A device according to any one of the preceding claims wherein each individual strip or plate in said stacks has a "C" section and those strips or plates which are disposed directly above one another or beside one another in the same layer are arranged alternatively at an offset from one another of 90" around an axis normal to the plane of the strips or plates.

12. A device according to any one of the preceding claims wherein the stacks are so disposed that the corner edges of the adjacent stacks are immediately adjacent one another and said corner edges extend between two side plates and are located in position by means of cross connection bars which engage the corner regions of the stacks adjacent said corner edges.

13. A device according to any one of the preceding claims wherein at least a longitudinal portion of the casing which is adjacent the said heat exchanger has on the inside thereof a supporting insert of sound-damping material.

14. A device according to any one of the preceding claims wherein the longitudinal walls of the casing extending parallel with the axes of the stacks are immediately adjacent the corner edges of the stacks.

15. A device according to any one of the preceding claims wherein at least one of the longitudinal walls of the casing extending parallel to the longitudinal axes of the stacks is provided with means for varying the distance between an element carried by the longitudinal wall and the adjacent stack corner edges.

16. A device according to any one of the preceding claims wherein one or more adjustable plates are associated with the or each casing longitudinal wall extending parallel to the stack longitudinal axes, said adjustable plates being movable transversely of themselves by displacement or pivoting or hinging thus serving to vary the distance relatively to the stack corner edges adjacent to them.

17. A device according to claim 16 wherein the relative position between the stacks and the or each said adjustable plate can be varied by one or more actuating elements which are manually or power operated.

18. A device according to any one of the preceding claims wherein the said longitudinal partition is rigidly secured to the adjacent end of the heat exchanger which is remote from said blower, said partition having a terminal portion which is bent or curved towards one of said air outlets.

19. A device according to claim 18 wherein said bent or curved portion of the partition engages behind said air outlet.

20. A device according to claim 2 or any claim dependent thereon wherein the retaining plate for the stator of the blower and the heat exchanger end near said blower engage with one another positively and releasably by way of push couplings extending perpendicularly to the length of the heat exchanger and the retaining plate for the stator, each coupling being embodied by a push pin and means defining a co-operating aperture.

21. A device according to claim 20 where the push pin is on the retaining plate and the push aperture is in the heat exchanger.

22. A device according to claim 20 or 21 wherein the push pin is secured by a resilient plug.

23. A device according to claim 22 wherein the plug is formed of rubber.

24. A device according to claim 18 or any claim dependent thereon wherein said bent or curved terminal portion of the longitudinal partition has a support projection which engages a support surface disposed near the air outlet and extending transversely of the casing length.

25. A device according to claim 24 wherein the total length of the heat exchanger combined with the longitudinal partition and of the retaining plate coupled therewith corresponds with the distance between one end of the casing and the support surface adjacent the air outlet.

26. A device according to claim 13 or any claim dependent thereon wherein the sound-damping support insert engaging with the heat exchanger on one side thereof is disposed on the inside of a cover plate which can be releasably and positively connected to the retaining plate and/or heat exchanger by way of push couplings and which by way of pivoting lugs, is movable transversely of its length within the casing.

27. A device according to any one of claims 1 to 26 wherein two air grilles are provided associated respectively with one of said inlets and one of said chambers, closure plates being provided for said grilles.

28. A device according to any one of the preceding claims wherein said closure plates form a single integral unit extending over the whole length of the casing, therebeing a longitudinally displaceable sound-damping insert disposed between said unit and the cover plate.

29. A room ventilating device substantially as herein described with reference to and as shown in Figures 1 to 8 of the accompanying drawings.

30. A ventilator substantially as herein described with reference to Figures 1 to 8 as modified by Figure 9 of the accompanying drawings.

31. A ventilator device substantially as herein described with reference to Figures 10 and 11 of the accompanying drawings.

32. A ventilator device substantially as herein described with reference to and as shown in Figures 12 to 21 of the accompanying drawings.

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