Heat-recovery units

Abstract: A heat-recovery unit includes an outer housing 2 and a heat-recovery cell 1 with two separate air passages 11 and 12 therethrough opening on faces 13, 15, 16, 18 of the cell. The upstream face 13, 15 of each passage is adjacent and inclined at 90° to the downstream face 16, 18 of the other passage. A turret 33, 35, 36, 38 on the housing 2 at each inlet 3, 4 and outlet 5, 6 is rotatable about its axis and has an angled coupling 43 rotatable on the turret about an axis at right-angles to the axis of the turret. The inlet, upstream turrets 33, 35 each contain a filter 133, 135 and the outlet, downstream turrets 36, 38 each contain a centrifugal fan 136, 138.

Description: This invention relates to heat-recovery units of the kind including a heat-recovery cell having two end faces at opposite ends of a first passage for warm waste air and two end faces at opposite ends of a second, separate passage for cool inlet air. Heat-recovery units are used in buildings to transfer some of the heat in stale air exhausted from the building to fresh air brought into the building. These units usually contain a heat-recovery cell having multiple paths for the warm exhaust air and the cool inlet air separated by thermally-conducting walls, so that the heat from the exhaust air is transferred through the walls to the inlet air. These units can operate with a high efficiency but have several disadvantages. The units tend to be large and heavy, making transport, installation and servicing difficult. The weight of the units can complicate installation, since heavy duty fixings are required and reinforcement of building structure may be needed. The size of the units and the location of their inlets and outlets often complicates installation especially in restricted spaces and may require additional lengths of ducting and contorted paths. This can increase resistance to flow and reduce output. FR-A-2 533 682 discloses a heat-recovery unit as claimed in the preamble of claim 1. In this document, the box-like casings may be re-oriented in increments of 90° following dismounting from the carcass. It is an object of the present invention to provide an alternative heat-recovery unit, in particular to afford the flexibility of locating the heat-recovery unit in any disposition or orientation. According to the present invention there is provided a heat-recovery unit including a heat-recovery cell and an outer housing having two inlets and two outlets for air passing through the unit, characterised in that at least one of the inlets or outlets includes a generally cylindrical turret mounted on the housing for angular displacement about its axis, that the turret has a port projecting substantially radially therefrom, and that the turret includes a fan arranged to move air through the housing via the turret and the port. The or each fan is preferably a centrifugal fan arranged axially of the or each turret. The or each turret may be provided with an angled coupling, preferably with an angle of substantially 135°, that is rotatable about an axis at right angles to the axis of rotation of the or each turret. The turret at each inlet may include a filter. A heat-recovery unit according to the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a plan view of the unit; Figure 2 is a perspective view of the unit; and Figure 3 is a perspective view of the cell. The unit includes a heat-recovery cell 1 located within a housing 2 having two inlet 3 and 4 and two outlets 5 and 6. The cell 1 may be of conventional construction comprising a stack of heat-conducting plates 10 spaced to define two, separate air passages 11 and 12. The cell 1 is of lozenge shape having six major vertical faces 13 to 18 and parallel upper and lower surfaces 19 and 20. One of the vertical faces 13 provides an upstream inlet for one of the air passages 11 and is inclined at an angle of about 45° to the length of the cell. The opposite face 16 is inclined parallel to the face 13 and provides a downstream outlet from the passage 11. The faces 14 and 17 extend parallel to one another and to the length of the cell and are both closed. The vertical face 15 provides the upstream inlet for the other passage 12 and is inclined at an angle of about 45° to the length of the cell, in the opposite sense from the face 13. The sixth face 18 lies parallel to the face 15 and provides the downstream outlet for the second passage 12. The inlet and outlet faces 13 and 18 lie adjacent one another at one end of the cell, whereas the other inlet and outlet faces 15 and 16 lie adjacent one another at the opposite end of the cell. The housing 2 is a box-like structure moulded of plastics material and has substantially the same shape as the cell 1. The interior of the housing 2 is thermally insulated such as by means of a foam material (not shown). The housing has six major vertical faces 23 to 28 located adjacent respective ones of the faces 13 to 18 respectively of the cell. The longitudinal faces 24 and 27 of the housing have a slightly concave profile and are closed. The faces 23 and 25 have circular openings providing the inlets 3 and 4 to the housing 2, whereas the faces 26 and 28 provide outlets 5 and 6. Each of the faces 23, 25, 26 and 28 support a respective turret assembly 33, 35, 36 and 38 comprising a cylindrical wall 40 closed at its outer end 41 and rotatably mounted at its inner end 42 on the housing 2 for angular displacement about its axis. The turret assemblies 33, 35, 36 and 38 also each include a port in the form of a tubular coupling 43 of dog-leg shape extending radially outwardly of the cylindrical wall 40. The coupling is bent at an angle of 135°. The tubular coupling 43 is mounted at its inner end on the cylindrical wall by means of a rotatable joint 44 so that it can be rotated about an axis extending at right angles to the axis of rotation of the turret assembly itself. The rotatable joints of the turrets on the housing and of the couplings on the turrets may include ratchets or detents so that the components locate in several predetermined fixed positions relative to one another and resist free rotation. Two fans 136 and 138 are mounted on the housing 2 and extend within the turret assemblies 36 and 38 respectively. The fans 136 and 138 are oriented to rotate about the axis of the turret assemblies. The fans 136 and 138 are of a centrifugal type, which move air radially outwardly, and are arranged axially of the turret, so that the air flows out through the tubular couplings 43 of the turrets 36 and 38. The other two turret assemblies 33 and 35 are located at inlets 3 and 4 of the housing 2 and contain filters 133 and 135 to filter air passing into the heat recovery unit. The housing 2 also has several short drain spigots 50 located at positions distributed about the housing so that water condensed within the housing will drain through one of the spigots regardless of the orientation at which the unit is mounted. The unit is installed by connecting the coupling 43 of the first inlet turret 33 to one end of a conduit (not shown) the other end of which connects with an air inlet vent located in a room from which warm air is to be vented, such as, for example, a bathroom or kitchen. The coupling 43 of the turret 36 on the opposite side of the housing 2 is connected to a conduit leading to an external vent. The coupling 43 on the second inlet turret 35 is connected via conduit to an external vent and its opposite turret 38 has its coupling connected to a conduit leading to a room to which fresh air is to be supplied. The turret assemblies 33, 35, 36 and 38 can be rotated to any convenient orientation to simplify connection with conduits and to avoid bends in the conduit. As illustrated , the turrets 35 and 36 are oriented with their couplings 43 extending outwardly, horizontal at right angles to the length of the unit, whereas the turrets 33 and 38 at the opposite end of the unit are oriented with the couplings extending parallel to the length of the unit. The turrets need not be oriented horizontally but could extend up or down, as desired. Because the inlet and outlet turrets can be oriented in many different positions, it greatly simplifies installation, especially in confined spaces. When the fans 136 and 138 are operating, stale, warm air is drawn by the fan 136 through the inlet turret 33 and its filter 133, passing directly into the face 13 of the cell 1 and along the air passage 11. As the air passes through the cell 1, it gives up a part of its heat to the plates 10 of the cell before emerging from the opposite face 16 and directly into the turret assembly 36. Similarly, cool, fresh air is drawn by the fan 138 through the inlet turret 35 and its filter 135, passing directly into the face 15 of the cell 1 and along the air passage 12. As the air passes through the cell 1, it takes up a part of the heat stored in the plates 10, emerging warmed from the opposite face 18 and passing directly into the turret assembly 138. The two paths for air flow through the housing 2 are, therefore, substantially unidirectional, that is, the air is not diverted through more than about 45° during its passage between the faces of the housing. Because the inlets and outlets of the housing are located directly adjacent the faces of the heat recovery cell, air flows directly into and out of the cell, without the need for it to be diverted or channelled within the housing itself. The configuration takes advantage of the fact that the fans themselves naturally cause the air flow to be diverted through 90° so, by locating the fans in the rotatable turrets, there is no need for significant additional diversion of the air flow paths. This enables the size and weight of the housing to be kept to a minimum.

Claims: A heat-recovery unit including a heat-recovery cell (1) and an outer housing (2) having two inlets (3,4) and two outlets (5, 6) for air passing through the unit, characterised in that at least one of the inlets (3,4) or outlets (5,6) includes a generally cylindrical turret (33, 35, 36, 38) mounted on the housing (2) for angular displacement about its axis, that the turret (33, 35, 36, 38) has a port (43) projecting substantially radially therefrom, and that the turret (36, 38) includes a fan (136, 138) arranged to move air through the housing (2) via the turret (36, 38) and the port (43). A heat-recovery unit according to Claim 1, characterised in that the or each fan (136, 138) is a centrifugal fan arranged axially of the or each turret (36, 38). A heat-recovery unit according to Claim 1 or 2 characterised in that the or each turret (33, 35, 36, 38) is provided with an angled coupling (43) that is rotatable about an axis at right angles to the axis of rotation of the or each turret (33, 35, 36, 38). A heat-recovery unit according to Claim 3 characterised in that the or each coupling (43) has an angle of substantially 135°. A heat-recovery unit according to any one of the preceding claims characterised in that the turret (33, 35) at each inlet (3, 4) includes a filter (133, 135).

Inventors: COTTINGHAM NEIL DOUGLAS, COTTINGHAM, NEIL DOUGLAS
Applicants: VENT AXIA GROUP LTD, VENT-AXIA GROUP LIMITED
Application year: 2001
Main classification: F24F12
IPC codes: F24F12, F24F13, F28D9, F28F3, F28F9