GB2269664A - Ventilator - Google Patents

Abstract

A ventilator for a room having a heating appliance is set in an outside wall. The ventilating passage is defined by interengaging identical sleeve parts 1a and 1b having opposed L-shaped baffles directing the air flow in a generally S-shaped direction to exclude light and draughts. An air brick 2 and a telescopically slidable member 3 with a grille 4 co-operate with parts 1a, 1b. The ventilator parts are plastics mouldings. The parts 1a, 1b may have a rectangular or circular cross-section. In an alternative construction, a cylindrical ventilator is defined by three extruded sectors having end portions of their radial partitions cut-away. <IMAGE>

Description

" Improvements in Ventilators " The present invention relates to a ventilator for admitting air to an enclosed space typically a living or working room. The ventilator will normally be passive, i.e. without a fan or equivalent.

Good building practice and now legislation insists that, if a room or other enclosed space incorporates a combustion appliance particularly a gas, oil or solid fuel fired heater or boiler the space is adequately vented. A combustion appliance burns not only fuel but also the oxygen in the air and if sufficient fresh air is not provided then the unit will tend to use available oxygen in the room. Additionally if air supply to the appliance is inadequate noxious or possibly toxic combustion products may find their way into the room.

The present practice is to form a hole in an outside wall and to provide at the outside of the hole an air brick or equivalent and at the inside a ventilator grill. An inserted structure usually prefabricated of plastic connects the air brick and grill and constitutes a cavity lining.

Such a ventilator may allow draughts and provides a see-through passage which may be a worrying factor.

The fitting of an internal screen tends to reduce airflow, may become blocked with dust or similar and is contrary to current regulations.

According to the present invention the inserted structure defines an indirect passage in which the airflow is caused to change direction. In an embodiment the structure includes baffles which direct the airflow initially forwardly i.e. in the entry direction then in a reverse direction and finally forwardly again to provide a generally S-shaped flow passage. The airflow is not substantially restricted, merely caused to change direction and the disadvantages set out above will be largely avoided.

This generally S-shaped flow path can conveniently be realised in an embodiment by making the lining of two similar matching parts, each with an internal L-shape baffle and formed to interengage with one another to define the passage in a manner to be described.

In an alternative embodiment longitudinally spaced baffles alternately upstanding and depending define the indirect air passage. This embodiment can conveniently be made of matching parts joined about a horizontal line.

First and second particular embodiments of the invention will now be described with reference to the accompanying drawing wherein: Figures 1 and la are exploded views of a ventilator in accordance with a first embodiment of the invention; Figure 2 is a view of the ventilator of Figure 1 installed in the wall; Figures 3 and 4 are schematic views showing the airflow; and Figure 5 is a schematic view of a second embodiment.

Referring initially to Figure 1 of the drawings the ventilator assembly illustrated comprises a lining 1 having, an airbrick member 2 fitted to the outer end and at the inner end a telescopically sliding extension member 3 terminated with a internal grill 4.

The airbrick 1 is moulded of plastic, as a honeycomb, with a plurality of passages. The grill 4 may be of any appropriate form typically with horizontal cross slats (not shown).

The lining 1 comprises two identical moulded plastics parts la (Figure la) and ib, which are slidably interconnected in the manner shown with one inverted relatively the other to define together with the airbrick 2, the extension member 3 and grill 4 the indirect air passage in accordance with the present invention. Each part la, ib is a sleeve of rectangular cross section with an internal Section flange 5 constituting a baffle and extending the full width.

Each flange 5 comprises a vertically disposed first part 6, upstanding or dependent as the case may be and a horizontal part 7 with an interconnecting inclined or chamfered part 8. The horizontal part 7 projects forwardly slidingly to engage the other part.

To achieve this each part la, 1b has grooves 9 into which the laterally extended parts 10 of flange part 7 are received. Each sleeve has a half rim 11 with the entries to grooves 9. A vertical stiffening vane 12 extends from the part 7 to the sleeve wall. On interconnection as shown in Figure 1 the half rims 11 co-operate to provide a complete rim which prevents the passage of moisture; obstructed moisture drips into the cavity between the wall sections. The telescopically slidable part 3 has locating side cut-aways (13) to engage the outer wall of slots 9 and ribs 15 on the underside of the lining part lb. The air brick 2 is fitted in a shallow socket at one end of lining part la, the socket being defined by a cut-away rim 16. The grill 4 is fixed to a flange i7 at one end of extension part 3.

The co-operation of baffle flanges 5 defines an S-shaped air passage allowing indirect air flow in the direction of arrows a.

Figure 2 shows the ventilator in position. The simulated airbrick 2 is embedded in bricks B of an outer wall whilst the effective length of the ventilator is adjusted by telescopic sliding of the extension part 3 which in turn is set in blocks C of an inner wall, the conventional cavity being provided between the bricks and the blocks.

Figures 3 and 4 illustrate airflow under a smoke test.

Figure 3 shows air and smoke passing forwardly and inwardly from the outside under natural draught from airbrick 2 through the indirect S-shaped passage to grill 4 and into the room. Flow direction is illustrated by arrows (a). No heating appliance is working within the room and the flow is sluggish with turbulence. The air and smoke may be regarded as being blown by external ambient conditions and in the situation shown in Figure 3 little internal draught is experienced. It will be appreciated moreover that the baffle flanges 5 block view through the ventilator.

When a heating appliance is working within the room the situation of Figure 4 prevails with internal suction and flow of air and smoke as in arrows B.

Turbulence is substantially eliminated and an effective ventilating air flow develops.

According to a development of the invention the ventilator outer casing may have a circular cross-section to be inserted into a cavity formed by a core drill, i.e. a drill with a cylindrical bit having a front cutting edge which on insertion and subsequent withdrawal removes a cylindrical core leaving the air passage. Core drilling is a convenient way of forming a passage through a masonry wall.

Apart from the cylindrical outer casing the ventilator may be described in the earlier application, the ventilator being preferably made in two halves as before.

Figure 5 of the drawings, however, shows an alternative construction wherein a cylindrical ventilator 21 for introduction into the cylindrical cavity formed by a core drill comprises three 1200 extruded sectors 22, 23, 24 fitting with one another to form the cylinder. Air flows in the direction of arrows (a) forwardly through one sector 22, rearwardly through the adjacent and second sector 23 and finally forward again through the third sector 24 to define the indirect air flow passageway as covered by the earlier patent application.

To achieve this at the far end of the ventilator in the direction of airflow the meeting walls of sectors 22 and 23 are cutaway at 25 whilst at the near end the meeting end parts of sectors 23 and 24 are cutaway at 26. The end parts of the sectors are closed.

With a cylindrical ventilator casing in a cavity formed by a core drill the air brick and the grill will be correspondingly disc-shaped or have disc-shaped parts.

Claims (7)

CLW

1. A ventilator for admitting air to an enclosed space comprising an insert structure for a cavity formed through a wall enclosing the space, characterised in that the said structure defines an indirect passage in which the airflow is caused to change direction.

2. A ventilator according to Claim 1 wherein the structure includes baffles which direct the air flow initially forward then in a reverse direction and finally forward again.

3. A ventilator according to Claim 1 or 2 wherein the structure is formed of two similar parts each with an I,shaped flange and formed to interengage with one another to define the indirect flow passage.

4. A ventilator according to any preceding claim wherein the air flow is turbulent and sluggish when a heating appliance within the space is inoperative but smooth to provide effective ventilation when the appliance is operating.

5. A ventilator according to Claim 1 or Claim 2 of cylindrical construction to fit a cavity formed by a core drill and having three extruded sectors fitting with one another to form the cylinder.

6. A ventilator substantially as herein described with reference to and as shown in Figures 1 to 4 of the accompanying drawings.

7. A ventilator substantially as herein described with reference to and as shown in Figure 5 of the accompanying drawings.