GB2285680A - Ventilators - Google Patents

Abstract

A ventilator (100) comprises a casing (102) and a plurality of spaced air flow baffles (110) each having a plurality of apertures (112) formed therein, the apertures of one plate being out of phase with the apertures of an adjacent plate. The apertures may be square, circular or irregular in shape. The baffles/plate 110 may be formed from sheets of a flexible plastics material interwoven as a mesh. The casing 102 is erected from a flat sheet of plastics and folded along score lines. The casing 102 includes grooves into which the baffles/plates 110 can fit. <IMAGE>

Description

TITLE: Ventilators DESCRIPTION This invention concerns ventilators.

Many properties now have double glazing and fitted carpets as well as other heat saving features, which reduce fresh air flow into a room. Unfortunately, these features also reduce the effect of a chimney to remove combustion products of gas fires and gas fired boilers. Ventilation of a room having a gas fire or gas fired boiler is, therefore, desirable and in some circumstances is a safety requirement.

To ventilate a room such as one having a gas fire or gas fired boiler, there are three types of ventilator which can be fitted in or to a wall opening.

The ventilator may be one that is permanently open, one that can be opened and closed or one that has a restricted air flow through it. These ventilators all have disadvantages. The first has the disadvantage of allowing draughts into a room, which can be unpleasant during cold weather. The second has the disadvantage that in cold weather it will usually be closed to prevent draughts and so required ventilation is not provided. The third type has the disadvantage of not providing sufficient ventilation.

An object of this invention is to provide an improved ventilator.

According to this invention there is provided a ventilator comprising a casing and a plurality of spaced air flow restricting plates in the casing, each air flow restricting plate having a plurality of apertures formed therein, the apertures of one plate being out of phase with the apertures of an adjacent plate.

It is preferred that each air flow restricting plate will have a regular pattern of apertures and that in one plate the pattern will be offset relative to the pattern of an adjacent plate. It is further preferred that when such a pair of air flow restricting plates are fitted in the casing the apertures of one plate will be substantially opposite solid material of the other plate.

The apertures in the plates may be of any desirable shape. Square or circular apertures are preferred but any regular or even irregular aperture shape may be used in the invention.

The amount of free space formed in an air flow restricting plate by the apertures is important and may depend on the ventilation requirements for a particular situation. In a typical situation of a room having a gas fired central heating boiler, a free space, in other words the aggregate size of any openings in an air flow restricting plate or baffle, of around 14 to 15 square inches is required. Thus, the sizing and shape of the apertures may be chosen accordingly.

The preferred air flow restricting plates for ventilators of the invention are formed from sheets, preferably of a flexible plastics material, with apertures cut out of the sheet. An alternative form of air flow restricting plate may be formed of strips of, preferably flexible plastics, material interwoven as a mesh.

The casing for a ventilator of the invention is preferably erected from a flat sheet, preferably of plastics material. The preferred casing has a rectangular cross-section and is preferably sized so that it can fit into a space created by removal of the equivalent of two common house bricks from a wall, although obviously smaller and larger ventilators may be made in accordance with the invention.

The flat sheet is preferably provided with fold lines, such as by scoring or removal of material, such as to form generally V-section grooves, whereby it can be folded up into the desired shape. One end of the flat sheet preferably has means for fixing it to the other end of the sheet in the folded up casing.

Adhesive tabs or strips may be used for that purpose, although any other suitable means may be used including one where interengageable parts are provided at opposite ends of the sheet.

The casing is preferably provided with means for locating the air flow restricting plates in place.

Preferably grooves are formed on the inner surface of the casing into which the plates can fit. The plates are preferably slightly larger than the general crosssectional size of the casing, so that they are retained in the grooves. By using flexible air flow restricting plates the plates may be fitted into the casing after the casing has been erected and installed in a wall opening.

By providing a series of air flow restricting plates each having in a ventilator the required free space provided by its apertures and at least one pair of plates having offset apertures, air flow through the ventilator is disturbed by turbulence created in the ventilator, so that it slows down and unpleasant draughts are not created in the room being ventilated.

Nevertheless the ventilation air requirement for the room can still be satisfied.

Another advantage of preferred ventilators according to the invention is that they can be supplied as a flat pack, which reduces storage and transport costs.

To complete ventilator instalment, grills may be fixed on opposite ends to provide a neat appearance.

This invention will now be further described by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows schematically a first ventilator according to the invention; Figure 2 shows two components of the ventilator of Figure 1; Figure 3 is a side view of a component of the ventilator of Figure 1; Figure 4 is a perspective view of a second ventilator according to the invention; Figure 5 is a front view of the ventilator of Figure 4; Figure 6 is another perspective view, partially cut away, of the ventilator of Figure 4; and Figure 7 shows a casing for the ventilator of Figure 4 laid flat.

Referring to Figures 1 to 3 of the accompanying drawings, a ventilator 10 comprises a rectangular section casing 12 and a series of spaced apart air flow restricting plates 14 in the casing. As shown, the ventilate is mounted in a wall 16 of a space requiring ventilation. Grills 18 are secured to the wall on opposite ends of the ventilator to give a neat appearance. Air flow through the ventilator is indicated by arrows.

Each plate 14 is constructed of a mesh of interwoven strips of plastics materials 22A and B (see especially Figure 3) leaving open areas 24 through which air can flow. The outer air flow restricting plates are the same but the middle plate is different in respect of the positioning of its open areas of the outer plates, so that open areas of the middle plate are in line with solid material of the outer plates when viewed in a direct line along an axis of the ventilator. Thus, any air flowing through the first plate will impact on the middle plate and air flowing through the middle plate will impact on the third plate. In this way turbulence is created within the ventilator which hinders air flow through it. However, air can still enter a room through the ventilator but at a much reduced speed compared to the exterior wind speed, so that ventilation is provided but without necessarily producing unpleasant draughts within the room.

The ventilator 10 is fitted into the wall opening in two stages. Firstly, the casing is inserted into the wall opening and then the air flow restricting plates, being flexible are inserted into the casing. The inside surface of the casing has locations whereby the plates can be correctly positioned and retained in the casing.

Finally the grills are secured to opposite sides of the wall to cover the ventilator ends.

Turning now to Figures 4 to 7, a ventilator 100 comprises a casing 102 of plastics material which is formed as a sheet (sse figure 7) with score lines or Vsection grooves 104, whereby it is folded up to form a rectangular sectioned open ended box. At one end of the sheet is an adhesive strip 106 whereby ends of the sheet are fixed together to form the rectangular section casing. The adhesive strip 106 is provided with a peel able barrier layer which has to be removed in order to form the casing. Thus, the casing can be provided as a flat pack to be erected prior to use.

The casing sheet has on its intended inner surface a series of longitudinal score lines 108, shallower than the fold lines. These score lines in the erected casing form locations for receiving air flow restricting panels 110. The air flow restricting panels 110 are made of flexible plastics sheet material and each has a plurality of circular holes 112 formed therein. There are four plates 110 in two pairs. The plates of each pair have a different arrangement of holes 112. The holes of one plate of a pair of plates are arranged to be directly opposite solid material of the other plate of the pair when they are fitted in the casing. In the illustrated embodiment, the outer plate of each pair has the same hole arrangement as the outer of the other pair and the inner of each pair has the same hole arrangement as the inner plate of the other pair.The size of the holes 112 has been chosen to provide a minimum of 14-15 square inches of open space through each plate which is desirable for ventilating a room containing a gas fired central heating boiler. The plates 112 being flexible are fitted into an erected casing by manoeuvering them into the appropriate location 108, where they are retained because they are slightly larger than the general internal size of the casing.

The result is that when all of the plates are fitted, there is no direct air flow path visible through the ventilator along an axis of the casing.

Therefore, air flowing into the ventilator from outside has its flow interfered with by successive plates 112, which in turn caused turbulence between adjacent plates causing further air flow interference. Therefore whilst air can flow through the ventilator to give required ventilation for a room, the speed of air flow entering the room is much reduced compared to air flow speed entering the ventilator, so that unpleasant draughts may be avoided in the room.

Because the ventilator casing can be supplied flat and, of course, the air flow restricting plates are themselves flat, the ventilator can be supplied as a flat pack and assembled on site when needed. Fitting the ventilator requires removal of sufficient wall area to fit an erected casing and the plates 112 are added once the erected casing is in the wall. Finally grills may be added on opposite ends of the ventilator to give a neat appearance.

It is be appreciated that the number of air flow restricting plates may be varied and the hole shape, size and pattern may be varied without departing from the scope and spirit of the invention.

Claims (14)

1. A ventilator comprising a casing and a plurality of spaced air flow restricting plates in the casing, each air flow restricting plate having a plurality of apertures formed therein, the apertures of one plate being out of phase with the apertures of an adjacent plate.

2. A ventilator as claimed in claim 1, wherein the casing is erected from a flat sheet.

3. A ventilator as claimed in claim 2, wherein the flat sheet is formable into a rectangular section casing.

4. A ventilator as claimed in claim 2 or 3, wherein the flat sheet has fold lines formed therein to enable erection of the casing.

5. A ventilator as claimed in claim 2, 3 or 4 wherein one end of the flat sheet has means for fixing it to the other end of the sheet in forming the erected casing.

6. A ventilator as claimed in claim 5, wherein said fixing means comprises an adhesive tab or strip.

7. A ventilator as claimed in any one of claims 1 to 6, wherein the casing has locations for receiving the plates.

8. A ventilator as claimed in claim 7, wherein said locations comprise grooves on the inner surface of the casing.

9 A ventilator as claimed in any one claims 1 to 8, wherein the plates are of flexible material.

10. A ventilator as claimed in any one of claims 1 to 9, wherein each plate has a plurality of circular apertures formed therein.

11. A ventilator as claimed in any one of claims 1 to 10, wherein in a pair of adjacent plates, apertures of one plate are substantially in line with solid material of the other plate.

12. A ventilator as claimed in any one of claims 1 to 11 having four air flow restricting plates in two pairs, in which each plate of a pair has its apertures out of phase with the apertures of the other plate of the pair.

13. A ventilator as claimed in any one of claims 1 to 9, wherein the air flow restricting plates are made of interwoven strips of material.

14. A ventilator substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 3 or Figures 4 to 7 of the accompanying drawings.