GB2477502A - Passive ventilation device having a three in one filter - Google Patents

Abstract

A passive ventilation device comprises a single filter inserted into a ventilation duct 'L. The filter comprises an upper `G' and lower thermal core `H' for heat loss, an uneven face `K' for managing noise transmission and an upper `E' and lower `F' air filtration medium for the removal of particulates in the air communicating through the duct. The filter is a three in one filter and may be removed for cleaning or replacement. The device may be installed in the duct without modification of the duct. The duct may be circular or rectangular. The length of the filter may be varied to suit a particular application. The thermal core of the filter may be angled towards a flow of air from outside the building thereby encouraging air flow through the filter to the outside and impeding incoming air flow from outside, i.e. creating a positive air flow and reducing draughts. The filter may have a compressive thermal insulation layer `M' around its perimeter that self seals with the duct, whereby the insulation layer may align with cavity wall insulation `A' to reduce cold bridging around the duct.

Description

Description Title

Managing air flow throughpassive ventilation ducts.

Background

The term passive ventilation' refers to ventilation that is not electrically powered. In domestic housing and commercial premises this would typically consist of air bricks and/or some form of ventilation ducts. Passive ventilation is mostly uncontrolled in terms of air flow management through the ventilation channel.

Should the occupant or user of a building wish to eliminate the unwanted elements contained within the freely moving air passing through a ventilation duct (such as street noise, cold drafts or airborne particles), previous options have been limited to installing new specialised (often mechanical) ventilation devices or blocking off the existing ventilation ducts completely.

Ventilation ducts can be upgraded with the introduction of a filter to deal with a particular unwanted element carried in the air but the use of multiples of filters to deal with different unwanted elements reduces air flow progressively with the addition of each filter. The air gap often required between filters also serves to reduce air flow.

Bonding filters together can result in the blocking of air flow completely.

Although older buildings are often improved to meet the latest standards of insulation, passive ventilation systems are widely overlooked. Uncontrolled ventilation through air bricks and other ventilation ducts is often out of step with modern air filtration, noise transmission and thermal insulation requirements.

Statement of invention

The vent filter device is designed for use in new ventilation duct installations or equally for upgrading existing ventilation ducts where it provides a low disturbance solution to managing air flow. The vent filter device is a completely separate component to the ventilation duct. It is non-electrical, non-mechanical and silent in operation.

The vent filter device is a self-contained single component inserted into a ventilation duct to manage air filtration, reduce noise transmission and reduce heat loss through the ventilation duct while reducing draughts in to the property.

Although primarily intended for ventilation ducts through solid walls, the vent filter device is also suitable for similar applications such as ducts in ceilings, windows and doors.

Advantages The vent filter device is hand push-fit installed into the receiving ventilation duct and is similarly removed.

The vent filter device has no moving parts.

The vent filter device has no air gaps between various filtration layers that reduce air flow through the ventilation duct.

The vent filter device compresses against the inner surface of the duct lining to form a seal without the need for additional components or supporting framework.

The vent filter device includes a thermal core shaped to encourage air flow through the device in the desired direction and reduce heat loss. Air flowing in the opposing direction is partially impeded by the thermal core.

The vent filter device restricts draughts and cold blasts of air passing through the ventilation duct.

Variants of the vent filter device are envisaged for circular and rectangular shaped ventilation ducts through solid walls, being suitable for a range of vent duct sizes, Variants of the vent filter device would be suitable for ventilation ducts through ceilings doors and windows.

Introduction to drawings

The enclosed drawings show a typical vent filter device and its application.

Figure 1 shows a side view of a ventilation duct through a typical cavity wall construction. The vent filter device is shown installed in the ventilation duct.

Label A shows the insulation within the wall cavity.

Label B shows the inner leaf of brickwork (or other construction material).

Label C shows the external leaf of brickwork (or other construction material).

Label D shows the internal face of the filter device.

Label E shows the primary upper air filter element of the device.

Label F shows the primary lower air filter element of the device.

Label G shows the upper part of the thermal core with a smooth top surface.

Label H shows the lower part of the thermal core with a shaped lower surface.

Label I shows the internal grill of the ventilation duct.

Label J shows the external grill of the ventilation duct.

Label K shows the uneven external (acoustic) face of the device.

Label L shows the ventilation duct.

Label M shows a compressive thermal layer around the perimeter of the device.

Figure 2 shows a side view of the vent filter device without the ventilation duct.

Figure 3 shows an end view of the internal face (D) of the filter device (rectangular duct version).

Figure 4 shows an end view of the uneven external face (K) of the filter device (rectangular duct version).

Figure 5 shows and end view of the internal face (D) of the filter device (circular duct version).

Figure 6 shows an end view of the uneven external face (K) of the filter device (circular duct version).

Figure 7 shows a side view of an alternative implementation of the vent filter device.

Label N shows the thermal core implemented in a triangular shape across the width of the filter.

Detailed description

The vent filter device (figure 2) is a single component with no moving parts. The device is hand-installed in to a suitable ventilation duct without modification of the duct. The device is a three in one filter as it manages air filtration (E, F), reduces noise transmission (K) and reduces heat loss (M, G, 1-1). The filter is easily removed for cleaning or replacement.

The length of the vent filter device would typically be in the range of 10-60mm. Vent filter devices of other lengths and various densities are however envisaged for different applications.

The vent filter device is installed into a ventilation duct (L). It is intended the filter device be located into the ventilation duct so that it aligns with any wall cavity insulation (A), thereby reducing cold bridges points (M) around the ventilation duct.

Positioning the filter device more towards the outside or inside is acceptable but may reduce thermal performance, particularly in respect of cold bridging.

The vent filter device has an uneven shape on the outer face (K) to increase resistance to noise transmission and incoming air flows. It is envisaged the degree of unevenness could be varied for a specific application.

The thermal core (G, H) is angled to encourage air flow towards the outside of the building. The shape of the thermal core partially impedes incoming air flows, allowing outgoing air to pass through the ventilation duct more easily than air travelling in the opposing direction, thereby creating a positive air flow in the desired direction and reducing unwanted draughts.

It is envisaged the size or shape of the thermal core may be varied (N) to suit a particular application. The implementation of the thermal core as shown in figure 7 combines an upwards and downwards angle coming to a more pointed edge on the internal side of the device to encourage air flow through the device. In this implementation, incoming air is disrupted by the blunter end of the thermal core on the outer side of the device while encouraging air flow either side of the core from inside.

The vent filter device is intended primarily to manage air flow through a ventilation duct from inside the property to the outside. In a situation where airflow is required in the opposite direction, the device can be fitted with a reverse orientation although this would also reverse the noise transmission resistance. An alternative version of the device with acoustic features on the reverse side is envisaged.

The vent filter is formed from a compressive insulation material (M) that self-seals within the correspondingly sized ventilation duct. In situations where an existing ventilation assembly does not include a lined duct, it may be necessary to pre-install a suitable duct before installing the vent filter device.

Claims (14)

1. SClaims 1. A non-electrical, non-mechanical vent filter device for installation in to passive ventilation ducts to enable the management of noise transmission, heat loss and air filtration through the use of a single filter.
2. 2. A vent filter device according to claim 1, which includes a thermal core shaped to encourage air flow in the required direction and disrupt air flow in the opposing direction.
3. 3. A vent filter device according to claim 1, which allows water vapour to escape while reducing heat loss.
4. 4. A vent filter device according to claim 1, which allows fresh air to enter the building in to which it is installed.
5. 5. A vent filter device according to claim 1, which includes a disrupted surface on its outer face designed to reduce noise transmission through the device.
6. 6. A vent filter device according to claim 1, which is formed from a compressive material that seals against the inner walls of the ventilation duct in to which it is installed.
7. 7. A vent filter device according to claim 4, which prevents the air travelling through the duct from circumventing the device.
8. 8. A vent filter device according to claim 1, which includes a thermal layer around its outer perimeter to reduce cold bridging across the ventilation duct.
9. 9. A vent filter device according to claim 1, which can be easily removed from the duct for cleaning or replacement.
10. 10. A vent duct filter device according to any of the preceding claims, which is distinguishable from the ventilation duct into which it is installed.
11. 11. A vent duct filter device according to any of the preceding claims, variants of which are suitable for rectangular and circular duct applications.
12. 12. A vent duct filter device according to any of the preceding claims, which can be shortened or lengthened to suit a particular application.
13. 13. A vent duct filter device according to any of the preceding claims, where the size and shape of the thermal core can be changed to suit a particular application.
14. 14. A vent filter device according to any of the preceding claims, variations of which can have different degrees of air filtration.