AN ARRANGEMENT FOR EQUALISING THE FLOW OF VENTILATION AIR

Abstract: An arrangement for taking ventilation air into a building. The air is taken into the building through an exterior wall that includes an air-permeable, thermal insulation layer (10). The substantial area of the thermal insulation layer forms a first wall (1) of an air distribution chamber that includes a second wall (3) which is generally parallel with the first wall. The chamber also includes a perimeter wall which defines the chamber together with said first and said second walls. The second wall includes an outlet opening (6) which takes-up a small part of the area of the second wall. The distribution chamber includes an air distribution membrane (2) which extends generally parallel with and is generally spaced from said first and said second walls (1 and 3) and which covers the outlet opening (6) in the plane of the second wall. The major part of the air flowing into the chamber is caused to flow generally parallel with the surface of said membrane (2) in a direction towards the chamber perimeter wall, and is then deflected to flow towards and out through said outlet opening.

Description: AN ARRANGEMENT FOR EQUALISING THE FLOW OF VENTILATION AIR The present invention relates to a ventilation arrangement of the kind defined in the preamble of Claim 1. SE-B-403 640 teaches a building construction of the kind included by the preamble of Claim 1. The known arrangement utilises the thermal insulation in the exterior wall/roof to recover heat and to filter outdoor air, which is sucked into the building through the layer of thermal insulating material. When air is drawn by suction into the building interior through the layer of heat-insulating material at a very low rate of flow, an exchange of heat takes place. As cold outdoor air passes through the insulation on its way into the building in the cold period of the year, it cools down the thermal-energy carrying insulation fibres, wherewith the outdoor air is heated and the heat returned back into the building. Even a thin thermal insulation layer will provide a highly effective heat-insulating effect. As a result of the low rate of flow, the thermal insulating layer will also engender an effective filtering effect, such that the through-passing air will be practically particle-free. Because the air is sucked in through a large thermal insulation area, loading of the thermal insulation with particles separated from the air sucked through the insulation will be negligible in light of the practical life span of the building. In practical applications, it has been found that this known technique results in less desirable effects in certain instances, inasmuch that the air flowing into the building obtains a low temperature, which indicates deficient flow distribution through the thermal insulation layer, which, in turn, indicates that~1ϊτe theoretical improvement of the thermal insulation effect obtained by sucking air into the building has been completely or partially lost. This problem has long been known, and attempts have been made to limit the problem by providing the thermal insulation layer with an air-distributing, air-permeable layer whose air resistance is higher than the resistance of the actual heat insulation layer although such measures have been unable to restrict the occasionally occurring problems to any appreciable extent. Accordingly, an object of the present invention is to provide a ventilation system with which the aforesaid problem is eliminated completely or partially. This object is achieved with a ventilation arrangement according to the accompanying Claim 1. Further developments of the arrangement are set forth in the accompanying dependent Claims. Thus, it has surprisingly been found that the aforesaid problem can be limited significantly by arranging in the air distribution chamber between its first and its second wall and in spaced relationship therewith an impervious membrane which is generally plane-parallel with said first and second walls, wherein the membrane leaves an airflow gap between an substantial part of its perimeter and the perimeter wall of the distribution chamber, and wherein the outlet opening is preferably disposed centrally of the membrane in the plane of the second wall. The distribution chamber may be filled-out with at least two groups of battens, with the battens of each group being mutually parallel, while intersecting the battens of adjacent groups. The membrane is placed conveniently between two mutually adjacent groups of battens. The membrane may also be suspended in an undulating fashion from the upper joist layer and optionally supported by the lower joist layer. The opening is suitably placed between two mutually adjacent battens of the group of battens that border on the second wall of the chamber. Naturally, air can be taken out through several openings in the second wall. For instance, an outlet opening may be provided through the second wall in each compartment between two mutually adjacent battens in that group of battens that borders on said second wall, wherein an air receiving box connects to the inner surface of the second wall, which may form a ceiling plate in a living space in the building. The air receiving box thus receives the combined airflow from all openings in the second wall, and the filtered and preheated air can be transported from said box to selected locations in the building, through appropriate channels and passageways that include a blower for blowing the collected outdoor air to desired locations. The invention can be applied equally as well in the walls of a building, in the same way as that described above, when desiring to conduct outdoor air through the wall insulation instead of through the roof insulation. Examples of applications are multistorey apartment blocks with separate apartments in the plane. The invention is applied in the manner described in the above paragraph, and measures are taken to prevent a direct through- flow of air at the openings. The invention has been described above with reference to operating conditions in wintertime, when heat is delivered to the building and when attempts are made to reduce the building heating requirements . The invention will now be described with reference to exemplifying embodiments thereof and also with reference to the accompanying drawings . BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic exploded view in perspective of part of the roof of a building which incorporates an inventive arrangement for the intake of outdoor air. Fig. 1A is a schematic sectional view taken immediately beneath the roof insulation 10 under an air-permeable resistance layer 1 (corresponds to the first wall) . The section also includes roof trusses 11. Fig. IB is a schematic, perspective sectional view taken in the upper batten layer 12 beneath an air distributing membrane 2. Fig. 1C is a perspective sectional view taken in the lower batten layer 13 beneath the sealing layer 3 (the second wall) having outlet openings 6. Fig. ID is a schematic sectional view in perspective of a collecting box 5. Fig. IE is a schematic sectional view in perspective of a collecting box 5 above the collecting-box bottom 4. Fig. IF is a schematic sectional view in perspective taken through the bottom 4 of the collecting box 5. Fig. 2 shows vertical sections A-A and B-B of the invention with a collecting box mounted in the wet-room of a building having circulating interior air. The building is shown in Figs. 2 to 5 inclusive. Fig. 3 is a schematic sectional view taken in the upper batten layer 12 above an air distributing membrane 2. Fig. 4 is a schematic sectional view taken in the lower batten layer 13 above the sealing layer 3 with through-flow openings 6. Fig. 5 is a schematic sectional view taken through the collecting box above the collecting-box bottom 4. DESCRIPTION OF EXEMPLIFYING EMBODIMENTS Fig. 1 is a schematic exploded view in perspective of part of the roof of a building that includes an inventive arrangement for the intake of outdoor air. The illustrated roof insulation 10 is of a known porous nature which allows outdoor air to seep slowly into the building interior in uniform distribution, such as supply air to the rooms and spaces in the building, as a result of a subpressure acting within the building or generated by a supply-air fan placed within the collecting box. The insulation 10 may be provided with an air-permeable pressure equalising layer 1, for instance a fabric material that has a resistance such as to distribute the air generally uniformly over the insulation area. Because it is desired in the application of the invention in this particular example to lead the air to a single supply air channel for outdoor air, there is a risk of local, more or less punctiform, air flows passing through the roof insulation immediately above the supply air channel 9. Consequently, there has been provided in a space beneath the roof insulation 10 and the distributing layer 1 two layers of battens or lathes 12 and 13 placed cross-wise above a bottom of a sealing layer 3, for instance a layer of flexible plastic foil on top of a false ceiling comprised of gypsum sealing board, for instance . In the layer between the battens above the opening 6, in the illustrated case two openings formed in the bottom of said space, there has been placed an air-impermeable, air- distribution membrane 2, for instance a flexible plastic foil, having an extension aimed at spreading the air sucked-in from the opening 6 to the outer extremities of the membrane. The air-impermeable air-distribution membrane 2 may also be suspended in an undulating fashion from the upper joist layer and optionally supported from beneath by the lower joist layer. Corridors (compartments or gaps) in which the outdoor air moves in a direction towards the edges of the membrane are formed above the membrane together with the battens 12 and the permeable resistance layer 1 in the region of the extension of the membrane . Corridors are also formed between the battens 13 and the sealing layer 3, beneath the membrane in the illustrated example. Outdoor air moves in these corridors in 90-degree (or 270- degree) directions relative to the direction over the membrane towards the outlet opening 6. The outdoor air is then further collected before being led to the channel 9. To this end, an impervious collecting box 5 is mounted beneath the openings 6. This also includes a collection opening 7 (or several) in one of the box walls, connected to the channel 9, or a collection opening 7' (or several) in the box bottom 4. The illustrated example also includes an air supply fan 8 fitted with a silencer and placed in the collection box in connection with the channel 9 through the collection opening 7. Fig. 1A is a sectional view taken immediately beneath the roof insulation 10 under the air-permeable resistance layer 1. The Figure also shows the roof trusses 11. Fig. IB is a sectional view taken in the uppermost (the first) batten layer 12 beneath the air distribution membrane 2. The upper batten layer 12 is fastened along and to the roof trusses in the illustrated case. Fig. 1C is a sectional view taken in the lower batten layer 13 beneath the second (the lower) wall 3 having two outlet openings 6. Fig. ID is a sectional view taken through a collection box 5 immediately above the collection-box bottom 4. The collection box covers all outlet openings 6. Fig. IE is a sectional view taken through the collection box 5. Mounted in the collection box is a fan 8 for further transportation into the living spaces, via the channel 9. Fig. IF is a sectional view taken through the collection box, the bottom 4 of which includes an outlet opening 7'. Figs. 2-5 show the invention applied in a two-storey building with circulating indoor air. Fig. 2 is a vertical sectional view taken on the line A-A in Fig. 5 and shows the collecting box disposed in the wet room in the upper storey of the building. Fig. 3 is a sectional view taken in the uppermost batten layer 12 above the air distribution membrane 2. The batten layer 12 is fastened along and to the roof trusses in the illustrated case. If desired, the battens 12 may be doubled so as to better support the roof insulation 10. The battens positioned between the roof trusses are then supported by the underlying batten layer 13. Naturally, the layer 12 may be commenced at right angles to the roof trusses or at an angle of, e.g., 45 degrees thereto, and the lower layer 13 orientated at, e.g., an angle of 90 degrees to the upper layer 12. Fig. 4 is a sectional view taken in the lower batten layer 13 above the sealing layer 3 having five outlet openings 6. Fig. 5 is a sectional view taken through the collection box immediately above the collection-box bottom 4. The collection box covers all through-flow openings 6 and is delimited longitudinally by the walls of the wet room. It will be seen that the relatively simple procedure of placing an impervious membrane 2, plastic foil, of relatively small extension between the batten layers 12 and 13 and cutting several holes in the plastic foil forming the sealing layer 3 takes only a moment to carry out and provides effectively a considerably larger suction area over the roof insulation 10 than would otherwise have been the case if the suction had been placed immediately above the channel 9. The suction area is also far greater than when located immediately above the opening 6, which would have been the case if the collection box was used immediately beneath the sealing layer 3. Many buildings that include dynamic outdoor air intakes have been constructed (almost a hundred in Sweden) although none of these buildings has functioned fully satisfactorily in this respect. (See the report issued by the National Swedish Institute for Building of Research "Optimat - a concept for energy efficient and ..." carried out by Lund's Technical Institute.) And still no one has arrived at the simple concept fundamental to the present invention. Supply air to the building is taken in through a channel system 9 that communicates with the surroundings in a conventional manner, wherein the supply air is preferably either led into supply air channels leading to a fan unit and through a heating arrangement and further channelway passing through the floor structure/ floor structures, or on other ways into the utilitarian spaces. Although the invention has been described and illustrated with reference to exemplifying embodiments of the invention, it will be understood that the invention is not restricted to these embodiments, but solely by the scope of the following Claims.

Claims: CLAIMS 1. An arrangement for taking ventilation air into a building, wherein the air is taken into the building through an exterior wall that includes an air-permeable, thermal insulation layer (10), wherein a substantial area of the thermal insulation layer forms a first wall (1) of an air distribution chamber that includes a second wall (3) which is generally parallel with the first wall, wherein the chamber also includes a perimeter wall which defines the chamber together with said first and said second walls, and wherein the second wall includes an outlet opening (6) which takes-up a small part of the area of the second wall, characterised in that the distribution chamber includes an air distribution membrane (2) which extends generally parallel with and is generally spaced from said first and said second walls (1 and 3) and which covers the outlet opening (6) in the plane of the second wall, whereby the major part of the air flowing into the chamber is caused to flow generally parallel with the surface of said membrane (2) in a direction towards the chamber perimeter wall, and is then deflected to flow towards and out through said outlet opening. 2. An arrangement according to Claim 1, characterised in that the main membrane (2) is attached to the first wall in an undulating fashion. 3. An arrangement according to any one of the preceding Claims, characterised in that the thermal insulation layer (10) includes an associated plane-parallel air-permeable layer (1) that has a greater resistance to air flow than the remaining part of the thermal insulation layer. 4. An arrangement according to any one of the preceding Claims, characterised in that the outlet opening (6) is centred in relation to the membrane. 5. An arrangement according to any one of the preceding Claims, characterised in that the distribution chamber includes at least two layers of battens (12, 13), wherein the battens of each layer are mutually parallel but intersect the battens of adjacent layers, wherein said batten layers have a height which corresponds to the distance of the distribution chamber between said first wall (1) and said second wall (3), whereby the first and the second walls of said chamber can be supported by said batten layers in a load distributing manner. 6. An arrangement according to any one of the preceding Claims, characterised in that the air distribution membrane is displaced towards the centre of the distribution when the outlet opening (6) of the second wall (3) is excentrically positioned in relation to the extension of the air distribution chamber; and in that the air distribution membrane is connected in sealing contact with the neighbouring perimeter wall of the air distribution chamber, when placing the outlet opening (6) in the proximity of the perimeter walls of said air distribution chamber. 7. An arrangement according to any one of the preceding Claims, characterised in that at least one collection box (5) is mounted in close connection inwardly of the outlet openings (6) in the sealing layer (3) of the air distribution chamber, wherein the collection box includes in at least one of the free walls a hole, and outlet opening (7; 7'), for further transportation of outdoor air. 8. An arrangement according to any one of the preceding Claims, characterised in that the air distribution membrane (2) is mounted between two batten layers (12, 13) with at least one batten layer (12) located between the insulation (10) and the air distribution membrane (2), wherewith outdoor air is forced to flow in the extension region of the air distribution membrane (2) , in the gap-forming compartment that is formed between the insulation layer and the air distribution membrane and the battens, mainly in one or the other direction along the battens (12; 13) in the neighbouring layer on both sides of the air distribution membrane (2). 9. An arrangement according to any one of the preceding Claims, characterised by a supply air fan (8) which is placed within the suction box in sealed connection with the collection opening (7) of said box, said fan functioning to suck air from within the collection box and blow the air through the collection opening (7).

Inventors: WEGLER GEORGE, WEGLER, GEORGE
Applicants: WEGLER GEORGE, WEGLER, GEORGE
Application year: 1998
Main classification: E04B1
IPC codes: F24F13