AU2015200818A1

AU2015200818A1 - Ventilation System

Info

Publication number: AU2015200818A1
Application number: AU2015200818A
Authority: AU
Inventors: David Mcgrath
Original assignee: SUSTAINABLE AGRICULTURAL MACHINERY DEVELOPMENTS Pty Ltd
Current assignee: SUSTAINABLE AGRICULTURAL MACHINERY DEVELOPMENTS Pty Ltd
Priority date: 2003-05-29
Filing date: 2015-02-18
Publication date: 2015-03-12
Anticipated expiration: 2024-05-31
Also published as: AU2014101263A4; AU2015200818B2

Abstract

A ventilation system comprises a duct 4 that defines an air passage and has an inlet; and at least one flap 5 to seal the duct 4 when the ventilation system 1 is quiescent, the system 1 preferably being associated with a motorized fan housed in the duct. The flap 5 has a first portion 11 and a second portion 8 about which it rotates about a pivot member 9, wherein the first portion 11 has a greater surface area than the surface area of the second portion 8 and the weighting of the second portion 8 is such that the flap 5 is biased to the closed position. Fig. 1

Description

-1 VENTILATION SYSTEM Technical Area This invention relates to a ventilation system and in particular to a method of controlling airflow through airconditioning systems. Background to the Invention The following references to and descriptions of prior proposals or products are not intended to be and are not to be construed as, statements or admissions of common general knowledge in the art, In particular, the following prior art discussion does not relate to what is commonly or well known by the person skilled in the art, but assists in the understanding of the inventive step of the present invention of which the identification of pertinent prior art proposals is but one part. When airconditioning systems are operative, either sending warm or cold air to an area, the air is passed through ducts and into the area through registers and the registers may have internal arrangements where the quantity of air which can pass therethrough can be varied to an overall balancing of the system. However, when the system is not operating, there can be effectively uncontrolled movement of air to or from the area which can be heated or cooled to the duct system. This can be annoying or can be somewhat more than that if, say, the volume concerned was heated by a wood fire or other heater, largely for appearance sake but also to provide certain heat. A high percentage of the energy in heating the air can be lost as the heated air, of course, rises, a percentage of this will strike the register and it can pass backwards through the ducts.

-2 Outline of the Invention It is an object of the present invention to provide a ventilation system which includes means whereby when the system is operative there is little or no resistance to the passage of air into an area but when the system is not operating, the flow of air from the area is restricted. In one aspect, the present invention provides a ventilation system comprising a duct adapted to be connected to an outlet; a pivotal closure in a closed position covering the outlet; and a stop attached to the duct to limit rotation of the pivotal closure, wherein: the closure has an outer portion and an inner portion rotatable about a pivot member positioned between the outer portion and the inner portion; the inner portion is biased to bias the closure towards the closed position when the ventilation system is quiescent; and the stop is axially adjustable to vary the resistance to the passage of air through the outlet when the closure is in an open position. It is preferred that the closure means is a flap pivotally mounted within a duct. It is further preferred that the flap has provided an outer portion that extends outwardly and downwardly such that they are adapted to abut an inner surface of a duct to provide a seal when the system is quiescent. It is preferred that the means of adjusting the degree of air flow through the system is an adjustment member in the form of a bar adapted to pass between the flaps. It is further preferred that the adjustment member can be adjusted upwardly and/or downwardly along the axis of the duct to enable the angle of opening for the flaps to be varied. It is preferred that the degree of rotation of the flaps be able to be controlled so that the ventilation system can also act as a balancer.

-3 In order that the invention may be more readily understood we shall describe one particular embodiment of system made in accordance with the invention. Brief description of the Drawing Figure Figure 1 is a side cross-sectional view of a preferred embodiment of the ventilation system according to the invention. Figure 2 is a perspective view of a preferred embodiment of the ventilation system according to the invention. Figure 3 is a plan view of a preferred embodiment of the ventilation system according to the invention. Description of an Embodiment of the Invention Figures 1 to 3 show a preferred embodiment of the invention as it relates to a ventilation system which is adapted to be located within a duct. In this embodiment, the ventilation system 1 is in the form of a sleeve 2 or the like which is adapted to be connected to the inlet of a ceiling register and which is also adapted to have the normal duct work connected thereto. The ventilation system 1 is adapted to be located within a cylindrical duct 4, although the invention could be equally applied to square or rectangular ducts. The ventilation system 1 is provided with two flaps 5, each of which has an external periphery 6 which is adapted to lie about the internal surface 7 of the duct 4. Each flap 5 has provided at its upper end an inwardly directed portion 8 which may be transverse to the duct.4 with the remainder being at an angle to this.

-4 The flap 5 is adapted for rotation in the duct 4 by means of a pivot member 9 which passes through the opposite walls of the duct 4 adjacent the centre plane through the duct. The inner ends 10 of the flaps 5 may be provided with weighting so that the rest situation is that the flap 5 rotates about the pivot member 9 with the external periphery 6 of the flap in abutment with the wall of the duct. The surface area of the flap portion 11 is greater than the surface area of the inwardly directed portion 8 however, the weighting is such that the inwardly directed portion 8 effectively causes positive rotation about the pivot member 9. Mounted in the duct 4 and having a transverse axis between the inner ends 10 of the inner portions of the flaps 5, there is an adjustment member 12. The adjustment member 12 is in the form of a bar which is adapted to pass between the two ends 10 of the flaps 5 and a cap 13 which may be effectively a continuation of the slope of the flaps, when at rest, or can take any other shape. The adjustment member 12 can be moved axially of the duct through a pair of slots 14 provided in the duct, through which attachments to the bar may also pass. Provided on the underside of the top of the adjustment member 12 are two downwardly protruding portions 15 which act as a stop for the flaps 5 as they move about their pivot axes, the shorter inner end 10 will tend to rise until it strikes the downwardly protruding portions 15 of the bar. Thus by adjustment of the adjustment member 12 relative to the inner ends 10 of the flaps 5 can enable the angle that the flaps 5 can open to be varied.

-5 The slots 14 in each side of the duct will normally be covered by the adjustment member 12 but can also have screws or the like which can be passed to lock the adjustment member 12 in a required position. About the internal periphery of the duct there can be a sealing member (not shown) which can be of a flexible material, such as a silicone or form of rubber member upon which the upper surfaces of the flaps can rest when the flaps are at rest so as to make a good seal and so that, there can effectively be no movement of air from the area beneath the ceiling register back into the ducting system. In practice, when there is no air passing through the air conditioning ducting, the counterweight on the flaps 5 will bring the external periphery 6 of the flaps into position beneath the sealing member so that there is effectively a good seal around the periphery of the duct 4. Thus, should there be air in the volume beneath the ceiling register tending to move upwardly, this will simply strike the underside of the flaps 5 and any pressure that is applied, which would not be great, would tend to further seal the area of contact. Thus, for example, if a fire was lit in the area beneath the duct and there was no air flowing through the airconditioning system, then there would be no hot air loss from the room as this would be restrained by the flaps 5 within the duct 4. Once the airconditioning system is started and air is passing through the ducts 4 this air will strike the flap portion 11 of the flaps 5, cause the flaps to move about the pivot member 9 so that the air passes through the device to the ceiling register and thus to the room being monitored.

-6 Once the airconditioning system again stops, say when the thermostat indicates that the room has reached the required temperature, then the flaps 5 will again rise, make contact with the periphery of the duct 4 and prevent the conditioned air from passing back into the duct. Any air entering the house through the registers from the outside, such as strong wind blowing into the airconditioning unit on your roof, will also be stopped as it will not exert sufficient force on the flap portion to cause it to open. The top of the adjustment member 12 may be formed so that there is little disturbance of the airflow as possible and it may be in an inverted "V" which acts as a splitter to cause the air to pass into different streams towards each of the flaps 5. The adjustment member 12, as indicated previously, can be adjusted upwardly and downwardly along the axis of the duct 4 and held into whatever position is required by screws passing through the slot 14 in the side of the duct 4 into the adjustment member 12. Depending upon the location of the adjustment member 12, the inner ends 10 of the flaps 5 will strike the downwardly protruding portions 15 of the cap 13 of the adjustment member 12 and this will be the maximum opening for the device. Thus, regardless of the volume and/or pressure of the air passing onto the flaps 5, they will be able to open only the required distance. In this way, adjustment can be achieved so that the quantity of air which passes through the ceiling register is as required. For example, it may be required to set up the flaps of various ventilation system in the building to give an air distribution of the type: Dining Room 20% Lounge Room 30& Kitchen 30% Bedroom 20% If at any time it is wanted to change this air quantity it is only necessary to raise or lower the adjustment member 12 so that the maximum opening of the flaps 5 is controlled. The ventilation system 1 is adapted so the degree of rotation of the flaps 5 is able to be controlled so that the system is also able to act as a balancer. It will be seen that, once the device of the invention is located and correctly adjusted, it is fully self-operating and no steps need to be taken by the user. In this specification we have described that there are two flaps 5 which, between them, cover effectively the whole of the duct 4. It is possible to provide three or even more flaps 5 to provide a better seal around the base of the device 1 in which case the form of location of the flaps 5 may have to be varied so that they do not foul each other's pivot arm. This may be done by locating the pivot member 9 onto the side of the duct 4 so that it only extends into the duct 4 the distance equivalent to the width of the flap 5. The flaps 5 could be made from injection moulded plastics material or any other form of material required to provide these and the actual size and shape, other than where they are constrained by the shape of the duct 4 with which they are to be used, can also be varied. Normally, the system of the invention will be used in close proximity to a ceiling register which can be of a standard form or it can be located in a duct 4, normally one which would be relatively close to a ceiling register.

-8 Thus the invention is useful either to retrofit, when it is located in a duct 4, or in new fittings, when it is located in a ceiling register. All such variations and modifications may be made without departing from the spirit and scope of the invention. Throughout the specification and claims the word "comprise" and its derivatives are intended to have an inclusive rather than exclusive meaning unless the contrary is expressly stated or the context requires otherwise. That is, the word "comprise" and its derivatives will be taken to indicate the inclusion of not only the listed components, steps or features that it directly references, but also other components, steps or features not specifically listed, unless the contrary is expressly stated or the context requires otherwise.

Claims

1. A ventilation system comprising: a duct defining an air passage and having an inlet; and at least one flap having an external periphery to abut and to seal a wall -of the 5 duct in a closed position when the ventilation system is quiescent, wherein the at least one flap comprises a pair of flaps, each flap configured to have a substantially round and curved sealing edge which forms the external periphery of each flap, each said flap being rotatable about at least one pivot member 10 which passes through opposite sides of the wall of the cylindrical duct, and each of the flaps being weighted to be biased to the closed position so that the ventilation system is self-closing to seal the cylindrical duct when quiescent.

2. A ventilation system according to claim 1, wherein each of the flaps comprises a primary portion that in the closed position is adapted to incline downwardly 15 from the at least one pivot member to the wall of the cylindrical duct.

3. A ventilation system according to claims 1 or 2, wherein the at least one pivot member passes through opposite walls of the cylindrical duct adjacent a centre plane through the duct.

4. A ventilation system according to any one of claims 1 to 3, wherein the at least 20 one pivot member comprises a pair of pivot members, with each said flap rotatably mounted to one said pivot member.

5. A ventilation system according to any one of claims 1 to 4, wherein each said flap has a second portion on the side of the pivot member opposed to the primary portion and there is a counterweight on the second portion. 25

6. A ventilation system according to claim 5, wherein the second portion lies in a plane transverse to the longitudinal axis of the cylindrical duct and the primary portion lies in a plane at an angle to the second portion. -10

7. A ventilation system according to any one of claims 1 to 6, wherein the system is associated with a motorized fan that, when activated, causes air to pass through the cylindrical duct and to strike the surface area of the primary portion, causing each said flap to move about the at least one pivot member so that air passes 5 through the ventilation system.