AU2016100030B4

AU2016100030B4 - Roof exhaust fan

Info

Publication number: AU2016100030B4
Application number: AU2016100030A
Authority: AU
Inventors: Asmir Causevic
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-01-13
Filing date: 2016-01-13
Publication date: 2016-06-30
Anticipated expiration: 2024-01-13
Also published as: AU2016100030A4

Abstract

The invention provides an exhaust fan assembly for ventilating a roof space, the exhaust fan assembly comprising: a fitting adapted to be installed in a roof or wall providing an outlet for ventilating air out of the roof space; an electrically powered fan configured to force the air through the outlet; an electrically activated gate mechanism adapted to close and open the outlet; a temperature sensor adapted to sense a temperature inside the roof space; and a controller connected to the temperature sensor, the electrically powered fan and the electrically activated gate mechanism; wherein the controller is adapted to open and close the gate mechanism according to the temperature inside the roof space, and to turn the fan on and off according to the temperature inside the roof space.

Description

ROOF EXHAUST FAN FIELD

[0001] The present invention relates to exhaust fans, in particular to an improved exhaust fan for ventilating roof spaces

BACKGROUND

[0002] Many types of exhaust fan are known for moving air from inside a roof space to the outdoors. Particular exhaust fans are known for ventilating roof spaces for the purpose of exhausting hot air which has accumulated under the roof, typically in a cavity between the roof and a ceiling. The process of exhausting the hot air serves to assist in cooling the living spaces below the roof (typically beneath the ceiling).

[0003] Existing exhaust fans for exhausting hot air comprise electrically driven fans which may be thermostatically controlled so as to operate only when a temperature inside the roof space exceeds a set point. However, even when such thermostatically controlled exhaust fans are not operating with the thermostat below the set point, substantial air is allowed to escape the roof space through the exhaust fan and past the blades of the fan. Because it is advantageous to retain warm air within the roof space particularly during winter months, in order to assist in keeping the living space warm beneath the roof space, this loss of air when the thermostat is below the set point is a disadvantage. While exhausting the air during the summer months increases occupant comfort and reduces energy costs during the summer, losing air in the roof space during the winter months reduces occupant comfort and increases energy costs during the winter.

[0004] There is therefore a need to provide an improved exhaust fan which overcomes this disadvantage.

SUMMARY OF THE INVENTION

[0005] According to a broad aspect of the invention there is provided an exhaust fan assembly for ventilating a roof space, the exhaust fan assembly comprising: a fitting adapted to be installed in a roof or wall providing an outlet for ventilating air out of the roof space; an electrically powered fan configured to force the air through the outlet; an electrically activated gate mechanism, activated by a motor in the exhaust fan assembly, adapted to close and open the outlet; a temperature sensor adapted to sense a temperature inside the roof space; and a controller connected to the temperature sensor, the electrically powered fan and the electrically activated gate mechanism; wherein the controller is adapted to open and close the gate mechanism according to the temperature inside the roof space, and to turn the fan on and off according to the temperature inside the roof space.

[0006] In one embodiment, the controller is configured with one or more temperature set points for opening and closing the gate mechanism and turning the fan on and off.

[0007] In one embodiment, the electrically activated gate mechanism is a damper valve.

[0008] In one embodiment, the electrically activated gate mechanism is disposed between the electrically powered fan and the outlet.

[0009] In one embodiment, the controller is configured to close the gate mechanism at a lower temperature than a temperature at which the controller is configured to turn off the fan.

BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is a perspective view of an exhaust fan assembly according to an embodiment of the invention; and [0011] Figure 2 is an exploded view of the components of the exhaust fan assembly of Figure 1.

DETAILED DESCRIPTION OF EMBODIMENTS

[0012] An embodiment of the current invention will now be described.

[0013] Referring first to Figure 1, the exhaust fan assembly of the embodiment described provides an outlet path for ventilating air out of a roof space according to the arrows shown. A cover 1 prevents the ingress of rain, sitting over an outlet within a roof fitting 2 typically comprised of galvanised sheet metal. Cylindrical duct component 3 contains a damper controlled by electrical motor 9 electrically connected to a controller 7 powered by electrical cord 6 and a power plug 5 for connection to an electrical supply. Affixed to duct component 3 through bolts 10 is an electrically powered fan assembly 11 within a cylindrical housing 4.

[0014] Referring now to Figure 2, an exploded view of the components of the apparatus of Figure 1 is provided. Cover 1 is shown adapted to fit over flange 14 in roof fitting 2. A gate mechanism in the form of a damper valve as a circular plate 13 is shown outside its housing inside cylindrical duct 3. Circular plate 13 is sized to close off the outlet path through cylindrical duct 3 and is rotatable about a horizontal axis 15 by electrical motor 9. Cylindrical housing 4 containing controller 7 is bolted to electrically powered fan assembly 11 comprising an axial fan 12 within a circular aperture.

[0015] Controller 7 in this embodiment is a standard thermostatic controllers used in an air-conditioning systems and the like (model WH7016C, Shenzhen Willhi Electronics Co., Ltd.), and control line 8 provides power to the damper motor 9 when appropriate. Controller 7 is operatively connected to a temperature sensor in the form of a Negative Temperature Coefficient (NTC) thermistor (which may be contained within the housing of controller 7 or which may be appropriately positioned inside cylindrical housing 4 or elsewhere) and controller 7 is configured with a temperature set point which may be programmable on installation, or in more sophisticated embodiments may be selectable by the occupants of the house. Controller 7 is configured so that when the temperature inside the roof space exceeds the set point, as sensed by the temperature sensor, fan 12 is turned on and circular plate 13 of the damper moves to an open position, opening the outlet path. Controller 7 is further configured so that when the temperature inside the roof space falls back below the set point (or a different set point such as may be specified as the above-mentioned set point minus a hysteresis value), fan 12 is turned off and circular plate 13 of the damper moves to a closed position, closing the outlet path.

[0016] By closing the outlet path using the gate mechanism, this embodiment prevents warm air from escaping roof space when the fan is not operating which as discussed above in the background to the invention is beneficial in maintaining warm conditions during colder weather.

[0017] Persons skilled in the art will appreciate the components comprising the invention are all readily obtainable as components already existing as building supplies including air-conditioning supplies. For example, the damper described above housed within cylindrical duct 3 is a standard component and air-conditioning systems designed for closing and opening air paths. Similarly, the fan and controller components, and the cover and roof fittings are all readily available components in existing exhaust fan assemblies.

[0018] Persons skilled in the art will also appreciate that many variations may be made to the invention without departing from the scope of the invention, which is determined from the broadest scope and claims.

[0019] For example, the positions of the gate mechanism and electrical fan can be reversed, and either or both of the electrical fan in the gate mechanism may be housed within the roof space or extending outside of the roof space in a chimney. Any gate mechanism and fan arrangement is within the scope of the invention. Further, many different file types of roof fitting are known in the art and are within the scope of the invention. Invention is not restricted to any particular type of roof space, and indeed extends to ventilation of roof spaces such as cathedral-type roof spaces which may not be above a ceiling.

[0020] Further, many different configurations of the controller are possible to appropriately control the gate mechanism and fan according to temperature. The invention is not restricted to a single set point, multiple set points or particular actions which must be performed but extends to the general capability provided by the provision of the combination of fan and gate mechanism arrangement which can be adapted by configuring the controller to act according to particular needs. For example, it may be considered advantageous to close the gate mechanism independently or at a lower temperature than a temperature at which the fan is turned off.

[0021] Further still, systems powered by any means of providing electrical power are within the scope of the invention including mains powered or solar powered.

[0022] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

[0023] It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

Claims

/ CLAIMS

1. An exhaust fan assembly for ventilating a roof space, the exhaust fan assembly comprising: a fitting adapted to be installed in a roof or wall providing an outlet for ventilating air out of the roof space; an electrically powered fan configured to force the air through the outlet; an electrically activated gate mechanism, activated by a motor in the exhaust fan assembly, adapted to close and open the outlet; a temperature sensor adapted to sense a temperature inside the roof space; and a controller connected to the temperature sensor, the electrically powered fan and the electrically activated gate mechanism; wherein the controller is adapted to open and close the gate mechanism according to the temperature inside the roof space, and to turn the fan on and off according to the temperature inside the roof space.
2. The exhaust fan assembly of claim 1, wherein the controller is configured with one or more temperature set points for opening and closing the gate mechanism and turning the fan on and off.
3. The exhaust fan assembly of claim 1 or 2, wherein the electrically activated gate mechanism is a damper valve.
4. The exhaust fan assembly of claim 1, 2 or 3, wherein the electrically activated gate mechanism is disposed between the electrically powered fan and the outlet.
5. The exhaust fan assembly of any one of claims 1-4, wherein the controller is configured to close the gate mechanism at a lower temperature than a temperature at which the controller is