This invention relates generally to the field of ventilation products and more particularly to exterior vents of the type that are used to vent the inside of buildings. Most particularly this invention relates to exterior vents which may be used to vent air from bathrooms, kitchens, dryers and the like or to allow air into the building in certain circumstances.
Modern buildings are being made ever more energy efficient which often translates into better insulation and less air infiltration through cracks, gaps or the like. As a consequence, the airflow into and out of the building envelope must be very carefully managed.
Another consequence of a tighter building envelope however is the need to manage the exhaust air flow which may be required from other building systems. Three systems in particular have localized blowers to force vent air in certain circumstances, and they include bathroom exhaust fans, to vent moisture laden air from bathrooms, kitchen exhaust fans to vent the by products of cooking which may include steam, greasy vapours and smoke, and electric dryer exhausts, which again are for the purpose of venting moist air from the drying of laundry inside a dwelling or building envelope.
Particular to these types of exhaust air is the back pressure created by the local appliance, such as the bathroom exhaust fan, the kitchen exhaust fan and the electric dryer exhaust blower. Also particular to these types of exhausts is the need to let the exhaust air out when there is a need to, but to prevent air from leaking out, or more precisely to prevent outside air from leaking in or infiltrating into the building envelope, when the appliance is not in use. Concomitant with this there is a need to make the air flow passageway impervious to pests, animals, rodents and the like, that might otherwise try to gain entry into the building.
As a result, there is a need for vents which permit the air to be vented outside of the building, but which prevent unwanted air from infiltrating back into the building and which are protected from pests. Typically a flapper valve is used for this purpose which can open when the air is being exhausted and which closes when there is no air flow. A secondary need is to provide a screen or other structure which can be used to prevent animals or pests from getting into the building through the vent opening.
Various designs have been proposed in the past including vents made from metal, but these tend to be expensive and easily damaged in transit. Further a metal flapper valve can make quite a bit of noise when it opens and closes. A problem with prior art designs is that wind or weather can change the air pressure around the exterior of the vent causing the flapper to flap up and down even when the inside appliance is not turned on and there is no need for the vent to be open. This constant chatter can become a serious issue to an occupant.
What is desired is a simple to use, inexpensive, easy to install, and aesthetically pleasing vent that will allow air to escape when it is desired and yet will protect the vent from unwanted opening and closing of the flapper valve. Such a design would preferably be quiet and reliable and should also prevent unwanted pests and the like from intruding into the building through the vent. Such a vent would preferably respond to the need to vent air, but would otherwise be reliably closed to prevent the infiltration of weather and outside air.
The present invention provides in a preferred embodiment a form of an inexpensive and yet durable vent. The vent may be formed from a flexible material such as sheet metal or molded plastic, such as polypropylene, which is durable and not easily damaged. Such a plastic vent will preferably have a flapper valve that opens and closes silently as compared to the prior art metal devices. The vent may include a built-in screen to limit weather and pests from impinging on the flapper valve or getting into the building through the vent. Most preferably the vent can be comprised of a number of separate elements that are easily molded and which can be easily assembled to form a complete vent structure having certain desirable features as explained below.
Therefore, according to a first aspect the present invention provides an exterior vent for venting an interior space through a sloped surface opening in a building envelope, the exterior vent comprising:
a base having a vent opening for registering with the surface opening in the building envelope and an attachment flange surrounding said vent opening for securing said vent to an outer surface of said building envelope around said surface opening; said base further having upstanding side and end walls to define said vent opening and to form a portion of a curved air flow pathway above said vent opening,
a screen,
a top which registers with said base to complete said curved air flow pathway and to define an air outlet opening which is facing generally in a different direction from said vent opening, said top including a screen secured to said top by means of a hinge, said top including attachment means to secure said top portion to said base and to trap said screen between said base and said top portion whereby said air outlet opening is covered by said screen, and
a flapper valve positioned across said curved air flow pathway, said flapper valve being hinged to said base and having a free end; said flapper valve being urged to a closed position by gravity and to an open position by air pressure from below, said vent including a rest for said free end of said baffle, said rest having an upstanding weather deflecting baffle extending above said free end to limit air gusts from passing through said screen and under said free end of said flapper valve.
In an alternate embodiment the present invention can be used as an air intake vent, with the flapper valve removed. The vent can also be used on a sloped roof surface. Another aspect of the invention includes an adaptor collar to interface with at least two and preferably three different duct sizes.
Reference will now be made by way of example only to preferred embodiments of the invention by reference to the following drawings in which:
A gooseneck style vent, according to a preferred embodiment of the invention, is shown as 10 in
The vent 10 of the present invention defines an air passageway having discreet sections. The first section 30 is the inside of the duct connector 20. The next section 32 is inside of base 14 above the nailing flange 18, but below a flapper valve shown as 34. The next section 36 is between the flapper valve 34 and a screen 38 inside of top 12. The next section is the flow through the screen 38. The last portion is below the screen 38 and may be called an air flow outlet 40 described in more detail below. Each section of the airflow passageway through the vent is separately described below.
The first section 30 of the air flow passageway is the duct connector portion 20. As noted above, the present invention is intended to be easily field fastened to a duct leading from an air exhausting source (not shown). The source can be any conventional type of blower such as a bathroom fan, a kitchen fan, a dryer blower or the like. In most cases the blower will be designed to work with a standard sized round duct, which is piped from the blower location to the location where the vent is to be installed. This may be, for example, on a sloped roof surface of a building. The three different diameters presented by the duct connector 20 permit the installer to connect the duct to the vent in an air tight manner with a minimum of effort. All that is needed is to remove the duct diameter connectors which are too small. The connector 20 may be made from an easy to cut material, such as plastic, to facilitate the removal of the unwanted connector sections. While the cut can be made in a number of places it is preferred to cut through the horizontal platforms or steps between each duct section for each of access. As described in more detail below, a thin cut line or guide can be provided to assist in the trim step.
The next section 32 of the airflow passageway is located in the base 14 of the vent 10 underneath the flapper valve 34. In general the flapper valve 34 is hinged at one end 50 and has free end 52 which sits on a seat 54. Gravity closes the flapper valve and urges the free end 52 onto the seat 54. Air pressure below the flapper valve, created for example by an air exhausting source, will lift the flapper valve off the seat allowing the air to escape.
The escaped air is now in the next section 36 between the flapper valve 34 and the screen 38. The air can pass through the three dimensional screen 38 and then is found in the air outlet section 40. This section 40 is defined by weather protecting side baffles 60 and an overhanging weather baffle 62. These baffles help protect the screen 38 from inclement weather by restricting the ability of precipitation to impinge directly upon the screen 38. It will be noted that the screen 38 is generally facing in a different direction in the air flow passageway from the duct connector 20. In addition the screen 38 is designed to have generally rectangular corrugations 42 having outwardly facing surfaces 44 and secondary surfaces 46 perpendicular to the outwardly facing surfaces. In a preferred embodiment the outwardly facing surfaces can be made solid and the perpendicular surfaces can be made with grills 48 so that the air can flow out but weather, such as precipitation, which impinges on the screen from directly below is blocked. This style of screen may be called a three dimensional screen.
Also shown is a ledge 80, which goes up one side and then across the back and then down the other side. The base 14 has an angled top edge 82 and the ledge 80 may be generally parallel to or angled relative to the top edge 82 as it goes around the base 14. The function of the ledge 80 is described in more detail below.
It can now be appreciated that two transverse weather baffles can be formed in association with the screen. One, close to the hinge, rotates downwardly as the screen is rotated under and ends up becoming the overhanging baffle 62. A second which extends in an opposite direction and is located towards a free end of said screen is rotated into place as an internal weather deflecting baffle 106 (best seen in
In another embodiment the invention may be used as an intake vent, in which case there would be no collar nor any flapper valve as part of the vent. As well, in some cases a form of dryer vent may be used, as noted above with a lint compatible or lint passing grill. The foregoing description describes various embodiments of the invention but the scope of the invention is limited only by the appended claims. Various modifications and alterations to the invention are possible without departing from the scope of the claims attached. Some of these have been discussed above and other will be apparent to those skilled in the art.
Number | Date | Country | Kind |
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2870440 | Nov 2014 | CA | national |