BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to ventilation systems, more particularly to active ventilation systems that can be used in a roof of a building.
2. Description of the Related Art
Ventilation of a building has numerous benefits for both the building and its occupants. For example, ventilation of an attic space can prevent the attic's temperature from rising to undesirable levels, which also reduces the cost of cooling the interior living space of the building. In addition, increased ventilation in an attic space tends to reduce the humidity within the attic, which can prolong the life of lumber used in the building's framing and elsewhere by diminishing the incidence of mold and dry-rot. Moreover, ventilation promotes a more healthful environment for residents of the building by encouraging the introduction of fresh, outside air. These and other benefits of ventilation tend to compound as ventilation increases. That is, the greater the flow rate of air that is vented through the building, the greater the benefits.
Consequently, power devices such as fans have been employed in active ventilation systems to force greater air flow into and out of an attic space. One drawback of some such active ventilation systems is their consumption of electricity from the local power grid. With increasing energy costs and heightening concerns for environmental impacts, devices that can operate with little or no electricity from the power grid are becoming more attractive.
Another consideration is ease of installation. Some ventilation systems require a relatively lengthy and confusing installation procedure, which may involve the use of more than one kind of tradesperson. Such systems are more expensive to install and may suffer failures during operation due to faulty installation. Accordingly, a ventilation system that is relatively easy to install and operate is desirable.
A ventilation system that improves on one or more of these concerns is needed.
SUMMARY OF THE INVENTION
Embodiments of the roof ventilation systems of the present invention have several features, no single one of which is solely responsible for their desirable attributes. Without limiting the scope of this invention, its more prominent features will now be discussed briefly. However, not all of the following features are necessary to achieve the advantages of the system. Therefore, none of the following features should be viewed as limiting. After considering this discussion, and particularly after reading the section entitled “Detailed Description of the Preferred Embodiments,” one will understand how the features of the preferred embodiments provide advantages over prior art.
The presently disclosed embodiments seek to address the issues discussed above by utilizing a solar panel to power a fan associated with a roof vent system. The fan can be positioned in the attic space in order to accommodate fans with larger blades, capable of moving greater amounts of air. In one embodiment, the fan housing can be sized and shaped to simplify installation, such as by employing a substantially cylindrical housing that is generally free of protrusions. In other embodiments, the fan housing has a substantially frustoconical shape, facilitating the use of a relatively larger fan without necessitating a large hole in the roof. Some embodiments include a one-piece vent, which can be of particular utility in a composition roof. Other embodiments can utilize an upper vent having an appearance that mimics one or more tiles, for use in a tile roof.
In accordance with one embodiment, a roof vent is provided. The vent includes an upper member comprising a first opening that permits air flow between regions above and below the upper member. The vent further includes a lower member in fluid communication with the region below the upper member. The lower member includes a second opening permitting air flow between a region below the roof and the region below the upper member. The lower member further includes a fan configured to generate air flow through the second opening. The fan resides in a fan housing extending downwardly from the second opening to a third opening below the roof. The fan housing has a first lateral cross sectional area at the second opening and a second lateral cross sectional area at the third opening. The second lateral cross sectional area is greater than the first lateral cross sectional area.
In accordance with another embodiment, a method of installing a roof vent comprising a fan is provided. The method includes providing an opening in a roof deck. A roof vent having a lower member and an upper member is provided, the lower member having a downwardly extending fan housing. A portion of the fan housing is inserted through the opening. A base portion of the lower member of the roof vent is permitted to rest above the roof deck while the fan housing is attached to the base portion. The method further includes providing a layer of tiles positioned above the roof deck, such that a batten cavity is defined between the roof deck and the layer of tiles. The upper member is positioned within the layer of tiles, such that the upper member replaces one or more of the tiles. The positioning of the upper member comprises displacing the upper member from the opening in the roof deck, so that air can flow along a flow path extending from a space below the roof, through the batten cavity and along the roof, and through the upper member of the vent.
In accordance with another embodiment, a roof vent is provided. The vent includes an upper member including a first opening that permits air flow between regions above and below the upper member. The vent further includes a lower member in fluid communication with the region below the upper member. The lower member includes a second opening permitting air flow between a region below the roof and the region below the upper member. The lower member further includes at least two fans configured to generate air flow through the second opening. The fans reside in a fan housing positioned below the second opening.
In accordance with still another embodiment, a roof ventilation system is provided. The ventilation system comprises a lower vent member, an upper vent member, a solar panel, a first actuator, and a controller. The lower vent member has an opening and a base portion extending outwardly from the opening. The base portion is adapted to rest upon a roof deck approximately at an opening in the roof deck, such that air can flow through the roof deck and vent member by flowing through the roof deck opening and the vent member opening. The upper vent member is configured to be secured to the lower vent member or to a field of roof cover elements above the roof deck. The solar panel is secured to the upper vent member, and the first actuator configured to rotate the solar panel about a first axis. The controller is configured to electronically control the first actuator to rotate the solar panel about the first axis.
In accordance with still another embodiment, a roof vent is provided. The vent includes an upper member including a first opening that permits air flow between regions above and below the upper member. The vent further includes a lower member in fluid communication with the region below the upper member. The lower member includes a second opening permitting air flow between a region below the roof and the region below the upper member. The lower member further includes a fan configured to generate air flow through the second opening. The fan resides in a substantially cylindrical fan housing positioned below the second opening. The fan housing is substantially free of protrusions extending laterally from the outer surface of the housing.
All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular embodiment(s) disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
The appended drawings are schematic, not necessarily drawn to scale, and are meant to illustrate and not to limit embodiments of the invention.
FIG. 1A is a schematic perspective view of a section of a roof including one embodiment of a roof vent;
FIG. 1B is a schematic top view of an upper member of the roof vent shown in FIG. 1A;
FIG. 1C is a schematic bottom view of the upper member of the roof vent shown in FIG. 1A;
FIG. 1D is a schematic front view of the upper member of the roof vent shown in FIG. 1A;
FIG. 1E is a schematic illustration of a control system of the roof vent shown in FIG. 1A, including a battery and a controller;
FIG. 1F is a schematic side view of a roof vent, including a movable solar panel;
FIG. 1G is a schematic top view of the roof vent shown in FIG. 1F;
FIG. 2 is a schematic perspective view of one embodiment of a lower member of a roof vent, including a fan housing;
FIG. 2A is a schematic top view of one embodiment of a lower member of a roof vent, including two fan assemblies;
FIG. 2B is a schematic front view of the lower vent member of the roof vent shown in FIG. 2A in accordance with an embodiment;
FIG. 2C is a schematic front view of the lower vent member of FIG. 2A in accordance with a different embodiment than shown in FIG. 2B;
FIG. 3 is a schematic perspective view of another embodiment of a lower member of a roof vent, including a frustoconical fan housing;
FIG. 3A is a schematic front view of another embodiment of a roof vent, comprising two or more fan assemblies housed within a fan housing that has a larger cross-sectional area at its lower end than at its top end;
FIG. 4 is a schematic exploded view of another embodiment of a roof vent;
FIG. 5A is a schematic cross-sectional view of a roof section including one embodiment of a roof vent;
FIG. 5B is another schematic cross-sectional view of the roof section shown in FIG. 5A;
FIG. 6A is a schematic cross-sectional view of a roof section including another embodiment of a roof vent;
FIG. 6B is a schematic cross-sectional view of a roof section including another embodiment of a roof vent;
FIG. 7 is perspective front view showing a rooftop having one embodiment of a roof vent;
FIG. 8 is a bottom view of an upper member of the roof vent shown in FIG. 7;
FIG. 9 is a bottom perspective view of a roof section with a lower member of an embodiment of a roof vent;
FIG. 10 is a top view of an embodiment of a roof vent with a solar panel;
FIG. 11 is a top perspective view of the roof vent shown in FIG. 10 without a solar panel;
FIG. 11A is a schematic top view of an embodiment of a roof vent, including two fan assemblies;
FIG. 11B is a schematic side view of the roof vent shown in FIG. 11A;
FIG. 12 is a bottom perspective view of the roof vent shown in FIG. 10; and
FIG. 13 is a front view of the roof vent shown in FIG. 10.
FIG. 14 is a perspective view of a building with a roof ventilation system in accordance with an embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1A is a schematic perspective view of a section of a tile roof including one embodiment of a roof vent 10. In particular, a roof vent 10 is shown including an upper member 16 and a lower member 18. The lower member 18 is sometimes referred to as a “subflashing” or “primary vent member,” and the upper member 16 is sometimes referred to as a “vent cover” or “secondary vent member.” The upper member 16 either lies on top of the roof or rests upon the lower member 18, and in some embodiments can be secured to the lower member 18. In the embodiments wherein the upper member is not secured to the lower member 18, the roof vent is described herein as a “non-integrated” roof vent. In the embodiments wherein the upper member is secured to the lower member 18, the roof vent is described herein as an “integrated” roof vent. The upper member 16 can be shaped and/or decorated (e.g., colored) to simulate the appearance of the surrounding tiles 54 so that the roof vent 10 visually blends into the appearance of the roof. The upper member 16 can be shaped to simulate many different types of tiles, such as tiles with “S”, “M”, or “Flat” profiles, as such profiles are known in the art. The upper member 16 in FIG. 1A simulates an “M” profile tile for illustration purposes only. In other kinds of roofs, such as slate or shingle, the upper member 16 may be configured differently to resemble those roof coverings.
The upper member 16 includes a solar panel 20, such as a photovoltaic (PV) panel. The solar panel 20 can be in electrical communication with and provide power to a fan assembly 38, and/or one or more control systems, as described further below. In some embodiments, the upper member 16 can include a bracket 60 that selectively receives the solar panel 20, thus facilitating maintenance and/or replacement of the solar panel 20. The bracket 60 may have grooves sized and shaped to slidably receive the solar panel 20. The bracket 60 shown in FIGS. 1A and 1D maintains the solar panel 20 in a low profile, which can be advantageous for aesthetics as well as for preserving the solar panel 20 against wind damages.
In other embodiments, the bracket 60 may be movable, such as by rotating the solar panel 20 about at least one and preferably two axes, such that solar panel 20 can face substantially any direction. FIGS. 1F and 1G are a side and top schematic view, respectively, showing a roof vent 10 with a bracket 60 that can rotate about two axes. Bracket 60 can comprise a hinge 27 for rotating a section of bracket 60 that holds panel 20 an angle θ1 about a first axis 29. The first axis 29 can extend through a portion of solar panel 20, such as through and approximately parallel to an edge of solar panel 20. A skilled artisan will understand that the hinge 27 can comprise any element capable of rotating the solar panel 20 about the first axis 29, such as bearings or pins at opposing ends of the edge of panel 20 and/or bracket 60, or an axle extending through the edge of the panel 20 and/or bracket 60.
Bracket 60 can also comprise a rotatable connection 22 for rotating a section of bracket 60 and panel 20 an angle θ2 about a second axis 34. The second axis 34 can extend approximately perpendicular to the roof field, and preferably, can extend approximately perpendicular to axis 29. A skilled artisan will understand that the rotatable connection 22 can comprise any element for rotating the solar panel 20 about the second axis 34, such as a bearing or a rotatable table.
The rotation of solar panel 20 about the first axis 29 and/or the second axis 34 allows a user to move solar panel 20 relative to the position of the sun. Moving solar panel 20 allows a user to adjust the amount of solar energy received by the solar panel 20. For example, a user may adjust the solar panel 20 to directly face the sun. Solar panel 20 can be moved to account for the sun's position due to the time of day and/or the time of year. In some embodiments, solar panel 20 can be moved to a retracted position in which it is substantially parallel with and close to the roof and/or upper member 16 (FIG. 1A). Solar panel 20 is in a retracted position when θ1 is approximately zero, or when θ1 and θ2 are both approximately zero. In one embodiment, the angle θ2 is approximately zero when two edges of a rectangular solar panel 20 are substantially parallel to the ridge and eave of the roof on which the vent 10 and solar panel 20 are installed. It may be desirable to move solar panel 20 to a retracted position to prevent damage thereto, such as during heavy rains and/or wind. It may also be desirable to move solar panel 20 to a retracted position when it is not being used or when it is not providing a power output above a desired predetermined threshold (such as during heavy cloud cover). In a preferred embodiment, solar panel 20 is moved to a retracted position automatically with a controller (as described further below), when the power output from the solar panel 20 is zero.
In some embodiments, solar panel 20 and bracket 60 can be moved manually by using the hinge 27 and/or rotatable connection 22, such as when a user grasps solar panel 20 and/or bracket 60 by hand or with a tool. In other embodiments, a first actuator 41 and second actuator 42 may be provided to move solar panel 20 and bracket 60. For example, each actuator 41, 42 can comprise an electric actuator with a motor controllable by a control system. Using a control system and electric actuators to move solar panel 20 and bracket 60 can increase the efficiency with which the solar panel 20 receives solar energy from the sun, because electric actuators can be activated more easily and frequently without the need to climb onto the roof, so as to track the position of the sun as it moves with respect to the panel 20.
FIG. 1E shows a schematic view of a control system 40 that can be used to move solar panel 20 and bracket 60 shown in FIGS. 1F and 1G described above. Control system 40 can receive power from the solar panel 20 and/or an associated battery 25 (described further below), or from an alternative power source. Referring to FIGS. 1E-1G, first actuator 41 and second actuator 42 can preferably move solar panel 20 automatically, or electronically, instead of or in addition to manually. Actuators 41 and 42 can comprise electric actuators, such as motor-driven electric actuators. Actuators 41 and 42 can be in communication with a controller 43 such that actuators 41 and 42 move in response to one or more electronic signals from controller 43. Controller 43 may comprise, for example, an electronic circuit or a computer microchip. Further, controller 43 may comprise hardware, firmware, software, or some combination thereof. Controller 43 can further comprise an optional timer 46, so that the solar panel 20 and bracket 60 can be moved at specific times or intervals. Timer 46 can be integrated with controller 43 or it can be separate, as shown in the illustration. Controller 43 can control the movement of actuators 41 and 42 to increase or optimize the solar energy solar panel 20 receives from the sun, or to automatically move solar panel 20 to a retracted position, as described above.
In an embodiment, control system 40 can comprise one or more sensors 44 that send electronic signals, or feedback, to controller 43. Sensor 44 can comprise many types, such as an optical sensor that can sense the position of the sun relative to the position of sensor 44. In this embodiment, controller 43 can be configured to analyze the incoming signal sent from sensor 44 and adjust the outgoing signal to actuator 41 and/or actuator 42 accordingly. As such, actuator 41 and/or actuator 42 can move to a desired position in response to the signal received by controller 43 from sensor 44. In a preferred embodiment, sensor 44 is positioned on solar panel 20 or bracket 60, forming a closed loop system for controlling the position of solar panel 20. In this embodiment, actuator 41 and/or actuator 42 can move solar panel 20 to follow the position of the sun or, alternatively, to move solar panel 20 to a retracted position, based on the signals that controller 43 receives from sensor 44.
In certain embodiments, sensor 44 can be configured to sense sunlight intensity or windspeed velocity. When sensor 44 comprises a sunlight intensity sensor, if the sunlight intensity moves above or below a predetermined threshold, sensor 44 can send a signal triggering controller 43 to move solar panel 20 from or to a retracted position, respectively. For example, it may be desirable to retract the solar panel if the sunlight intensity is low. Similarly, when sensor 44 comprises a windspeed velocity sensor, if the windspeed moves above or below a predetermined threshold, sensor 44 can send a signal triggering controller 43 to move solar panel 20 to or from a retracted position, respectively. For example, it may be desirable to retract the solar panel 20 at high wind speeds, to prevent damage thereto. A skilled artisan will understand that more than one sensor 44 can be used, such as embodiments in which multiple sensed conditions (e.g., sun position, sunlight intensity, wind speed) are used as inputs to the controller 43.
In another embodiment, actuator 41 and/or actuator 42 can move solar panel 20 to correspond to one or more desired predetermined position(s). The desired predetermined position(s) can comprise a retracted position, or a plurality of different positions to which solar panel 20 can be moved at different times to optimize the solar energy it receives from the sun, as described above. The desired predetermined position(s) can be stored in a data storage system 45. Controller 43 can adjust its output signals so that actuator 41 and/or actuator 42 move solar panel 20 to predetermined positions stored in data storage system 45. In an embodiment, controller 43 can adjust its signal to move actuator 41 and/or actuator 42 in a sequence of predetermined positions, separated by time intervals by using the timer 46. Data storage 45 can comprise any data storage system known in the art, such as a hard drive integrated with controller 43, or separate from controller 43. The predetermined positions can be paired with corresponding times of day and/or year at which the predetermined positions will efficiently orient the solar panel 20 to receive solar energy from the sun, and the controller 43 can be configured to move the solar panel 20 to each predetermined position at its corresponding time of day and/or year.
In another embodiment, data storage system 45 comprises sun position data that controller 43 uses to adjust its output signals so that actuator 41 and/or actuator 42 move solar panel 20 to face the sun throughout the day and/or the year, as described above. For example, the sun position data may comprise empirically observed information detailing the sun's position relative to the Earth, for a variety of times of the day and/or year.
The accuracy in using the sun position data stored in storage system 45 to move solar panel 20 may be related to the geographic position or the orientation of solar panel 20. Thus, it may be desirable for controller 43 to receive the solar panel's geographic position and/or orientation. In some embodiments, the controller 43 is configured to use the actuators 41 and 42 to move the solar panel 20 to an optimal position for receiving solar energy, based at least on (1) the position and orientation of the solar panel in its installed, retracted position, and (2) the sun position data in the data storage system 45. In one embodiment, the control system includes a user interface (e.g., keypad, touch screen, and/or network interface) for receiving the solar panel's position (e.g., longitude, latitude, city, zip code, state, country, street address, or the like) and orientation (e.g., the direction in which it faces, its angle with respect to the local horizon, north, south, east, west designations, etc.) in the panel's installed, retracted position. In another embodiment, the control system includes a GPS or like device for determining the solar panel's location, and other sensors (e.g., accelerometers) for determining the panel's orientation.
A skilled artisan will appreciate that certain embodiments of system 40 do not include all the components shown in FIG. 1E. For example, in some embodiments, controller 43 can be used with sensor(s) 44 to move solar panel 20 as described above, without the use of the position data 45. In other embodiments, controller 43 can be used with position data 45 to move solar panel 20 as described above, without the use of the sensor(s) 44. In yet other embodiments, the solar panel 20 can be moved using both the position data 45 and sensor(s) 44.
System 40 can further comprise a battery 25. Referring to both FIG. 1E and FIG. 1A, the solar panel 20 can be in electrical communication with and can provide power to the fan assembly 38 of the lower member 18. The fan assembly 38 can be used to provide forced air flow through the roof vent 10, and in some embodiments, to hinder the ingress of rain, snow, embers, vermin, insects, leaves, or other debris through the vent. In some embodiments, the solar panel 20 may provide power to the battery 25, which can store power for later use by the fan assembly 38. Battery 25 can provide stored power to fan assembly 38 when solar energy from the sun is not available, for example, if cloud cover prevents the solar panel 20 from providing power to the fan assembly. In an embodiment, battery 25 can provide power to fan assembly 38 through the controller 43, which controls fan assembly 38. Controller 43 can comprise a timer 46 and/or sensors 44, as described above, that provide(s) one or more signals to controller 43. Controller 43 can use the signal from timer 46 and/or sensors 44 to determine whether fan assembly 38 should be powered by the solar panel 20, the battery 25, or not powered at all, as in an “off” position. In an embodiment, the battery 25 can provide the increased power required to start the fan assembly 38 from an off position, such as in the morning (e.g., just after sunrise) when solar energy from the sun may not be sufficient to initiate fan rotation. The increased power from battery 25 allows fan assembly 38 to operate with a smaller or lower wattage solar panel 20, decreasing the cost of the ventilation system.
Control systems for controlling fans in vent systems using batteries powered by rooftop solar panels are disclosed in U.S. application Ser. No. 11/736,498, entitled “AUTOMATIC ROOF VENTILATION SYSTEM,” filed Apr. 17, 2007, and the publication of the same application in U.S. Patent Application Publication No. 2007/0243820, published Oct. 18, 2007, the disclosures of which are hereby incorporated by reference herein in their entireties. In other embodiments, the solar panel 20 may provide power to the local power grid. A skilled artisan will appreciate that fan assembly 38 can comprise either an AC or a DC system, regardless of whether the ventilation system includes battery 25. For example, an AC fan can be used with the battery 25 if the power is provided after an inverter in the system (not shown). This can improve the efficiency of the system. Additionally, using an AC fan may allow the roof ventilation system to use certain commercially available solar panel systems, such as the photovoltaic system marketed by Eagle Roofing Systems as the SolarSave™ integrated panel system. A skilled artisan will understand that the embodiments illustrated in FIGS. 1E-1H and described above can be implemented with any of the ventilation systems described herein, and that the ventilation system design in these figures is for illustration purposes only. Further, the dashed lines connecting the components in FIG. 1E are for illustrative purposes only. For example, the electronic communication between the components described above can be achieved through electrical conduits (e.g. wires), or wirelessly, as is known in the art. Further, in some embodiments, the components are in electronic communication, even if a dashed line is not shown in FIG. 1E. For example, the panel 20 can be connected to and/or in electronic communication with controller 43, and the battery 25 can be connected to and/or in electronic communication with fan 38.
As shown in FIG. 1D, the upper member 16 can have a first part 16a spaced closely above a second part 16b. The first and second parts 16a and 16b are joined together but separated by a space 16c. FIG. 1B is a top view of the first part 16a of the upper member 16, with the solar panel 20 attached. The first part 16a includes apertures 22, or openings, through which air can flow between regions above and below upper member 16. In other embodiments, other openings, such as louver slits, grating or screened openings, can be used in place of apertures 22. FIG. 1C is a bottom view of the second part 16b of the upper member 16. The second part 16b includes screened openings 24 through which air can flow. In other embodiments, other openings, such as louver slits or apertures, can be used in place of screened openings 24. In use, air flows through the screened openings 24 in the second part 16b, then through the space 16c, and then through the apertures 22 in the first part 16a.
Referring again to FIG. 1A, a fan housing 30 of the lower member 18 projects through a hole 50 in the roof deck into the attic space. The lower member 18 includes a preferably planar top portion, or base, 19 and the fan housing 30. The top portion 19 sits on top of the roof deck (e.g., on top of a wooden roof deck underneath the tiles 54, wherein the hole 50 is cut into the roof deck) and can be secured to the roof deck in a sealed manner, such as by nailing the top portion 19 to the roof deck and then sealing the top portion to the roof deck. The top portion 19 includes a hole 21 that is sized and shaped to match or be smaller than the hole 50 in the roof deck. In some embodiments, a rise 31 extends upward from the hole 21 in the top portion 19 in order to prevent the ingress of water flowing along the top portion 19 through the hole 50 in the roof deck. The rise 31 can have a height that is effective to divert the flow of water, such as between about ⅜ inch to about ¾ inch, particularly about ½ inch.
Extending downwardly from the hole 21 in the top portion 19 is the fan housing 30. Positioning the fan housing 30 below the roof deck in the attic space advantageously permits a larger size fan assembly 38, as compared to systems in which a fan is positioned above the roof deck but below a top portion of the vent. In such systems, the size of the fan is constrained by the limited space available between the roof deck and the top portion of the vent. The larger fan assembly 38 afforded by embodiments disclosed herein are capable of moving a greater volume of air per minute. This increased air flow capacity can enhance the performance of the roof vent 10. For convenience and simplicity, this application refers to the space beneath the roof deck as an attic space. However, skilled artisans will appreciate that embodiments can be used in buildings that do not have attics, such as buildings with vaulted ceilings.
With continued reference to FIG. 1A, in use, the fan assembly 38, powered by the solar panel 20, causes air to flow from the attic space, through the fan housing 30 to a space between the upper and lower members 16, 18, then through the upper member 16 as described above. For convenience, this application generally describes air flow in an upward direction, from the attic to a space above the roof, or as also used herein, to exhaust air, as in an exhaust fan. Skilled artisans will appreciate that vents are sometimes designed to draw air from above the roof into the attic, and in those cases the fan can be mounted to direct air in the opposite direction, or as used herein to induct air, as in an induction fan. The roof vent 10 in those uses will perform substantially as described but with the air flows substantially reversed. For example, U.S. Patent Application Publication No. 2007/0243820, which was incorporated by reference hereinabove, and FIG. 14 in the present application, described below, disclose roof vents near a roof's eaves that have fans that draw outside air into the attic, and roof vents near the roof's ridge that have fans that expel attic air to the outside.
FIG. 2 illustrates one embodiment of a lower member 18 having a substantially cylindrical fan housing 30. As shown in FIG. 2, the fan housing 30 may also include a screen 39 at its bottom opening, which helps to prevent the ingress of leaves, debris, insects, or vermin. Note that the screen 39 is shown detached from fan housing 30 for illustrative purposes only. Also, the screen 39 can additionally be configured to prevent the ingress of embers. For example, the screen can comprise a baffle structure or mesh material as shown and described in Provisional Patent Application No. 61/052,862, filed May 13, 2008, the entire disclosure of which is incorporated herein by reference. In other embodiments, the screen 39 may be positioned at the top opening of the fan housing 30, as shown in FIG. 12. Referring again to FIG. 2, the fan housing 30 is preferably substantially free of protrusions extending laterally from the outer surface of the housing 30, which greatly simplifies installation of the lower member 18. Once an appropriate sized hole has been created in the roof deck, an installer can simply drop the cylindrical housing 30 from above the roof deck and through the hole in the roof deck, until the top portion 19 rests upon the roof deck.
In some embodiments, the size of the hole 21 of the top portion 19, and the lateral cross section of the cylindrical fan housing 30, is less than or substantially equal to 144 square inches, or an alternative size limit imposed by a building code. Building codes in some areas require extra structural enhancements, sometimes called blocking, when a hole in the roof exceeds a certain value, such as 144 square inches. Blocking may require the work of a workman in a different trade than the person ordinarily tasked with installing roof vents. The involvement of another trade and another workman can delay and increase the expense of installation. Accordingly, it may be preferable to employ a cylindrical fan housing 30 with a cross sectional area less than or substantially equal to a size required under a building code (such as 144 sq. in.), in order to avoid the need for blocking. A smaller hole in the roof deck can be desirable for other reasons as well, including to preserve the structural integrity of the roof and building against seismic events, and to guard against wind shear and lateral uplift.
In certain applications, greater air flow may be required than can be accommodated using a roof vent 10 with a single cylindrical fan housing 30 as described above and shown in FIGS. 1A and 2. FIGS. 2A and 2B are schematic top and side views, respectively, of an embodiment of a roof vent 10a that comprises two fans to provide greater air flow. In the illustrated embodiment, the roof vent 10a includes two or more openings 21, two or more fan assemblies 38, and two or more cylindrical fan housings 30, each hole 21 and fan housing 30 having a cross sectional area less than the size limit imposed by the building code. In these embodiments with two or more fan assemblies 38, the roof vent 10a can comprise two adjacent and connected top portions 19, or as the exemplary illustrated embodiments show, a single top portion 19a, that can function similar to that described above for a single fan embodiment. Using this configuration, the necessity for blocking may be obviated while still increasing potential airflow. In some embodiments with two or more fan assemblies 38, a single fan housing 30a that extends around the two or more fan assemblies 38 and downwardly from the top portion 19a can be used. An exemplary illustration of a side view of the roof vent 10a that comprises two or more fan assemblies 38 and a single fan housing 30a is shown in FIG. 2C. An example of a commercially available component for a two-fan assembly is Sofasco—DC Brushless Fan Motor Model: sD12038V12HBL-55) DC 12V Motor 0.90 Amps.
Another embodiment of a lower member 18 is shown in FIG. 3. This embodiment increases airflow while still avoiding the need for blocking. In the illustrated embodiment, the increased airflow is achieved with a fan housing 30 comprising an opening 21a at its bottom end. The bottom opening 21a has a larger, or greater, lateral cross sectional area than the opening 21 at the upper end of the housing 30. This larger bottom opening 21a permits a larger fan assembly 38 capable of moving larger amounts of air. In a preferred embodiment, shown in FIG. 3, the fan housing 30 has a frustoconical shape. However, the opening 21 at the upper end of the frustoconical fan housing 30 may be sized such that the cross sectional area is less than or substantially equal to a size required under a building code, such as 144 sq. in. Unlike the substantially cylindrical fan housing illustrated in FIG. 2, the shape of the frustoconical fan housing 30 can preclude installation from above the roof. Accordingly, installation of the frustoconical housing 30 shown in FIG. 3 typically involves a two-step process. In one step, the planar top portion 19 is placed above the roof, and in the other step, the frustoconical housing 30 is connected to the top portion 19 from within the attic.
A skilled artisan will understand that it may be desired to employ two or more fans (e.g., as shown in FIGS. 2A-2C) in combination with a fan housing with a larger lower end to promote increased airflow (e.g., as illustrated in FIG. 3). In the illustrated exemplary embodiment shown in FIG. 3A, a roof vent 10b comprising two or more fan assemblies 38 can comprise a housing 30b that flares outwardly and downwardly. The outwardly flaring housing 30b functions similarly to housing 30a described above and shown in FIG. 2C, but extends outwardly to provide the additional functionality of the frustoconical housing 30 shown in FIG. 3. As such, housing 30b can extend outwardly from and around one or more fan assemblies 38 and downwardly from top portion 19a. Housing 30b can also comprise a bottom opening 21a with a larger, or greater, lateral cross sectional area than the opening 21 at the upper end of the housing 30b. In this way, roof vent 10b can generate greater air flow through the use of two or more fans, and can provide increased airflow through the use of housing 30b. A skilled artisan will appreciate that fan assembly or assemblies 38 described herein can be positioned anywhere within the fan housing described herein. For example, although FIG. 3A shows fan assemblies 38 positioned near opening 21 and an upper portion of housing 30b, fan assemblies 38 can be positioned anywhere within housing 30b, such as at or near the bottom opening 21a. Positioning fan assemblies 38 near the bottom opening 21a allows fan assemblies 38 to be larger, thus promoting increased airflow without needing blocking.
Skilled artisans will appreciate that many other variations are also possible. For example, a cylindrical fan housing 30 may be employed in which the cross sectional area is greater than a size limit imposed by a building code (such as 144 sq. in.), wherein blocking is also carried out. Other configurations may employ a fan housing 30 with an increasing (e.g., gradually increasing) cross section from top to bottom in some shape other than a frustocone, such as the shape of a layer cake or an inverted funnel. Further, a roof vent with two or more fans as described above is possible for other ventilation designs, such as the integrated vent embodiments described below and shown in FIGS. 4 and 10-13.
FIG. 4 is a schematic exploded view of an integrated roof vent 10. The integrated vent shown in FIG. 4 may be of particular use in so-called composition roofs formed of composite roof materials. Although FIG. 4 shows the system with its upper and lower portions separated, in use these two portions can be joined together and sold and installed as a single unit. The lower portion can include all the variations described above with reference to the lower member 18 of the non-integrated roof vents shown in FIGS. 1A-1D.
The upper portion of the vent can be configured to selectively receive a solar panel 20. As shown more clearly in FIGS. 11 and 12, the upper portion can include a tapered top 33 with louver slits 26 on its top surface and an opening 28 on its front edge (See also FIG. 13). Between the upper portion and the lower portion is a cavity, which may include screens, baffles, or other filtering structures to prevent the ingress of debris, wind-driven rain, and pests. In use, air from the attic is directed through the fan housing 30 by the fan assembly 38, then through a cavity between the lower portion and the upper portion, then through the louver slits 26 and/or the opening 28. The tapered design of the integrated vent may advantageously increase the velocity of air flowing through the vent into the building, as the tapered top acts as a kind of nozzle or flow restriction on the air inducted into the vent. It will be appreciated that air flow into the building can occur naturally or can be assisted by using a fan assembly 38 that draws air into the building rather than exhausts air therefrom. For example, the controller 43 (FIG. 1E) can be configured to select a direction of rotation of the fan assembly 38 based on whether it is desired to induct air into the building or exhaust air therefrom. Alternatively, the fan assembly 38 can simply have fan blades designed to only draw air into the building. An increased air flow velocity through the vent and into the building may be particularly advantageous in some applications. In other embodiments, wherein the fan assembly 38 is used or configured to exhaust air, the tapered design of the integrated vent reduces resistance to the exhaust of the air flow out of the building.
FIGS. 5A and 5B illustrate the air flow in a non-integrated roof vent 10 as described with reference to FIGS. 1A-1D. FIG. 5A is a cross sectional view of a sloped roof along the sloped direction. Battens 53 traverse the roof in a direction parallel to the roofs ridge and eave and support the tiles 54. The battens 53 separate the tiles 54 from the roof deck 56, thereby providing a batten cavity 52 through which air can flow. The battens 53 can be designed to provide pathways for airflow through or across the battens. For example, a batten 53 can be perforated or can be installed with a spacer to allow air flow through batten 53. As such, a batten 53 can comprise a “flow through batten”. FIG. 5B is a cross sectional view of the roof along the direction perpendicular to the sloped direction (i.e., parallel to the roofs ridge and eave). In the embodiment shown in FIGS. 5A and 5B, the upper member 16 is positioned substantially directly above the lower member 18. Note that the upper member 16 can be shaped and/or decorated to simulate the appearance of many different types of tiles as described above. The upper member 16 in FIG. 5B simulates an “M” profile tile for illustration purposes only.
In some embodiments, it may be desirable to position the upper member 16 in a different portion of the roof than the lower member 18. For example, the shadow cast by a tree may hinder the performance of the solar panel 20 in certain areas of the roof. In such cases, the upper member 16 can be offset (i.e., displaced) from the position of the lower member 18, such as illustrated in FIGS. 6A and 6B. FIG. 6A is a cross sectional view of a sloped roof along the sloped direction. FIG. 6B is a cross sectional view of the roof along the direction perpendicular to the sloped direction. As shown in FIGS. 6A and 6B, air flows from below the roof, up through the lower member 18, then through the batten cavity 52, and along the roof, between the roof deck 56 and the tiles 54 until it reaches the upper member 16, then through the upper member 16. Airflow within a batten cavity is typically referred to by those skilled in the art as “Above Sheathing Ventilation” (ASV). In the embodiment shown in FIG. 6A, the upper member 16 is upwardly offset, or upslope from the lower member 18, and the aforementioned flow “along the roof” is in an upward direction. A skilled artisan will appreciate that the upper member 16 can alternatively be downwardly offset, or downslope, from the lower member 18, and the aforementioned flow “along the roof” can be in a downward direction. In the embodiment shown in FIG. 6B, the upper member 16 is laterally offset from the lower member 18, and the aforementioned flow “along the roof” is lateral. In other words, in FIG. 6B, the members 16 and 18 can be in a single course of tiles (if in a tile roof), both equidistant from the roofs ridge or eave. Also, the distance the upper member 16 is offset from lower member 18 can vary, and the distance shown in FIGS. 6A and 6B is for illustrative purposes only. In a preferred embodiment, upper member 16 is offset from lower member 18 by within 2-5 courses of tiles when upper member 16 is upwardly or downwardly offset from lower member 18, as in FIG. 6A. In another preferred embodiment, upper member 16 is offset from lower member 18 by within 2-5 tiles when upper member 16 is laterally offset from lower member 18, as in FIG. 6B.
In an alternative embodiment, only the solar panel 20 is offset from the lower vent member 18. In such an embodiment, the solar panel 20 is preferably still hardwired to the fan assembly 38 and/or other elements of the control system of FIG. 1E.
A skilled artisan will also appreciate that some air flow may be permitted between the various tiles 54, such that some of the air leaves the batten cavity 52 without flowing through the upper member 16. Tile roofs employing tiles of this nature are shown and described in U.S. Pat. No. 6,491,579, the entirety of which is hereby incorporated herein by reference. Further, although the foregoing description describes a primary direction of air flow in some embodiments, other air currents may also be present in the batten cavity 52, including air flow in a reverse direction from that described above. In some embodiments, the tiles 54 overlying the lower member 18 can be replaced with a solar panel or an array of solar panels. In such embodiments, the air flow along the underside of the panels between the upper member 16 and the lower member 18 can advantageously aid in the cooling of the solar panels, thereby preventing overheating of the panels and enhancing their energy collection performance.
Offsetting the upper and lower members 16, 18 can have other performance advantages. For example, it has been found that offsetting can help to prevent backloading of the vent. Backloading occurs when unusual conditions, such as strong winds or violent storms, force air to flow through a vent system in a direction opposite from the direction for which the vent system was designed. Backloading can be particularly problematic in an active vent system because the reversed air flow can cause the fan to reverse the direction in which it is driven, potentially leading to severe mechanical damage or failure.
Note that the upper member 16 can be shaped and/or decorated to simulate the appearance of many different types of tiles as described above. The upper member 16 in FIG. 6B is shown simulating an “M” profile tile for illustrative purposes only. Further note that fan assembly 38 is shown in FIGS. 5A-6B for illustrative purposes only, and the vents can be used without a fan assembly to achieve the airflow described above. Also note that when the upper member 16 is offset from the lower member 18 as described above, a wire or plurality of wires (not shown) can extend above and/or below the roof deck 56 and/or tiles 54, and/or within batten cavity 52. The wires can be used to provide power and/or communication between solar panel 20, fan assembly 38, battery 25, timer 46, sensor 44, controller 43, actuators 41, 42, and/or position data device 45, as described above and shown in FIG. 1E.
FIGS. 7 and 8 illustrate an embodiment of a roof vent. FIG. 7 is a top schematic view showing a rooftop with the roof vent installed. The upper member 16 of the roof vent, with the solar panel 20 attached, is shown in FIG. 7. On either side of the solar panel 20, apertures 22 are visible. The apertures can allow air to flow from the space 16c between the first part 16a and second part 16b of the upper member 16 when the vent is in use, as described above and shown in FIG. 1D. FIG. 8 is a bottom schematic view of the upper member of the roof vent shown in FIG. 7. Screened openings 24 in the second part 16b of the upper member 16 are shown in FIG. 8, which openings can allow air to flow from the batten cavity into the space between the first and second parts of the upper member when the vent is in use.
FIG. 9 is a bottom perspective view showing a lower portion of member 18 (e.g., FIG. 2) of an embodiment of a roof vent. The lower portion of member 18 can be used as part of a non-integrated roof vent, as shown in FIGS. 7 and 8, or as part of an integrated vent, as shown in FIGS. 10-13. As shown in FIGS. 1A and 9, the opening 50 in the roof deck need not be the same size or shape as the hole 21 in the lower member 18 of the vent. The embodiment shown in FIG. 9 includes mounting brackets 32 for the fan assembly 38 that extend laterally beyond the outer surface of the fan housing 30. However, as noted above, in other embodiments, the fan housing can be substantially free of protrusions extending laterally from the outer surface of the housing, such as by using mounting brackets that are joined to the interior of the fan housing.
FIGS. 10-13 are illustrations of an embodiment of an integrated roof vent 10b. In some embodiments, the integrated roof vent 10b includes a solar panel 20, and in some embodiments, the integrated vent 10b does not include a solar panel 20. FIG. 10 is a top view of the integrated vent 10b with a solar panel 20 attached. FIG. 11 is a top perspective view of the integrated vent 10b without a solar panel. In some embodiments, the integrated vent 10b can comprise two or more fans that function similarly to the embodiments described above and illustrated in FIGS. 2A-2C and 3A. An exemplary illustration of an embodiment of the integrated vent 10b with two fans 38 is shown in FIG. 11A (top view) and 11B (side view). The integrated roof vent 10b illustrated in FIGS. 11A and 11B can comprise a rectangular fan housing 30c. The rectangular fan housing 30c is shown in FIGS. 11A and 11B for illustrative purposes only. For example, a rectangular fan housing can be employed with the other roof vents described above, and the other fan housing embodiments 30, 30a, 30b can be employed with the integrated roof vent 10b shown in FIGS. 11A and 11B. Further, the rectangular fan housing 30c can flare outwardly and downwardly to function similarly to the fan housing 30b described above. FIG. 12 is a bottom perspective view of the integrated vent with the fan assembly 38 removed. FIG. 13 is front view of the integrated vent. As described above, in some embodiments, an integrated vent can include a bracket 60 (FIG. 1F) for selectively attaching and/or moving the solar panel 20.
FIG. 14 is a perspective view of a building 100 having roof vents 6, 7 in accordance with an embodiment. The building can comprise a roof 2 with a ridge 4 and two eaves 5. Roof 2 can be a sloped roof, as shown in the illustrated embodiment. In certain other embodiments, the ventilation system can be modified for other types of roofs. Between the ridge 4 and each eave 5 is a roof field 3, one of which is shown in the figure. It will be understood that more complex roofs may have more than two fields 3. In an embodiment, at least one of the fields 3 of the building 100 can include a plurality of field vents 6, 7, at least one of which comprises one of the roof vents described above, such as vents 10, 10a or 10b. In the illustrated embodiment, a plurality of field vents 6 is provided near the ridge 4, preferably aligned substantially parallel to the ridge. In certain embodiments, the field vents 6 are spaced by 1-4 courses of roof cover elements (e.g., tiles) from the ridge 4. In a preferred embodiment, the field vents 6 are spaced one course of roof cover elements from the ridge 4. In the illustrated embodiment, a plurality of field vents 7 is provided near the eave 5, preferably aligned substantially parallel to the eave. In certain embodiments, the field vents 7 are spaced by 1-4 courses, and preferably 2-3 courses, of roof cover elements (e.g., tiles) from the eave 5. In other embodiments, the plurality of field vents 6, 7 can be positioned non-linearly or non-parallel relative to each other. A skilled artisan will appreciate that field vents 6, 7 can be positioned a distance from eave 5 and ridge 4 such that field vents 6, 7 will not interfere with eave 5 and ridge 4, or other structures within building 100. For example, in an embodiment wherein field vent 7 comprises a housing 30 as shown in FIG. 1A, field vent 7 can be positioned so that housing 30 does not interfere with the structure of building 100 proximate to eave 5 (e.g., an attic floor and possibly an insulation layer on said floor) or an upper portion of a sidewall 9 of building 100. In some embodiments, field vents 6 and/or 7 can be positioned to be a desired distance from structures within building 100. For example, field vents 6 and/or 7 can be positioned so that a desired clearance (e.g., 6-18 inches, and more preferably about 12 inches) is provided between the top of an insulation layer in an attic of building 100 to the bottom of the field vents 6 and/or 7.
In use, the vents 6, 7 in this arrangement promote air flow through the building as indicated by the arrow 8. That is, air tends to flow into the building (e.g., into an attic or crawlspace of the building or into an area below a vaulted ceiling defined by the roof fields 3) through the vents 7, and air tends to exit the building through the vents 6. The roof can also have a batten cavity, as described above, through which air may also flow. This airflow can be provided without fan assemblies in vents 6, 7, such as from the thermal effects of air rising through the attic, along the vaulted ceiling, or through the battens and/or tiles, or through the effect of wind blowing across the roof 2 and ridge 4. The fan assemblies as described above can also be used in vents 6, 7 to increase these natural thermal and wind effects. In some embodiments, fan assemblies 38 are provided in the vents 6 but not the vents 7. In some embodiments, fan assemblies 38 are provided in the vents 6 and 7, wherein the fan assemblies in the vents 7 are configured to draw air into the building, and the fan assemblies in the vents 6 are configured to exhaust air from the building.
Although the invention has been disclosed in the context of certain embodiments and examples, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses and obvious modifications and equivalents thereof. Accordingly, the invention is not intended to be limited by the specific disclosures of preferred embodiments herein.
Patent Application
20100330898
