Patent Application
20120028563
1. Technical Field
This disclosure generally relates to the field of building construction and, more particularly, to energy efficient buildings.
2. Description of the Related Art
There is ever increasing concern regarding energy consumption. Reducing energy consumption may provide numerous benefits. For example, such may reduce the costs paid by individual consumers. Such may reduce the infrastructure costs incurred by energy suppliers, for example reducing the number of new generation facilities required. Such may also reduce negative environmental effects, for instance the generation of greenhouse gases or spoilation of the natural environment. In light of such concerns various governmental agencies or departments are promulgating new rules and regulations regarding energy conservation. Various private individuals and business are proposing new approaches and new technologies to address these concerns.
The heating and cooling of buildings is one of the major uses of energy. Many residential and commercial buildings require heating, particular during winter months to maintain a comfortable interior climate. Likewise, many residential and commercial buildings require cooling, particular during summer months to maintain a comfortable interior climate. Various approaches to heating and cooling are used. Most such approaches are active approaches using, for instance using furnaces and air conditioners, which rely on a variety of energy sources, including electricity, natural gas, coal.
Many building owners or managers, particularly owners and managers of commercial buildings, are expending large sums of money and time to achieve greater energy efficiency and/or “green” certification. Some such approaches employ solar insolation, for instance to heat water or generate electricity. Other such approaches are more passive, for instance improved insulation and specialty glazing. Some approaches are more suitable for new construction, while other approaches are suitable for both new and existing construction.
While numerous improvements in energy efficient buildings have been made, yet still further gains are desirable.
A building includes exterior walls that form spaces which are selectively vented under control of a control system. Vents are operated to retain trapped air or exhaust trapped air to improve the energy performance of the building. Vents with selectively operable dampers may be located proximate a top of a wall or wall section of wall. Vents may also be located proximate a bottom of a wall or wall section to allow drainage of liquid and circulation of air. Various specific wall constructions provide for an air gap between layers of exterior sheathing of the exterior wall. The air gap may be in addition to a space between interior and exterior sheathing, which space may include a thermal insulation material (e.g., fiberglass batting).
An environmental control system for a building having at least one exterior wall may be summarized as including at least one lower vent positioned proximate a bottom portion of at least one exterior wall portion of the exterior wall of the building and which provides fluid communication between an exterior environment outside of the building and at least one space in the at least one exterior wall portion, the at least one space formed between at least a first exterior wall member and at least a second exterior wall member, the first and the second exterior wall members which form at least a portion of the at least one exterior wall portion of the exterior wall of the building, the first exterior wall member spaced interiorly of the second exterior wall member; an upper vent positioned proximate a top of the at least one exterior wall portion of the exterior wall of the building and which provides fluid communication from the at least one space in the at least one exterior wall portion of the building; and a vent actuation system configured to selectively open or close the upper vent to allow air to exhaust out of the upper vent from the at least one space of the at least one exterior wall portion when open and to trap air in the at least one space of the at least one exterior wall portion when closed. The upper vent may, for example provide fluid communication with the exterior environment outside of the building or may provide fluid communication to an interior space within the building, for example an attic. The vent actuation system may include at least one of an electric motor or a solenoid coupled to open and close the upper vent; and a controller coupled to the at least one of the electric motor or the solenoid. The vent actuation system may include at least one temperature sensor communicatively coupled to the controller provide signals indicative of temperature. The temperature sensor may be posited to sense a temperature in the exterior environment outside of the building and the controller may be configured to open the upper vent in response to the sensed temperature in the exterior environment exceeding a first threshold temperature. The vent actuation system may be communicatively coupled and responsive to at least one of an independent heating or air conditioning system of the building which is distinct from the environmental control system of the building. The vent actuation system may be communicatively coupled and responsive to at least one of a user actuated input device, a timer, a wireless communications device or an external computer system. At least a portion of the upper vent may form a Venturi shaped conduit or passage.
The environmental control system may further include a fan fluidly coupled to the at least one space of the at least one exterior wall portion and selectively operable to cause air to flow from the at least one lower vent to the at least one upper vent. A first one of the at least one exterior wall may be opposed across the building to a second one of the at least one exterior wall, each of the first and the second exterior walls having respective exterior wall portions having at least one lower vent and at least one upper vent, and the vent actuation system may be configured to selectively open or close the at least one upper vent of the exterior wall portion of the first exterior wall separately from the at least one upper vent of the exterior wall portion of the second exterior wall.
The environmental control system may further include the at least one exterior wall, wherein the at least one exterior wall portion of the at least one exterior wall further comprises a lath separating the first and the second exterior wall members to defined the at least one space therebetween.
The at least one exterior wall portion of the at least one exterior wall may further include at least one outer flexible web material positioned proximate an interior facing face of the second exterior wall member. The at least one outer flexible web material may be a Kraft paper retained by the lath.
The at least one exterior wall portion of the at least one exterior wall may further include at least one inner flexible web material positioned proximate an exterior facing face of the first exterior wall member. The at least one inner flexible web material may be a building wrap or paper adhesively or mechanically secured to the exterior facing face of the first exterior wall member. The second exterior wall member may be a stucco containing an expanded perlite. The first exterior wall member may be a gypsum and fiberglass mat sheathing, foam board, oriented strand board (OSB), or plywood.
At least one exterior wall portion of the at least one exterior wall may further include at least one interior wall member on an interior of the building; and a plurality of studs coupling the interior wall member to the first exterior wall member. The studs may be steel, wood, or alternatively the wall construction may be some other material such as concrete, concrete masonry unit (CMU) or other building material.
At least one exterior wall portion of the at least one exterior wall may further include fiberglass batting received between the interior wall member and the first exterior wall member between the studs.
A method n environmental control system for a building having at least one exterior wall may be summarized as including at a first time, closing at least one upper vent positioned proximate a top of at least one exterior wall portion of the at least one exterior wall of the building to trap air in at least one space of the at least one exterior wall portion, and which at least one top vent selectively provides fluid communication from the at least one space in the at least one exterior wall portion, the at least one space formed between at least a first exterior wall member and at least a second exterior wall member, where the first and the second exterior wall members form at least a portion of the at least one exterior wall portion of the exterior wall of the building with the first exterior wall member being spaced interiorly of the second exterior wall member; and at a second time, opening the at least one upper vent to allow air to exhaust out of the upper vent from the at least one space of the at least one exterior wall portion into the exterior environment.
The method may further include allowing air to continually pass through at least one lower vent positioned proximate a bottom portion of the at least one exterior wall portion of the at least one exterior wall of the building and which at least one lower vent provides fluid communication between the exterior environment outside of the building and the at least one space in the at least one exterior wall. Closing at least one upper vent may include operating at least one of an electric motor or a solenoid. At least one of the opening or the inclosing at least one upper vent may be responsive to a temperature. At least one of the opening or the closing at least one upper vent may be responsive to a timer or a user input.
The method may further include actively moving air through the at least one space when the at least one upper vent is open. The at least one upper vent in at least one exterior wall portion of the at least one exterior wall of the building may include opening the at least one upper vent in a first one of the at least one exterior wall portion of the at least one exterior wall of the building while maintaining the at least one upper vent closed in a second one of the at least one exterior wall of the building.
In the drawings, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not drawn to scale, and some of these elements are arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn, are not intended to convey any information regarding the actual shape of the particular elements, and have been solely selected for ease of recognition in the drawings.
In the following description, certain specific details are set forth in order to provide a thorough understanding of various disclosed embodiments. However, one skilled in the relevant art will recognize that embodiments may be practiced without one or more of these specific details, or with other methods, components, materials, etc. In other instances, well-known structures associated with building materials, ducts, fans or blowers, control systems and communications have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the embodiments.
Unless the context requires otherwise, throughout the specification and claims which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense that is as “including, but not limited to.”
Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Further more, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
The headings and Abstract of the Disclosure provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.
The building 100 includes a number of exterior walls 102a-102d (four shown, collectively 102), a number of interior walls 104a-104f (collectively 104), doors 106a-106c (collectively 106) and windows (not shown). The exterior walls 102 separate an interior 108 of the building 100 from an exterior 110 thereof.
The building 100 may be constructed according to any variety of construction techniques and/or materials. As is common in many parts of North America, the exterior walls 102 may include a plurality of spaced apart studs, 112a-112n (only three called out in
The exterior wall portion 120 may include at least one space 122 between the interior and the exterior sheathing or material 114, 116, 118, including between two or more layers of the exterior sheathing or material 116, 118. In some instances, these spaces 122 may be filled or partially filled with a thermally insulative material (not shown in
The exterior wall portion 120 of the exterior wall 102 includes a number of vents 124 positioned or located proximate a bottom of the exterior wall portion 120, and hence denominated herein as lower vents. The lower vents 124 provide fluid communication between the space 122 in the exterior wall 102 and the external environment 110. The lower vents 124 may be positioned and configured to allow fluid, for instance a liquid such as water, to drip out of the space 122. The lower vents 124 may also be configured to allow circulation of a fluid, such as air, into the space 122 from the external environment 110. The lower vents 124 may be configured to prevent the intrusion of insets, vermin or other pests into the space 122, for example by appropriately sized apertures.
The exterior wall portion 120 of the exterior wall 102 includes a number of vents 126 positioned or located proximate a bottom of the exterior wall portion, and hence denominated herein as upper vents. The upper vents 126 may be opened and closed to selectively provide fluid communication between the space 122 in the exterior wall 102 and the external environment 110. The upper 126 may be positioned and configured to allow exhausting of a fluid, such as air, out of the space 122 into the external environment 110. The upper vents 126 may be configured to prevent the intrusion of insets, vermin or other pests into the space 122, for example by appropriately sized apertures or a screen.
A control subsystem 128 may be communicatively coupled to control an opening and closing of at least some of at least the upper vents 126. In some embodiments, at least some of the lower vents 124 may also be selectively opened and closed under control of the control subsystem 128. While explained in more detail below with particularly with later reference to
Optionally, one or more fans or blowers 136a-136n (only two called out in
The environmental control system 200 includes a number of vent actuators 202a-202d (only four illustrated, collectively 202) and a control subsystem 204 communicatively coupled to control the vent actuators 202 based on certain conditions. The vent actuators 202 may take the form of electric motors, solenoids, electromagnets or other actuators that can be selectively operated to open and close the vents. For example, the electric motors, solenoids, electromagnets or other actuators may be physically or magnetically coupled to a damper or door (not illustrated in
The environmental control system 200 optionally includes a number of fans or blowers 206a-206b (only four illustrated, collectively 206). As explained above, the fans or blowers 206 may be positioned and selectively cause air to circulate in the space 122 (
The control subsystem 204 may include one or more controllers 208, for instance a microcontroller, microprocessor, programmable gate array or application specific integrated circuit. The control subsystem 202 may also include one or more computer- or processor-readable non-transitory storage mediums that store instructions executable by the controller that cause the controller to control the vent actuators and/or fans or blowers based on at least one condition. The computer- or processor-readable non-transitory storage mediums may, for example, take the form of one or more read-only memories (ROMs) 210 and/or random access memories (RAMs) 212. The controller 208, computer- or processor-readable storage mediums 210, 212 and/or other components such as ports 214a-214c (only three called out, collectively 214) may be coupled by one or more buses 215. The buses 215 may take a variety of forms including power buses, communications buses, instruction buses, and/or data buses.
The ports 214 may provide communications to and/or from the vent actuators 202, fans or blowers 206 and/or other components such as user input devices and sensors. For example, one or more external or exterior temperature sensors 216 (only one illustrated in
Additionally, or alternatively various user input devices may be employed. For example, a user may employ a keypad with or without a display, for instance a wall mounted keypad 224 to interact with the control subsystem 204. Also for example, the user may employ a computer or computer system 226 to interact with the control subsystem 204. The user may employ a mobile communications device, for instance a cellular phone or smart or wireless personal digital assistant (PDA) 228 to interact with the control subsystem 204. The user may employ a timer 230 to interact with the control subsystem 204. The user may use the various user input devices to program the control subsystem 204 or to manually control or even override the programming of the control subsystem 204. Thus, a user may set various temperature thresholds for opening or closing the vents, or may cause the vents to open and close independent of, measured or sensed temperatures.
The ports may take the form of wired connectors or couplers, for instance Universal Serial Bus ports (USB) or Firewire® ports. The ports may take the form of wireless connectors or couplers for instance infrared transceivers or radio transceivers and antennas such as those compatible with 802.11 wireless communications standards or other protocols. Communications may be via any of a variety of protocols including power line communications protocols for communications over standard electrical wiring or Ethernet protocols for communications over twisted pair wiring.
In use, at a first time the control system 204 closes at least one upper vent positioned proximate a top of at least one exterior wall portion of the at least one exterior wall of the building to trap air in at least one space of the at least one exterior wall portion. The control system 204 may close the at least one upper vent in response to a variety of conditions. For example, the control system 204 may close the at least one upper vent in response to a temperature sensed or measured in the external environment or in the interior of the building falling below some threshold temperature. The control system 204 may close the at least one upper vent in response to occurrence of a time of day or a season. The control system 204 may close the at least one upper vent in response to a level or magnitude of light exceeding or falling below a defined threshold magnitude, or in response to a duration of a level or magnitude of light exceeding or falling below a defined threshold duration. The control system 204 may close the at least one upper vent in response to a signal from any of the various sensors or input devices previously described.
At a second time, the control system 204 may open the at least one upper vent to allow air to exhaust out of the upper vent from the at least one space of the at least one exterior wall portion into the exterior environment. The control system 204 may open the at least one upper vent in response to a variety of conditions. For example, the control system 204 may open the at least one upper vent in response to a temperature sensed or measured in the external environment or in the interior of the building raising above some threshold temperature, which may be the same as or different form a threshold temperature at which the upper vent is closed. The control system 204 may open the at least one upper vent in response to occurrence of a time of day or a season. The control system 204 may open the at least one upper vent in response to a level or magnitude of light exceeding or falling below a defined threshold magnitude, or in response to a duration of a level or magnitude of light exceeding or falling below a defined threshold duration. The control system 204 may open the at least one upper vent in response to a signal from any of the various sensors or input devices previously described.
The control system 204 may open and or close vents, for instance upper vents, in one exterior wall separately from the vents in other ones of the exterior walls. For example, the upper vents in an exterior wall with a southern exposure may be open and/or closed at different times than upper vents in an exterior wall with a northern exposure to adjust for different levels of solar insolation experienced by the respective exterior walls.
As explained above the lower vents may not be closeable, thus allowing air to continually pass through at least one lower vent positioned proximate a bottom portion of the at least one exterior wall portion of the at least one exterior wall of the building. In other embodiments, the lower vents may include dampers, doors or other mechanisms that allow the control system 204 to selectively open and close the lower vents. If closeable, the control system 204 should periodically open the lower vents to ensure that moisture or collected water may be exhausted. Some embodiments may include a moisture sensor to detect the buildup or collection of water at the bottom of the spaces. The control system 204 may then open the lower vents from time-to-time when the sensed or measured moisture exceeds a defined threshold.
The control system 204 may close or open selective vents by communicating signals or closing a switch or relay to provide power to at least one of an electric motor, a solenoid or other actuator coupled to move the damper, door or other device of the vent. For example, the control system 204 may open at least one upper vent in a first one of the exterior walls of the building while maintaining at least one upper vent closed in a second one of the exterior walls of the building.
Further, the control system 204 may selectively operate one or more fans or blowers to assist in circulating the air in the spaces in the walls. The control system may operate the fans or blowers by transmitting signals or closing a switch or relay to provide power to the fans or blowers. For example, the control system 204 may turn ON selected blowers to exhaust one exterior wall while maintaining other fans or blowers in an OFF state. Also for example, the control system 204 may operate selected fans or blowers to circulate trapped air from one or more exterior walls to other exterior walls. For instance, the control system 204 may selectively operate the fans or blowers to circulate warm air entrapped in an exterior wall with a southern exposure to an exterior wall with a northern exposure and/or exterior walls with an eastern or western exposure. Additionally or alternatively, passive options for enhancing circulation may be employed, for example including vents with a portion forming a Venturi tube or wind driven fans (e.g., similar to chef's hat turbine vent, roof ventilator).
The cross-sectional view of the illustrated exterior wall portion 300 is located between studs 112 (
The exterior wall portion 300 includes one or more layers of an interior sheathing or material 312, for example wall board or plaster board. One or more layers of plaster and/or paint 314 may be carried on an interiorly facing surface of the interior sheathing or material 312.
The exterior wall portion 300 includes a number of layers of an exterior sheathing and/or material. In particular, the exterior wall portion 300 is illustrated as a stucco installation. From an interior toward an exterior of the exterior wall portion 300, the layers may include a sheathing 316, a weather resistant barrier for example a building wrap or paper 318, a lath 320, a Kraft paper 322 or other web material, and a cladding 324 in the form of stucco. The lath 320, for instance a truss lath, provides a frame for keying the stucco cladding 324 as well as supporting the Kraft paper 322 and forming a space 326 in the exterior wall portion 300, sometimes denominated herein as an air gap. The laths described in U.S. Pat. No. 6,820,387 and U.S. Patent Application Publication Number 2007-0175145 A1 may be suitable. The air gap 326 is in addition to a space 328 defined between the interior sheathing 312 and the exterior sheathing and/or material layers 316-326, which space 328 may be filled with an insulating material 330, for instance fiberglass batting or closed cell foam. The sheathing 316 is intermediate the interior sheathing 312 and the cladding 324, so may in certain instances be denominated as intermediate sheathing or layer. The sheathing 316 may take any of a variety of forms, for example fiberglass mat sheathing (e.g., DENSGLASS® sheathing) or other suitable sheathing material (e.g., foam board, oriented strand board, plywood). The building wrap 318 may take the form of TYVEK® building wrap or some other building paper which forms a weather resistant barrier. The building wrap 318 may take the form of a corrugated building wrap, for example Tyvek® StuccoWrap® commercially available DuPont™. The building wrap 318 may be mechanically attached to the sheathing 316. Alternatively, a trowel on membrane may be employed as a weather resistant barrier, which may be applied by spraying, brushing and/or rolling. As discussed in more detail below, the stucco cladding 324 may take any of variety of forms, for example the forms described in U.S. patent application Ser. No. 12/508,384 filed Jul. 23, 2009. Such may advantageously reduce the weight of and/or enhance the thermal insulation provided by the stucco cladding 324. Optionally, the exterior wall portion 300 may include a strip of drainage matting 332 positioned between the sheathing 316 and the stucco cladding 324.
The lath 320 may be attached to the sheathing 316 via fasteners, for instance screws 334. A frame 336 may be provided in an opening 338 (
The vent assembly 340 may include the hood 306, damper or door 308 and a vent actuator 310. As previously explained the vent actuator 310 may take the form of an electric motor, solenoid, electromagnet or other actuator. An electrical connector 344a is located in the opening to physically and electrically mate with an electrical connector 344b of the vent assembly 340 to provide power and control of the vent actuator 310. The damper or door is illustrated in the closed position in solid line as 308a, and in the open position in broken line as 308b. The vent assembly 340 may include an insect screen 346. While not illustrated as such, the vent assembly 340 may have a fan or blower including an electric motor, blades and electrical connector.
As explained above, an electrical connector 344b of the vent assembly 340 may be physically and electrically coupled to a complimentary connector 344a in the exterior wall portion 300. Electrical wiring 348 may run through the exterior walls 102 (
The illustrated exterior wall portion 300 may represent the upper portion of one floor or story of a building 100 (
Similar to the upper exterior wall portion 300, the lower exterior wall portion 500 includes one or more layers of an interior sheathing or material 512, for example wall board or plaster board. One or more layers of plaster and/or paint 514 may be carried on an interiorly facing surface of the interior sheathing or material 512.
The exterior wall portion 400 includes a number of layers of an exterior sheathing and/or material. In particular, the exterior wall portion 500 is illustrated as a stucco installation. From an interior toward an exterior of the exterior wall portion 500, the layers may include a sheathing 516, a weather resistant barrier for example a building wrap or paper 518, a lath 520, a Kraft paper 522 or other web material, and a cladding 524 in the form of stucco. The lath 520 provides a frame for keying the stucco cladding 524 as well as supporting the Kraft paper 522 and forming a space 526 in the exterior wall portion 500, sometimes denominated herein as an air gap. The laths described in U.S. Pat. No. 6,820,387 and U.S. Patent Application Publication Number 2007-0175145 A1 may be suitable. The air gap 526 may be in addition to a space (not called out in
The lower vent 504 includes a perforated drip screen 550 which provides fluid communication to exterior or external environment 110 (
The perforations 552 (only one called out in
The perforated drip screen 550 may be secured to the sheathing 516 via fasteners (e.g., screws, nails, tacks) and/or adhesives. The perforated drip screen 550 may function as a frame. In particular, the perforated drip screen 550 may include a stucco stop 554 and a bottom edge 556 that protects a bottom edge of the stucco cladding 524. The perforations 552 are spaced rearwardly from the stucco stop 554 to prevent the stucco cladding 524 from blocking or otherwise interfering with the perforations 552. The perforated drip screen 550 may have a generally L-shape profile, with a relatively longer leg extending generally vertically when in use and a relatively shorter leg through which the perforations 552 extend through extending generally horizontally when in use.
The construction of the lower exterior wall portion 600 is similar or identical to the lower exterior wall portion 500 (
In contrast to the embodiment of
In a first example, an exterior wall may include steel studs having a depth of 3½ inches, and spaced 16 inches on center. The interior sheathing may be drywall of ½ inch thick with an associated thermal resistance or R value of approximately 0.45. The intermediate sheathing may be DensGlass® sheathing with an R value of approximately 0.56. The exterior wall may include fiberglass batting between the interior sheathing and the intermediate sheathing, having an associated R value of approximately 13. The wall wire lath may provide an air gap of approximately ⅜ inches with an R value of approximately 1.7 for heating and an estimated R value of from approximately 3 to approximately 4 for cooling. The exterior most sheathing may take the form of an approximately 1 inches layer of stucco containing an expanded perlite and having an associated R value of approximately 1. When determining thermal resistance, there is an air film associated with each surface/air interface which air films have an R value of approximately 0.68. In the described exterior wall structure there is an air film associated with the interior facing surface or face of the interior sheathing material and an air film associated with the exterior facing surface or face of the stucco. There are also two air films associated with the materials forming the air gap. The total R value for the described structure is 18.92, less steel framing loss estimated at 1.7, for a total effective R value of 17.22 for the exterior wall.
In a second example, an exterior wall may include steel studs having a depth of 5½ inches, and spaced 24 inches on center. The interior sheathing may be drywall of ½ inch thick with an associated thermal resistance or R value of approximately 0.45. The intermediate sheathing may be DensGlass® sheathing with an R value of approximately 0.56. The exterior wall may include fiberglass batting between the interior sheathing and the intermediate sheathing, having an associated R value of approximately 19. The wall wire lath may provide an air gap of approximately ⅜ inches with an R value of approximately 1.7 for heating and an estimated R value of from approximately 3 to approximately 4 for cooling. The exterior most sheathing may take the form of an approximately 1 inches layer of stucco containing an expanded perlite and having an associated R value of approximately 1. When determining thermal resistance, there is an air film associated with each surface/air interface which air films have an R value of approximately 0.68. In the described exterior wall structure there is an air film associated with the interior facing surface or face of the interior sheathing material and an air film associated with the exterior facing surface or face of the stucco. There are also two air films associated with the materials forming the air gap. The total R value for the described structure is 24.92, less steel framing loss estimated at 1.7, for a total effective R value of 23.22 for the exterior wall.
While the above examples employ certain dimensions, other dimensions may be suitable. For example, the exterior wall may include a space or air gap of a different size. For instance, a large space of air gap may provide a higher total R value. A space or air gap of ¾ inch to 1½ inches may easily achieved using conventional building materials or the lath discussed above.
Additionally, or alternatively, the exterior wall may include one or more additional layers of material, which may increase the total R value. For example, the exterior wall may advantageously include a radiant barrier positioned between the intermediate sheathing and the cladding. For instance, a radiant barrier of a material bearing a reflective coating (e.g., aluminum) may be adhered or otherwise attached to an interior facing surface of the Kraft paper. Suitable radiant barriers may be commercially available from various sources, including the Fi-Foil Company of Auburndale Fla. Use of a corrugated building wrap may also increase the total R value.
Various embodiments are directed to venting a space or air gap in at least a portion of an exterior wall, the space formed between at least a first and second exterior wall members. In the illustrated embodiments, the second exterior wall member may be a cladding or Kraft paper and the first exterior wall member is may be the intermediate layer of sheathing positioned between the cladding and an interior sheathing or material (e.g., plaster board) and/or the building wrap carried thereon. In other embodiments, the space may be formed between different structural elements of the exterior wall. Walls employing an open frame construction may omit the intermediate sheathing and place the building wrap or paper directly over the studs. In open frame construction, the space or air gap may be formed between the building wrap and either the cladding and/or the Kraft paper. Where an EIFS installation is employed, the space or air gap may be formed between the insulation board and some other element of the EIFS installation or the framing. The concepts described herein are also applicable to other construction techniques, including those which do not employ studs, for example concrete, tilt up panels, concrete masonry units, insulated concrete forms, etc. For instance, any of the above construction materials may form the first exterior wall member in conjunction with a cladding material as the second exterior wall member and a standoff structure (e.g., lath, hat track, Z-grits) to form a space or air gap therebetween, with vents positioned in the cladding operable to selectively vent the space or air gap. Yet even further embodiments my employ continuous insulation such as rigid insulation sheets, which may or may not have tongues and grooves. In such construction, the rigid insulation sheets may form the first exterior wall member, a cladding or some other material may form the second exterior wall member, and a standoff structure may form the space or air gap between the rigid insulation sheets and the cladding or other material.
The illustrated embodiments include vents located proximate a bottom of the portion of the wall and vents proximate a top of the wall portion, which may be selectively closed or opened to respectively retain air in the space or exhaust air from the space. The wall portion may, for example, be a floor or story of a house. Thus, the terms lower and upper are used to indicate a relative position with respect to each other in a given wall portion. As previously explained, it is possible, for example, to have the upper vents in a first or lower story to be spaced relatively above the lower vents in a second or upper story.
While illustrated as having a roughly square perimeter, the vent assembly 340 (
While illustrated as exhausting to the external environment, in some embodiments air in the space may be exhausted from the space or air gap in the exterior wall into some other space, for instance into a room in the house which is typically inhabited or into an attic or other typically uninhabited space. Advantageously, the exterior wall may include another space, positioned between the intermediate layer of sheathing and the interior sheathing, which may include a thermally insulative material other than air.
While the illustrated embodiments show cladding in the form of stucco, other cladding materials may be employed. For example, various substantially air tight claddings may be advantageously used, for instance stucco, brick, manufactured stone, exterior insulation finishing system (EIFS) installations, etc. EIFS installations typically include an insulation board which is attached to the substrate or sheathing, a reinforcing mesh and a base or brown coat (e.g., polymer and cement) overlying the insulation board, and a textured finish coat of material overlying the base or brown coat. Less advantageously, various non-air tight claddings may be employed, for instance cement board, wood siding, vinyl siding, aluminum siding. It may be advantageous to employ an air barrier (e.g., another layer of building wrap) outwardly toward the exterior of the space or air gap where the exterior wall employs a non-air tight cladding.
While the illustrated embodiments show a lath that forms the space or air gap, numerous other structures or elements may be employed to form the space or air gap between the intermediate sheathing and cladding. For example, the external wall may include wood strapping, drainage mats or metal (e.g., steel) spacers such as hat track, corrugated sheets or channels, Z girts or other spacer or standoff structures.
The above description of illustrated embodiments, including what is described in the Abstract, is not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. Although specific embodiments of and examples are described herein for illustrative purposes, various equivalent modifications can be made without departing from the spirit and scope of the disclosure, as will be recognized by those skilled in the relevant art. The teachings provided herein of the various embodiments can be applied to other context, not necessarily the exemplary vented space building construction generally described above. To the extent they are not inconsistent, the teachings of U.S. Pat. No. 6,820,387; U.S. patent application Ser. No. 10/935,821 filed Sep. 8, 2004; U.S. patent application Ser. No. 11/679,526 filed Feb. 27, 2007; and U.S. patent application Ser. No. 12/508,384 filed Jul. 23, 2009; and are incorporated herein by reference in their entirety.
In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.
