TECHNICAL FIELD

The present invention relates to the field of air vent cover for use in testing air leakage of an air duct system.

BACKGROUND ART

As the trend to conserve energy continues, more individuals are demanding and more governmental entities are mandating that houses and commercial facilities undergo periodic energy audits. An energy audit is a service where a building structure's energy efficiency is evaluated by a person using professional equipment (such as blower door and infra-red cameras), with the aim to suggest the best ways to improve energy efficiency in heating and cooling the structure.

An energy audit involve recording various characteristics of the building envelope including the walls, ceilings, floors, doors, windows, and skylights. For each of these components the area and resistance to heat flow (R- value) is measured or estimated. The leakage rate or infiltration of air through the building envelope is of concern and is strongly affected by window construction and quality of door seals such as weather stripping. The goal of an audit is to quantify the building's overall thermal performance. The audit may also assess the efficiency, physical condition, and programming of mechanical systems such as the heating, ventilation, air conditioning (HVAC) equipment, and thermostat.

Leaks in an air duct system often account for a large percentage of energy being wasted in a typical home. In a residence, the percentage of air that escapes out of an air duct system due to leaks, on average, is approximately twenty-five percent (25%). Given that in some areas of the country, sixty percent (60%) to seventy percent (70%) of the cost of a households monthly utilities bill is due to the operation of the HVAC system, air leakage in an air duct system may represent a significant waste of both monetary and energy resources.

Measuring the leakage in an air duct system is generally the most time consuming portion of a home energy audit. In fact, as much as fifty percent (50%) of the time required to perform a home energy audit is consumed in testing air leakage of an air duct system. The majority of that time is spent sealing off the various air vents so that the air duct system can be pressurized or depressurized to measure the air leaks.

Current methods of sealing off the air vents involve the use of a special adhesive tape that adheres to the face of an air vent. There are, however, certain drawbacks to the use of this adhesive tape. Applying and removing the adhesive tape to all of the air vents takes a significant amount of time because the adhesive tape is cumbersome and awkward to use. Commonly, the tape sticks to itself and those pieces have to be thrown away unused. The tape is generally stored in bulky spools that are heavy and difficult to maneuver. When the tape is removed from the spools, it can generate an extremely loud noise that may wake up members of a home that are asleep during the day, such as, for example a baby or elderly person taking a nap, or be disruptive to ongoing business concerns.

Another drawback is that the tape does not provide the best seal possible for the air duct system. Even after the tape is applied to the air vent, air may still enter and leave the air duct system beneath the face of the air vent that touches the wall or ceilings surface because the tape only blocks the openings of the air vent on the face of the air vent. The tape does not block openings between the air vent and surface on which the air vent is installed. An additional drawback occurs when the tape is removed. Because the tape uses a strong adhesive, damage often occurs to the wall, ceiling, or air vent when the tape is removed.

SUMMARY OF INVENTION

The present invention discloses an improved air vent cover for use in testing air leakage of an air duct system. The air vent cover includes a cover portion shaped to define a hollow cavity for enclosing an air vent. The air vent has a grill adjacent to a surface surrounding the air vent, and the grill has one or more louvers. The air vent cover includes a flexible connector extendable from the cover portion through the hollow cavity to the air vent. The flexible connector is removeably attachable to at least one of the louvers on the grill of the air vent. The flexible connector adjusts to secure an edge of the cover portion against a region of the surface surrounding the air vent, thereby creating a seal for inhibiting air flow through the air vent.

The present invention also discloses a method of testing air leakage of an air duct system. The air duct system includes a plurality of air supply vents. The method includes: sealing the plurality of air supply vents to obstruct the flow of air through the air duct system, including, for at least one of the plurality of air supply vents, removeably attaching with a flexible connector an enclosure to a louver of the one air vent so as to secure an edge of the enclosure against a region of a surface surrounding the air vent; changing air pressure within the air duct system; measuring air leakage during the change in air pressure; recording the measured air leakage; and unsealing the plurality of air supply vents, including detaching the flexible connector from the louver of the one air vent.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an implementation of apparatus and methods consistent with the present invention and, together with the detailed description, serve to explain advantages and principles consistent with the invention. In the drawings,

Figure 1 sets forth a drawing illustrating a perspective view of an exemplary air vent cover for use in testing air leakage of an air duct system according to embodiments of the present invention.

Figure 2 sets forth a drawing illustrating a perspective view of an exemplary air vent cover for use in testing air leakage of an air duct system according to embodiments of the present invention.

Figure 3A sets forth a drawing illustrating a top view of an exemplary air vent cover for use in testing air leakage of an air duct system according to embodiments of the present invention. Figure 3B sets forth a drawing illustrating the cross section A-A from Figure 3A.

Figure 4A sets forth a drawing illustrating a top view of an exemplary air vent cover for use in testing air leakage of an air duct system according to embodiments of the present invention.

Figure 4B sets forth a drawing illustrating the cross section B-B from Figure 4A. Figure 5A sets forth a drawing illustrating a top view of an exemplary air vent cover for use in testing air leakage of an air duct system according to embodiments of the present invention. Figure 5B sets forth a drawing illustrating the cross section C-C from Figure 5A.

Figure 6A sets forth a drawing illustrating a top view of an exemplary air vent cover (620) for use in testing air leakage of an air duct system according to embodiments of the present invention. Figure 6B sets forth a drawing illustrating the cross section D-D from Figure 6A.

Figure 7 sets forth a drawing illustrating a portion of a flexible connector in an exemplary air vent cover for use in testing air leakage of an air duct system according to embodiments of the present invention.

Figure 8 sets forth a flow chart illustrating a method of testing air leakage of an air duct system according to embodiments of the present invention.

Figure 9 sets forth a line drawing illustrating a perspective view of an exemplary air vent cover for sealing an air vent for use with an installation and removal tool according to embodiments of the present invention.

Figure 10 sets forth a line drawing illustrating a cross-sectional view of the adjustable fastener with the spring and actuator removed for use with an installation and removal tool according to embodiments of the present invention.

Figure 11 sets forth a line drawing illustrating an adjustable fastener with actuator for use with an installation and removal tool according to embodiments of the present invention.

Figure 12 sets forth a line drawing illustrating a cross-sectional view of the adjustable fastener with the spring and actuator for use with an installation and removal tool according to embodiments of the present invention.

Figure 13 sets forth a line drawing illustrating an adjustable fastener with actuator for use with an installation and removal tool according to embodiments of the present invention.

Figure 14 sets forth a line drawing illustrating a cross-sectional view of the adjustable fastener with the spring and actuator for use with an installation and removal tool according to embodiments of the present invention. Figure 15 sets forth a line drawing of an exemplary installation and removal tool being used to install an air vent cover according to embodiments of the present invention.

Figure 16 sets forth a line drawing of a cross-sectional view of at least a portion of the installation and removal tool according to embodiments of the present invention. Figure 17 sets forth a line drawing illustrating an exemplary installation and removal tool being used to install an air vent cover after the hook has been connected to the louvers of an air vent according to embodiments of the present invention.

Figure 18 sets forth a line drawing illustrating an exemplary installation and removal tool being used to position an air vent cover in place according to embodiments of the present invention.

Figures 19A and 11B set forth line drawings illustrating an exemplary installation and removal tool being removed from an air vent cover after installing an air vent cover in place according to embodiments of the present invention.

Figures 20A-E set forth line drawings illustrating further exemplary installation and removal tools according to embodiments of the present invention.

Figures 21A-G set forth line drawings illustrating further exemplary installation and removal tools according to embodiments of the present invention.

Figures 22A-B set forth line drawings illustrating an exemplary air vent cover for use with installation and removal tools according to embodiments of the present invention.

DESCRIPTION OF EMBODIMENTS Exemplary embodiments of air vent covers for use in testing air leakage of an air duct system are described herein with reference to the accompanying drawings, beginning with Figure 1. Figure 1 sets forth a drawing illustrating a perspective view of an exemplary air vent cover (100) for use in testing air leakage of an air duct system according to embodiments of the present invention. Air duct systems are used in heating, ventilation, and air conditioning (HVAC) to deliver, circulate, or remove air using supply, return, or exhaust airflows. Air duct systems, therefore, are one method of ensuring acceptable indoor air quality as well as thermal comfort. Though air duct systems vary from one installation to another, many air duct system share a common set of components. Air duct systems generally include an air handler unit that may be composed of a blower or fan, heating or cooling elements, filters, humidifier, mixing chamber, heat recovery device, controls, and vibration isolators. In addition, air duct systems typically include a network of plenums and ducts that direct airflow between the air handler unit and various air vents used to supply air to or return air from the spaces served by the air duct system. Readers will note that much of the air vent system is omitted from Figure 1 and the remaining Figures 2-8 for clarity.

In Figure 1, the air duct system includes an air vent (106). An air vent is an opening, typically covered by a grill, in an air duct system that serves to supply air to or return air from a space served by the air duct system. Those of skill in the art often may refer to an "air vent' as an air diffuser, an air grate, or a terminal unit.

The air vent (106) of Figure 1 has a grill (108) adjacent to a surface (110) surrounding the air vent (106). In the example of Figure 1, the surface (110) is the interior wall of a room served by the air duct system. In embodiments of the present invention, however, the surface surrounding an air vent may be any surface of a room or structure, including a wall, floor, ceiling, or any other surface as will occur to those of skill in the art. The grill (108) provides a face for the air vent (106) and may serve a decorative or functional purpose. For example, the grill (108) may include an ornamental design, provide a mechanism for directing airflow, or be used to secure the air vent (106) to the surrounding surface (110).

The grill (108) of Figure 1 has one or more louvers (112). A louver is a baffle used to direct or control the flow of air through an air vent. A louver may extend beyond the face of the air vent, as in the example of Figure 1 , or may be inset into the face of the air vent. Still further, some louvers may be placed inside the air vent. A louver may be fixed in place or allowed to move through a range of positions. In fact, many air vents are designed with both fixed and moveable louvers. Whether fixed or moveable, a louver may be configured at a slanted angle or perpendicular to the face of the air vent. In the example of Figure 1, the louvers (112) are fixed in place at slanted angles and are formed as integral components with the grill (108).

In the example of Figure 1, an air vent cover (100) is placed over the air vent (106) to create a seal for inhibiting air flow through the air vent (106) while testing air leakage of the air duct system. The air may attempt to flow through the air vent (106) due to either pressurization or depressurization of the air duct system during the leak testing process. Systems used to pressurize or depressurize an air duct system are known to those of skill in the art and may include, for example, the Minneapolis Duct Blaster ^® or the Retrotec Duct Testing Blower System.

The air vent cover (100) of Figure 1 includes a cover portion (102) shaped to define a hollow cavity (104) for enclosing the air vent (106). The air vent cover (100) of Figure 1 is composed of a single layer of polyurethane. The air vent cover (100) may be fashioned out of a variety of materials, including but not limited to, polyurethane, plastic, harden rubber, or any other material as will occur to those of skill in the art.

In the example of Figure 1, the hollow cavity (104) is generally large enough to receive the portion of the air vent (106) extending from the surface (110) into the space served by the air duct system. Typically, the portion of the air vent extending from the surface includes the grill and any levers for changing the position of any moveable louvers.

The cover portion (102) in the example of Figure 1 is large enough in circumference that the edge (114) of the cover portion (102) surrounds the air vent (106) when placed against the surface (110). In Figure 1, the cover portion (102) is shaped as a trapezoidal prism. This shape, however, is for example only, and not for limitation. Readers of skill in the art will recognize that the cover portion (102) may be any shape so long as the hollow cavity (104) defined by the cover portion can enclose the portion of the air vent extending from the surface into the surrounding space. Such exemplary shapes may include a hemisphere, cuboid, cone, pyramid, parallelepiped, prism, or any other shape as will occur to those of skill in the art.

The exemplary air vent cover (100) of Figure 1 also includes a flexible connector (116). The flexible connector (116) extends from the cover portion (102) through the hollow cavity (104) to the air vent (106). In the example of Figure 1, the flexible connector (116) is removeably attached to one of the louvers (112) on the grill (108) of the air vent (106) using a hook (130). Readers will note that the use of a hook is for example only, not for limitation. Other components for removeably attaching the flexible connector (116) to the louver (112) as will occur to those of skill in the art may also be used such as a clip or other fastener. Preferably, though not required, the flexible connector is configured for easy attachment and detachment using one hand while holding the cover portion with the other hand.

The flexible nature of the flexible connector (116) facilitates quick and easy attachment to and detachment from the air vent (106). A flexible connector provides certain advantages over a rigid connector, which is often used in long-term or permanently installed covers. Rigid connectors, such as those fashioned from a system of nuts and bolts, are cumbersome and more time-consuming to attach and detach because the air vent cover must be precisely placed in the proper orientation for a rigid connector to connect with the air vent. For example, when using a rigid connector made up of a bolt through the air vent cover, typically the air vent cover has to be lined up with the connection point on the air vent. After lining up the air vent cover, however, the air vent cover often blocks or covers the connection point for the rigid connector on the air vent, thereby enhancing the difficulty associated with making the connection between the rigid connector and the air vent. When using a flexible connector, however, there is no requirement that the air vent cover be aligned with the air vent when attaching the connector the air vent because the flexible connector can bend or twist in the manner needed to quickly and easily connect to the air vent.

In the example of Figure 1, the flexible connector (116) adjusts to secure the edge (114) of the cover portion (102) against a region of the surface (110) surrounding the air vent (106), thereby creating a seal for inhibiting air flow through the air vent (106). Securing the edge (114) of the cover portion (102) against a region of the surface (110) surrounding the air vent (106) rather than securing the edge (114) against the air vent (106) itself prevents airflow from bypassing the air vent cover (100) by escaping through the small space that often exists between the air vent (106) and the surface (110) beneath the grill (108). The flexible connector (116) of Figure 1 includes a flexible cord (118) and an adjustable fastener (120) affixed to the cord (118) at a connection point (122) outside of the cover portion (102). In Figure 1, the adjustable fastener (120) is capable of adjusting the connection point (122) to change an amount of the cord (118) extending into the hollow cavity (104) by pressing the button (132) on the adjustable fastener (120) and sliding the cord (118) through the adjustable fastener (120) to increase or decrease the length of cord (118) extending through the hollow cavity (104). By increasing the length of cord (118) extending through the hollow cavity (104), enough slack is provided in the flexible connector (116) of Figure 1 to permit fast, easy attachment of the flexible connector (116) to the louvers (112). Then, decreasing the length of cord (118) extending through the hollow cavity (104) allows the edge (114) of the cover portion (104) to be secured against the surface (110) surrounding the grill (108). Conversely, the air vent cover (100) may be easily removed by increasing the length of cord (118) extending through the hollow cavity (104) to provide enough slack in the flexible connector (116) of Figure 1 to permit fast, easy detachment of the flexible connector (116) from the louvers (112). For further explanation, Figure 2 sets forth a drawing illustrating a perspective view of an exemplary air vent cover (220) for use in testing air leakage of an air duct system according to embodiments of the present invention. The exemplary air vent cover (220) of Figure 2 is similar to the air vent cover (100) of Figure 1. Specifically, the air vent cover (220) of Figure 2 includes a cover portion (102) shaped to define a hollow cavity (104) for enclosing an air vent (106). The air vent (106) of Figure 2 has a grill (108) adjacent to a surface (110) surrounding the air vent. The grill (108) of Figure 2 has various louvers (112) for ornamental or functional purposes.

In the example of Figure 2, the air vent cover (220) includes flexible connectors (200) extendable from the cover portion (102) through the hollow cavity (104) to the air vent (106). The flexible connectors (200) of Figure 2 are removeably attachable to two of the louvers (112) on the grill (108) of the air vent (106). In the example of Figure 2, each flexible connector (200) includes a spring (202). A first end of each spring (202) is attached to a central region (204) of the cover portion (102). Each spring (202) of Figure 2 may be attached by molding a socket for holding the spring (202) on the inner side of the cover portion (102), gluing or bonding the spring (202) to the cover portion (102) or in any other manner as will occur to those of skill in the art. A second end of each spring (202) of Figure 2 is removeably attachable to a louver (112) on the grill (108) of the air vent (106). Each spring (202) may removeably attach to one of the louvers (112) on the grill (108) of the air vent (106) using a hook, a clip, or other fastener as will occur to those of skill in the art (130). The flexible connectors (200) of Figure 2 adjust to secure an edge (114) of the cover portion (102) against a region of the surface (110) surrounding the air vent (106), thereby creating a seal for inhibiting air flow through the air vent (106). In the example of Figure 2, the flexible connectors (200) adjust to secure the edge (114) as the springs (202) compress along their longitudinal axis. To remove the air vent cover (220), an operator may pull the cover portion (220) away from the surface (110), thereby stretching the springs (202) along their longitudinal axis. The operator may then reach with one hand and disconnect each of the springs from the louvers (112) in the grill (108).

Figures 3-6 depict embodiments of various configurations of the flexible connector that secures an exemplary air vent cover against a surface surrounding an air vent. Figure 3A sets forth a drawing illustrating a top view of an exemplary air vent cover (320) for use in testing air leakage of an air duct system according to embodiments of the present invention. Figure 3B sets forth a drawing illustrating the cross section A-A from Figure 3A. The exemplary air vent cover (320) of Figure 3 is similar to the air vent cover (220) of Figure 2. Specifically, the air vent cover (320) of Figure 3 includes a cover portion (102) shaped to define a hollow cavity (104) for enclosing an air vent (106). The air vent (106) of Figure 3 has a grill (108) adjacent to a surface (110) surrounding the air vent. The grill (108) of Figure 3 has various louvers (112) for ornamental or functional purposes.

In the example of Figure 3, the air vent cover (320) includes flexible connectors (310) extendable from the cover portion (102) through the hollow cavity (104) to the air vent (106). The flexible connectors (310) of Figure 3 are removeably attachable to the louvers (112) on the grill (108) of the air vent (106). In the example of Figure 3, each flexible connector (310) is implemented as a spring. A first end of each flexible connector (310) is attached to a central region (204) of the cover portion (102), and a second end of each flexible connector (310) of Figure 3 is removeably attachable to a louver (112) on the grill (108) of the air vent (106) in the manner similar to that described above with reference to Figure 2.

The flexible connectors (310) of Figure 3 adjust to secure an edge (114) of the cover portion (102) against a region of the surface (110) surrounding the air vent (106), thereby creating a seal for inhibiting air flow through the air vent (106). In the example of Figure 3, the flexible connectors (310) adjust to secure the edge (114) as the springs compress along their longitudinal axis. To remove the air vent cover (320), an operator may pull the cover portion (102) away from the surface (110), thereby stretching the springs (202) along their longitudinal axis. The operator may then reach with one hand and disconnect each of the springs from the louvers (112) in the grill (108).

In the example Figure 3, the edge (114) of the cover portion (102) includes a flange (302) extending along a circumference of the cover portion (102) closest to the surface (110). The flange (302) of Figure 3 provides additional surface area to touch the surface (110), which may enhance the ability of the air vent cover (320) to seal against the surface (110). The flange (302) of Figure 3 may be integrally formed as part of the remaining cover portion (102) or may be formed separately from the remaining cover portion (102) and subsequently attached or bonded to the remaining cover portion (102).

The exemplary cover portion (102) of Figure 3 also includes a gasket (300) along the edge (114) of the cover portion (102). A gasket is a mechanical seal that fills the space between two mating surfaces. Gaskets allow 'less-than-perfecf mating surfaces to seal by filling in irregularities of the mating surfaces. For example, the gasket (300) of Figure 3 may help the air vent cover (320) seal with a rough surface such as an interior ceiling or wall with a popcorn texture or other rough texture. In this manner, a gasket blocks the flow of air between the inside and outside of the air vent cover (320) while under compression.

The gasket (300) of Figure 3 may be formed from a variety of materials as will occur to those of skill in the art, including, for example, foam, rubber, nylon, or plastic. When formed from material such as foam, readers will note that there are two types of foam that could be used to create a gasket according to embodiments of the present invention-open-cell foam and closed- cell foam.

In open-cell foam, the cell walls, or surfaces of the bubbles, are broken and air fills all of the spaces in the material. In this manner, open-cell foam creates a permeable barrier that may allow air to flow through it when uncompressed. When compressed, however, the open-cell foam may provide enough of a barrier to serve as a seal. The open-cell nature makes the foam soft or weak, as if it were made of broken balloons or soft toy rubber balls. The insulation value of this foam is related to the insulation value of the calm air inside the matrix of broken cells. In closed-cell foam, most of the cells or bubbles in the foam are not broken; they resemble inflated balloons or soccer balls, piled together in a compact configuration. This makes the closed-cell foam strong or rigid because the bubbles are strong enough to withstand high- pressure. Although closed-cell foam is rigid, it has varying degrees of hardness, depending on its density. Because the cell walls of closed-cell foam are not generally broken, closed-cell foam provides greater resistance to air leakage than that of open-celled foam.

Figure 4A sets forth a drawing illustrating a top view of an exemplary air vent cover (420) for use in testing air leakage of an air duct system according to embodiments of the present invention. Figure 4B sets forth a drawing illustrating the cross section B-B from Figure 4A.

The exemplary air vent cover (420) of Figure 4 is similar to the air vent cover (220) of Figure 1. Specifically, the air vent cover (420) of Figure 4 includes a cover portion (102) shaped to define a hollow cavity (104) for enclosing an air vent (106). The air vent (106) of Figure 4 has a grill (108) adjacent to a surface (110) surrounding the air vent. The grill (108) of Figure 4 has various louvers (112) for ornamental or functional purposes.

In the example of Figure 4, the air vent cover (420) includes a flexible connector (400) extendable from the cover portion (102) through the hollow cavity (104) to the air vent (106). The flexible connector (400) of Figure 4 is removeably attachable to the louvers (112) on the grill (108) of the air vent (106). In the example of Figure 4, the flexible connector (400) of the air vent cover (420) includes a cord (402) and an adjustable fastener (404). The adjustable fastener (404) of Figure 4 is affixed to the cord (402) at a connection point outside of the cover portion (102). The adjustable fastener (404) of Figure 4 is capable of adjusting the connection point to change an amount (406) of the cord (402) extending into the hollow cavity (104).

The flexible connector (400) of Figure 4 adjusts to secure an edge (114) of the cover portion (102) against a region of the surface (110) surrounding the air vent (106), thereby creating a seal for inhibiting air flow through the air vent (106). Similar to Figure 3, the edge (114) of the cover portion (102) in Figure 4 includes a flange (302) extending along a circumference of the cover portion (102) and a gasket (300) to facilitate the seal between the air vent cover (420) and the surface (110).

Figure 5A sets forth a drawing illustrating a top view of an exemplary air vent cover (520) for use in testing air leakage of an air duct system according to embodiments of the present invention. Figure 5B sets forth a drawing illustrating the cross section C-C from Figure 5 A.

The exemplary air vent cover (520) of Figure 5 is similar to the air vent covers (100, 220) of Figures 1 and 2. Specifically, the air vent cover (520) of Figure 5 includes a cover portion (102) shaped to define a hollow cavity (104) for enclosing an air vent (106). The air vent (106) of Figure 5 has a grill (108) adjacent to a surface (110) surrounding the air vent. The grill (108) of Figure 5 has various louvers (112) for ornamental or functional purposes.

In the example of Figure 5, the air vent cover (520) includes a flexible connector (500) extendable from the cover portion (102) through the hollow cavity (104) to the air vent (106). The flexible connector (500) of Figure 5 is removeably attachable to the louvers (112) on the grill (108) of the air vent (106). In the example of Figure 5, the flexible connector (500) of the air vent cover (520) includes a first segment (502) and a second segment (504). The first segment (502) has two or more louver connectors (506) and a region (508) for connecting the second segment (504) to the first segment (502). Each of the louver connectors (506) connects the first segment (502) to one or more of the louvers (112). In this manner, when the flexible connector (500) of Figure 5 is adjusted to seal the cover portion (102) to the surface (110), the static forces between the air vent (106) and the air vent cover (520) are more evenly spread across the grill (108) of the air vent (106). In the example of Figure 5, each segment (502, 504) may be composed of rubber, plastic, nylon, bungee material, or any other material as will occur to those of skill in the art.

The air vent cover (520) of Figure 5 seals with the surface (110) in much the same way as the air vent cover (420) of Figure 4. The flexible connector (500) includes an adjustable fastener (518). The adjustable fastener (518) of Figure 5 is affixed to the second segment (504) at a connection point outside of the cover portion (102). The adjustable fastener (518) of Figure 5 is capable of adjusting the connection point to change an amount of the second segment (504) extending into the hollow cavity (104).

The flexible connector (500) of Figure 5 adjusts to secure an edge (114) of the cover portion (102) against a region of the surface (110) surrounding the air vent (106), thereby creating a seal for inhibiting air flow through the air vent (106). Similar to Figures 3 and 4, the edge (114) of the cover portion (102) in Figure 5 includes a flange (302) extending along a circumference of the cover portion (102) and a gasket (300) to facilitate the seal between the air vent cover (520) and the surface (110). Figure 6A sets forth a drawing illustrating a top view of an exemplary air vent cover

(620) for use in testing air leakage of an air duct system according to embodiments of the present invention. Figure 6B sets forth a drawing illustrating the cross section D-D from Figure 6A.

The exemplary air vent cover (620) of Figure 6 is similar to the air vent covers (100, 220) of Figures 1 and 2. Specifically, the air vent cover (620) of Figure 6 includes a cover portion (102) shaped to define a hollow cavity (104) for enclosing an air vent (106). The air vent (106) of Figure 6 has a grill (108) adjacent to a surface (110) surrounding the air vent. The grill (108) of Figure 6 has various louvers (112) for ornamental or functional purposes.

In the example of Figure 6, the air vent cover (620) includes a flexible connector (600) extendable from the cover portion (102) through the hollow cavity (104) to the air vent (106). The flexible connector (600) of Figure 6 is removeably attachable to the louvers (112) on the grill (108) of the air vent (106). In the example of Figure 6, the flexible connector (600) includes an expandable cord (602). An example of an expandable cord that may be useful in air vent covers according to embodiments of the present invention may include a bungee cord or similar cords as will occur to those of skill in the art. A first end of the expandable cord (602) is attached to a central region (204) of the cover portion (102). A second end of the expandable cord (602) is removeably attachable to at least one of the louvers (112) on the grill (108) of the air vent (106). In Figure 6, the expandable cord (600) may attach directly to the louvers or through some other device such as a clip or another segment of the flexible connector used to distribute the static forces across the grill (108) of the air vent (106).

In the example of Figure 6, the flexible connector (600) includes a clip (604) for removeably attaching the flexible connector (600) to at least one of the louvers (112) on the grill (108) of the air vent (106). The clip (604) of Figure 6 is attached and detached by applying pressure to points (610) on the clip. This application of pressure can typically be carried out by an operator using one hand, while the other hand holds the air vent cover (620). After the clip (604) is in place, the operator may expand the expandable cord (602) and attached it to the clip (604). As the expandable cord contracts, pressure is applied to the surface (110) and the air vent cover (620) seals along the edge (114) with the surface (110). In the example of Figure 6, the clip (604) may be composed of rubber, plastic, polyurethane, or any other material as will occur to those of skill in the art.

The flexible connector (600) of Figure 6 adjusts to secure an edge (114) of the cover portion (102) against a region of the surface (110) surrounding the air vent (106), thereby creating a seal for inhibiting air flow through the air vent (106). Similar to Figures 3, 4, and 5, the edge (114) of the cover portion (102) in Figure 6 includes a flange (302) extending along a circumference of the cover portion (102) and a gasket (300) to facilitate the seal between the air vent cover (620) and the surface (110). Turning to Figure 7, Figure 7 sets forth a drawing illustrating a portion of a flexible connector (700) in an exemplary air vent cover (620) for use in testing air leakage of an air duct system according to embodiments of the present invention. The flexible connector (700) of Figure 7 includes a cord (704) that extends through the hollow cavity formed by the cover portion of an air vent cover in accordance with embodiments of the present invention. In the example of Figure 7, the flexible connector (700) includes a flat hook (702) for removeably attaching the flexible connector (700) to at least one of the louvers on a grill of an air vent. The flat hook (702) of Figure 7 has a thickness (706) and a width (708) such that the thickness (706) is smaller than the width (708). The small thickness (706) permits the hook (702) to slide easily between the louvers of the air vent, while the larger width (708) provides structural strength. This configuration also makes it easier for an operator to hold and manipulate the hook (702) with one hand. The flat hook (702) in the example of Figure 7 is made of flexible material that allows the hook (702) to bend. The flexible nature of the flat hook (702), combined with the flexible nature of the flexible connector (700) in general, facilitates the sealing ability of the air vent cover over a wider range of positions around the air vent than those provided from the use of rigid material. Such rigid materials might force the air vent cover too far to one side of the air vent, which could hinder the sealing ability of the air vent cover to the surface surrounding the air vent cover. The flexible, flat hook (702) of Figure 7 may be composed of rubber, plastic, polyurethane, or any other material as will occur to those of skill in the art.

Figure 8 sets forth a flow chart illustrating a method of testing air leakage of an air duct system according to embodiments of the present invention. The air duct system referenced in Figure 8 includes a plurality of air supply vents. The method of Figure 8 includes sealing (800) the plurality of air supply vents to obstruct the flow of air through the air duct system.

Sealing (800) the plurality of air supply vents according to the method of Figure 8 includes, for at least one of the air supply vents, removeably attaching with a flexible connector an enclosure to a louver of an air vent so as to secure an edge of the enclosure against a region of a surface surrounding the air vent. The edge of the enclosure may include a flange or a gasket to facilitate sealing the enclosure with the surface regardless of the surface texture.

In the example of Figure 8, removeably attaching an enclosure to a louver with a flexible connector may be carried out using a cord and an adjustable fastener such as those described with reference to Figures 1, 4, and 5. Removeably attaching an enclosure to a louver with a flexible connector according to the method of Figure 8 may also be carried out using one or more springs such as those described with reference to Figures 2 and 3. Still further, removeably attaching an enclosure to a louver with a flexible connector according to the method of Figure 8 may be carried out using an expandable cord such as those described with reference to Figure 6 or any other method as will occur to those of skill in the art.

The method of Figure 8 also includes changing (802) air pressure within the air duct system, measuring (804) air leakage during the change in air pressure, and recording (806) the measured air leakage. These steps may be carried out using an air duct pressurization or depressurization system known to those of skill in the art such as, for example, the Minneapolis Duct Blaster ^® or the Retrotec Duct Testing Blower System. The method of Figure 8 also includes unsealing (808) the plurality of air supply vents. Unsealing (808) the plurality of air supply vents according to the method of Figure 8 includes detaching the flexible connector from the louver of the air vent. Detaching the flexible connector from the louver of the air vent according to the method of Figure 8 may be carried out by removing a hook, clip, or other fastener from the louver.

Figure 9 sets forth a line drawing illustrating a perspective view of an exemplary air vent cover (1100) for sealing an air vent. Air vent covers may often be utilized for use in testing air leakage of an air duct system. Air duct systems are used in heating, ventilation, and air conditioning (HVAC) to deliver, circulate, or remove air using supply, return, or exhaust airflows. Air duct systems, therefore, are one method of ensuring acceptable indoor air quality as well as thermal comfort.

Though air duct systems vary from one installation to another, many air duct system share a common set of components. Air duct systems generally include an air handler unit that may be composed of a blower or fan, heating or cooling elements, filters, humidifier, mixing chamber, heat recovery device, controls, and vibration isolators. In addition, air duct systems typically include a network of plenums and ducts that direct airflow between the air handler unit and various air vents used to supply air to or return air from the spaces served by the air duct system. Readers will note that the air vent system is omitted from Figure 9 and the remaining Figures 2-8 for clarity. Readers should note that the air vent cover (1100) of Figure 9 and other air vent covers that may used in conjunction with the installation and removal tool would typically be installed over an air vent so as to seal off the air vent.

Readers will note that the exemplary air vent cover (1100) in Figure 9 is for example only and not for explanation. In addition to the exemplary air vent cover of Figure 9, exemplary embodiments of an air vent cover may include air vent covers as described in the non- Provisional U.S. Patent Application No. 12/757,397, which is incorporated in its entirety herein by reference.

As mentioned, an air duct system includes an air vent. An air vent is an opening, typically covered by a grill, in an air duct system that serves to supply air to or return air from a space served by the air duct system. Those of skill in the art often may refer to an "air vent' as an air diffuser, an air grate, or a terminal unit. An air vent has a grill adjacent to a surface surrounding the air vent. The surface may be an interior wall of a room served by the air duct system, however, the surface surrounding an air vent may be any surface of a room or structure, including a wall, floor, ceiling, or any other surface as will occur to those of skill in the art. The grill provides a face for the air vent and may serve a decorative or functional purpose. For example, the grill may include an ornamental design, provide a mechanism for directing airflow, or be used to secure the air vent to the surrounding surface.

An air vent grill typically has one or more louvers. A louver is a baffle used to direct or control the flow of air through an air vent. A louver may extend beyond the face of the air vent or may be inset into the face of the air vent. Still further, some louvers may be placed inside the air vent. A louver may be fixed in place or allowed to move through a range of positions. In fact, many air vents are designed with both fixed and moveable louvers. Whether fixed or moveable, a louver may be configured at a slanted angle or perpendicular to the face of the air vent. An air vent cover (1100) of Figure 9 used in conjunction with the installation and removal tool may be placed over the air vent to create a seal for inhibiting air flow through the air vent while testing air leakage of the air duct system. The air may attempt to flow through the air vent due to either pressurization or depressurization of the air duct system during the leak testing process. Systems used to pressurize or depressurize an air duct system are known to those of skill in the art and may include, for example, the Minneapolis Duct Blaster ^® or the Retrotec Duct Testing Blower System.

The air vent cover (1100) of Figure 9 includes a cover portion (1102) shaped to define a hollow cavity for enclosing the air vent. The air vent cover (1100) of Figure 9 may be composed of a variety of materials, including but not limited to, polyurethane, plastic, harden rubber, or any other material as will occur to those of skill in the art.

In the example of Figure 9, the hollow cavity of the air vent cover (1100) is generally large enough to receive the portion of the air vent extending from the surface into the space served by the air duct system. Typically, the portion of the air vent extending from the surface includes the grill and any levers for changing the position of any moveable louvers. The cover portion (1102) in the example of Figure 9 is large enough in circumference that the edge (1106) of the cover portion (1102) surrounds the air vent (1106) when placed against the surface. In Figure 9, the cover portion (1102) is shaped as a rectangular prism. This shape, however, is for example only, and not for limitation. Readers of skill in the art will recognize that the cover portion (1102) may be any shape so long as the hollow cavity defined by the cover portion can enclose the portion of the air vent extending from the surface into the surrounding space. Such exemplary shapes may include a trapezoidal prism, hemisphere, cuboid, cone, pyramid, parallelepiped, prism, or any other shape as will occur to those of skill in the art.

The exemplary air vent cover (1100) of Figure 9 also includes a flexible cord (shown as 1108 in Figure 11). The flexible cord (1108) extends from outside the cover portion (1102) through a hole (1110) in an adjustable fastener (1112) and through the hollow cavity to the air vent. The flexible cord is removeably attached to one of the louvers on the grill of the air vent using a hook. Readers will note that the use of a hook is for example only, not for limitation. Other components for removeably attaching the flexible connector to the louver as will occur to those of skill in the art may also be used such as a clip or other fastener. Preferably, though not required, the flexible connector is configured for easy attachment and detachment using one hand while holding the cover portion with the other hand.

The use of a flexible cord (1108 in Figure 11) and an adjustable fastener (1112) allows an operator to change an amount of the cord (1108) extending into the hollow cavity by pressing the actuator (1114) on the adjustable fastener (1112) and sliding the cord (1108) through the adjustable fastener (1112) to increase or decrease the length of cord (1108) extending through the hollow cavity of the air vent cover (1102). By increasing the length of cord extending through the hollow cavity, enough slack is provided in the flexible cord of Figure 9 to permit fast, easy attachment of the flexible cord to the louvers. Then, decreasing the length of cord extending through the hollow cavity allows the edge (1106) of the cover portion (1102) to be secured against the surface surrounding the grill. Conversely, the air vent cover (1100) may be easily removed by increasing the length of cord (1108) extending through the hollow cavity to provide enough slack in the flexible cord (1108) to permit fast, easy detachment of the flexible connector from the louvers of the air vent.

Turning to Figure 10, Figure 10 sets forth a drawing illustrating a cross-sectional view of the adjustable fastener (1112) with the spring (1113) and actuator (1114) removed. Figure 10 shows the cord (1108) passing through the adjustable fastener (1112). When installed, the spring and actuator (1114) hold the cord (1108) in place relative to the adjustable fastener by pinching the cord with a force along the cross-section of the cord (1108). For further explanation consider Figures 11-14. In Figures 11 and 12, the spring and actuator (1114) are installed in the adjustable fastener (1112). The spring and the actuator (1114) are in a released position, which means that they are not depressed or pushed-in by an operator or other device. In the released position, the spring pushes the actuator (1114) laterally through the adjustable fastener (1112) to pinch the cord (1108), thereby holding the adjustable fastener and anything to which it is attached (such as the air vent cover (1100) of Figure 9) fixed relative to the cord (1108). In Figures 13 and 14, the spring and actuator (1114) are installed in the adjustable fastener (1112). The spring and actuator (1114) are depressed (or pushed-in) by an operator or other device. Depressing the actuator (1114) removes the lateral force pinching the cord (1108) in the adjustable fastener (1112) and allows the cord (1108) to slide in relationship with the adjustable fastener (1112).

Turning to Figure 15, Figure 15 sets forth a line drawing of an exemplary installation and removal tool (1200) being used to install an air vent cover. The installation and removal tool (1200) of Figure 15 is used to install an air vent cover over an air vent (1202) mounted on a ceiling (1204). The installation and removal tool (1200) of Figure 15 advantageously assists an operator in installing and removing air vent covers that are too high for the operator to reach while standing on the ground.

The installation and removal tool (1200) of Figure 15 includes a socket portion (1208) that receives one of the components of the air vent cover being installed over the air vent (1202). In the example of Figure 15, the socket portion (1208) receives the hook that fastens to the air vent (1202) and receives the cord (1108) that passes through the air vent cover that is subsequently installed. In the example of Figure 15, there is a slot along the right and bottom of the socket portion (1208) of the installation and removal tool (1200) that allows the cord (1108) to hang substantially unrestricted from the hook by the installation and removal tool (1200). In the example of Figure 15, the socket portion (1208) is hollowed out to receive a hook having a corresponding shape. Having the socket portion (1208) and the hook with corresponding shapes will allow the operator to have rotational control over the hook even from a distance using the extension pole (1210). The operator can keep tension on the cord (1108) to ensure that the hook does not fall out or becomes separated from the socket portion (1208) of the installation and removal tool (1200). While maneuvering the extension pole (1210), which is connected to or integral with, the installation and removal tool (1200), the operator connects the hook of the air vent cover to the louvers of the air vent. After the hook is connected to one or more louvers, the operator can release tension from the cord (1108) and allow the hook to slip out of the installation and removal tool (1200).

The installation and removal tool (1200) of Figure 15 also includes a pivot portion (1206) that is shaped to provide a pivot point (1212) for the tool (1200). The pivot point (1212) is typically utilized when installing the cover portion of an air vent cover by providing stability when attaching or removing the cover portion to or from the tool (1200).

Figure 16 depicts a cross-section of at least a portion of the installation and removal tool (1200). Figure 16 illustrates how the hooks base (1214) may be designed to fit inside the socket portion (1208) of the installation and removal tool (1200). Further, Figure 16 depicts one manner of connecting the extension pole (1210) to an exemplary installation and removal tool. In the example of Figure 16, the extension pole (1210) connects to the tool (1200) using a screw thread interface. Readers will understand, however, that in some embodiments the extension pole may be integrally formed with and a part of the tool (1200).

Turning to Figure 17, Figure 17 depicts an installation and removal tool (1200) being used to install the cover portion (1102) of the air vent cover (1100) after the hook has been connected to the louvers of an air vent. In Figure 17, the cord (1108) is threaded through the adjustable fastener (1112), and the adjustable fastener (1112) is placed inside the socket portion (1208) of the installation and removal tool (1200). The inside of the socket portion (1208) not only corresponds with the base of the hook described with reference to Figures 15 and 16, but the inside of the socket portion (1208) is also designed to correspond with the shape of the adjustable fastener (1112) such that when the actuator (1114) is depressed, the adjustable fastener (1112) and depressed actuator (1114) fit inside the socket portion (1208) of the installation and removal tool (1200). To assist the adjustable fastener (1112) in sliding into the socket portion (1208), the inside walls of the socket portion (1208) may be tapered. Because the actuator (1114) is depressed when the adjustable fastener (1112) is positioned in the socket portion (1208) of the tool (1200), the cord (1108) slides through the adjustable fastener (1112) without much resistance. The operator, therefore, can apply tension to the cord (1108) from the ground while lifting up on the extension pole (1210) to guide the cover portion (1102) of the air vent cover (1100) in place over the air vent. As the cover portion (1102) is being raised into place, the pivot portion (1206) may be used to provide some level of stabilization so that the cover portion (1102) does not tip over one way or the other. In Figure 18, the air vent cover (1100) is positioned in place such that the cover portion (1102) seals off the air vent from the surrounding environment. The operator may still apply tension to the cord (1108) and an upward force on the installation and removal tool (1200) to hold the air vent cover in place. As long as the adjustable fastener (1112) is positioned inside the socket portion (1208), the cover (1100) would not remain over the air vent so the operator must keep an upward force on the tool (1200) via an extension pole.

Figure 19A illustrates the removal of the installation and removal tool after the cover (1100) is in place over the air vent. The operator need only pivot the installation and removal tool (1200) at the pivot point on the pivot portion (1206) to continue applying upward pressure on the cover portion (1102) while allowing the adjustable fastener (1112) to be removed from the socket portion (1208). As the adjustable fastener (1112) is removed from the socket portion (1208), the actuator (1114) is released, and the lateral force from the actuator (1114) on the cord (1108) holds the cover (1100) in place. In this manner, the operator can lower the installation and removal tool (1200) as shown in Figure 19B. Readers will understand that the removal of an air vent cover entails using an exemplary installation and removal tool (1200) in substantially the opposite manner. That is, the operator raises the tool (1200) using an extension pole so that the adjustable fastener (1112) slides into the socket portion (1208) of the tool (1200). The operator then applies tension to the cord (1108) and allows the cover (1100) to slide down the chord (1108) as the actuator (1114) of the adjustable fastener ( 1112) is depressed.

In some embodiments of the installation and removal tool, the tool may include a gripping mechanism to assist with lowering the air vent cover. The gripping mechanism may be implemented as an element that engages a slot or portion of the adjustable fastener or the actuator or the cover portion of the air vent cover so that while the operator pulls an exemplary installation and removal tool downward, the operator is applying a downward force on the air vent cover rather than merely relying on gravitational forces to lower the air vent cover. The gripping mechanism may be operated by a spring that keeps the gripping mechanism disengaged from the corresponding feature on the air vent cover. The operator may apply a force to overcome the spring's force by pulling on a cord that runs the length of the extension pole down to the operator.

Figures 20A-E illustrate similar exemplary installation and removal tools useful according to embodiments of the present invention. Figures 21A-G illustrate a similar exemplary installation and removal tool according to embodiments of the present invention and also depict various exemplary dimensions for an exemplary installation and removal tool useful according to embodiments of the present invention. Readers will note that these exemplary dimensions and examples are for explanation only and not for limitation. Other embodiments of the present invention are also well within the scope of the invention, particularly those embodiments that permit an operator to allow an cover portion of an air vent cover to slide along the fastening cord after the fastening mechanism (e.g., a hook) has been secured to the louvers of an air vent.

Turning to Figures 22A-B, Figures 22A-B depict an air vent cover (1100) for use with exemplary installation and removal tools useful according to embodiments of the present invention that includes a pressurized testing interface (1312) and a vent cover extender (1300). The air vent cover (1100) of Figures 22A-B includes the components already described above such as, for example, a cover portion (1102), an adjustable fastener (1112), an actuator (1114), and a cord (1108). These components work together in the manner already described above and in the non-Provisional U.S. Patent Application No. 12/757,397, which is incorporated in its entirety herein by reference.

The air vent cover (1100) of Figures 22A-B also includes a gasket (1304) at the base of the air vent cover (1100). Readers will note that the gasket may also be present on the air vent covers described earlier in this application. The gasket (1304) of Figures 22A-B may be formed from a variety of materials as will occur to those of skill in the art, including, for example, foam, rubber, nylon, or plastic. When formed from material such as foam, readers will note that there are two types of foam that could be used to create a gasket according to embodiments of the present invention-open-cell foam and closed-cell foam.

In open-cell foam, the cell walls, or surfaces of the bubbles, are broken and air fills all of the spaces in the material. In this manner, open-cell foam creates a permeable barrier that may allow air to flow through it when uncompressed. When compressed, however, the open-cell foam may provide enough of a barrier to serve as a seal. The open-cell nature makes the foam soft or weak, as if it were made of broken balloons or soft toy rubber balls. The insulation value of this foam is related to the insulation value of the calm air inside the matrix of broken cells. In closed-cell foam, most of the cells or bubbles in the foam are not broken; they resemble inflated balloons or soccer balls, piled together in a compact configuration. This makes the closed-cell foam strong or rigid because the bubbles are strong enough to withstand high- pressure. Although closed-cell foam is rigid, it has varying degrees of hardness, depending on its density. Because the cell walls of closed-cell foam are not generally broken, closed-cell foam provides greater resistance to air leakage than that of open-celled foam.

The air vent cover (1100) of Figures 22A-B is connected to a vent cover extender (1300) to permit the air vent cover (1100) to be use in conjunction with air vents larger than the air vent cover (1100). In Figure 22A, the air vent (1306) installed on surface (1308) is larger than the air vent cover (1100), but the extender (1300) allows an operator to use the same air vent cover (1100) that would otherwise fit smaller air vents. The air vent cover (1100) of Figures 22A-B connects to the air vent extender (1300) when the clips (1302) snap around the outer lip of the air vent cover (1100). Readers will note that other fasteners may be used other than snaps, such as, for example, rotatable fasteners in which a portion of the faster rotates into position over the lip of the air vent cover. Still further, the fastener could be formed from the outer surface of an extender so that the lip of an air vent cover snaps into place when the lip enters a socket created in to the surface of an extender. As shown in Figure 22A, there is a opening in the surface of the extender (1300) to permit air flow between the region inside the air vent cover and the region inside the vent extender (1300). The gasket (1304) between the air vent cover (1100) and the extender (1300), however, forms a seal that operates to resist air leakage. Similarly, the gasket (1310) between the air vent extender (1300) and the surface (1308) also operates to seal and thereby resist air leakage between the air vent extender (1300) and the surface (1308).

The air vent cover (1100) of Figures 22A-B also includes a pressurized testing interface (1312). The pressurized testing interface (1312) includes a small opening to air pressure from inside the air vent cover (1100) to be communicated to an external testing device. In the example of Figures 22A-B, the pressurized testing interface (1312) is implemented using a protrusion formed in the cover portion (1102) of the vent cover (1100), the protrusion having a hole through itself that extends through the cover portion (1102) of the vent cover (1100). An operate may connect one end of a small tube to the protrusion and the other end of the tube to the testing device to measure the air pressure inside the air vent cover (1100). Use of the pressurized testing interface (1312) avoid the sealing problems associated with running the testing device's hose between the air vent cover and/or a vent extender and the surface along which the air vent is installed. While certain exemplary embodiments have been described in details and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not devised without departing from the basic scope thereof, which is determined by the claims that follow.