Wall curb for HVAC system

Information

  • Patent Grant
  • 6431979
  • Patent Number
    6,431,979
  • Date Filed
    Friday, December 22, 2000
    24 years ago
  • Date Issued
    Tuesday, August 13, 2002
    22 years ago
Abstract
A wall curb 10 for attachment to the exterior wall 32 of a building to removably secure a wall mounted HVAC unit 38 to the exterior surface 44 of the wall 32. The wall curb 10 serves to attach the supply air duct 34 from within the building to the supply air opening of HVAC unit 38 and to attach the return air duct 36 from within the building to a return air opening of the HVAC 38. An alternate embodiment of the invention 10A includes an outside air opening 60 with a controllable damper 62 for regulating the ratio of outside air verses return air from the building that enters the HVAC unit 38.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to a wall mounted curb that secures to the exterior of a wall so that both the supply duct and return air duct from the interior of the wall secure to the wall curb at corresponding openings that have been cut through the wall curb to align with and seal to the two ducts. A heating, ventilation, and air conditioning (hereafter referred to as HVAC) unit mounts to the wall curb on the exterior of the wall so that the supply air opening of the HVAC is aligned with and sealed to the supply air duct from the interior of the wall, and the return air opening of the HVAC is aligned with and sealed to the return air duct from the interior of the wall.




2. Description of the Related Art




Currently roof curbs are available that attach to the exterior surface of a roof of a building to attach a roof mounting HVAC unit to the roof. These roof curbs are located on the roof at a point on the roof to encompass the exits of the supply air duct of the building and the return air duct. Generally these roof curbs and their associated roof mounted HVAC units are used in large industrial or commercial buildings.




However, there are no wall curbs currently available for similarly mounting a wall mounted HVAC unit to an exterior wall of a building at the point where the supply air duct and return air duct exit the building. The present invention addresses this need by providing a wall curb for attachment to the exterior wall as a means of connecting the supply air duct and the return air duct from the interior of the building to the corresponding supply air opening and return air opening of a wall mounting HVAC located on the exterior of the building. The present invention also serves as a means of removably attaching the HVAC unit to the exterior of a building. Further, because the openings in the wall curb where the supply air duct and the return air duct attach to the wall curb are custom cut at the building site by installation personnel, a single type of wall curb will work with a wide range of sizes and shapes of supply air and return air ducts. The present invention come is two different styles, one without any outside air inlet and with an outside air inlet. The style of the present invention wall curb that has an outside air inlet is provided with a controllable damper for regulating the ratio of outside air verses return air form the building that enters the HVAC unit.




SUMMARY OF THE INVENTION




The present invention is a wall curb for attachment to the exterior wall of a building to removably secure a wall mounted HVAC unit to the exterior surface of the wall. The wall curb serves to attach the supply air duct from within the building to the supply air opening of HVAC unit and to attach the return air duct from within the building to a return air opening of the HVAC. Openings in the wall curb where the supply air duct and the return air duct attach to the wall curb are custom cut at the building site by installation personnel. One embodiment of the invention does not have any outside air inlet, and a second embodiment of the invention does have an outside air inlet with a controllable damper for regulating the ratio of outside air verses return air from the building that enters the HVAC unit.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view of a first embodiment of the present invention with an exterior wall of a building shown to the right of the invention in outline and a HVAC shown to the left of the invention in outline.





FIG. 2

is a front view of the invention of

FIG. 1

shown attached to a wall.





FIG. 3

is a right side view of the invention of

FIG. 2

taken along line


3





3


.





FIG. 4

is a top view of the invention of

FIG. 2

taken along line


4





4


.





FIG. 5

is a perspective view of a second embodiment of the present invention with an exterior wall shown to the right of the invention in outline and a HVAC shown to the left of the invention in outline.





FIG. 6

is a front view of the invention of

FIG. 5

shown attached to a wall.





FIG. 7

is a top view of the invention of

FIG. 6

taken along line


7





7


.





FIG. 8

is a right side view of the invention of

FIG. 6

taken along line


8





8


.





FIG. 9

is an enlarged cross sectional view of the damper of

FIG. 6

taken along line


9





9


showing the damper in a position for admitting only return air into the HVAC unit.





FIG. 10

is the damper of

FIG. 9

shown in position for admitting only outside air into the HVAC unit.





FIG. 11

is a cross section view taken along line


11





11


of

FIG. 9

showing the damper in a position for admitting only return air into the HVAC unit.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




THE INVENTION




Referring now to

FIGS. 1

,


2


,


3


and


4


there is illustrated a wall curb


10


constructed in accordance with a first preferred embodiment of the present invention. As illustrated in

FIG. 1

, the wall curb


10


is provided with a top


12


, a back wall


14


, and two parallel side walls


16


and


18


that secure together at approximately right angles to each other. For the wall curb


10


, two partitions


20


and


22


are provided within the wall curb


10


. Each of the partitions


20


and


22


extends from the back wall


14


to a front edge


24


provided on the front


26


of the wall curb


10


at the top


12


and along each side wall


16


and


18


. The first partition


20


of the two partitions


20


and


22


is spaced apart from the top


12


to define a supply air passageway


28


formed by the two side walls


16


and


18


, the top


12


, the back wall


14


, and the first partition


20


. The second partition


22


of the two partitions


20


and


22


is spaced apart from the first partition


20


to define a return air passageway


30


formed by the two side walls


16


and


18


, the back wall


14


, and the first and second partitions


20


and


22


.




As shown in

FIG. 3

, the wall curb


10


permanently secures to an exterior wall


32


of a building so that the wall curb


10


secures over the supply air duct


34


emanating from within the building and secures over the return air duct


36


also emanating from within the building for the purpose of providing a fast, easy and removable way of connecting a wall mounted HVAC system together, i.e. connecting a HVAC unit


38


to a building's supply air and return air ducts


34


and


36


.




Before the wall curb


10


is secured to the wall


32


, the back wall


14


of the wall curb


10


is solid and must be cut to provide two openings


40


and


42


therethrough, i.e. a first wall curb opening


40


to which attaches the supply air duct


34


from the building and a second wall curb opening


42


to which attaches the return air duct


36


from the building. It is preferable to cut the two wall curb openings


40


and


42


in the back wall


14


at the installation site so that the wall curb openings


40


and


42


can be created in the proper shape and size to match, respectively, the shape and size of the corresponding supply air and return air ducts


34


and


36


emanating from the building. Properly cut wall curb openings


40


and


42


allow the installer to make a good, air tight fit of the wall curb


10


with the supply air and return air ducts


34


and


36


.




As illustrated in

FIGS. 2

,


3


, and


4


, once the two wall curb openings


34


and


36


have been cut into the back wall


14


of the wall curb


10


, the back wall


14


of the wall curb


10


is then secured to an exterior surface


44


of the exterior wall


32


of the building. Although not illustrated, the wall curb


10


secures to the exterior surface of the wall with screws or other suitable fastening devices that extend through the back wall


14


of the wall curb


10


and into the supporting studs located within the exterior wall


32


of the building. The wall curb


10


is secured onto the wall


32


so that the two previously cut wall curb openings


40


and


42


align, respectively, with the supply air duct


34


and the return air duct


36


from within the building. The supply air duct


34


is fastened to the first wall curb opening


40


in the back wall


14


with suitable fastening devices and are taped together or otherwise secured to make an air tight seal between the supply air duct


34


and the supply air passageway


28


provided within the wall curb


10


. Likewise, the return air duct


36


is fastened to the second wall curb opening


42


in the back wall


14


with suitable fastening devices and are taped together or otherwise secured to make an air tight seal between the return air duct


36


and the return air passageway


30


provided within the wall curb


10


.




Although not illustrated, before the HVAC unit


38


is secured to the wall curb


10


, some type of sealant or sealing gasket is applied to the front edge


24


of the wall curb


10


and a front edge


46


of each partition


20


and


22


located within the wall curb


10


so that when the HVAC unit


38


is secured to the wall curb


10


, an airtight seal is formed between a return air opening (not illustrated) provided on the HVAC unit


38


and the return air passageway


30


in the wall curb


10


, and also an airtight seal is form between a supply air opening (not illustrated) provided on the HVAC unit


38


and the supply air passageway


28


in the wall curb


10


.




Next, the HVAC unit


38


is removably secured to the wall curb


10


. As best illustrated in

FIG. 3

, an upwardly extending U-shaped lip


48


is provided along the front edge


24


of the top


12


of the wall curb


10


to removably receive a downwardly extending lip


50


provided at the rear edge


52


of the top


54


of the HVAC unit


38


. Once the downwardly extending lip


50


of the HVAC unit


38


is received in the upwardly extending lip


48


of the wall curb


10


, the lip


48


of the wall curb


10


supports the HVAC unit


38


and the HVAC unit


38


hangs from the lip


48


of the wall curb


10


. Bolt openings


56


are provided in the front edge


24


near the bottom


10


of the wall curb


10


to accommodate cage nuts (not illustrated) as a means of securing the HVAC unit


38


to the wall curb


10


after the HVAC unit


38


has been hung on the upwardly extending lip


48


of the wall curb


10


. The installer inserts bolts (not illustrated) through the HVAC unit


38


to engage the cage nuts (not illustrated) that are attached to the bolt openings


56


of the wall curb


10


as the final step in removably securing the HVAC unit


38


to the wall curb


10


.




The first partition


20


within the wall curb


10


separates the supply air passageway


28


from the return air passageway


30


so when the HVAC unit


38


is secured and sealed to the front edge


24


of the wall curb


10


and the appropriate front edges


46


of the partitions


20


and


22


, the supply air passageway


28


seals to the supply air opening (not illustrated) provided on the HVAC unit


38


and the return air passageway


30


seals to the return air opening (not illustrated) provided on the HVAC unit


38


. When the HVAC unit


38


is thus sealed to the wall curb


10


, there is airtight communication between the supply air duct


34


, through the supply air passageway


28


of the wall curb


10


, and into the supply air opening (not illustrated) on the HVAC


38


. Likewise, when the HVAC unit


38


is sealed to the first embodiment wall curb


10


, there is airtight communication between the return air duct


36


, through the return air passageway


30


, and into the return air opening (not illustrated) of the HVAC


38


.




Referring now to

FIGS. 5-11

, an alternate second preferred embodiment


10


A of the present invention is illustrated. As best illustrated in

FIG. 5

, the alternate embodiment


10


A differs from the first embodiment


10


in that the alternate embodiment


10


A has an outside air opening


60


provided at the bottom


58


A of the alternate wall curb


10


A that communicates with the outside air. Because the outside air opening


60


is located at the bottom


58


A of the alternate wall curb


10


A, it is preferred that when the alternate wall curb


10


A is installed on the exterior surface


44


of the wall


32


, that the bottom


58


A of the alternate wall curb


10


A be located above ground level so that air can freely enter the alternate wall curb


10


A via the outside air opening


60


. This is illustrated in FIG.


8


.




Referring now to

FIGS. 8

,


9


and


10


, the alternate embodiment


10


A is provided with a controllable damper


62


that separates the outside air opening


60


from the return air passageway


30


A. Because the alternate embodiment


10


A contains this controllable damper


62


, this requires a slight increase in the thickness of the alternate embodiment


10


A as compared to the first embodiment


10


in order that the alternate embodiment


10


A has sufficient depth to can accommodate the damper


62


. This increase in thickness can be see by comparing

FIGS. 3 and 8

and by comparing

FIGS. 4 and 7

.




The controllable damper


62


is used to regulate the ratio of return air, as indicated by Arrow A in

FIG. 9

, to outside air, as indicated by Arrow B in

FIG. 10

, flowing into the return air opening (not illustrated) of the HVAC unit


38


. The damper


62


controls this ratio by moving between the positions


64


and


66


, as illustrated in

FIGS. 9 and 10

. In

FIG. 9

, the damper


62


is located in its fully closed position


64


where no outside air is admitted to the HVAC unit


10


A and only return air from the building is recirculated to the HVAC unit


10


A. In

FIG. 10

, the damper


62


is located in its fully open position


66


where no return air from the building is recirculated to the HVAC unit


38


and only outside air is admitted to the HVAC unit


38


.




The alternate wall curb


10


A differs from the first embodiment


10


in one other way. Only one partition


20


A is provided within the alternate wall curb


10


A. This difference is best illustrated in

FIGS. 5 and 8

. The alternate wall curb


10


A is provided with an inverted L-shaped partition


20


A that extends from the back wall


14


of the alternate wall curb


10


A to the front edges


24


of the alternate wall curb


10


A and extends downward at the front


26


of the alternate wall curb


10


A so that an upper edge


68


of the damper


62


is removably engagable with a lower leg


70


of the L-shaped partition


20


A. The supply air passageway


28


A of the alternate embodiment


10


A is formed by the two side walls


16


and


18


, the top


12


, the back wall


14


, and the L-shaped partition


20


A. The return air passageway


30


A for the alternate embodiment


10


A is formed by the two side walls


16


and


18


, the L-shaped partition


20


A and the damper


62


. The L-shaped partition


20


A separates the supply air passageway


28


of the alternate embodiment


10


A from the return air passageway


30


of the alternate embodiment


10


A.




Referring now to

FIGS. 9 and 10

, the L-shaped partition


20


A forces the air that is ultimately received by the air return opening (not illustrated) of the HVAC


38


to first flow past the damper


62


, thereby allowing the damper


62


to control the ratio of air it receives from the return air duct


36


and from the outside air opening


60


, i.e. the ratio of return air to outside air entering the HVAC unit


38


. As shown also in

FIG. 11

, the damper


62


can be operated by rotating the damper


62


on its axis


72


, thus moving or rotating the damper


62


between the fully closed and fully open positions


64


and


66


and through a plurality of positions lying intermediate between the fully closed and full open positions


64


and


66


. To achieve this control of air, the damper


62


can be rotated on its axis


72


either manually or automatically, depending on the type of control mechanism attached to the axis


72


.




While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the embodiments set forth herein for the purposes of exemplification, but is to be limited only by the scope of the attached claim or claims, including the full range of equivalency to which each element thereof is entitled.



Claims
  • 1. A wall curb for removably securing a wall mounted HVAC unit to the return air and supply air ducts emanating from a building comprising:a top secured approximately perpendicularly to two spaced apart parallel side walls, a back wall secured approximately perpendicularly to the two side walls and to the top, a front edge provided on both said two side walls and said top, a first partition provided between the side walls and extending from the back wall to said front edge, said first partition spaced apart from said top to form a supply air passageway with said top, said back wall, and said two side walls, said back wall provided with a supply air opening such that the supply air opening communicates with the supply air passageway and the supply air opening secures to a return air duct from within a building, the first partition forming a return air passageway with said back wall, and said two side walls, said back wall provided with a return air opening such that the return air opening communicates with the return air passageway and the return air opening secures to a return air duct from within a building, and means to removably secure a HVAC unit to said front edges, and means to secure said back wall to an exterior surface of a wall of a building at a location on the wall so that said back wall encompasses the return air and supply air ducts emanating from the building.
  • 2. A wall curb according to claim 1 wherein said means to secure a HVAC unit to said front edges comprises:an upwardly extending lip provided at the front edge of said top for removably engaging a downwardly extending lip provided at the top of the back of a HVAC unit.
  • 3. A wall curb according to claim 2 wherein said means to secure a HVAC unit to said front edge further comprises:bolts that engage cage nuts provided in cage nut openings at the bottom of the front edges of the side walls.
  • 4. A wall curb according to claim 1 wherein said means to secure said back wall to an exterior surface of a wall of a building comprises:fastening devices that extend through the back wall and engage the wall of a building.
  • 5. A wall curb according to claim 1 further comprising:a second partition provided between the walls and extending from the back wall to said front edge of the side walls, said second partition forming said return air passageway with said first partition, said back wall, and said two side walls.
  • 6. A wall curb according to claim 1 further comprising:a rotatable damper provided between said side walls for removable engagement with a lower portion of said second partition, said rotatable control damper communicating with said return air passageway and an outside air opening provided at the bottom of the side walls.
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Number Name Date Kind
3246643 Stark et al. Apr 1966 A
4315415 Wilson Feb 1982 A
4403481 Yoho, Sr. Sep 1983 A
4714194 Eckman Dec 1987 A
4781008 Lyons, Jr. Nov 1988 A
4843839 Davis Jul 1989 A
4854376 Tunekawa et al. Aug 1989 A
4895066 Carnahan Jan 1990 A
5044260 Avari Sep 1991 A
6041557 Brown et al. Mar 2000 A