The present invention relates generally to heating, ventilating and air conditioning systems and, more particularly, to single-package, wall-mount air conditioners for use in cooling buildings or rooms within buildings in need of cooling and/or ventilation.
Single-package, wall-mount air conditioners are mounted to an exterior side of an exterior wall of a building or a room within a building and incorporate both evaporator and condenser coil assemblies within a single cabinet. These wall-mount air conditioners are typically used to deliver conditioned or ventilation air to enclosed structures such as classrooms, telecommunication shelters, electronic equipment rooms, and any other buildings or rooms within buildings in need of cooling and/or ventilation.
In a typical construction, these wall-mount air conditioners include an internal evaporator compartment that is positioned at an upper portion of the cabinet and houses the evaporator coil assembly, a blower box that is positioned below the evaporator coil assembly and houses one or more blowers, and a condenser compartment positioned that is positioned below the blower box and houses the condenser coil assembly. Conditioned supply air is delivered from the evaporator compartment through a supply air opening in the exterior wall of the building and into the building. Return air is delivered from within the building to the blower box through a return air opening in the exterior wall 12 and is then recirculated by the blowers to the building through the evaporator compartment as conditioned supply air. A large fan in the condenser compartment draws in outside air and blows it across the condenser coil assembly to cause cooling of the heat exchange medium within the condenser coils.
Some types of these wall-mount air conditioners include an economizer unit that allows the air conditioner to be operated without mechanical cooling by drawing in fresh outside air when that air is sufficiently cool to handle the heating load within the building. When the air conditioner is operating in this economizer cooling mode, a damper assembly is placed in a position to allow fresh outside air to be drawn by the blowers into the blower box and then delivered into the building through the evaporator compartment. Some or all of the return air from the building is then redirected to the condenser compartment and exhausted outwardly from the cabinet during the economizer cooling mode of operation.
The economizer unit is positioned generally in-line with the return air opening in the exterior wall between the blower box and the condenser compartment. The fresh outside air intake for the economizer unit may thus be positioned in close proximity to the exhaust for the condenser compartment. As a result, some of the return air that is exhausted from the condenser compartment may enter the economizer unit through the fresh outside air intake. The mixing of the warmer return air with the fresh outside air is disadvantageous because it may increase the temperature of the air mixture enough to exceed the set point temperature that causes the air conditioner to switch from the economizer cooling mode to the mechanical cooling mode. A need has thus arisen for improvements to these wall-mount air conditioners that will reduce the mixing of return air with fresh outside air so that they may operate in the economizer cooling mode for extended periods of time and thereby benefit from the reduced operational costs that result from operating in the economizer cooling mode.
In one aspect, the present invention is directed to a single-package, wall-mount air conditioner operable in a mechanical cooling mode and an economizer cooling mode. The single-package, wall-mount air conditioner comprises: a cabinet comprising a pair of side panels, a front panel, a rear panel, a top panel, and a bottom panel that are interconnected together; a supply air opening in the rear panel through which cooling supply air may be discharged from the cabinet; a return air opening in the rear panel through which the cooling supply air after discharge from the cabinet may be recirculated to the cabinet as return air; a compression refrigeration system positioned within the cabinet and operable to cause cooling of the supply air within the cabinet when the air conditioner is operating in the mechanical cooling mode; an opening in the cabinet through which fresh outside air may enter the cabinet; a return air discharge opening in the cabinet through which the return air in the cabinet may be outwardly discharged; a return air recirculation opening within the cabinet through which the return air in the cabinet may be routed to the supply air opening; a duct in communication with the return air discharge opening and having an imperforate portion positioned to upwardly turn the outwardly discharged return air; a blower within the cabinet for effecting movement of the supply air, the return air, and the fresh outside air within the cabinet; and an economizer unit positioned within the cabinet and comprising a conduit through which the fresh outside air may flow and a damper system that is selectively operable to open and close said conduit to said flow of the fresh outside air through the conduit and to open and close said return air recirculation opening to said routing of the return air to the supply air opening.
In another aspect, said single-package, wall-mount air conditioner comprises: a cabinet comprising a pair of side panels, a front panel, a rear panel, a top panel, a bottom panel, that are interconnected together, said cabinet including divider walls that extend between the side, front and rear panels to separate an evaporator compartment from a blower compartment, the blower compartment from an economizer compartment, and the economizer compartment from a condenser compartment within the cabinet; a supply air opening in the rear panel through which cooling supply air may be discharged from the evaporator compartment; a return air opening in the rear panel through which the cooling supply air after discharge from the cabinet may be recirculated to the economizer compartment as return air; a compression refrigeration system positioned within the cabinet and operable to cause cooling of the supply air within the cabinet when the air conditioner is operating in the mechanical cooling mode, said compression refrigeration system comprising an evaporator coil assembly positioned in the evaporator compartment and a condenser coil assembly and an exhaust fan unit positioned in the condenser compartment; an opening in the cabinet through which fresh outside air may enter the condenser compartment; a return air discharge opening in the cabinet through which the return air in the economizer compartment may be outwardly discharged from the cabinet; a return air recirculation opening in the divider wall separating the blower compartment from the economizer compartment through which the return air in the economizer compartment may be routed to the blower compartment; a duct extending from the return air discharge opening and having an imperforate portion positioned to upwardly turn the outwardly discharged return air; a blower positioned in the blower compartment for effecting movement of the supply air, the return air, and the fresh outside air within the cabinet; and an economizer unit positioned within the economizer compartment and comprising a conduit through which the fresh outside air may flow from the condenser compartment to the blower compartment and a damper system that is selectively operable to open and close said conduit to said flow of the fresh outside air through the conduit and to open and close said return air recirculation opening to said routing of the return air from the economizer compartment to the supply air opening.
In another aspect, the present invention is directed to a method of operating an economizer unit in a single-package, wall-mount air conditioner. While the single-package, wall-mount air conditioner is operating in an economizer cooling mode, the method comprises the steps of: drawing fresh outside air upwardly through a conduit in the economizer unit and delivering it to a blower compartment for subsequent delivery as cooling supply air to a building; and fully or partially blocking delivery of return air through the economizer unit to the blower compartment and redirecting it outwardly from the economizer unit. While the single-package, wall-mount air conditioner is operating in a mechanical cooling mode, the method comprises the steps of: blocking said fresh outside air from being drawn upwardly through the conduit in the economizer unit; and allowing the return air to flow through the economizer unit to the blower compartment for subsequent cooling and then delivery to the building.
In the accompany drawings that form part of the specification and in which like reference numerals are used to indicate like components in the various views:
Turning now to the drawings in greater detail and initially to
The air conditioner 10 has an exterior box-like cabinet 14 that is formed from spaced-apart side panels 16 and 18, front and rear panels 20 and 22, and top and bottom panels 24 and 26. Each of the panels 16, 18, 20, 22, 24 and 26 is typically fashioned from sheet metal and may be attached to adjoining panels by screws that extend through the panels and into flanges that are formed along the edges of at least some of the panels.
The front panel 20 in one embodiment includes an upper access panel 28, a middle access panel 30 and a lower access panel 32. The rear panel 22 includes a flanged supply air opening 34 positioned close to the top panel 24 for delivering supply air through an aligned opening (not shown) in the exterior wall 12 and then into the enclosed structure. The rear panel 22 includes a flanged return air opening 36 position roughly midway between the top panel 24 and the bottom panel 26 for delivering return air from the enclosed structure through an aligned opening (not shown) in the exterior wall 12 and then into the cabinet 14.
As can best be seen in
A blower compartment 50 immediately underlies the evaporator compartment 44 and is bounded at the top by the divider wall 38 and at the bottom by the divider wall 40. The blower compartment 50 houses a pair of blowers 52 that circulate air through the cabinet 14 and deliver the supply air into the enclosed structure. When the air conditioner 10 is operating in the mechanical cooling mode, the blowers 52 draw return air from the enclosure structure and deliver it to the evaporator compartment 44. When the air conditioner 10 is operating in the economizer cooling mode, the blowers 52 draw fresh outside air into the cabinet 14 and deliver it to the evaporator compartment 44 through a pair of openings 54 in the divider wall 38 that are aligned with respective discharge outlets of the blower 52. When the fresh outside air is at a relatively low temperature as described in greater detail below, the blowers 52 may also draw some return air from the return air opening 36 for mixing with the fresh outside air that is delivered to the evaporator compartment 44. The resulting mixture may thus be warm enough to avoid the need for activation of the heating unit 48 while obtaining the ventilation benefits of circulating the fresh outside air as part of the supply air that is delivered into the enclosed structure.
An economizer compartment 56 is positioned immediately below the blower compartment 50 and is bounded at the top by the divider wall 40 and at the bottom by the divider wall 42. An economizer unit 58 is positioned within the economizer compartment 56 and comprises a pair of vertically-extending conduits 60 and a damper system 62 associated with the conduits 60. The conduits 60 each have a lower inlet end 64 in communication with a source of fresh outside air and an upper discharge end 66 in fluid flow communication with one of the blowers 52. As a result of operation of the blowers 52, a pressure differential is created within the conduits 60 and fresh outside air is able to flow upwardly through the conduits 60 for delivery by the blowers 52 to the evaporator compartment 44 and then to the enclosed structure.
Turning additionally to
In one embodiment, the damper system 62 includes one or more plates 74 that may be positioned to block passage of fresh outside air through the conduits 60 and to block passage of return air through the return air recirculation openings 72. Each one of the plates 74 may be movable to restrict or totally block the flow of fresh outside air through one of the conduits 60 and the same plate may be movable to also restrict or totally block the flow of return air through one of the return air recirculation openings 72.
In one particular exemplification, the upper discharge ends 66 of the conduits 60 are coplanar with the return air recirculation openings 72 and are shaped and arranged so that they form opposing sectors of a common circle. The return air recirculation openings 72 are likewise shaped and arranged so that they form opposing sections of the same common circle containing the upper discharge ends 66 of the conduits 60. The sector formed by one of the upper discharge ends 66 of the conduits 60 is normally of the same, but may be of a different, angular dimension as the other one of the upper discharge ends 66 of the conduits 60. Likewise, the sector formed by one of the return air recirculation openings 72 may be of a different, angular dimension as the other one of the return air recirculation openings 72. The angular dimensions of the sectors of the upper discharge ends 66 of the conduits 60 may be the same as or different from the angular dimensions of sectors of the return air recirculation openings 72. In one embodiment, the sectors are the same angular dimension and are within a few degrees of being quadrants.
In the exemplification described above, the plates 74 of the damper system 62 may be formed as opposing sectors of a common circle with each sector having a sufficient angular dimension so that each one of the plates 74 is able to fully close one of the conduits 60 and is rotatable about a vertical axis to fully close one of the return air recirculation openings 72. The plates 74 have a radial extent that allows them to overlay and be supported by a perimeter margin of the divider wall 40 surrounding the sectors of the upper discharge ends 66 of the conduits 60 and the return air recirculation openings 72. The plates 74 may be connected to an upper end of a vertically-extending center rod 76 that is connected at its lower end to an actuator 78 mounted to an underside of the divider wall 42 (
The economizer unit 58 is open to the return air opening 36 in the rear panel 22 and is also open to return air discharge ducts 80 positioned on opposite sides of the cabinet 14. Each of the return air discharge ducts 80 includes a return air discharge opening 82 in the respective side panel 16 or 18 and an aligned return air discharge opening 82a in any separate side wall that may form part of the economizer unit 58. The return air discharge ducts 80 each include a hinged damper plate 84 that operates as a one-way valve that, when open, allows the return air to be discharged from within the economizer compartment 56 to the outside of the cabinet 14 and, when closed, prevents fresh outside air from flowing through the duct 80 and the return air discharge opening 82 into the economizer compartment 56. A biasing force, such as the force of gravity, urges the damper plate 84 towards a closed position to prevent entry of fresh outside air or debris into the return air opening 82. Sufficient pressure within the economizer compartment 56 is able to overcome the biasing force to allow the return air to be exhausted through the return air discharge ducts 80. This pressure results from operation of the blowers 52 and positioning of the damper system 62 to fully or partially close the return air recirculation openings 72 in the divider wall 40 during operation of the air conditioner 10 in the economizer cooling mode.
In one exemplification, the damper plate 84 is spaced outwardly at its hinged lower end from the side panel 16 or 18. When in the closed position, the damper plate 84 is angled toward the side panel 16 or 18 and rests on a pair of inclined side supports 86 with a top end of the damper plate 84 positioned against the side panel 16 or 18. When in the open position, the top end of the damper plate 84 is moved away from the side panel 16 or 18 and off of the side supports 86 so that the duct 80 is open to allow the discharge of the return air from within the cabinet 14. A stop 88 may be provided to prevent the damper plate 84 from fully opening so that it maintains an inclined orientation that facilitates the return of the damper plate 84 to the closed position under the force of gravity.
Each of the return air discharge ducts 80 comprises a box-like structure have an imperforate lower portion 90, a perforated upper portion 92, and a closed top 94 that shields against entry of debris into the duct 80. The lower imperforate portion 90 is in horizontal alignment with the return air discharge opening 82 in the side panel 16 or 18 so that return air that exits in a horizontal direction from the economizer compartment 56 through the return air discharge opening 82 is turned upwardly by the imperforate lower portion 90 and exits with an upward momentum through the perforated upper portion 92.
Returning to
The front panel 20 of the cabinet 14 includes a circular fan opening 104 that is aligned with the exhaust fan unit 102 to allow operation of the exhaust fan unit 102 to expel air outwardly through the front panel 20 during operation of the air conditioner 10 in the mechanical cooling mode. The side panels 16 and 18 of the cabinet 14 include inlet openings 106 aligned with the condenser coil assemblies 98 to allow fresh outside air to be drawn into the condenser compartment 96 and through the condenser coil assemblies 98 for heat transfer during operation of the exhaust fan unit 102. During operation of the air conditioner 10 in the economizer cooling mode, fresh outside air is drawn through the circular fan opening 104 and/or the side panel inlet openings 106 by operation of the blowers 52 and opening of the conduits 60. Protective grills 108 and 110 are positioned over the side panel inlet openings 106 and the circular fan opening 104, respectively.
Operation of the air conditioner 10 in the mechanical cooling mode and in the economizer cooling mode will now be described with reference to
The air conditioner 10 may be switched by a suitable controller to the economizer cooling mode when the fresh outside air is below a set temperature and dew point. As shown in
In situations where mixing of some amount of return air with the entering fresh outside air, the damper system 62 can be activated to move the plates 74 so that they only partially block the upper discharge ends 66 of the conduits 60 and the return air recirculation openings 72, as shown in
From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objectives hereinabove set forth together with other advantages that are inherent to the structure.
It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the invention.
Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.
Number | Date | Country | |
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Parent | 15601839 | May 2017 | US |
Child | 16670470 | US |