Abstract:
An air conditioning unit having an indoor section and an outdoor section separated by a dividing wall. The outdoor heat exchanger and fan are enclosed within a housing that is split into a stationary lower wall section and a removable upper wall section which, when removed, provides ready access to the outdoor heat exchanger. A hole is placed in the bottom of the lower wall section in front of the fan so that condensate can be drawn into the unit by the fan and distributed over the heat exchanger surfaces. Vanes are placed on the inside wall of the housing to enhance the distribution of the condensate.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention relates to a split outdoor fan housing for use in an air conditioning system and, in particular, to a package terminal air conditioner (PTAC) unit.  
           [0002]    More specifically, this invention relates to a housing for use in a PTAC unit employing an outdoor fan having the capability of distributing condensate over the outdoor heat exchanger surfaces to improve the unit efficiency when the unit is operating in a cooling mode. Many package terminal air conditioners are used in hotels and motels to provide conditioned air to specific indoor areas such as rooms and the like. The unit is generally housed in a rectangular sleeve that is mounted in an outside wall of the area or room being serviced. The unit is separated into an indoor section and an outdoor section by a dividing wall. Each section includes a heat exchanger and a fan for moving air over the heat exchanger. When operating in a cooling mode, the outdoor heat exchanger acts as a condenser for reducing refrigerant vapors leaving the system compressor to a liquid state. To improve the efficiency of the outdoor heat exchanger, the outdoor section is sometimes provided with a slinger type fan that is arranged to distribute condensate provided by the indoor heat exchanger to aid in the condensing process and thus improve the overall efficiency of the unit. A housing is placed about the outdoor heat exchanger and fan to contain the condensate and to help in distributing outside air and condensate over the heat exchanger. A housing of this type is disclosed in U.S. Pat. No. 6,007,812.  
           [0003]    The outdoor heat exchanger, because it is exposed to outdoor elements, collects dirt and other air borne contaminants which lodge in the heat exchanger surfaces, thereby reducing the unit performance. These surfaces must therefore be cleaned periodically. It has heretofore been rather difficult to gain access to these surfaces involving the removal of a large number of unit parts. As a consequence, the unit down time during cleaning has been relatively long and the cost of maintaining this type of unit relatively high.  
         BRIEF SUMMARY OF THE INVENTION  
         [0004]    It is an object of the present invention to improve air conditioners and, in particular packaged terminal air conditioners.  
           [0005]    It is a further object of the present invention to facilitate cleaning of the outdoor heat exchanger of a packaged terminal air conditioner.  
           [0006]    It is a still further object of the present invention to minimize the amount of time required to clean the outdoor heat exchanger of a packaged terminal air conditioner.  
           [0007]    Another object of the present invention is to provide easy access to the outdoor heat exchanger of an air conditioner.  
           [0008]    Yet another object of the present invention is to improve the distribution of condensate over the surfaces of the outdoor heat exchanger of a PTAC unit.  
           [0009]    These and other objects of the present invention are attained in a packaged terminal air conditioner having an indoor section and an outdoor section, both of which contain a heat exchanger and a fan for moving air over the heat exchanger. A dividing wall is used to separate the indoor section from the outdoor section of the unit. A two piece housing is mounted in the outdoor section of the unit that encloses the area between the outdoor fan and the outdoor heat exchanger. The housing has a front wall with an opening that surrounds the outdoor fan through which air is drawn into the housing and passed over the heat exchanger surfaces. The housing includes a stationary lower wall section and a removable upper wall section that is secured to the lower wall section by any suitable type fastener. A hole is provided in the bottom of the lower wall section through which condensate is drawn by the outdoor fan into the housing and distributed over the outdoor heat exchanger. Vanes are placed upon the inner wall surfaces of the housing to enhance the distribution of condensate over the heat exchanger. The housing is split about along the horizontal axis of the fan thereby furnishing ready access to the outdoor heat exchanger when the upper wall section is removed from the housing. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    For these and other objects of the present invention, reference will be made to the following detailed description of the invention which is to be read in association with the accompanying drawings wherein:  
         [0011]    [0011]FIG. 1 is a front perspective view of an air conditioner embodying the teachings of the present invention;  
         [0012]    [0012]FIG. 2 is an exploded view in perspective of the air conditioner unit illustrated in FIG. 1 showing the unit removed from its sleeve and portions broken away to better illustrate the outdoor heat exchanger and fan;  
         [0013]    [0013]FIG. 3 is a front perspective view of the unit with parts broken away to show the front wall of said housing; and  
         [0014]    [0014]FIG. 4 is a partial perspective view of the outdoor heat exchanger housing with the outdoor heat exchanger removed and further illustrating the housing mounting brackets connected to the dividing wall of the air conditioning unit. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]    Turning now to the drawings, there is illustrated a packaged terminal air conditioner (PTAC), generally referenced  10 , that embodies the teachings of the present invention. The unit includes a rectangular shaped sleeve  12  which is normally mounted in an outside wall of a building that houses the room or comfort area being serviced by the air conditioning unit. The unit contains a front cover  13  that closes tightly against the sleeve. The cover further contains an inlet opening  14  through which air from the comfort region is drawn into the unit and an outlet opening  15  through which conditioned air is returned back into the comfort region. Internally, the unit is separated by a dividing wall  19  (FIG. 2) into an indoor section  18  that is located beneath the front cover of the unit and an outdoor section  20 . Each section contains a heat exchanger and a fan for passing air over the heat exchanger surfaces. The controls for the unit are recessed behind the front cover and access to the controls is provided through a door  17  that is hinged to the cover.  
         [0016]    Most PTAC units are provided with a cooling mode of operation and a heating mode of operation which can be selected by an occupant of the comfort region being serviced by the unit. As is well known in the art, the function of the heat exchangers will be reversed, depending upon the mode that is selected. The present invention will be described with specific reference to a unit that is operating in the cooling mode wherein the indoor heat exchanger is functioning as an evaporator and the outdoor heat exchanger is functioning as a condenser.  
         [0017]    As best illustrated in FIGS. 2 and 3, the outdoor section  20  of the unit includes an outdoor heat exchanger  25  that is mounted along the back edge  26  of the base pan  27  of the unit. An outdoor fan  30  is mounted in front of the outdoor heat exchanger  31  and is driven by a motor  32  that is mounted in a motor support  34 . The fan includes a series of blades  35  that are contained within a rotating shroud  37  and which are arranged to draw outside air through the back of the fan and distribute the air over the surfaces of the heat exchanger. As will be explained in further detail below, the fan and the shroud are also arranged to draw condensate that is collected in the base pan of the unit into the air stream and distribute the condensate along with the air over the heat exchanger. A fan of this nature is described in further detail in the above noted U.S. Pat. No. 6,007,812, the details of which are herein incorporated by reference.  
         [0018]    The outdoor fan  30  and the outdoor heat exchanger  31  are both mounted within a split housing, generally referenced  40 , with the heat exchanger forming the back wall of the housing. The front wall  41  of the housing contains a circular opening  42  that surrounds the outdoor fan and through which outdoor air is drawing into the housing by the fan. A pair of co-joined side panels  44  and  45  extend outwardly from the opposing side edges of the front wall. The panels are canted toward the two ends of the heat exchanger with the outer panels  45  being joined to the two opposed tube sheets  47  and  48  of the heat exchanger. The outer panels are connected to the tube sheets by a series of clips  49  so that the heat exchanger can be easily disconnected from the housing when necessary, such as during periods when the unit requires servicing. The housing further includes a horizontally disposed top wall  52  that extends outwardly from the front wall of the housing over the top of the outdoor heat exchanger.  
         [0019]    As noted above, the outdoor section of the unit is exposed to the elements and dirt and air borne contaminants can be drawn into the housing where they collect upon the heat exchanger surfaces. As a consequence, the efficiency of the unit is adversely effected and more energy must be consumed to maintain the comfort air at a desired level. Depending upon a number of factors, the outdoor heat exchanger must be periodically cleaned to maintain the unit&#39;s performance at a high level. This has heretofore been accomplished by sliding the base pan out of the sleeve and dismounting the entire housing so that sufficient access could be gained to all the heat exchanger surfaces.  
         [0020]    The present outdoor heat exchanger housing  40  is split along a parting line  50  into two sections which are the lower section  56  and the upper section  57 . In assembly, the lower section of the housing is secured in a stationary upright position to the base pan of the unit by screws or any other suitable fasteners as known and used in the art. The upper section of the housing, in turn, is seated upon the lower section. The top edge of the lower section and the lower edge of the upper section are provided with horizontally disposed rims  60  and  61 , respectively, which come together in assembly and are secured in abutting contact by removable clips  63  or threaded fasteners so that the upper section can be quickly disassembled from the lower section. The parting lien  50  of the housing lies in a horizontal plane that is described by the horizontal axis  69  of the fan opening in the front wall of the housing so as to furnish a maximum amount of access to the outdoor heat exchanger when the upper section of the housing is removed.  
         [0021]    A pair of brackets  70 - 70  are arranged to connect the top wall  52  of the upper housing section to the dividing unit  19  of the air conditioning unit. A tab  72  on one end of each bracket is received in a recess  73  formed in the top wall  52  of the housing and is secured therein by a screw  74 . The opposite end of each bracket is further provided by a raised tab  77  that is arranged to be received with a slot  78  (FIG. 4) formed in the dividing wall  19 . Screws  79  are passed through holes in the top of the wall and engage threaded holes  80  in the raised tabs to secure the brackets in the wall.  
         [0022]    With further reference to FIG. 4, the inner surfaces of the outdoor heat exchanger housing are provided with stationary vanes  80 - 80  that are contoured to direct condensate leaving the fan across the heat exchanger surfaces. The base pan  27  of the unit is provided with inclined surfaces  82  and  83  that slant downwardly toward an orifice  85  (FIG. 4) provided in the bottom of the lower wall of the outdoor heat exchanger housing so that the condensate collected in the pan is brought to the orifice entrance. The orifice is positioned along the vertical axis  86  of the fan opening at an elevation such that the fan can effectively draw condensate through the orifice. As explained in the previously noted U.S. Pat. No. 6,067,812, the pressure differential that is developed over the outdoor fan causes the condensate drawn through the orifice to move into the path of the slinger, which in turn, redirects the condensate toward the outdoor heat exchanger. The vanes  80 - 80  are designed to act in concert with the slinger to produce a uniform distribution of the condensate over the entire surface of the heat exchanger, thereby improving the efficiency of the outdoor heat exchanger and the overall performance of the unit when the unit is in a cooling mode of operation.  
         [0023]    While this invention has been explained with reference to the structure disclosed herein, it is not confined to the details set forth and this invention is intended to cover any modifications and changes as may come within the scope of the following claims: