Abstract:
A fan coil unit is provided including a cabinet formed from a plurality of panels. A fan assembly is configured to circulate air through the cabinet. A heat exchanger assembly is positioned within the cabinet. The heat exchanger assembly includes at least one heat exchanger coil arranged in a heat transfer relationship with the air circulating through the cabinet. An inner surface of at least one of the plurality of panels is partially lined with an elastomeric foam insulation so that the air circulating through the cabinet does not contact the portion of the at least one panel lined with the elastomeric foam insulation.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. provisional patent application Ser. No. 61/821,399 filed May 9, 2013, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The invention relates generally to a fan coil unit of a heating, ventilation, and air conditioning system, and, more particularly, to insulation configured for use around the interior of a fan coil unit. 
         [0003]    In humid environments, condensation may collect on the outside of a housing of a fan coil unit installed in an unconditioned space, such as a garage, basement, or attic for example. This condensation forms as a result of the conditioned air within the housing contacting the metal surfaces of the housing resulting in a thermal bridge. Some housings include bent metal flanges that extend directly into the conditioned air stream. In other housings, the conditioned air stream leaks around the insulation lining the interior surfaces of the housing. Over time, the condensation that collects on and ultimately drips from the outside of the housing of the fan coil unit may result in water damage to a customer&#39;s property. 
         [0004]    Conventional fan coil units limit the amount of leakage using gaskets and other sealing technologies. Some geographic regions are adjusting the allowable leakage standard for low leakage certified units. For example, California has proposed a new regulatory leakage standard of 1.4% at 0.5IN. WC. Some existing systems may not be able to meet these newer standards without significant modification and added expense. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0005]    According to an aspect of the invention, a fan coil unit is provided including a cabinet formed from a plurality of panels. A fan assembly is configured to circulate air through the cabinet. A heat exchanger assembly is positioned within the cabinet. The heat exchanger assembly includes at least one heat exchanger coil arranged in a heat transfer relationship with the air circulating through the cabinet. A portion of an inner surface of at least one of the plurality of panels is lined with an elastomeric foam insulation. The air circulating through the cabinet does not contact the inner surface of the portion of the at least one panel lined with the elastomeric foam insulation. 
         [0006]    According to another aspect of the invention, a drain pain is provided including a substantially rigid body having a horizontal section adjacent a first end and an angled section adjacent a second, opposite end. The second end is spaced apart from a plane of the first end by a vertical distance. A first connector configured to receive and support a plastic drain pan extends from the first end of the rigid body. An elastomeric foam insulation lines a surface of the rigid body. 
         [0007]    These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
           [0009]      FIG. 1  is a cross-sectional view of an exemplary fan coil unit of a heating, ventilation, and air conditioning system; 
           [0010]      FIG. 2  is a perspective view of a cabinet of a fan coil unit according to an embodiment of the invention; 
           [0011]      FIG. 3  is a top, cross-sectional view of a cabinet of a fan coil unit according to an embodiment of the invention; 
           [0012]      FIG. 4  is a cross-sectional view of a portion of a fan coil unit according to another embodiment of the invention; 
           [0013]      FIG. 5  is a perspective view of a drain pan of a fan coil unit according to an embodiment of the invention; 
           [0014]      FIG. 6  is a detailed perspective view of a drain pan arranged within a cabinet of a fan coil unit according to an embodiment of the invention; and 
           [0015]      FIG. 7  is a perspective view of a drain pan arranged adjacent a heat exchanger coil within a cabinet of a fan coil unit according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    Referring now to the FIGS., a fan coil unit  10  of a heating, ventilation, and air conditioning (HVAC) system is illustrated. The fan coil unit  10  includes a cabinet or housing duct  12  within which various components are located. For example, housed within the cabinet  12  of the fan coil unit  10  is a heat exchanger assembly  14  configured to heat or cool the adjacent air and a fan assembly  16  configured to circulate air through the heat exchanger assembly  14 . Depending on the desired unit characteristics, the fan assembly  16  may be positioned either downstream with respect to the heat exchanger assembly  14  (i.e. a “draw through” configuration), as shown in  FIG. 1 , or upstream with respect to the heat exchanger assembly  14  (i.e. a “blow through” configuration). 
         [0017]    The heat exchanger assembly  14  may include any of a plurality of configurations. As illustrated in  FIG. 1 , the heat exchanger assembly  14  is a single heat exchanger coil  18  arranged at an angle with respect to the flow path of air through the cabinet  12 . Alternative configurations of the heat exchanger assembly  14  may include multiple heat exchanger coils  18  arranged in a generally V-shaped configuration, a generally A-shaped configuration, or a generally N-shaped configuration, as is known in the art. In embodiments where the fan coil unit  10  is configured to provide cool air, the heat exchanger assembly  14  absorbs heat from the air passing through the heat exchanger assembly  14  and the resultant cool air is provided to a space to be conditioned. 
         [0018]    Referring now to  FIGS. 2-4 , the cabinet  12  of the fan coil unit  10  is provided in more detail. The cabinet  12  is formed from a plurality of panels  20  including an opposing left side panel  22 , right side panel  24 , and rear panel  26 . The cabinet  12  also includes end panels  28 ,  30  which enclose both the upper and lower ends of the cabinet  12 , respectively. A front panel  32  is arranged opposite the rear panel  26  and generally encloses the fan coil unit  10 . In one embodiment, the front panel  32  is mounted to one of the left side panel  22  and the right side panel  24 . The front panel  32  is configured to move between a closed position and an open position to provide access to the plurality of components stored within the cabinet  12 . The cabinet  12  includes at least one inlet opening  34  through which air to be conditioned travels to the interior of the cabinet  12 . The air being heated or cooled in the fan coil unit  10  may be provided from a return air duct (not shown) connected to a space to be conditioned, or alternatively, may be fresh air drawn in from an outside source or a mixture of return air and fresh air. The cabinet  12  similarly includes at least one outlet opening  36 , such as formed in end panel  30  for example. The outlet opening  36  may, but need not be, connected to ductwork (not shown) to guide and deliver the supply air from the fan cod unit  10  to one or more locations spaces to be conditioned. 
         [0019]    As illustrated in  FIG. 3 , pieces of elastomeric foam insulation  40  having a substantially closed cell structure are arranged about the interior surface  38  of the cabinet  12  to prevent the cool supply air generated within the fan coil unit  10  from contacting the metal panels of the cabinet  12 . In one embodiment, the elastomeric foam insulation  40  is bonded to the interior surface  38  of each panel  20 , such as with glue or another adhesive for example. Each piece of elastomeric foam insulation  40  may have a size substantially similar to the size of the panel  20  to which the insulation sheet is configured to attach. Alternatively, a plurality of smaller pieces of insulation  40  may attach to each panel  20  of the cabinet  12 . Exemplary elastomeric foam insulations  40  that may be used include, but are not limited to, Armacell AP/Armaflex®, K-FLEX USA K-FLEX Clad®, and K-FLEX USA K-FLEX Duct® for example. In one embodiment, adjacent pieces of insulation  40  positioned generally perpendicularly to one another, such as near the corners  21  of the cabinet  12  for example, are arranged to have an interference fit. As a result of the resilient nature and compressive strength of the elastomeric foam insulation  40 , the interference fit forms a tight seal, thereby preventing cool air from leaking between the adjacent pieces of elastomeric foam insulation  40  and contacting the metal panels  20  of the cabinet  12 .  FIG. 4  also illustrates that the elastomeric foam insulation  40  may be configured to substantially surround a bent metal flange  37  extending inwardly from a panel  20  of the cabinet. In one embodiment, illustrated in  FIG. 4 , a slit  42 , substantially parallel to the panel  20 , is formed in the piece of elastomeric foam insulation  40 . The end  39  of the flange  37  is received within the slit  42  to prevent the cool air within the fan coil unit  10  from contacting the flange  37 . 
         [0020]    Referring now to  FIGS. 5-7 , the fan coil unit  10  includes at least one drain pan  50  arranged adjacent the heat exchanger assembly  14 . As the air flowing through the heat exchanger assembly  14  is cooled, at least a portion of the water within the air condenses and collects on the fins of the heat exchanger  14 . Gravity and the continued air flow through the heat exchanger assembly  14  may cause a portion of the collected condensation to fall from the heat exchanger  14  onto the adjacent drain pan  50 . Another portion of condensate may run down the fin edges of the heat exchanger  14  to the plastic drain pan  80 . 
         [0021]    The drain pan  50  includes a body  52  generally formed from a thin, structurally rigid material, such as sheet metal for example. The body  52  includes a generally horizontal section  58  adjacent a first end  54 . A generally angled section  60  extends from the horizontal section  58  to a second, opposite end  56  such that the second end  56  is spaced apart from the plane of the first end  54  by a vertical distance. The slope of the angled section  60  causes condensate on the drain pan  50  to flow towards the first end  54  thereof. In one embodiment, the sides  62 ,  64  of the angled section  60  may be similarly arranged at an upward angle to the center of the angled section  60  to direct water towards the middle of the drain pan  50 . Elastomeric foam insulation  40  having a closed cell structure is positioned over the surface (not shown) of the angled section  60  and the adjacent horizontal section  58 . In one embodiment, the elastomeric foam insulation  40  is bonded to the surface of the body  52 , such as with glue or another adhesive for example. 
         [0022]    Arranged at the first end  54  of the body  52  is a first connector  66  configured to couple the first end  54  of the body  52  to a portion of the cabinet  12 . In one embodiment, the first connector  66  includes a channel  68  configured to align with a panel  20  of the cabinet  12  such that the drain pan  50  may not move in a direction substantially perpendicular to the plane of the panel  20 . Between the channel  68  and the first end  54  of the body is a substantially transition portion  70 . Though the transition portion  70  is generally triangular in the non-limiting illustrated embodiment, a transition portion having another shape is within the scope of the invention. The transition portion  70  is generally complementary to and is configured to receive a plastic drain pan  80 . When the plastic drain pan  80  engages the transition  70  of the first connector  66 , a portion  82  of the plastic drain pan  80  extends over the horizontal section  58  of the body  52 . The portion  82  of the plastic drain pan  80  overlapped with the horizontal section  58  and the elastomeric foam insulation  40  positioned on the angled section  60  of the body  52  may be substantially aligned. In one embodiment, the plastic drain pan  80  may be angled such that the condensate flows to at least one drain  84  arranged at a side of the plastic drain pan  80 . The second end  56  of the body  52  may similarly include a second connector  72  including a channel  74  configured to align with another panel  20  of the cabinet  12  such that the body  52  may not move in a direction substantially perpendicular to the plane of the panel  20 . As the fan coil unit  10  operates, condensation that forms on the heat exchanger assembly  14  will fall onto the elastomeric foam insulation  40  lining the angled section  60  of the drain pain  50 . The condensate will flow from the elastomeric foam insulation  40  onto the plastic drain pan  50  and out at least one drain  84  arranged at the sides of the cabinet  12 . In one embodiment, multiple drain pans  50  may be arranged within a fan coil unit  12 , such as adjacent opposing sides of a heat exchanger assembly  14  for example. 
         [0023]    By lining the panels  20  of the cabinet  12  of a fan coil unit  10  with an elastomeric foam insulation  40 , the amount of cool air that contacts the panels  20  of the cabinet  12  is reduced, thereby resulting in a significant reduction in the amount of condensation formed on the exterior of the unit  10 . In addition, the elastomeric foam insulation may be easily cleaned and generally includes anti-bacterial properties. Inclusion of the sloped drain pan  50  lined with elastomeric foam insulation  40  will also reduce the internal static pressure within the cabinet because an additional, plastic horizontal drain pan is not necessary, thus resulting in lower power consumption by the fan assembly  16 . Multiple drain pans  50  arranged within a fan coil unit  10  allow the unit to be installed without any additional positioning of the pans  50  based on the orientation of the unit  10 . 
         [0024]    While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.