Patent Publication Number: US-10316516-B2

Title: Insulated panel assembly

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to insulated enclosures, and more specifically to a thermally insulating panel assembly for forming an insulated enclosure. 
     BACKGROUND 
     Thermally insulated enclosures are useful in many contexts. For example, the use of thermally insulated enclosures for HVAC equipment (e.g., heat exchangers, compressors, blowers, filters, fans, motors, cooling elements, heating elements, humidifying elements) is commonplace. Other types of thermally insulated enclosures such as walk in coolers and freezers often need to be constructed rapidly and with an ability to be readily knocked down. Thermally insulated enclosures are often constructed with panels filled with insulation to minimize the transmission of thermal energy from the interior to the exterior of the enclosure. Typically, the panels include inner and outer (first and second) panel members of metal that are joined together to form a volume that receives the insulation. The panel members can be connected together using plastic fasteners and/or gaskets to reduce thermal transmission. However, the inner and outer panel members are often difficult to manufacture, and it can be difficult and time-consuming to attach the panel members to each other to form the insulated enclosure. 
     SUMMARY 
     In one aspect, an insulated panel assembly for use in forming a thermally insulated enclosure generally comprises a housing having inner and outer major surfaces and edge surfaces extending between the inner and outer major surfaces. An interior cavity is defined by the housing, and an insulating core is located within the interior cavity of the housing. An elongate slot in at least one of the edge surfaces of the housing extends inward of the edge surface toward the interior cavity. 
     In a still further aspect, a method of assembling an insulated panel assembly for use in forming a thermally insulated enclosure includes the step of locating a first panel member relative to a second panel member such that the first panel member opposes the second panel member and is spaced apart from the first panel member. Insulation is positioned between the first and second panel members. The located first panel member and second panel member define a housing having inner and outer major surfaces and edge surfaces extending between the inner and outer major surfaces and an interior cavity in which the insulation is positioned. A slot is provided in the housing extending inward from at least one of the edge surfaces of the housing toward the interior cavity. 
     In yet another aspect of the present invention, a method of assembling a thermally insulated enclosure generally comprises providing a first thermally insulated panel assembly having inner and outer major surfaces and edge surfaces extending between the inner and outer major surfaces and an interior cavity in which insulation is disposed. A slat is inserted into a slot in one of the edge surfaces of the housing. A second thermally insulated panel assembly is provided having inner and outer major surfaces and edge surfaces extending between the inner and outer major surfaces and an interior cavity in which insulation is disposed next to the first panel assembly. The slat is received in a slot in one of the edge surfaces of the housing of the second thermally insulated panel assembly thereby connecting the first and second panel assemblies together. 
     Other objects and features of the present invention will be in part apparent and in part pointed out herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective of a thermally insulated enclosure formed from insulated panel assemblies; 
         FIG. 2  is an enlarged, horizontal section of the enclosure, partially broken away, illustrating the connection between panel assemblies of the thermally insulated enclosure; 
         FIG. 2A  is a horizontal section of a thermally insulated enclosure, partially broken away, showing the connection between panel assemblies of the thermally insulated enclosure having an alternative panel assembly arrangement; 
         FIG. 3  is an enlarged fragmentary portion of  FIG. 2  showing a corner connection; 
         FIG. 3A  is an enlarged fragmentary portion of  FIG. 2A  showing a corner connection; 
         FIG. 4  is an enlarged fragmentary portion of  FIG. 2  showing panel assemblies forming a side of the thermally insulated enclosure; 
         FIG. 4A  is an enlarged fragmentary portion of  FIG. 2A  showing panel assemblies forming a side of the thermally insulated enclosure; 
         FIG. 5  is a fragmentary vertical section of the thermally insulated enclosure of  FIG. 1  showing a panel assembly to base connection; 
         FIG. 5A  is a fragmentary vertical section similar to  FIG. 5 , but showing an alternate panel assembly to base connection; 
         FIG. 6  is a fragmentary vertical section of the thermally insulated enclosure of  FIG. 1  showing connection of a side panel assembly to a roof panel assembly; 
         FIG. 6A  is a fragmentary vertical section similar to  FIG. 6 , but showing an alternate arrangement of panel assemblies in the side and roof of an enclosure; 
         FIG. 7  is a front perspective of a panel assembly; 
         FIG. 7A  is a rear perspective of a panel assembly; 
         FIG. 8  is an enlarged, horizontal section of a first panel member of the panel assembly of  FIG. 7  with portions broken away; 
         FIG. 9  is a vertical section of the first panel member of  FIG. 8  with portions broken away; 
         FIG. 10  is a horizontal section of a second panel member of a panel assembly of  FIG. 7  with portions broken away; 
         FIG. 11  is a vertical section of the second panel member of  FIG. 10  with portions broken away; 
         FIG. 12  is a horizontal section of the panel assembly of  FIG. 7 ; 
         FIG. 13  is an enlarged fragmentary portion of  FIG. 12 ; 
         FIG. 14  is a vertical section of the panel assembly of  FIG. 7 ; 
         FIG. 15  is an enlarged fragmentary portion of  FIG. 14 ; 
         FIG. 16  is an illustration of a connection between adjacent panel assemblies; and 
         FIG. 16A  is an illustration of a connection between adjacent panel assemblies having an alternative arrangement. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the drawings. 
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1-2A , a thermally insulated enclosure, shown generally at  10 , comprises a number of insulated panel assemblies  12 ,  12 ′. The panel assemblies comprise side wall panel assemblies  12  and roof panel assemblies  12 ′ each having generally the same construction. It is noted however that, as illustrated in  FIG. 1 , the side wall panel assemblies  12  may have a different length than the roof panel assemblies  12 ′. The insulated panel assemblies are attached to each other, as described below, and may also be attached to a base  13  including a framing channel  14  and floor  15  ( FIGS. 5 and 5A ) to form the thermally insulated enclosure  10 . As explained more fully hereinafter, the insulated panel assemblies  12 ,  12 ′ are configured to permit easy and rapid construction of thermally insulated enclosures such as the enclosure  10 . These thermally insulated enclosures can serve as housing for equipment or form structures such as a walk in cooler or freezer. In all applications, the enclosures prevent ready heat transfer to or from an interior of the enclosure. 
     Referring to  FIGS. 2, 2A, and 7-12 , each panel assembly  12  includes a first panel member  16 , a second panel member  18 , and a thermally insulating core  20 . The first panel member  16  includes a front portion  22  having an outer face  24  and an inner face  26 . A top portion  28  extends from a top edge margin of the front portion  22  ( FIG. 9 ). The top portion  28  extends generally perpendicular from the front portion  22  in a direction inward away from the inner face  26 . A bottom portion  30  extends from a bottom edge margin of the front portion  22  opposite the top portion  28 . The bottom portion  30  extends generally perpendicular from the front portion  22  in a direction inward away from the inner face  26 , such that the bottom portion and the top portion are generally in spaced, parallel alignment. A first side portion  32  extends from a first side edge margin of the front portion  22  ( FIG. 8 ). The first side portion  32  extends generally perpendicular from the front portion  22  in a direction inward away from the inner face  26 . A second side portion  34  extends from a second side edge margin of the front portion  22  opposite the first side portion  32 . The second side portion  34  extends generally perpendicular from the front portion  22  in a direction inward away from the inner face  26 , such that the first and second side portions are generally in spaced parallel alignment. 
     Each of the top, bottom, and first and second side portions  28 ,  30 ,  32 ,  34  of the first panel member  16  includes a mounting flange configured for attachment to the second panel member  18 . A top mounting flange  38  extends generally perpendicular from the top portion  28  in a direction toward the bottom portion  30 . A bottom mounting flange  40  extends generally perpendicular from the bottom portion  30  in a direction toward the top portion  28 . A first side mounting flange  42  extends generally perpendicular from the first side portion  32  in a direction toward the second side portion  34 . A second side mounting flange  44  extends generally perpendicular from the second side portion  34  in a direction toward the first side portion  32 . The mounting flanges  38 ,  40 ,  42 ,  44  preferably lie in the same plane (parallel to the plane of the front portion  22 ) for level attachment to the second panel member  18 . 
     The first panel member  16  can be formed as one piece from a metal blank (not shown) that is stamped from a sheet metal roll and bent into shape. The first panel member  16  can be stamped from galvanized steel, stainless steel, aluminum, or any other suitable material. The first panel member  16  is preferably formed of light gauge metal, such as 14-22 gauge metal. In one embodiment, the first panel member  16  is stamped from 20 gauge galvanized steel, although other thicknesses and other suitable materials are within the scope of the present invention. 
     Referring to  FIGS. 7, 7A, 10 and 11 , the second panel member  18  includes a front portion  52  having an outer face  54  and an inner face  56 . A top portion  58  extends from a top edge margin of the front portion  52  ( FIG. 11 ). The top portion  58  extends generally perpendicular from the front portion  52  in a direction inward away from the inner face  56 . A bottom portion  60  extends from a bottom edge margin of the front portion  52  opposite the top portion  58 . The bottom portion  60  extends generally perpendicular from the front portion  52  in a direction inward away from the inner face  56 , such that the bottom portion and the top portion  58  are generally in spaced parallel alignment. A first side portion  62  extends from a first side edge margin of the front portion  52  ( FIG. 10 ). The first side portion  62  extends generally perpendicular from the front portion  52  in a direction inward away from the inner face  56 . A second side portion  64  extends from a second side edge margin of the front portion  52  opposite the first side portion  62 . The second side portion  64  extends generally perpendicular from the front portion  52  in a direction inward away from the inner face  56 , such that the first and second side portions are generally in spaced parallel alignment. 
     Referring still to  FIGS. 10 and 11 , each of the top, bottom, and first and second side portions  58 ,  60 ,  62 ,  64  of the second panel member  18  includes a mounting flange configured for attachment to the first panel member  16 . A top mounting flange  68  extends generally perpendicular from the top portion  58  in a direction toward the bottom portion  60 . A bottom mounting flange  70  extends generally perpendicular from the bottom portion  60  in a direction toward the top portion  58 . A first side mounting flange  72  extends generally perpendicular from the first side portion  62  in a direction toward the second side portion  64 . A second side mounting flange  74  extends generally perpendicular from the second side portion  64  in a direction toward the first side portion  62 . The mounting flanges  68 ,  70 ,  72 ,  74  of the second panel member  18  preferably lie in the same plane (parallel to the plane of the front portion  52 ) for level attachment to the first panel member  16 . 
     The second panel member  18  can be formed as one piece from a metal blank (not shown) that is stamped from a sheet metal roll and bent into shape. The second panel member  18  can be stamped from galvanized steel, stainless steel, aluminum, or any other suitable material. The second panel member  18  is preferably formed of light gauge material, such as 14-22 gauge material. In one embodiment, the second panel member  18  is stamped from 18 gauge galvanized steel, although other thicknesses and other suitable materials are within the scope of the present invention. The second panel member  18  and the first panel member  16  may be formed of the same material or different materials and may have the same thickness or different thicknesses. 
     To form the insulated panel assembly  12 , one of the first and second panel members  16 ,  18  can be laid down in a jig (not shown) or simply on the floor. For purposes of this description we will refer to second panel member  18  as being laid down. A gasket  78  or gaskets (broadly, “spacer(s)”) are laid on top of the mounting flanges  68 ,  70 ,  72 ,  74  to provide a thermal barrier and a spacing between the first and second panel members  16 ,  18 . The first panel member  16  is laid upon the second panel member  18  so that the mounting flanges  38 ,  40 ,  42 ,  44  of the first panel member face the mounting flanges  68 ,  70 ,  72 ,  74  of the second panel member. The mounting flanges of the first and second panel members  16 ,  18  do not engage, but are separated by the gasket  78 . The first and second panel member  16 ,  18  can be temporarily secured together using tape or clamps (not shown). It is also possible that no temporary securement is employed. Together, the first and second panel members  16 ,  18  form a housing that has inner and outer major surfaces (corresponding to the outer faces  24 ,  54  of the panel members). Edge surfaces of the housing extend between the major surfaces. The edge surfaces are mostly defined by the side portions  32 ,  34 ,  62 ,  64  of the first and second panel members  16 ,  18 . 
     The panel subassembly is taken to a press (not shown) for injection of material to form the insulating core  20  into the cavity  82  defined by the first and second panel members  16 ,  18 . For example, in one embodiment, the assembled first and second panel members  16 ,  18  are placed in a heated press and the cavity  82  is injected with urethane foam to form the core  20  having a density of about 2.5 lbs/ft 3  (40.05 kg/m 3 ). The thermal insulating core  20  can comprise other suitable insulating materials or other suitable densities within the scope of the present invention. The press is capable of holding the first and second panel members  16 ,  18  in position with respect to each other and to hold them from being pushed apart or having their front portions  22 ,  52  bow out under the pressure of the insulation material forming the core  20  being injected. The material of the insulating core  20  operates as an adhesive joining the first and second panel members  16 ,  18  together permanently. 
     The panel assembly  12  is taken from the press and a cut is made between the panel members  16 ,  18  on both sides. The cut effectively removes the gasket  78  on the side and leaves a slot  90  on each side of the panel assembly  12  that extends into the panel assembly toward the interior cavity  82  between the opposed mounting flanges  42 ,  72  or  44 ,  74 , and past the respective mounting flange  72  or  74  of the second panel member. In the illustrated embodiment, the slot extends the full length of the side of the panel assembly  12 . The purpose of the slot  90  will be described hereinafter. As finally assembled, the first and second panel members  16 ,  18  are attached together such that the inner face  26  of the first panel member  16  is spaced from and opposes the inner face  56  of the second panel member  18 , forming the cavity  82  that holds the insulated core  20 . The edge margins of the first panel member  16  are aligned with the corresponding edge margins of the second panel member  18 . In particular, the top edge margin of the first panel member  16  is aligned with the top edge margin of the second panel member  18 , the bottom edge margin of the first panel member is aligned with the bottom edge margin of the second panel member, and the first and second side edge margins of the first panel member are aligned with the first and second side edge margins of the second panel member. For example, it may be seen in  FIG. 14  that the top portion  28  of the first panel member  16  is laterally aligned with the top portion  58  of the second panel member  18 . Similarly, the bottom portion  30  of the first panel member  16  is laterally aligned with the bottom portion  60  of the second panel member  18 . As shown in  FIG. 12 , the first side portion  32  of the first panel  16  is laterally aligned with the first side portion  62  of the second panel  18 , and the second side portion  34  of the first panel member is laterally aligned with the second side portion  64  of the second panel member. It will be appreciated that other ways of assembling the panel assembly  12  may be used within the scope of the present invention. 
     Referring to  FIGS. 4 and 4A , a stiffener  94  may be disposed in the cavity  82  of each panel assembly  12 . At least one stiffener may be disposed within the cavity  82  of a panel assembly  12 . In some embodiments, two stiffeners  94  are disposed within the cavity  82  of a panel assembly  12 . In the embodiment shown in  FIG. 4 , the stiffeners  94  are disposed in opposed side edge margins in the second panels  18  of adjacent panel assemblies  12  between the mounting flange  72  and the inner face  56  and between mounting flange  74  and the inner face  56 . Each stiffener  94  comprises a U shaped channel member received within a side edge margin of the second panel  18  of a panel assembly. As shown in  FIGS. 4 and 4A , a first section  96  of the stiffener  94  extends generally parallel to the front portion  52  along the inner face  56  of the front portion. A second section  98  extends from the first section  96  along the second side portion  64  generally parallel to the second side portion. A third section  100  extends from the second section  98  along the second side mounting flange  74  generally parallel to the second side mounting flange. A stiffener  94  may also be disposed in the opposing side margin of the second panel  18  of the adjacent panel assembly  12 . In the embodiment shown in  FIG. 4A , the second panels  18  of adjacent panel assemblies  12  are disposed on an outer side of the assemblies. The stiffeners  94  have the same construction as those shown in  FIG. 4 . 
     Panel assemblies identical to panel assembly  12  can be taken to a site for construction of an insulated enclosure  10 . In the illustrated embodiment, each panel assembly  12  has a rectangular parallelepiped configuration. The panel assembly  12  is free of any outwardly projecting structure. The panel assemblies  12  can be used to rapidly construct the enclosure  10 , as will be described. A feature of this construction is the use of elongate, thermally insulating slats  80 . Referring to  FIG. 4 , one of the slats can be inserted edgewise into the slot  90  on one side of a first of the panel assemblies  12 . The slat  80  has a length substantially equal to the height of the panel assembly  12 . The slat  80  is received with a friction or interference fit in the slot  90  to at least temporarily hold the slat in the slot. Gasket  78  is selected to have a thickness so that it spaces the mounting flanges of the first and second panel members to ultimately provide that the slot  90  has an appropriate width for fitting the slat  80 . In the illustrated embodiment, the fit is such that the slat  80  can be held in the slot  90 , but is not so tight as to prevent manual removal. The next adjacent (second) panel assembly  12  can be placed next to the first panel assembly so that the projecting portion of the slat  80  is received in the slot  90  of the second panel assembly. Caulk  92  is located between the adjacent panel assemblies  12  to facilitate an air tight connection between them. Typically, the caulk  92  is applied to one of the panel assemblies  12  before connection to another of the panel assemblies. It will be appreciated that this procedure can be continued for each subsequent panel assembly  12  until a side wall of a desired length has been constructed. No conventional fasteners (e.g., screws) are required to make connection between adjacent panel assemblies  12 . The use of the construction of panel assemblies  12  and slats  80  can reduce the time to assemble the panel assemblies to form the enclosure  10  by about 85% (e.g., from about 35 minutes to about 5 minutes). 
     The slats  80  connecting adjacent panel assemblies  12  do not significantly resist the panel assemblies being pulled apart in the plane of the side wall of the enclosure  10 , but do hold the connected panel assemblies from movement with respect to each other out of the plane of the enclosure side wall. The slats  80  can be formed of any suitable material, such as a thermoplastic polymer. Examples of suitable material include, without limitation, Lexan™, Acrylonitrile Butadiene Styrene (ABS), polyvinyl chloride (PVC), fiberglass, etc. 
     A more complete description of the construction of the thermally insulated enclosure  10  will now be provided. A base  13  comprising the framing channel  14  and floor  15  is constructed to have the dimensions of the footprint of the thermally insulated enclosure  10 . In the illustrated embodiment, an angle iron  14 A is mounted on a top flange of the framing channel. Lips  15 A (only one of which is shown) are formed by upturned portions of the floor  15  around its perimeter. The angle iron  14 A and lip  15 A are used to locate the panel assemblies  12  forming the side walls of the enclosure  10  as will be described. The base  13  will have any drains or other features (not shown) required for the particular application. The base will be brought into place or constructed at the location where the thermally insulated enclosure is to be erected. 
     In one embodiment, two panel assemblies  12  are positioned at right angles to each other. For purposes of this description, the two panel assemblies  12  are those shown in the upper left hand corner of the enclosure in  FIG. 2 . The two panel assemblies  12 , shown on a larger scale in  FIG. 3 , have an arrangement where the first panel member  16  is the outer panel member and the second panel member  18  is the inner panel member.  FIG. 3A  shows the panel assemblies  12  having an arrangement where the first panel member  16  is the inner panel member and the second panel member  18  is the outer panel member. In both instances, the panel assemblies  12  are connected using an interior angle member  102 , an exterior bracket  104 , and a corner flashing  106 . 
     The interior angle member  102  is L-shaped in cross section and extends generally from the bottom edge margins of the corner panel assemblies  12  to the top edge margins of the panel assemblies. The interior angle member  102  has a first leg  103  that extends along the front portion  52  of a second panel member  18  of a first corner panel assembly  12 , and a second leg  105  that extends generally perpendicular from the first leg along the front portion  52  of a second panel member  18  of an abutting second corner panel assembly  12 . The legs  103 ,  105  of the interior angle member  102  are screwed into the panel members  18  using screws  108 . Caulk (not shown) may be provided between the first angle  102  and the second panel members  18  preventing metal-to-metal contact between the interior angle member  102  and second panel members  18 , and helping to form an air tight seal along the corner. 
     The exterior bracket  104  extends generally from the bottom edge margins of the corner panel assemblies  12  to the top edge margins of the panel assemblies. The exterior bracket  104  is generally channel-shaped, including a first section  110  that extends along the first side portions  32 ,  62  of the first and second panel members  16 ,  18  of the first corner panel assembly  12 , and a second section  112  that extends generally perpendicular from the first section along the second side portions  34 ,  64  of the first and second panel members  16 ,  18  of the abutting second corner panel assembly  12 . Gaskets  113  are disposed between the first section  110  and the first side portions  32 ,  62  of the first corner panel assembly  12 , and between the second section  112  and the second side portions  34 ,  64  of the second corner panel assembly  12  to prevent metal-to-metal contact thus providing a thermal break between the exterior bracket  104  and the panel assemblies  12 . In the arrangement in  FIG. 3 , the first section  110  of the exterior bracket  104  is screwed into the first side portion  32  of the first panel member  16  of the first corner panel assembly  12  using screws  108 , and the second section  112  of the exterior bracket is screwed into the second side portion  64  of the second panel member  18  of the second corner panel assembly  12  using screws  108 . The interior angle member  102  and exterior bracket  104  extending substantially the full heights of the panel assemblies  12 . The interior angle member  102  and exterior bracket  104  are connected to the respective first and second corner panel assemblies by screws  108  at intervals along the height. 
     In the  FIG. 3A  arrangement, the first section  110  of the exterior bracket  104  is screwed into the first side portion  62  of the second panel member  18  of the first corner panel assembly  12  using screws  108 , and the second section  112  of the exterior bracket is screwed into the second side portion  64  of the second panel member  18  of the second corner panel assembly  12  using screws  108 . In both the  FIGS. 3 and 3A  arrangements, a first flange  114  extends generally perpendicular from the first section  110  of the exterior bracket  104  away from the first corner panel assembly  12 , and a second flange  116  extends generally perpendicular from the second section  112  of the exterior bracket toward the second corner panel assembly  12 . In the  FIG. 3  arrangement, the second flange  116  extends along the outer surface  24  of the front portion  22  of the first panel member  16  of the second corner panel assembly  12 . In the  FIG. 3A  arrangement, the second flange  116  extends along the outer surface  54  of the front portion  52  of the second panel member  18  of the second corner panel assembly  12 . The first and second flanges  114 ,  116  strengthen the exterior bracket  104  against bending about axes perpendicular to its length. 
     The corner flashing  106  extends generally from the bottom edge margins of the corner panel assemblies  12  to the top edge margins of the panel assemblies. The flashing  106  includes a first section  118  attached to the first corner panel assembly  12  using screws  108 , and a second section  120  extending generally perpendicular from the first section toward the second corner panel assembly  12 . The second section  120  is attached to the second corner panel assembly using screws  108 . A first flange  122  is bent from the first section  118  and extends generally parallel to the first section. A second flange  124  is bent from the second section  120  and extends generally parallel to the second sections. The screws  108  attaching the first and second sections  118 ,  120  to the panel assemblies  112  extend through both the first and second sections and the first and second flanges  122 ,  124 . The first and second flanges help to prevent enlargement of or tearing of the flashing  106  at the hole formed by the screw. 
     In the  FIG. 3  arrangement, the first section  118  and first flange  122  are attached to the outer surface  24  of the front portion  22  of the first panel member  16  of the first corner panel assembly  12  using screws  108 , and the second section  120  and second flange  124  are attached to the outer surface  24  of the front portion  22  of the first panel member  16  of the second corner panel assembly  12  using screws  108 . In the  FIG. 3A  arrangement, the first section  118  and first flange  122  are attached to the outer surface  54  of the front portion  52  of the second panel member  18  of the first corner panel assembly  12  using screws  108 , and the second section  120  and second flange  124  are attached to the outer surface  54  of the front portion  52  of the second panel member  18  of the second corner panel assembly  12  using screws  108 . In one embodiment, the flashing  106  is not applied until after the enclosure  10  is constructed. The flashing  106  may be made out of any suitable material, such as extruded aluminum that provides an aesthetically pleasing appearance. 
     The assembled first and second panel assemblies  12  can be lifted up onto the base  13  of the enclosure  10 . Referring to  FIG. 5 , each of the panel assemblies  12  is received on a top wall of a respective one of the framing channels  14  of the base  13 . The panel assembly  12  is received between the angle iron  14 A and the lip  15 A of the floor  15  and is thereby located on the base  13 . The connection is further secured by drilling screws through the lip  15 A and into the panel assembly  12 . Although not shown, screws may be drilled through the angle iron  14 A and into the panel assembly  12  from the exterior to further secure the panel assembly to the base  13 . Prior to placing the first and second panel assemblies  12  on the base, a gasket  125  is laid down on the top wall of the framing channel  14 . The gasket  125  provides a thermal break between the panel assembly  12  and the framing channel  14 . Also, caulk (not shown) may be applied between the lip  15 A and the panel assembly  12  to inhibit heat transfer from the floor. 
     Once the first and second corner panel assemblies  12  forming one corner of the enclosure  10  are mounted on the base  13 , side walls of the enclosure can be formed using other panel assemblies  12  of the same construction. It will be understood that other corners of the enclosure  10  could be formed in the same way and mounted on the base  10  prior to forming the side walls. The precise order of construction can be varied from what is described herein within the scope of the present invention. Formation of the side walls of the enclosure  10  can be carried out rapidly. A thermally insulating slat  80  can be inserted into the slot  90  of the second panel assembly  12  at the upper left hand corner of the enclosure being formed. A third panel assembly  12  can be placed on the base  13  so that a projecting portion of the slat  80  is received in the slot  90  of that panel assembly. The bottom of the third panel assembly  12  is received in the space between the angle iron  14 A and the lip  15 A of the floor  15  and secured with screws  108 . There is no direct fixed attachment (e.g., as by fasteners or welding) of the third panel assembly  12  to the second panel assembly. The slat  80  has sufficient strength to hold them in plane with each other as the construction continues. 
     It will be appreciated that construction of the side wall of the enclosure  10  may continue rapidly.  FIGS. 4 and 4A  illustrate the connections between the third and a fourth side wall panel assembly  12 .  FIG. 4  shows the third and fourth panel assemblies  12  having an arrangement where the first panel member  16  is the outer panel member and the second panel member  18  is the inner panel member.  FIG. 4A  shows the panel assemblies  12  turned around, where the first panel member  16  is the inner panel member and the second panel member  18  is the outer panel member. The adjacent panel assemblies  12  are attached using another one of the thermally insulated slats  80  that extends between the edge surfaces of the adjacent panel assemblies. In the same way the second and third panel assemblies  12  where connected, another thermally insulating slat  80  is inserted into the slot  90  along the vertical edge of the third panel assembly  12 . Caulk  92  is applied to the fourth panel assembly on opposite sides of the slat  80 . As shown in  FIG. 4 , caulk  92  is applied to the side portion  32  of the first panel member  16  and to the side portion  62  of the second panel member  18 . The fourth panel assembly  12  is placed on the base  13  so that the projecting portion of the slat  80  is received in the slot  90  of the fourth panel assembly. The caulk  92  is compressed between the third and fourth panel assemblies and forms a seal. The slat  80  extending between the third and fourth panel assemblies  12  also helps to block air flow. The fourth panel assembly  12  can be attached to the angle iron  14 A and lip  15 A of the floor  15  in the same way as the third panel assembly using screws  108 . 
     Any number of panel assemblies  12  may be connected together in the same fashion to produce a side wall of a desired length for an enclosure. In the illustrated embodiment, the fourth panel assembly  12  is connected to panel assemblies forming another corner of the enclosure  10 , for example the lower left hand corner as shown in  FIG. 2 . Each corner may be formed of two panel assemblies  12  at right angles to each other, in the same way as described above for the first and second corner panel assemblies. After or prior to completion of all side walls of the enclosure  10 , a roof may be assembled and attached to the side walls. Referring now to  FIGS. 6 and 6A , the roof may be assembled from panel assemblies  12  of the same construction or a different construction. As shown in  FIGS. 1 and 6  panel assemblies  12 ′ that are shorter in length than the panel assemblies  12 . The panel assemblies  12 ′ are otherwise of the same construction as the panel assemblies  12 . Corresponding parts of the panel assemblies  12 ′ will be given the same reference numerals with the addition of a prime. 
     The panel assemblies  12 ′ can be laid on top of the side walls formed by panel assemblies  12 . Adjacent panel assemblies  12 ′ can be connected to each other using a thermally insulating slat (not shown), but having the same construction as the thermally insulating slat  80 , only shorter in length. Connection of the roof to the panel assemblies  12  of the side walls can be made using an interior angle  142  and an exterior bracket  144  which are substantially the same as the angle  102  and bracket  104  used to make the corner connection between the first and second panel assemblies  12 . Gaskets  113  are placed between the bracket  144  and the panel assemblies  12 ,  12 ′. A flashing  146  substantially identical to flashing  106  can be placed over the exterior bracket  144  when the connection is complete. Thus, the same components can be used to make the roof connection as were used to make the corner connections.  FIG. 6A  illustrates the roof connection when each of the panel assemblies  12 ′ is inverted from the configuration shown in  FIG. 6 . 
     By using the thermally insulating slats  80  to connect the panel assemblies  12 , screws are not required to attach the internal side panel assemblies  12  together. This provides a smooth outer surface for the enclosure  10  which facilitates cleaning of the enclosure. A smooth outer surface may also provide an aesthetic benefit to the enclosure  10 . In addition to applications for HVAC equipment, the enclosure  10  can also be used in other applications such as large walk-in coolers and freezers, in part because of the connection between the panel assemblies  12 . 
     In some instances, the air pressure differential between the interior and exterior of the enclosure  10  will require additional reinforcement and interconnection between the adjacent panel assemblies  12 ,  12 ′. Referring to  FIGS. 16 and 16A , a reinforced connection between adjacent side wall panel assemblies  12  is shown. In this embodiment, a bracket assembly  130  secures the panel assemblies  12  together. The bracket assembly  130  comprises a first bracket  132  attached to the third panel assembly  12  by screws  108 , a second bracket  134  attached to the adjacent fourth panel assembly  12  by screws  108 , and a tie bolt  136  and nut  137  configured to secure the brackets together thereby securing the panel assemblies  12  together. Each bracket  132 ,  134  comprises a channel shaped member including a base  138  and opposing sides  140  extending from ends of the base. Flanges  139  extend from the opposing sides  140  and are generally parallel to the base  138 . Each flange  139  on a bracket  132 ,  134  extends in the same direction. In the arrangement shown in  FIG. 16 , screws  108  extend through the flanges  139  to attach the brackets  132 ,  134  to the front portions  22  of the first panel members  16  of the panel assemblies  12 . An elongate tie sheet  142  extends along a junction between the panel assemblies  12  at the second panel members  18 . Screws  108  attach the tie sheet  142  to the front portions  52  of the second panel members  18  of the panel assemblies  12 . The screws  108  further pass into respective ones of the stiffeners  94 . 
     In the arrangement shown in  FIG. 16A , the panel assemblies  12  are inverted so screws  108  extend through the flanges  139  to attach the brackets  132 ,  134  to the front portions  52  of the second panel members  18  of the panel assemblies  12 . In the configuration of  FIG. 16A , the screws  108  attaching the brackets  132 ,  134  pass into and connect with the stiffeners  94 . The tie sheet  142  extends along a junction between the panel assemblies  12  at the first panel members  16 . Screws  108  attach the tie sheet  142  to the front portions  22  of the first panel members  16  of the panel assemblies  12 . The brackets  132  and  134  may be attached to the panel assemblies  12  at the factory. The tie bolt  136  and nut  137  can be applied in the field to connect the brackets  132 ,  134  together. During installation of the enclosure  10  in the field, the tie bolt  136  and nut  137  can be tightened to fully secure the panel assemblies together. 
     Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. 
     When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
     In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. 
     As various changes could be made in the above products without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.