"Evaporator Coil Support Structure"

Technical Field

This invention relates generally to evaporator units for air conditioning systems and, more particularly, to apparatus for mounting an evaporator coil in an evaporator housing.

Background Art

In many air conditioning, heating and ventilating systems, conditioned air is discharged into an internal space through an air distribution or conditioning unit. For example, one general type of air conditioning system, often referred to as a split system, includes separate indoor and outdoor units.

The outdoor unit includes a compressor, a heat exchanger and a fan. The indoor unit includes a heat exchanger and a fan and is referred to as an evaporator unit. In operation, the indoor fan draws air into the evaporator unit, through an inlet thereof, and forces the air over the heat exchanger and then out of the evaporator unit, through an outlet opening therein.

The outdoor fan draws outdoor air into the outdoor unit, and circulates it over the outdoor heat exchanger and then back out to ambient. At the same time, a compressor causes a refrigeration fluid to circulate through and between the indoor/outdoor heat exchangers. At the indoor heat exchanger, the refrigerant absorbs heat from the air passing over that heat exchanger to cool the air. At the same time, at the outdoor heat exchanger, the air passing over the heat exchanger absorbs heat from the refrigerant passing therethrough.

Split type air conditioning units of this type are typically manufactured in a wide range of cooling capacities. In manufacturing such units, particularly as the units become larger, the fabrication and assembly of the various components, becomes onerous and cumbersome. Typically, the larger the unit, the more components are required and the more fasteners are required in order to assemble all of the components. It is considered extremely desirable to minimize the number of components and fasteners required in the fabrication and assembly process.

Disclosure of the Invention

An evaporator unit for an air conditioning system includes a housing having a back panel and a front section defining an air inlet and an air outlet. The housing defines an airflow path extending through the unit from the inlet to the outlet. An evaporator coil is supported in the housing and within the airflow path, and an evaporator fan causes air to flow along the airflow path and through the evaporator coil to be conditioned. The entire support for the evaporator coil is provided by a pair of side members attached to the back panel and having on their inner sides, a cavity for receiving an end of the evaporator coil. The side panels have planar surfaces to be engaged by the rear and top edges of the evaporator and a single fastener secures each side member to the evaporator coil. One planar surface of the side members forms an oblique angle with the back panel and the other planar surface is substantially normal to the one planar surface. ^" When assembled to the side panels, the evaporator coil provides structural rigidity to the unit. Associated with at least one of the planar surfaces of the side members, a notch is provided such that, during assembly, an edge of the evaporator coil can be placed in the notch so as to temporarily hold it

in place until the fasteners can be inserted.

Brief Description of the Drawings

Fig. 1 is a perspective view of an installed evaporator in accordance with one embodiment of the invention.

Fig. 2 is an exploded view thereof.

Fig. 3 is a perspective, partial view of the inner portion of the left internal side assembly.

Fig. 4 is a partial perspective view of the coil as installed in the left internal side assembly.

Fig. 5 is a sectional view as seen along lines 5-5 of Fig. 4. Fig. 6 is a partial perspective view of an inner portion of the right internal side assembly.

Fig. 7 is a perspective view of the evaporator unit of the present invention with certain components removed, for clarity.

Fig. 8 is a sectional view as seen along line 8-8 of Fig. 7. Fig. 9 is a sectional view as seen along lines 9-9 of Fig. 7.

Detailed Description of the Invention Referring now to Fig. 1, the evaporator unit 11 is shown in one of its possible installed positions with its rear side 12 butted against a side wall. Although the same unit is adapted to be alternatively installed with its rear side 12 against the ceiling of a room, it will be described herein, in the context of installation in a vertical disposition as shown. The unit has a front side 13, a left end 14, a right end 15, a top 16 and a bottom 17.

In operation, the unit includes a blower to draw air in from the room by way of an inlet opening 18, with the air then being passed through a heat exchanger coil and then discharged from the unit by way of a discharge opening 19.

Referring to Fig. 2, the evaporator unit is shown in an exploded view to include all the various components prior to assembly. The sequences and manner of assembly will now be described.

A back panel 21 forms the primary structural component and a portion of the housing of the evaporator unit. An upper closure assembly 22 is secured to the back panel 21 by first engaging an upper edge thereof over an upper edge of the back panel 21 and then securing the two components together with fasteners 23. The left and right internal side assemblies, 24 and 26 are attached to the back panel 21 by fasteners. The fan assembly 27 is then secured to the lower portion of the back panel 21 by fasteners 28.

The next step in the assembly process is to install the evaporator coil 29 into the housing by placing its ends in the respective left and right internal side assemblies 24 and 26. The evaporator coil 29 is then secured in its installed position by a single screw at each end thereof which passes through the internal side assembly and into a tube sheet at the end of the evaporator coil 29. The evaporator coil 29 is so disposed within the evaporator compartment, which is partially defined by the back panel 21 and the left and right internal side assemblies 24 and 26. However, it is still necessary to close the ends of the evaporator compartment to prevent the flow of air therethrough. This is

accomplished by way of left and right closure elements 31 and 32 which are simply placed in position without fasteners and then are held in place by engagement with the drain pan 33 which further defines the evaporator compartment. The drain pan 33 is secured in place by a fastener in each end to secure the respective left and right internal side assemblies 24 and 26 to the drain pan 33. A drain hose 34 is attached to a drainage element of the drain pan 33. A front panel 36 is then placed over the drain pan 33 and secured in place by fasteners, attached it to both the left and right internal side assemblies 24 and 26 and also to the fan deck portion of the back panel 21.

Returning to the sides of the unit, a control box 37 is installed by snap fit into the left internal side assembly 24 and a stepping motor 38 is also secured to the side assembly 24.

The blower compartment, which is partially formed by the lower portion of the back panel 21 and by the fan assembly 27, has an air intake opening therein. The intake opening is partially closed by way of a grill 39 into which a plurality of filter elements 41 are placed.

The next step is to connect the stepping motor 38 to a horizontal louver mechanism on the upper closure assembly 22 and the horizontal louver 42 is secured at its ends to the left and right internal side assemblies 24 and 26 and, in its intermediate portion, to the upper closure assembly 22. The left and right end caps, 43 and 44, are then secured to the respective left and right internal side assemblies 24 and 26 respectively, to complete the assembly process.

Referring now the structure for supporting the evaporator coil 29 within the unit, there is shown in Figs. 3 and 6, the respective portions of the left and right internal side assemblies 24 and 26, each of which is adapted to receive and retain one end of the evaporator coil 29. The internal side assemblies 24 and 26 are secured at their respective rear edges 46 and 47 to the back panel 21 with a closure assembly 22 also being attached to the back panel 21.

Referring to Fig. 3, the internal structure of the internal side assembly 24 is shown to include a ramp surface 48 which forms an oblique angle with the rear edge 46 and at the bottom of which is a rounded base structure 49. The base structure 49 includes a substantially horizontal surface 51 at the back of which there is formed a small notch 52. The horizontal surface 51 and the notch 52 are designed for receiving an end flange of the evaporator coil 29 as will be described hereinafter.

Near the top end of the ramp surface 48 there is provided a substantially vertical wall 53, and above that is a retainer structure 54 with a planar surface 56. The ramp surface 48, and the base structure 49, the vertical wall 53, and the planar surface 56 cooperate to form the boundary of a cavity for receiving the one end of the evaporator coil 29 therein.

The manner in which the evaporator coil is installed into the cavity

57 is shown in Figs. 4 and 5. The evaporator coil flange 58 extends substantially normally outwardly from the end as shown in Fig. 4 and rests on the ramp surface 48 with its lower end 59 sliding over the horizontal surface 51 to be engaged with the notch 52 as shown in Fig. 5. The upper end of the coil is then

captured by the vertical wall 53 and the planar surface 56. The notch 52 is not intended to be the means of securing the evaporator coil 29 in its installed position but rather holding it in that position until it can be finally secured by way of fasteners. In this manner, it is very helpful to the assembler as it temporarily holds the evaporator coil 29 in position until it can be properly secured.

At the other side of the unit, the internal side assembly 26 includes similar structure for holding the other end of the evaporator coil 29 by way of its associated flange. That is, there is provided a ramp surface 61, a horizontal surface 62, a vertical wall 63, and a retaining structure 64 and a planar surface 66 which collectively define a cavity for receiving the right end of the evaporator coil 29 therein. The primary difference from the Fig. 3 embodiment is that a notch 52 is not provided, although, such a structure may be provided if desired.

Referring now to Fig. 7, the unit is shown with evaporator coil 29 in its installed position, but without a drain pan 33 and the front panel 36 being installed. The evaporator coil 29 is secured in place by a pair of fasteners, with each one passing through the respective internal side assembly and into the tube sheet of the evaporator coil. The fastener for the right internal side assembly 26 is shown at 67. It is significant to note that when the evaporator coil 29 is so secured in its installed position, the evaporator coil 29, together with the respective left and right internal side assemblies 24 and 26, and the back panel 21 form a rigid and stable backbone of the unit.

Figs. 8 and 9 show the coil as installed in the unit as seen along lines 8-8 and 9-9 of Fig. 7, respectively.

In operation, the fan assembly 27 draws air inwardly from the room by way of the grill 39 and passes it upwardly into the heat exchanger compartment 68 to be passed through the evaporator coil 29 to be conditioned.

Conditioned air is then discharged from a discharge opening near the upper closure assembly 22.