Roof assembly for an air handler

An air handler (or air handler section) includes an enclosure containing various internal HVAC components and a bi-directional alignment system that during factor assembly of the enclosure helps align the enclosure's entire roof to the internal components. To help align the roof in a widthwise direction, a tapered lead-in edge in the upper corners of a block-off panel for an evaporator, filter rack, damper, fan and/or other HVAC component engages a roof rail that runs along the length of the roof. The upper corners of the block-offs also include a landing edge that engages the underside of the roof rail to help support the weight of the roof. Cross rails attached to the underside of the roof and extending along the width of the enclosure include an inclined lead-in flange that engages the upper edge of the various internal HVAC components, thereby helping align the roof in a lengthwise direction.

FIELD OF THE INVENTION

The subject invention generally pertains to refrigerant air handling systems and more specifically to a roof assembly for such a system.

BACKGROUND OF RELATED ART

Air handlers or the air handler section of an air conditioning unit for meeting the HVAC (heating, ventilating and air conditioning) needs of a building often comprise a refrigerant or other fluid based system housed within a sheet metal enclosure. The refrigerant system may include one or more compressors, a condenser, an evaporator, fans, filters, dampers, and various other equipment. When serving a large commercial, institutional or industrial building, it is not unusual for an air handler to have an enclosure that is over thirty feet long, twelve feet wide, and eight feet tall.

Such large enclosures can be difficult to assemble in the factory. Installing the massive roof in proper alignment with all the various components inside the enclosure can be particularly challenging, time consuming and potentially hazardous. Fitting the roof to the components underneath it usually involves the use of relatively large, cumbersome fixtures, braces, lifting devices, and multiple workers to assure alignment and fit up. Due to the height of the enclosure, it is also difficult to ergonomically secure the internal components in place and assure proper sealing.

Consequently, there is a need for large air handler enclosures that are quicker, easier and safer to assemble.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an enclosure for an air handler with alignment features that help guide an entire roof onto various components underneath the roof.

Another object of some embodiments is to provide alignment features that help align the roof in two dimensions, lengthwise and widthwise.

Another object of some embodiments is to incorporate a tapered lead-in edge in the upper corners of a block-off for an evaporator, filter rack, damper, fan and/or other HVAC equipment so that the lead-in edge engages a roof rail to help align the roof in a widthwise direction.

Another object of some embodiments is to fasten cross rails to the underside of the roof, wherein the cross rails include an inclined lead-in flange that engages the upper edge of various internal HVAC equipment, thus helping align the roof in a lengthwise direction.

Another object of some embodiments is to install a gasket that not only provides sealing between the underside of the roof and the upper surface of a block-off but also helps fill a generally triangular gap created by the tapered lead-in edge of the block-off.

Another object of some embodiments is to provide lateral structural support for internal components, wherein the cross rails include a vertical flange that mates to various internal components thus reducing the need for mechanical fasteners.

Another object of some embodiments is to provide some vertical clearance between an upper surface of an internal panel and the underside of a roof, thereby providing some vertical “float” between the internal panel and the roof.

One or more of these and/or other objects of the invention are provided by an air handler comprising an enclosure that contains various HVAC components and bi-directional alignment features. During factory assembly, the alignment features help align the enclosure roof to the components in both lengthwise and widthwise directions.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1-6illustrate a novel roof assembly10for an air handler12. An air handler is defined herein as any apparatus comprising a roofed enclosure containing various components for providing heated, cooled, or otherwise conditioned air to a room, area or comfort zone of a building. Although the subject invention is being described with reference to the example air handler schematically illustrated inFIG. 2, it should be understood by those of ordinary skill in the art that the invention is readily applicable to various other air handlers having different components with different structural arrangements.

For the illustrated example, air handler12comprises one or more compressors14for providing compressed refrigerant, a condenser coil heat exchanger16for condensing the compressed refrigerant from compressors14, one or more fans18for cooling condenser16, an evaporator coil heat exchanger20(or some other type of heat exchanger containing a fluid) for providing a cooling effect caused by refrigerant expanding as a flow restriction (not shown) conveys the fluid from condenser16to evaporator20, a supply fan22that forces air through evaporator20to produce cool air that can be supplied to a comfort zone via a supply air outlet24, a filter rack26holding one or more elements for filtering air prior to passing through evaporator20, a fresh air inlet28for receiving outdoor air, a return air inlet30for receiving return air from the comfort zone, a damper32for creating a certain mixture of return air and outdoor air, and an exhaust fan34for discharging a portion of return air.

Many of the aforementioned components of air handler12are housed within an enclosure36comprising a base38, a plurality of side panels40, an end wall42, a bulkhead wall44, and a roof46. Enclosure36has an overall length48, a width50(FIG. 6), and a height52.

Since the active area of some or all of the air handler's internal components might not extend the full width or height of enclosure36, to prevent airflow from bypassing those components, an internal panel or block-off can be added along the outer periphery of the components. For the illustrated example, evaporator20includes block-off extension20′, damper32includes block-off extension32′, filter rack26includes block-off extension26′, and fan22includes block-off extension22′ (also known as a fan board). In some cases, an internal panel or block-off can simply serve as a standalone divider in an enclosure and not necessarily be connected to any active component.

It would not be unusual for an air handler to be thirty feet long, twelve feet wide, and eight feet tall. A unit of such size can be difficult to assemble. Installing the roof in proper alignment with all the various internal HVAC components can be particularly challenging. To address this problem, air handler12includes two alignment features that ensure the assembly is properly aligned along both the length48and width50of enclosure36.

To align the internal components to roof46along length48, a plurality of cross rails54are attached to the underside of roof46. Cross rails54are elongate along the width50of air handler12but do not necessarily extend the full width. Cross rails54are shown running perpendicular to length48; however, rails54could also lie at some other angle. Each rail54includes a lead-in flange56that lies at an incline to help guide roof46onto a component. Referring toFIGS. 3 and 4, for instance, a first cross rail54awith a first lead-in flange56aand a second cross rail54bwith a second lead-in flange56bhelp align block-off extension20′ of evaporator20between rails54aand54b. Upon lowering roof46into position, a relatively thick foam gasket58becomes compressed between block-off extension20′ and the underside of roof46. In some cases, gasket58has an uncompressed thickness60(FIG. 5) of about one inch.

To assist alignment in a direction parallel to width50, each internal panel or block-off includes a pair of upper corners that are beveled to help guide a roof rail62of roof46into position. InFIGS. 5 and 6, for instance, block-off extension20′ of evaporator20includes an upper corner64with a lead-in edge66and a preferably horizontal landing edge68. Roof rail62can run partially or fully along length48and is fastened to the underside of roof46with a gasket70between rail62and roof46. As roof46is lowered onto the internal components within enclosure36, lead-in edge66helps guide roof rail62into position. When completely lowered, rail62is just above landing edge68, and roof46is just above the upper edge of the evaporator's block-off extension20′. Gasket58, which has sufficient uncompressed thickness, helps fill a generally triangular gap75defined by lead-in edge66, the inward facing surface of roof rail62, and the underside of roof46. Another gasket72can provide a seal between roof rail62and upper corner64of block-off20′. Gasket72can also provide a seal between side panel40and roof rail62. A short filler block74can help support gasket72and close off a central opening that might otherwise exists within roof rail62.

Although the invention is described with respect to a preferred embodiment, modifications thereto will be apparent to those of ordinary skill in the art. The scope of the invention, therefore, is to be determined by reference to the following claims: