Abstract: An access door to an air handler unit is provided, having a double seal set in the door frame. The double seal is composed of an outer seal which provides a moisture barrier, having an aperture to permit air to pass through, and an inner seal which provides an air barrier. The inner and outer seal are spaced apart to provide an air gap therebetween. A lip is provided along the side and top of the door to shed water away from the outer seal. The door is hingedly supported in the frame, where the outer surface of the door comes in sealing contact with the outer seal and the inner surface of the door comes in sealing contact with the inner seal when the door is closed. A set of door handles is provided to lock the seals in place when the door is closed and latched properly.

Abstract: A plate fin heat exchanger is made such that the distance between the trailing edge of its plate fins and the nearest row of tube openings is substantially greater than the distance between the leading edge and its tube openings, thereby reducing the occurrence of condensate carry-over into the airflow stream.

Abstract: A lead screw is coated with Teflon to protect the screw from a high humidity atmosphere and to eliminate the need for lubricants which would tend to collect corrosion products and form a grinding compound. A nylon nut is used in combination with the Teflon coated screw since the nylon deforms to load all of the threads whereby the Teflon coating is not peeled off.

Abstract: The belt of a variable speed fan drive is replaced without the use of tools. The high speed limit switch is bypassed and an override connection switch striker is provided which permits further movement of the motor base beyond the high speed limit when the high speed limit switch is bypassed.

Abstract: A vapor compression refrigeration system comprising a condenser including a plurality of generally parallel heat exchange fins and a plurality of refrigerant circuits running through the condenser generally transverse to the heat exchange fin, wherein groups of the refrigerant circuits cover in overlapping fashion the area of the condenser transverse to the direction of the flow of an external heat exchange medium moving thereover.

Abstract: A fan assembly including a fan scroll having a discharge opening. The relative position of the opening may be altered from one unit to the next to direct the air in a desired direction. The fan shaft is mounted off-center relative to the center of the side walls of the fan assembly housing. The position of the fan shaft is varied about the circumference of an imaginary circle in accordance with the position of the discharge opening. The center of the imaginary circle is coincident with the center of the side walls.