Abstract: A wrapped fin heat exchanger having a plurality of circuits is disclosed. A bottom circuit of the wrapped fin heat exchanger is arranged in multiple rows and has circuiting to provide hot gaseous refrigerant to the areas of highest frost concentration during operation in the defrost mode. The circuiting allows for hot gaseous refrigerant to enter the inner loop and then flow downwardly to the bottom of the coil where the highest frost accumulation is concentrated. Refrigerant then flows upwardly through the outer row of the coil to an intermediate transition loop. The refrigerant then flows upwardly through the inner row and then back to the outer row and downwardly to an inner stop loop before being connected to the header. Hence, by circuiting the heat exchanger in the appropriate configuration it is possible to achieve the optimal frost melting and heat transfer arrangement.

Abstract: Apparatus for use in a heat exchange unit for securing a heat exchanger assembly to the remaining components of the unit. A pin which acts to secure a tubular member and a lateral support to either a fan assembly or a base pan is disclosed. This pin has an insertion portion having pin teeth which is inserted into a tube for securing the pin to the tube, a spacer portion for locating in a fixed relationship a lateral support relative to the heat exchange unit and a top portion for securing the pin to the component to which it is being fastened.

Abstract: Method of assembly of a heat exchange unit wherein an annular orifice having a U-shaped cross section is assembled to a heat exchange assembly. The grille of the unit is supported on a support ledge of the fan orifice. An annular top cover having an L-shaped cross section may be engaged to the fan orifice to define a control area space therebetween. The top cover engages a top cover support ledge of the fan orifice and the grille engages a grille support ledge of the fan orifice to form a subassembly.

Abstract: Apparatus and method of assembly of a heat exchange unit wherein an annular orifice having a U-shaped cross section is assembled to a heat exchange assembly. The grille of the unit is supported on a support ledge of the fan orifice. An annular top cover having an L-shaped cross section may be engaged to the fan orifice to define a control area space therebetween. The top cover engages a top cover support ledge of the fan orifice and the grille engages a grille support ledge of the fan orifice to form a subassembly.

Abstract: Apparatus and a method for controlling refrigerant flow through the indoor coil of air conditioning equipment including a refrigeration system such that upon predetermined humidity conditions being sensed refrigerant flow will be routed to provide additional latent cooling and dehumidification. Within the liquid header of the indoor coil in the refrigeration system a solenoid valve is mounted to isolate at least one of a plurality of refrigerant circuits. This valve is closed when a need for dehumidification is detected by a humidistat located in communication with the air of the enclosure to be conditioned. When a need for dehumidification is not detected by the humidistat the valve is opened and refrigerant flows through all of the circuits of the indoor coil. Additionally, a check valve is mounted in parallel with the solenoid valve such that if a reversible refrigeration system is utilized refrigerant flow can bypass the solenoid valve in the heating mode of operation.