Abstract: A heating, ventilation, and air conditioning (HVAC) module includes a housing and a valve. The housing defines a protruding portion that substantially conforms to a portion of an arching pathway defined by a distal end of the valve. The protruding portion may be configured so a distance between the protruding portion and the distal end may vary from more to less as the distal end moves toward where the valve is in a closed position.

Abstract: An assembly for heating, ventilating and conditioning air in an automobile including an air inlet case chamber for receiving air. The air inlet case has a recirculation air inlet for receiving recirculation air from the passenger compartment of the automobile and an ambient air inlet for receiving ambient air from outside of the automobile. The air inlets are disposed adjacent to one another. An inlet valve plate is pivotally supported between the air inlets for rotation between a recirculation position, an ambient air position, and a partial recirculation position therebetween. The assembly further includes a check valve disposed in the recirculation air inlet adjacent the inlet valve plate. The check valve allows recirculation air to flow from the passenger compartment to the air inlet case chamber and prevents air from flowing from the air inlet case chamber to the passenger compartment when the valve plate is in the partial recirculation position.

Abstract: An independent mixing valve sub-assembly which includes a casing defining a cold bias inlet, a hot bias inlet and a second zone inlet and a mechanism for mechanically attaching the casing to the housing of a HVAC module with the cold bias inlet, the hot bias inlet and the second zone inlet of the mixing valve sub-assembly in sealing engagement with a cold bias outlet, a hot bias outlet, and a second zone outlet of a HVAC module, respectively. The mixing valve sub-assembly may provide one or more streams of temperature-controlled air. Accordingly, different mixing valve sub-assemblies may be attached to one universal HVAC module to provide varying numbers of temperature zones.

Abstract: An independent mixing valve sub-assembly which includes a casing defining a cold bias inlet, a hot bias inlet and a second zone inlet and a mechanism for mechanically attaching the casing to the housing of a HVAC module with the cold bias inlet, the hot bias inlet and the second zone inlet of the mixing valve sub-assembly in sealing engagement with a cold bias outlet, a hot bias outlet, and a second zone outlet of a HVAC module, respectively. The mixing valve sub-assembly may provide one or more streams of temperature-controlled air. Accordingly, different mixing valve sub-assemblies may be attached to one universal HVAC module to provide varying numbers of temperature zones.

Abstract: A heating, ventilating, and air conditioning (HVAC) assembly for a motor vehicle includes an evaporator core for cooling air and a heater core for heating air. A heater casing of the HVAC assembly surrounds the heater core. A drain portion of the HVAC assembly extends from the heater casing and includes a partition. The partition defines two basins in the drain portion for separate drainage of evaporator condensate generated at the evaporator core and liquids from the heater core.

Abstract: The cylindrical end of the shaft of a rotating valve door in an automotive HVAC case is closely supported without either excessive clearance or binding, accommodating expected tolerance variations in the final, assembled location of the shaft end. The expected tolerance range is divided up into components along, and perpendicular to, the direction in which two housings of the case are assembled. One slot is cut into one housing along the direction of assembly, and another perpendicular thereto. When the housings are assembled, the two slots cross one another, capturing the shaft end closely on all four sides between the two pairs of slots. The closed ends of the slots have enough clearance from the nominal location of the shaft end to let the shaft end float to its final location without binding.

Abstract: A valve flapper door return spring mechanism for an automotive HVAC housing is modified so as to compensate for tolerance variations, so that the door is held in a substantially rattle free return position regardless. One of a pair of resilient spring fingers sits in a V shaped notch created by the intersection of a pair of spring finger stop surfaces that are opposed in slope. The one spring finger can therefore continually seat itself into an equilibrium position at the bottom of the V, and always make solid contact.

Abstract: The individual air temperature sensors normally mounted within each outlet duct in an automatic automotive heating and air conditioning system are eliminated in favor of a dual temperature sensor incorporated directly into the swinging mode door. The door swings back and forth through the central air mix area within the housing, and one end or the other of a dual sensor mounted through the door is always exposed to the air flow before it enters an outlet duct. This presents a better location for air sensing, and reduces or eliminates the time lag involved in temperature sensing when a different duct is selected, in addition to reducing part count.

Abstract: In a refrigeration system, an apparatus and method for providing low refrigerant charge detection before and during compressor operation. For detection before compressor operation, a very low refrigerant charge condition is indicated if the measured refrigerant pressure at the inlet of the compressor is too low based on a comparison of the measured pressure and a reference pressure related to the saturation pressure at the measured ambient temperature. If a low refrigerant charge condition is detected, the compressor may be inhibited from operating. If the system is stable with compressor non-operation, a warning also occurs. While the compressor is operating, a moderately low refrigerant charge condition is detected if the measured refrigerant temperature at the inlet of the compressor is too high based on a comparison of the measured temperature and a reference temperature related to the saturation temperature of the refrigerant for the measured refrigerant pressure.

Abstract: A receiver dehydrator for a refrigeration system for heating and cooling accommodates flow in either direction. It comprises a canister with openings near the top for coupling to refrigerant lines, and tubes inside the canister extending from the openings to tube mouths at the bottom of the canister for either intake or withdrawal of liquid. A baffle between the mouths allows liquid passage from either mouth to the other but inhibits flow of gas bubbles. The baffle has many perforations for liquid flow and an inclined vane outside each opening directs rising bubbles away from the perforations to encourage migration to the top of the canister. Alternate perforations have vanes on opposite sides of the baffle for gas-liquid separation in either flow direction. A desiccant bag between each tube mouth and the baffle further aids in such migration.

Abstract: An air pressure control system for the passenger compartment of a vehicle including an open-loop for generating an open-loop valve position command, a closed-loop for generating a closed-loop correction signal, and a valve control for positioning a valve as a combined function of the open-loop position command and the closed-loop correction command, thereby regulating the flow of air from the passenger compartment and the compartment pressure.