Auxiliary active heating and air conditioning system for motor vehicle applications

An auxiliary active heating and air conditioning system using a fuel fired heater for both heating and air conditioning a passenger area of a motor vehicle and comprising:

• a heat exchanger in the passenger area including a passage for circulating heat transfer fluid,
• a sorber cooling system located in an auxiliary heating and air conditioning module mounted to the exterior of the motor vehicle and having a refrigerant loop including an evaporator piped to deliver heat transfer fluid to the heat exchanger during air conditioning and two sorber beds, each of sufficient capacity to meet the cooling requirements of the passenger area for a predetermined interval and each having a passage for the circulation of heat transfer fluid,
• a fuel fired heater located in the auxiliary heating and air conditioning module and of sufficient capacity to desorb a single sorber bed during the predetermined interval,
• a heat transfer fluid circulatory system which selectively circulates heated heat transfer fluid from the fuel fired heater to either the heat exchanger, the first sorber bed, or the second sorber bed,
• valve means in the heat transfer fluid circulatory system for directing the heated heat transfer fluid from the fuel fired heater, the valve means being controllable between a plurality of modes including:
• a heating mode wherein the heat transfer fluid from the fuel fired heater is circulated through the heat exchanger, and
• a cooling mode wherein the heat transfer fluid from the fuel fired heater is alternately circulated at the predetermined interval to heat transfer fluid passages of the two sorber beds in order to heat one sorber bed for desorption while the other bed cools for adsorption thereby driving refrigerant in the refrigerant loop.

A method of selectively heating or air conditioning a passenger area of a motor vehicle, the motor vehicle having an engine and fuel source located on board the motor vehicle, the method comprising the steps of:

• providing an heating and air conditioning module on the vehicle external of the passenger area containing a two bed sorber cooling system and having a passenger compartment heat exchanger piped to receive conditioned heat transfer fluid from the module,
• circulating heat transfer fluid from the module to the heat exchanger for selectively heating or air conditioning the compartment,
• operating a fuel fired heater from the on-board fuel source whenever heating or air conditioning is required,
• in heating directing heated heat transfer fluid from the fuel fired heater to the passenger compartment heat exchanger,
• in air conditioning, alternately directing heated heat transfer fluid from the fuel fired heater to operate the sorber beds and thereby the sorber cooling system for air conditioning the passenger area.