Plumbed thermal energy storage system

Thermal energy storage for a vehicle compartment which comprises:

• a first coolant loop comprising an engine and a heater coil with hot coolant supplied from the engine to the heater coil to provide positive thermal potential to the heater coil;
• a main air conditioning loop comprising a compressor, a condenser, a refrigerant receiver, a metering device, an evaporator, and first means to interrupt refrigerant flow to the evaporator and arranged to provide negative thermal potential to the evaporator;
• a vehicle air supply duct and a blower, the duct having an inlet and outlet, the heater coil and the evaporator both located in the duct;
• thermal energy storage means comprising an enclosed volume of thermal storage medium to store at least one of negative thermal potential and positive thermal potential;
• a refrigerant direct expansion coil to deliver to the thermal storage medium negative thermal potential during a negative thermal potential charging cycle;
• a coolant coil to deliver to the thermal storage medium positive thermal potential during a positive thermal potential charging cycle;
• a supplemental fan arranged to flow air to recover thermal potential from the thermal energy storage means to condition the air, and to return the conditioned air to the compartment during a thermal potential discharging cycle;
• a supplemental refrigerant loop comprising said refrigerant direct expansion coil in direct contact with the thermal storage medium to provide negative thermal potential to the thermal storage medium, the supplemental refrigerant loop arranged in communication with the compressor, the condenser, and the refrigerant receiver of the main air conditioning loop to supply refrigerant flow to the direct expansion coil and second means to interrupt this flow to the direct expansion coil;
• a second coolant loop for providing hot coolant flow to the thermal storage medium, the second coolant loop comprising third means to interrupt hot coolant supply to the second coolant loop, the third means arranged for fluid communication with the first coolant loop;
• an air conditioning first control means for activating the compressor and the first means;
• and,
• a control system to select one of the negative thermal potential charging cycle and activate the compressor and the second means to store negative thermal potential, and the positive thermal potential charging cycle and activate the third means in the second coolant loop to store positive thermal potential, and to deactivate both the second and third means when not in a thermal potential charging cycle,
• the control system controlling the flow of refrigerant through the supplemental refrigerant loop to permit flow of refrigerant through the refrigerant direct expansion coil and the resulting storage of negative thermal potential in the thermal storage medium without regard to whether the control system is permitting coolant flow through the heater coil to heat the vehicle compartment, and the control system controlling the flow of coolant through the coolant coil to permit storage of positive thermal potential in the thermal storage medium without regard to whether the control system is permitting coolant flow through the heater coil and the resulting heating of the vehicle compartment and without regard to whether the control system is permitting refrigerant flow through the main air conditioning loop to remove heat from the vehicle compartment,
• the control system controlling operation of the supplemental fan to flow air to recover thermal potential from the thermal energy storage means to condition the air, and to return the conditioned air to the compartment during a thermal potential discharging cycle without regard to the status of the blower.