The EV1 was designed to be a clean, "green" car in every way. So, when considering which heating and ventilation unit to use, its engineers wondered: Why not take a heat pump and put it in the car?
Like the one used in some homes, the EV1’s heat pump system functions as either a heater or an air conditioner, depending on your needs. When heat is required, outside air goes through the radiator and the heat exchanger, which transfers the heat to the passenger compartment. As an air conditioner, it reverses that process — removing heat from the air entering the passenger compartment and transferring it to the air passing through the radiator. Since it is transferring heat, this system is capable of putting about twice the heat energy into the air going into the passenger compartment as it uses in battery energy to run itself. It provides good cooling and heating capacity just like a traditional HVAC system, but consumes only 1/3 the energy. And it uses only ozone-friendly, CFC-free R134A air conditioning refrigerant.
To optimize cabin temperature on cooler days, an electric heater works with the heat pump to warm the passenger compartment.
For Gen II, a thermal management system was added to the EV1 to accommodate the new, advanced battery technologies. This system cools or warms the pack as necessary for optimal performance of the vehicle, battery and charger.
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