HVAC SYSTEM

A secondary loop HVAC system including an evaporator, a condenser, an expansion valve, and a compressor. A refrigerant loop is in fluid communication with each of the evaporator, the condenser, and the expansion valve. An HVAC case includes a first heat exchanger and a second heat exchanger. A first coolant loop is in fluid communication with the first heat exchanger, the second heat exchanger, and either the evaporator or the condenser. A valve system is configured to control flow of the coolant through the first coolant loop. In a maximum hot heating mode, the valve system is configured to direct the coolant through the condenser, the first heat exchanger, and the second heat exchanger. In a maximum cold cooling mode, the valve system is configured to direct the coolant through the evaporator, the first heat exchanger, and the second heat exchanger.