An HVAC gas pack is a heating and cooling system with the heat pump and the air conditioner housed together in a single unit. HVAC gas packs use propane, natural gas or oil for heating purposes, and for cooling purposes, it uses electricity.
HVAC gas packs are simple to maintain in comparison to other systems and repairs are generally cost effective. Other types of HVAC systems include heat pump and duel fuel units. Duel fuel units feature a coil and electric heat pump connected to a gas furnace, and an outdoor thermostat helps the system decide which device to run.