The definition of a HVAC cooler is a system that is used to cool the air in a building or home. It is typically composed of an air conditioner, a furnace, and a fan. The air conditioner is used to cool the air by removing heat from the air and transferring it outside. The furnace is used to heat the air by transferring heat from the air outside into the air inside. The fan is used to circulate the air throughout the building or home. HVAC coolers are designed to maintain a comfortable temperature in the building or home and can be used in both residential and commercial settings. They are also energy efficient, helping to reduce energy costs. HVAC coolers are a great way to keep your home or business comfortable and energy efficient.