The Adirondack-Aire HCA series zerOzone replacement chassis provides environment friendly, high efficiency cooling and heating where individual, quiet control is a priority. This application flexible unit is also a direct replacement for Singer/McQuay HC, EH (models 070, 090, 120, 140, 180, and 240) series vertical stacked water source heat pump chassis. The chassis is a part of a complete system, which consists of the chassis, blower section, control box, and furred-in room cabinet with risers. The chassis contains the compressor, air side heat exchanger, water side heat exchanger, and refrigerant circuit control and safety components.