The Friedrich FSHSR12B1C 12,000 BTU Floating Air Select Series condenser is a single zone outdoor unit. It can be used with the Friedrich FAHSW12A1C Wall Unit only. The Friedrich Floating Air Select Series Single Zone Systems feature high efficiency ratings, low ambient heating and cooling capacities. The Friedrich FSHW121C Single Zone System is rated for 12,000 BTU cooling and 12,000 BTUs heating capacity. It will operate in the cooling mode with outdoor temperatures as low as 5°F. In the heating mode, it will offer operation down to -5°F. While it cannot be used as your primary heat source in the majority of the country, it is a great option for secondary heat and in fact will heat at about 73% capacity or 8,800 BTUs when it is as cold as 17°F outside!