Extra-low-temperature Heating

A feature (often in cold-climate heat pumps or mini-splits) that allows reliable heating at very low outdoor temperatures. Units labeled for extra-low-temperature heating (sometimes called XLTH) are engineered to operate in conditions as cold as -15°F (-26°C) or lower. This usually involves advanced components (like a basepan heater and enhanced refrigeration circuitry) so that the heat pump can provide full heating capacity even in freezing weather, extending the usable range of the unit.