Low-ambient Cooling

The ability of an air conditioning unit to provide cooling even when the outdoor temperature is unusually low. Some heat pumps and AC units are designed to operate in cooling mode at low outdoor temperatures (for example, to remove humidity in the off-season). In practice, low-ambient-capable units can often start and run reliably down to 40–50°F outside, whereas standard units might have a higher minimum OAT for cool mode. This is the counterpart to “high-ambient cooling” for very hot conditions.