Excellent Cooling Performance, Over-sized Condenser & Evaporator Coil and slow running fan motors keeping food fresh. Our defrost timer system keeps cooling systems separate from the evaporator. It doesn’t ice up or inhibit the compressor, giving the unit outstanding performance and a longer life even in the most difficult environments.These models are designed to operate in an environment where temperature and humidity do not exceed 75°F and 65% relative humidity. Self-contained system , No plumbing required.