The COOL-15 is a mobile, Diesel-Electric, air conditioning unit designed to cool or, when equipped, heat an aircraft to obtain the adequate temperature in the cockpit and cabin during pre-flight operations, boarding and maintenance. It has sufficient cooling power for narrow body aircraft (B and C types) and meets the needs and requirements of civil aircraft in continental, tropical or desert climates. The COOL-15 is built with top-of-the-line material, resulting in extremely low maintenance requirements during its lifetime. The main features of this unit are high efficiency, smart equipment, compactness, and simplicity.