Mainstream’s 5-tonR RECU is the latest in ultra-efficient, military-ready, ducted, unitary, heat pump systems. It provides heating, ventilation, and air conditioning to USAF BEAR Base shelters. The RECU is compatible with NBC filter/blower equipment and is certified to operate with Collective Protection (ColPro) equipment in a chemical, biological, radiological, and nuclear (CBRN) environment. The RECU also includes compressor soft-start technology and microprocessor-based embedded diagnostics/prognostics. These units were designed to replace the FDECU, LECU, and the IECU while improving performance, reducing weight, simplifying maintenance, and increasing reliability. Optional wye ducts are available, allowing one RECU to cool two shelters.