Mainstream’s MECU is designed to provide cooling, heating and ventilation to the Tent Extendable Modular Personnel (TEMPER), Modular General Purpose Tent System (MGPTS) or CP EMEDS shelters. A single MECU has sufficient capacity to provide thermal control to shelters as large as 1,000 square feet in ambient temperatures as high as 130°F or as low as – 40°F. The MECU allows for air plenum configuration and installation requirements without bends in the supply or return ducts. The MECU has been designed to replace both the FDECU, LECU and the IECU with a smaller cube, improved performance, reduced weight, improved power-factor and improved maintenance/reliability.