Abstract: An integrated air exchanger (10) is disclosed for controlling the volume and temperature of air exchanged between an external environment (14) and a supplied environment (16). In that regard, a relatively simple crossed damper (72) controls air introduced to the air exchanger along an external air path (18) and return air path (20) to be returned to the supplied environment in an external environment through a supply air path (24) and exhaust air path (22) in a controlled relationship. A supply coil (56) is included to effect heat transfer to the air provided to the supplied environment. A system controller (70) controls a heat source (60), compressor (62), valves (64 and 66) and the damper to achieve the desired temperature and air direction. Exchangers (134 and 178) are also disclosed for use in satisfying the heating, ventilation, and cooling demands of a plurality of different environments.