Energy recovery in laboratories has some special concerns because of the possibility of cross contamination between the supply and exhaust streams. This article illustrates two methods of improving energy recovery in laboratory air-handling systems (with 100% outside air), where fume hoods and similar exhaust are considered to be hazardous (as defined by the International Mechanical Code [IMC]) and the energy recovery system is designed to preclude the possibility of cross-contamination between supply and exhaust. With both methods of recovery, the air-handling system supplies air at a neutral air temperature using dual energy recovery.