States that for installations requiring a high percentage of outside air for ventilation, the energy consumption to cool and heat the outside air, especially in cold winter and hot summer climates, is usually very high. These requirements often foster high humidity problems, especially at part-load conditions in hot and humid areas. To reduce ventilation-based energy consumption, heat recovery systems such as heat wheels, air-to-air heat exchangers, heat pipes or runaround coil systems can be used to recover heat from exhaust systems. Uses a 1,000ft² (93m²) smoking room located in the interior space of a building as a model to explain the process and to compare the cooling and reheat loads of dehumidifying with reheat system (no heat recovery coil), runaround loop heat recovery system (two coils in the runaround loop) and a runaround loop heat recovery/dehumidification system (three coils in the runaround loop). Sets out the design parameters in a table. Supplies a yearly energy comparison of the systems and draws conclusions.