Desiccant Wheel Heat Recovery Unit | HVAC Energy Efficiency
This is a desiccant wheel in a heat recovery unit. Mainly used in HVAC commercial applications where codes require a specified amount of fresh air for buildings. The old way was to pull the unconditioned fresh air and then condition the air using the mechanical equipment installed in the building. Using a heat recovery wheel will save energy by conditioning the air before it is introduced into the building and the mechanical equipment used to condition the air inside the building. Exhaust air flows through the desiccant wheel one way while fresh outside air flows through the wheel going the other way. The exhaust, while containing conditioned air, transfers energy to the wheel. The wheel turns slowly and the incoming outside air absorbs this energy or conditioned air. In the summer, the wheel reduces the humidity and temperature of the incoming outside air while in the winter increases the temperature of the incoming outside air.