PreHeat Ventilation Vs. Heat Recovery Ventilation System
A residential heat-recovery ventilator uses separate blowers to move incoming fresh and outgoing stale air. The heat-exchange core transfers heat to fresh air without mixing the airstreams. The damper automatically stops cold air for defrosting.
Energy recovery ventilation systems provide a controlled way of ventilating a home while minimizing energy loss. They reduce the costs of heating ventilated air in the winter by transferring heat from the warm inside air being exhausted to the fresh (but cold) supply air. In the summer, the inside air cools the warmer supply air to reduce ventilation cooling costs.
Most energy recovery ventilation systems can recover about 70%–80% of the energy in the exiting air and deliver that energy to the incoming air. However, they are most cost effective in climates with extreme winters or summers, and where fuel costs are high. In mild climates, the cost of the additional electricity consumed by the system fans may exceed the energy savings from not having to condition the supply air.
Heat Recovery Loss diagram