What is the primary function of local exhaust fans in the configuration of HRVs and ERVs?

Local exhaust fans play a crucial role in the configuration of Heat Recovery Ventilators (HRVs) and Energy Recovery Ventilators (ERVs) by facilitating the removal of indoor air pollutants while simultaneously allowing outside fresh air to enter. This process helps maintain a healthy indoor environment by ensuring that stale or contaminated air is expelled from the living spaces.

In the context of HRVs and ERVs, these ventilation systems are designed to exchange indoor and outdoor air in a way that minimizes energy loss. The local exhaust fans enhance this by directly targeting areas with high pollutant concentrations, such as kitchens and bathrooms, where moisture and odors are often generated. By effectively removing these pollutants, local exhaust fans work in tandem with HRVs and ERVs to ensure that the incoming ventilation air is of high quality, thereby improving overall indoor air quality.

Circulating heat throughout the home, increasing humidity levels, or merely filtering indoor air contaminants do not capture the primary function of local exhaust fans. While related ventilation systems may incorporate humidity control or air filtering capabilities, the most essential duty of local exhaust fans is to be proactive in expelling unwanted air and facilitating a continuous exchange that promotes a healthier indoor atmosphere.