BROAD ERV Fresh Air series are designed for the general public who pursue better and healthy living quality. Anyone who lives in a house and desire fresher indoor air quality are encouraged to purchase. Furthermore, the series is aim to help people who are more fragile to the changing and uncontrolled air quality, including but not limited to, infants and toddlers, senior citizens, respiratory patients, and whoever are sensitive to seasonal allergies, dust and smoke.This series is expected to lower the energy cost in the long term. Without opening windows, people can enjoy fresher, cleaner and 99.9% filtered healthier air all the time.