Balanced ventilation remedies indoor air quality issues without the drawbacks of standard one-way ventilation methods. Fresh outdoor air is often in short supply in today’s tightly air-sealed, energy-efficient homes. Often, the indoor environment stagnates as fumes and airborne particulates accumulate. Exhaust-only approaches that merely pull air out of the house depressurize the premises, sucking unhealthy, non-filtered air into living spaces from zones such as the attic, crawl space or an attached garage. During winter, this also results in heat loss and increased energy costs.
The basic theory behind balanced ventilation is to exhaust stale indoor air while replacing it with an exactly equal volume of fresh outdoor air. Two systems—heat recovery ventilation (HRV) and energy recovery ventilation (ERV)—offer effective balanced alternatives to inefficient one-way ventilation.
Heat Recovery Ventilation
This system incorporates a smart central blower unit connected to small-diameter dedicated ductwork. The blower draws in a selected volume of fresh outdoor air, efficiently filtered as it passes through the central unit. This fresh filtered air is distributed throughout the living spaces by dedicated ductwork. At the same time, the central unit exhausts an exactly equal volume of stale indoor air into the outdoors. Equalizing the intake/exhaust air volume prevents depressurization issues that are a drawback of one-way ventilation systems.
What About Temperature Control?
To avoid destabilizing indoor temperatures, the HRV also incorporates a heat exchanger in the central unit. In winter, it extracts heat from the outgoing exhaust air and adds it to the colder incoming stream to prevent heat loss from the home. During summer, the effect reverses so heat is removed from incoming air and added to the stream of exhaust air.
Energy Recovery Ventilation
An energy recovery ventilator (ERV) also adds indoor humidity control to the standard features of an HRV. The unit extracts humidity from the incoming air stream and adds it to the flow of exhaust air. This prevents humidity gain during summer and enhances indoor comfort while also effectively ventilating the house.
For more information about the health and comfort benefits of balanced ventilation, contact Beyer Boys.