Balanced home ventilation won't happen by itself. Most houses today are tightly sealed to minimize air exchange with the outdoors and maximize energy efficiency. Simply installing spot exhaust fans or opening a window here and there doesn’t get the job done. For optimum cooling and heating performance and efficiency, interior living spaces should always be in a state of neutral air balance. A heat recovery ventilation (HRV) system, or its close cousin the energy recovery ventilator (ERV), ensures balanced home ventilation and preserves indoor temperatures and air quality. Let's look at how these two systems are similar and different.
- Both systems utilize separate blower fans installed in a central controller and dedicated, small diameter ductwork to remove stale air from areas like kitchens and utility rooms while inducting fresh outdoor air into living spaces. The controller equalizes the volume of fresh air added to the house to the volume of stale air being removed, thus maintaining neutral indoor air balance.
- Both an HRV and ERV incorporate a heat-exchanger in the central controller. In winter, heat extracted from the exhaust stream of warm indoor air is added to the incoming stream of cold outdoor air to preserve indoor temperatures. About 75 percent of heat can be recovered. During summer, the system reverses, taking heat out of the incoming stream of warm air and transferring it to the exhaust stream.
- While an ERV performs all ventilation and heat-extraction functions of an HRV, it also incorporates enthalpy transfer technology to control indoor humidity levels. In summer, water vapor is extracted from humid incoming outdoor air and moved to the exhaust stream to keep living spaces more comfortable. In winter, humidity accumulated in indoor air is transferred to dry incoming outdoor air to address low indoor humidity issues common to cold weather.
- Most HRVs and ERVs are sized to the ventilation requirements of the house and run continuously at low speed. A typical unit consumes about as much electricity as a large light bulb.
In Fort Wayne, ask the experts at Hartman Brothers Heating & Air Conditioning Inc. for more information about the benefits of balanced home ventilation.
Our goal is to help educate our customers in New Haven, Indiana and surrounding Fort Wayne area about energy and home comfort issues (specific to HVAC systems). For more information about home ventilation and other HVAC topics, download our free Home Comfort Resource guide.
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