The answer is: quite a lot! Energy recovery ventilators (ERVs) are special devices that professionals can install into HVAC systems to allow for better indoor air quality without the sacrifice of significant energy efficiency indoors.
Here is the conundrum that an ERV helps a homeowner face: The best way to enjoy fresher air in your house is to allow for more air circulation from outside. An influx of outdoor air replaces the stale indoor air and sweeps out numerous pollutants. But to bring in that outdoor air requires opening up windows and doors, and this isn’t ideal during the height of winter or summer. Opening up the house either brings in the heat (summer) or lets the heat escape (winter). An HVAC system must work overtime trying to maintain comfortable levels inside when the house is open like that, and this wastes energy.
How does an ERV help overcome this problem? We’ll get into that below.
The Energy Recovery Ventilator in Action
An ERV is a type of heat exchanger positioned in the ventilation system of your house that allows for fresh air to either lose heat or gain it before it enters the house, using the energy already in the house from the heater or the AC.
To better explain this, we’ll take an example of a cold day in winter:
The ERV activates and draws fresh, cold air from outside through an external vent. At the same time, it draws warm, stale indoor air into the ventilation system through an indoor vent. The indoor is warm because of the energy used to run the heating system. These two currents of air move through the ERV where they pass through each other in cross-currents. As this happens, the currents exchange heat: the warmer indoor air naturally loses its heat to the cold air coming from outside, which raises the temperature of the fresh outdoor air. The stale indoor air is then exhausted outdoors, and the now pre-warmed fresh outdoor air enters the home.
The process is similar during the summer, with the warm outdoor air cooling down as it loses its heat to the cooler indoor air, thus pre-cooling it before it enters the house.
The Big Benefits of an ERV
An ERV is a great way to enjoy fresh air in your home without having to pay a high price either in heating/cooling bills or in discomfort. You’re getting the advantages of open windows and fresh air circulation without the penalties of outdoor temperatures. A properly installed ERV can recover around 80% of the energy that would otherwise have gone to waste from opening up doors and windows—and you’ll get this benefit throughout the year, in all kinds of weather. You don’t even have to make any adjustments to the unit.
Additionally, ERVs exchange humidity between their air currents, which helps to create balanced humidity levels indoors. During winter, the cold dry air picks up moisture from the indoor air, and in summer, the humid outdoor air loses its moisture to the drier indoor air.
To find out more about installing an energy recovery ventilator in West Chester, OH, talk to our HVAC experts.