What Is a Heat Recovery Ventilator?
An HRV is an attachment to an HVAC system that draws in outdoor air and pre–conditions it with inside air before sending it to the heater or air conditioner. Fresh indoor air crosses through a stream of stale indoor air, and a heat transfer occurs between them: the cooler air warms up, and warmer air loses heat and cools down.
Imagine a hot summer day in Los Angeles. The heat recovery ventilator in a home draws in hot fresh air, and then runs it through a current of indoor air, which is stale but also cool. The hot outdoor air loses much of its heat to the indoor air. The stale indoor air is vented outside, and the fresh outdoor air, now much cooler than before, heads on to the air conditioning system. The AC had much less work to do with this fresh air because it is already cooled down. The fresh air enters the home, and very little energy is lost. The process reverses during the occasional cold days outside.
The Benefits of an HRV System
The main reason to install a heat recovery ventilator is that it allows you to increase your home’s indoor air quality without having a negative impact on the heating or air conditioning system. HRVs recover approximately 85% of the energy that a home would otherwise lose because of exposure to the outside air, and this will make a significant improvement in your heating and cooling bills while concurrently improving indoor comfort.
Heat recovery ventilators are similar to energy recovery ventilators; one important difference is that ERVs do not transfer moisture between air currents, and therefore do not affect indoor humidity. If humidity is not an issue in your home, an HRV will do the job you require.