How Critical are Heat Recovery Ventilators for a Healthy Indoor Environment in Energy-Efficient Homes?

3/26/2014

Heat Recovery Ventilation (HRV) and Energy Recovery Ventilation (ERV) systems provide a range of advantages for a healthy indoor environment in high-performance homes. Over the course of their lifetime, individuals will spend an estimated 80 percent of their time indoors. If these individuals are exposed to poor air quality within the home, it can contribute to chronic and acute health conditions such as allergies and asthma. HRV systems ventilate homes with a continuous supply of fresh filtered outdoor air.

Indoor Air Quality

Good indoor air quality is a key component in maintaining long-term health within the home. However, a lack of proper indoor ventilation can threaten this health. Today’s buildings have become increasingly tighter and more insulated due to building codes and energy-efficiency awareness. This provides certain benefits, such as the reduction of heat loss and energy bill savings. However, a primary disadvantage is that the air in these homes can become stagnant without a proper ventilation strategy.

Household Pollutants

Certain chemicals such as household cleaners, building materials, smoke, and other harmful substances can become trapped inside a poorly-ventilated home. Additional substances such as pollen and dust may collect inside the home, which can cause discomfort to the inhabitants. Natural moisture from bathrooms, kitchens, and laundry rooms can contribute to the development of mold and mildew.

These air contaminants can lead to health conditions and symptoms such as sleepiness, fatigue, and headaches. Health conditions such as allergies and asthma may be aggravated, causing residents to sometimes experience more symptoms than they would if their homes had improved ventilation.

HRV Ventilation

The primary function of a heat recovery ventilation system is to properly ventilate a home in addition to recovering the heat from the exhaust stale air. Properly designed and installed heat recovery ventilation systems work continuously to remove old, stale and contaminated air from the home and replace it with outside fresh, tempered and filtered air.

Indoor Comfort

Heat recovery ventilation systems are also designed to maintain temperature regulation within the home. With a high-efficiency HRV in the 85%+ heat recovery range, assuming a 70 degrees room temperature and an outdoor temperature of 30 degrees, the incoming air through the heat exchanger comes into the home typically within a few degrees of the inside room temperature. This eliminates uncomfortable drafts in certain rooms and variation in temperature. The consistent supply of fresh outdoor air combined with a comfortable and appropriate temperature allows residents to reap the benefits of consistent indoor comfort.