Results Are In: Testing Confirms Zehnder ERV Boosts Indoor Air Quality in Family Home


This is the second post in a two-part series about the Mastrangelo residence and the family’s efforts to address chronic health problems by resolving indoor air quality issues.

When the Mastrangelo family had renovated and expanded their Massachusetts cape home several years ago, they added spray foam insulation to the entire second floor and roof. They wanted to make their home as energy efficient and comfortable as possible. Sadly, the family soon started suffering from indoor air quality issues that took years to solve, until they discovered and installed a Zehnder ComfoAir 200 energy recovery ventilator (ERV).


Poor home air quality causes chronic health problems

The Mastrangelos’ daughter had been suffering from chronic Lyme disease, which is often aggravated by poor indoor air quality and other environmental contaminants. After installing the Zehnder ventilation system, the family noted a significant improvement in their daughter’s health. The air in the home seemed much fresher, but was there a quantifiable difference in the indoor air quality of their home? Jeff Bradley, the owner of IndoorDoctor, an indoor environmental assessment company was brought in to find out.

Tests confirm a significant improvement in indoor air quality

Jeff had previously tested the indoor air quality in the home in July 2017, when the Mastrangelos had a 3rd party ERV connected through the home’s heating and cooling ductwork (before the Zehnder ERV was installed). He found that certain contaminants were above normal ranges (see graph).

He then retested the home in February 2018, after the 3rd Party ERV was removed and the Zehnder ComfoAir 200 had been installed. The air quality tests revealed a drastic improvement in the indoor air quality of the home!

The second test reflected a significant reduction in:

  • Chemical levels (total volatile organic compounds)
  • Microbial volatile organic compounds
  • Formaldehyde
  • Airborne particulate matter
  • Carbon dioxide

Occupant health improves

Before learning about Zehnder clean air solutions, the Mastrangelos had tried everything they could think of and were considering selling their home if the associated health issues weren’t resolved. Installing the Zehnder system coincided with the family noticing a significant increase in home air quality and overall health.

The air quality test results confirmed with what the Mastrangelos observed. “It was noteworthy that the family noticed an improvement in indoor air quality and felt a lot better,” says Jeff. “They are very sensitive to a lot of things, and the Zehnder ventilation system reduced the contamination levels on multiple fronts. It exceeded my expectation.”

Lower carbon dioxide levels

Typical carbon dioxide levels are between 350 to 900 parts per million (ppm). The first indoor air quality testing demonstrated the Mastrangelo home had unhealthy levels of carbon dioxide on the second floor (between 908 and 1016 ppm) and in the attic (1000 ppm). The follow-up air quality test revealed healthy carbon dioxide levels of between 403 and 530 ppm.

Elevated levels are often associated with a home that is too tightly constructed and does not have adequate ventilation. Occupants may even experience a stuffy feeling and odors are likely to develop. Common health effects associated with excess carbon dioxide in the air can include difficulty breathing, nausea, headaches, and fatigue.

“The elevated carbon dioxide levels in the Mastrangelo home were an indicator that something was off and there was an imbalance,” Jeff explains. “ These levels are key metrics and were a sign that there were not enough fresh air exchanges in the home. In these situations, most contaminants will build up, including mold, carbon monoxide, airborne particulates, allergensformaldehyde, sewer gases, and radon.”

Zehnder ERV provides fresh air

The Zehnder ComfoAir ERV system boosts home air quality because it continuously ventilates the Mastrangelo house by removing stale, contaminated air from the bathrooms, storage room, and kitchen while supplying fresh, filtered air to the bedrooms.

Healthy indoor air quality is commonly associated with restful sleep, mental clarity, and a reduction in allergy symptoms. The Mastrangelos are thrilled that years of searching for solutions has resulted in them finally solving their home air quality issues. According to Christine, installing the Zehnder ERV and the associated benefits have been “life-changing.”