When the Crawfords moved into their new high-performance home in Prospect, Ohio, two years ago, the family of four was delighted to have more space and low energy bills. Their 2,900 square foot home had been meticulously air sealed and featured a geothermal system for heating and cooling.
“My biggest regret with the home was that we didn’t install an ERV [energy recovery ventilator] system when the home was constructed,” explains Scott Crawford. “There was a lingering new home smell.”
Despite using non-toxic finishes, the Crawfords were concerned about lingering odors that they think resulted from construction products. Could these smells be harmful to their health?
Air Sealing & Airborne Pollutants Create Indoor Air Quality Concerns
Because the home was air sealed for energy efficiency, there were few leaks and gaps to passively exchange air between the interior and exterior of the home. The air exchange rate of the home was tested with a blower door test and scored 0.9 ACH (air changes per hour). Lower scores indicate that less air is exchanged with the outside. Many new homes test around 5 ACH, demonstrating how tightly the Crawford home had been constructed.
The Crawfords did have exhaust fans in all three of the bathrooms. They would sometimes run the exhaust fans and open the windows to remove odors and ventilate the home, even though this wasted energy. The home just didn’t have an energy-efficient way to let fresh air in and remove stale, contaminated air.
Selecting a Zehnder ERV System
After extensive research, the Crawfords decided to install a Zehnder ERV themselves to promote indoor air quality and energy efficiency. Scott likes that Zehnder ERV and heat recovery ventilator (HRV) systems are certified Passive House components, demonstrating that they meet a rigorous standard of energy efficiency and performance.
Scott, a financial analyst, says, “I have been trained to manage risk. After conducting research, I knew that installing a Zehnder ERV system gave me the best chance of being satisfied for the money and time spent.”
Using Zehnder Components
Scott decided to use Zehnder components when installing the ERV system, streamlining the installation. “The main thing that appealed to me was how everything goes together, and I knew it would be very easy to complete,” he explains. “Looking back, I wanted it to be done right. I wanted to make sure if I spent all the time and money, I would be getting the right supply and exhaust rates throughout my home.”
Technical Support from Zehnder America
Although Scott installed the Zehnder system himself, he received technical support from Zehnder staff to determine the air supply to each room. The final step in the installation process involved a Zehnder representative measuring the airflow from the ventilation system in each room. “Zehnder also commissions all of their systems, so I have proof that each room is getting the air flow it should be getting.”
Installing the Ventilation System
Scott installed a ComfoAir 550 ERV unit in the home himself on evenings and weekends, with help from his father. “The installation was relatively easy because of how the ComfoTubes work,” says Scott. “One of the reasons I went with Zehnder is the fact that they have the ComfoTubes. It was much easier to run these tubes and make sure they were completely airtight.”
Removing Bathroom Exhaust Fans
The Crawford home previously used four exhaust fans in their three bathrooms. “The bathroom exhaust fans leaked a noticeable amount of air into the home, which was especially obvious on cold, windy days,” he says. “I was so happy to close them off. If our house was tested [with a blower door test for the air exchange rate] now, I think it would have been more airtight. The exhaust fans created four 6-inch holes, and I could feel a draft from them.”
Fresher Indoor Air
The Crawfords have been happy with the impact of the Zehnder system. “Before installing the ERV, there was a lingering new home smell. The ERV made a noticeable difference in the air quality of our home,” explains Scott. “I feel healthier, and the smells that bothered us before are gone. Our house seems fresher now.”