Balancing Home-Performance Demands with Ventilation Needs
Properly Ventilating Tight Homes a Priority for Home-Performance Contractors
While new homes are being built tighter than ever, more and more contractors are helping their customers identify and rectify sources of energy loss in their homes, ensuring future energy savings and comfort for homeowners. But, as contractors seal up these homes, they also need to consider proper ventilation, avoid common mistakes, and follow industry protocols to ensure occupant health and safety.
Importance of Ventilation
Drake Erbe, chair of ASHRAE Standard 90.1 and vice president of market development at Airxchange Inc., said that while mechanical ventilation is mandated in most commercial building codes in the U.S., it is rarely required on the residential side. That means many of the tightly built or sealed homes aren’t bringing in enough fresh air to ensure occupant health and safety.
Robert Wilkos, a contractor and consultant with Grow HVAC, which helps residential contractors grow their businesses, agreed that residential building codes are lacking when it comes to ventilation.
“I believe fresh air is helpful to everyone. It is industry standard in commercial applications, but not in residential,” Wilkos said. “Door openings do provide some fresh air, but maybe not enough to satisfy the situation. Hence, another product may be the best solution.”
Brian McDonald, general manager at Outer Banks Heating & Cooling, Kill Devil Hills, N.C., added that humans aren’t the only things that need fresh air in a home. “Possibly the older gas appliances that use combustion air from within the structure need to breathe, also,” McDonald said. “It is required based on ASHRAE and BPI [Building Performance Institute Inc.] standards that homes have mechanical ventilation once they are sealed to a certain point due to high levels of VOCs [volatile organic compounds] and carbon dioxide.”
Domenic DeLeo, department manager at Isaac Home Energy, Rochester, N.Y., agreed, stating, “Back drafting of natural draft appliances can also be an issue in a home without proper ventilation,” he said. “It’s critical for houses to have proper ventilation to make sure the air you are breathing is healthy and clean.”
When leak testing a home, McDonald said the biggest mistake technicians make is rushing through the process. He suggested they “allocate ample time beforehand to conduct the testing.”
DeLeo agreed. “The biggest mistake techs make is they are quick to jump to conclusions,” he said. “Patience and building science will get you to the best solutions.”
Frank Spevak, marketing and sales manager, The Energy Conservatory (TEC), said TEC’s products, which include the Minneapolis Blower Door and Ductblaster, help identify leaks and other issues when used properly. But, as with any piece of equipment, user error can occur, and effective troubleshooting is key.
“Some of the basic problems we see in troubleshooting are hoses,” Spevak said. “The others are configuration. Do all of the settings on the gauges match the fan and how the fan is configured? For example, if you have Ring A on the fan, but you forgot to tell the gauge that you’re using Ring A, you can get an incorrect number.”
Spevak suggested contractors always double check equipment before beginning. “We provide quick guides, which are visual one-page documents,” he added. “You just want to make sure that the gauges and the fans are all set up the way they should be.”
Wilkos added that the most common mistake he sees isn’t necessarily in the testing itself. Instead, he said technicians and sales representatives often mishandle home-performance upgrade sales. It’s a common problem, he said, though it can be solved with proper training.
Seal Tight and Vent Right
Most contractors have their preferred methods and tools for the job, and home-performance contractors are no exception.
“I like the blower door most, since the homeowners can see the air leaks when they are using the smoke pencil,” McDonald said, adding that he uses Retrotec products to perform the testing and Flir thermal imagers to identify hot and cold spots. “The infrared is pretty cool, especially when the homeowner is the one finding the problems.”
“We use blower doors and Fluke thermal imagers — both critical tools for energy auditing,” DeLeo said.
DeLeo, Wilkos, and McDonald all said the kind of ventilation equipment they use depends a lot on how much ventilation is needed as well as where the home is located.
“Dehumidifiers that condition outside air being brought into residences are a common [solution] in hot and humid climates, such as in Florida,” Wilkos explained.
DeLeo said he uses energy recovery ventilators, heat recovery ventilators, and dampers to increase outside air intake, depending on how much outside air is needed.
“We test out the house after we do our work and compare the results to the BAS [building automation system] and make adjustments, if needed,” he added.
McDonald suggested letting the homeowner know, perhaps even before testing begins, they may need to add fresh-air intake. He added that it is best to bring in fresh air from a controlled location, rather than relying on the house to breathe on its own.
“I look at it from the point that the home’s infiltration is controlled, and it’s being filtered,” McDonald said. “If it’s not controlled and filtered, it can be coming in from anywhere — attic or crawl space with rodent and animal urine and feces, or termite poison and radon gas.”
DeLeo said testing, sealing, and properly ventilating a home can save customers up to 25 percent on their utility bills.
“We feel that home performance is the future of our industry,” he said. “It takes the guesswork out of home improvement and gives our customers a list of prioritized solutions based on efficiency, comfort, and, most importantly, safety.”
Publication date: 4/21/2014