Setting the Standard for Good Residential IAQ

June 1, 2011
ASHRAE has improved Standard 62.2 for Indoor Air Quality. Key issues have been clarified, based on real-life applications over the past eight years.

Contractors who strive to provide the best indoor air quality (IAQ) for their residential customers know that Standard 62.2 from the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) is an important means to that end.

Recent changes made to the standard, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings, serve to clarify certain aspects of the standard, but they don’t change its core or its intent. Rather, the updates simply reflect the typical life of a standard, and actually make it easier to use and more helpful.

"The updates simply reflect the typical life of a standard," says Steve Emmerich, chairman of the ASHRAE 62.2 committee. "Standard 62.2 was brand new in 2003, and it takes some time for a standard to get used in the field and incorporated into codes. As that process goes on, people identify issues that need clarifying and things that could be improved upon."

According to Emmerich, the three main categories of actions residential HVAC contractors can take to help ensure acceptable IAQ to their customers remain unchanged. Those are:

  • provide background whole-house mechanical ventilation
  • provide local exhaust ventilation to eliminate sources of moisture and contaminants from kitchens and bathrooms
  • implement source control measures that limit contaminants that might otherwise be brought into a house from undesirable areas such as a garage or crawlspace.

Emmerich says contractors who take the time to truly evaluate a home's needs in light of standard 62.2 and other codes and ordinances are well positioned to provide good IAQ for their customers.

"For example, combustion safety and the potential for carbon monoxide problems is such an immediate issue that contractors always want to make sure they're doing the right things in that area," he says. "Although 62.2 does have some requirements related to that, you also want to apply the requirements in your local code, the national fuel gas code, and so on."

Then, once homeowners' safety has been ensured, the next step is to meet the home's ventilation needs and provide the proper equipment to meet the 62.2 standard.

"Houses have always had some sources of pollutants in them, but traditionally they were so leaky that infiltration was relied upon to keep the levels of those pollutants down," Emmerich says. "We've learned over the years that we're better off building a tight envelope and putting in a mechanical ventilation system. This allows us to reduce contaminants through controlled ventilation rather than uncontrolled infiltration, and save energy."

Finally, contractors play an important role not only in properly designing controlled ventilation systems to ensure good IAQ, but also in educating customers about the importance of using the systems, Emmerich says.

"We know that many of the contaminants generated from inside a house come from the kitchen and bathrooms," Emmerich says. "It's really important to use your local exhaust ventilation system and get those things out of the house right here, rather than let them mix into the air throughout the house and breathe them for the next several hours.

"Making sure the system moves the proper volume of air is obviously an important part of the contractors' job, but equally important is making sure people actually use their ventilation systems," he adds. "Emphasize to homeowners why you're providing this type of ventilation for their homes Convey to them, 'These pieces of equipment are there for a reason, please use them.'"