While there are many resources to improve the indoor air quality (IAQ) of commercial and institutional buildings, little has been placed on improving the IAQ in residential structures — until now.

It appears ASHRAE is on the verge of releasing for public review Standard 62.2P, Ventilation for Acceptable Indoor Air Quality in Low-Rise Residential Buildings. At the association’s recent 2000 Winter Meeting in Dallas, the much-debated standard apparently passed its final hurdles in a public question-and-answer session. Therefore, as reported on the front page of this issue, expect the association to place the much-needed standard up for public review soon.

It is about time, too. Since people spend 90% of their day indoors — and 65% of that time is spent inside the friendly confines of your own home — making sure all buildings are properly ventilated is a must. Generally speaking, contractors agree with this.

The standard itself is rather short, having only about four pages containing requirements. In addition to the requirements, there is guidance and informative language to help the contractor — and all users and designers — make informed choices.

According to 62.2P chair Max Sherman, key requirements of the draft include the following:

  • An industry-favored spillage test is required for all vented combustion appliances.
  • Kitchens and bathrooms must have mechanical exhaust capacity.
  • A mechanical whole-house ventilation system is required and must be sized as a function of house size and number of bedrooms.
  • All fans must meet minimum performance requirements.
  • And carbon dioxide detectors are required for all houses.

Rocky road up to now

Three years ago, ASHRAE split off residential ventilation from Standard 62 and initiated a new project committee. It tried to rush through a standard for public review, but it met plenty of opposition along the way, including from the American Gas Association, the National Association of Home Builders, and the Gas Appliance Manufacturers Association. Each of these groups objected to the release of the draft for various reasons, including technical and (yes) political. Let’s just say the NAHB is very cautious when it comes to adding expenses to the cost of a new home.

In the end, the committee met last September and compromised to resolve most of their concerns. Of course, not all of the issues raised by the three institutions were (or could be) resolved. However, the committee believed it had a standard ready for public review at the fall meeting of the Standards Committee.

In an unprecedented reversal a month later, however, they reconsidered the release and decided to pull it back. This is why, among many other reasons, Sherman and his committee held a public Q&A session at the recent Winter Meeting. They wanted to make sure that all was in order and no objections surfaced.

Knowledge is power

Why is this standard so important for contractors? Well, as with most ASHRAE standards, expect 62.2P to eventually become incorporated into building codes throughout this country. While the standard does not currently address existing structures, expect the committee to address and tackle this hurdle in the future, too.

While there may still be arguments regarding the “dos” and “don’ts” of the standard, most contractors will agree that some residential IAQ guidelines are better than no IAQ guidelines.

“Much as I hate to have things legislated, the homebuilding industry should sign on to the standard,” said St. Louis, MO contractor Butch Welsch, who installs heating-cooling systems in about 3,000 new single-family homes a year. “We see new homes with three, four, even five furnaces, to say nothing about multiple water heaters. This will starve the house of combustion air if ventilation rates aren’t sufficient.”

There are many positive things that the standard does at minimal cost, including:

  • It provides source control of moisture and other specific pollutants through the use of local exhaust fans.
  • It provides criteria to minimize backdrafting and other combustion-related contaminants.
  • It has provisions for reducing contamination from attached garages.
  • It provides minimum whole-house ventilation rates.
  • And it sets performance criteria for air-moving equipment to help ensure that equipment will operate as intended.

Implementing the proposed standard will cost the typical builder an incremental cost of between $150 and $250 per house, estimated Joe Lstiburek, a member of 62.2P and owner of Building Sciences Corp.

The bottom line? The benefit of this standard should be the reduction of callbacks due to condensation and mold problems and a reduction in liability associated with indoor air quality issues. Said Lstiburek, it levels the playing field by establishing a defensible standard of care in addressing indoor air quality contaminants.

It’s all good news.