Air King's motion-sensing exhaust fan.
Air King's motion-sensing exhaust fan.

Recent energy code updates are pushing builders and remodelers to work harder on improving indoor air quality. Many contractors undoubtedly will regard the codes’ standards as a burden, but dealers should point out that the rules also are an opportunity for pros to sell a new concept: customized ventilation.

By measuring a house’s levels of formaldehyde, combustible gases, and carbon dioxide and monoxide, builders can tailor a system specific to the home and its owners, says Paul Francisco, a research specialist at the Building Research Council at the University of Illinois at Urbana-Champaign. Francisco and several other experts all predict that fine-tuning a home to reflect its occupants’ ventilation needs will be a coming trend in construction when the builder knows who is moving in.

Such customization matters because the effects of bad air and poor ventilation vary based on both who lives in the home and what materials they’re living with. Paints, coatings, and sealants that are applied when wet, along with synthetic materials used in furniture and in flooring systems, all rank among the main causes of volatile organic compounds (VOCs) in the home, says Dr. Marilyn Black, founder of the Greenguard Environmental Institute, a third-party green-product certifier. Cooking and cleaning release heat, organic compounds, and dangerous chemicals into the air, creating what Black calls a cocktail of dangers that is increasingly being shown to endanger occupants’ health.

Ventilation has always been important in homes, but before the 1970s builders didn’t worry much about it because their houses were so leaky a breeze naturally flushed out bad air. But then oil embargoes and skyrocketing energy costs prompted builders to add insulation and weatherization barriers. Those changes cut fuel bills, but they also meant off-gassing from building materials and furnishings had no easy exit.

“Homes aren’t leaky anymore,” Black says. “We either have to mechanically ventilate or make sure that all the products we put in there don’t contribute anything to the air. In tight homes, there’s just not enough air to dilute or help flush out any of these pollutants we are generating in the home.”

Ultra series ventilation fan from Broan-NuTone.
Ultra series ventilation fan from Broan-NuTone.

The Environmental Protection Agency (EPA) reports that the short-term health effects of poor indoor air quality can range from eye, nose, and throat irritation to asthma, dizziness, and fatigue. Repeated exposure can cause respiratory and heart diseases, even cancer. Children are at higher risk compared with adults because they breathe more rapidly, increasing their exposure to pollutants, and their immune systems and organs are immature.

The extent of these effects varies by person and location, although the EPA estimates that the levels of many pollutants can be two to five times higher indoors than outdoors. Radon, a naturally occurring outdoor element absorbed into the home, contributes to approximately 14,000 deaths annually, according to the EPA, which in 1991 found that indoor radon levels in the U.S. were three times higher than outdoors.

Code Talk

Codes are often seen as a minimum standard, and lately that bar has been rising. Most states operate at or above the 2009 International Energy Conservation Code (IECC) or something similar. That code calls for R-20 cavity insulation or R-13 cavity plus R-5 continuous exterior insulation; wood-framed wall insulation in climate zones 3, 4, and 5 (roughly the middle belt of the nation); and mandatory duct system pressure tests. IECC’s 2012 update lowers the acceptable leakage rates and mandates whole-house blower-door tests.

ASHRAE 62.2 sets a minimum standard for continuous ventilation in residential applications. It rolled out as a separate residential code in 2009, but only recently has it begun finding its way into more state and local building codes. Early adopters include the states of California, Washington, and Alaska.

Energy Star Version 3, a voluntary home certification program, went into effect earlier this year and calls for building insulation levels to meet insulation standards for the 2009 IECC and achieve Grade I installation per RESNET (Residential Energy Services Network) standards. It also requires that all exhaust fans be Energy-Star qualified, except in half bathrooms.

But predicting the activities that will take place in the space once homeowners move in, experts say, is key to determining which guidelines and standards to look to when deciding on systems and materials.

“The more builders and remodelers know about the family, the more helpful they can be. It’s a process of getting to know the customer better,” says Allen Rathey, president of the Healthy House Institute, an educational platform for consumer information on sustainable home products.

Ultra series ventilation fan from Broan-NuTone.
Ultra series ventilation fan from Broan-NuTone.

Smart Fans

Customization is possible in part because local-source ventilation systems are getting smarter. Fans whose primary function was to decrease humidity during showers or remove cooking odors now are becoming part of a whole-house network, capable of operating at fluctuating levels rather than at the same rate all the time.

Bathroom fans, in particular, are rising to the challenge. Because the excess moisture generated in the room increases the risk for bacteria and mold, manufacturers are rolling out products that activate using timers and humidity and motion sensors to limit energy consumption. Plus, they’re increasingly quiet—ASHRAE 62.2 mandates one sone or less—and some even include lights and heaters. Similar systems are now incorporated in kitchens and are even making appearances in attached garages, experts say—all largely in response to the relative growth in remodeling.

What’s more, many are now powerful enough to offer the required number of air changes for the whole house, says John Fox, board chairman of the Home Ventilating Institute, a third-party product certifier based in Wauconda, Ill. “In this application, the fan runs continuously or is cycled on and off with a timer,” he says. “By continuously introducing outside air, the home can have acceptable indoor air quality.”

Panasonic’s WhisperRecessed fan combines an 80 CFM (cubic feet per minute) fan and an 18-watt compact fluorescent light bulb in a recessed unit that operates at 0.8 sone. It can be installed in a 4-inch or 6-inch duct using a single adapter and is designed for architectural-grade residential applications.

A new exhaust fan from Air King adds to the growing motion-sense market and comes in single- or dual-speed models to meet ASHRAE 62.2 and California’s Title 24 standard. The fan runs at 80 CFM or 130 CFM and users can preset the amount of time after which it will shut off once the room is empty.

New Is Ideal

Most local-source and systems-based ventilation products added to houses today are new rather than replacements. This makes new construction an ideal market for builders to sell consumers on the long-term financial payout—and comparatively small short-term cost—in installing these systems up front. This includes ventilators, electronic air cleaners, and equivalent passive filters.

Energy recovery ventilators and heat recovery ventilators offer a cost-effective medium for circulating outdoor air, a shift from ductless or recirculating range hoods and microwaves that experts say helps control contaminants, moisture, and odor. Like ventilators, air-filtration and air-cleaning products can work in both new construction and remodels, says Rob Goodfellow, vice president of marketing at Princeton, N.J.-based Dynamic Air Quality Solutions.

Air quality encompasses more than just harmful pollutants. Moisture, temperature, and how tight or loose the building is also matter. And with this range of potential causes comes a few considerations and potential restrictions to ventilation’s effectiveness.

Panasonic's WhisperRecessed fan.
Panasonic's WhisperRecessed fan.

Pat Nielsen, marketing manager at Broan-NuTone, cautions that CFM rates are only as good as the depth, length, and straightness of a ventilation system’s ducts. Termination fittings, too, should be kept clear to improve efficiency. “The ducting is, in most cases, running through your attic, and at the end of the duct run it either goes to a roof, to a gable wall, or to a soffit,” he says. “You have to have some kind of cap there so birds, bugs, and wind aren’t coming back in.”

Rathey adds that it’s important to coordinate which exhaust fan or appliance is turned on or off, and where and when. “Let’s say you’re running the bath fan, the kitchen fan, your central vacuum, and the dryer all at the same time,” he explains. “You can create a negative pressure situation” that he says could cause gases to come back down the flue and into the home.

And if a local-source fan is serving double duty to ventilate the entire house, Francisco says it’s important to gauge how far away the fan is from where many of the contaminants are being produced to avoid pulling them through the house on their way out.

Ultimately, the experts agree that while advising on and installing ventilation systems isn’t for amateurs, it is something that can be learned—and, lately, is proving to be a boon for contractors who are looking to compensate for slow business.

“In the past, they wouldn’t have thought to go out and ask homeowners if they want to replace their bath fans,” says Nielsen. “They thought that by the time they got into the attic and messed around, they’d have to quote a number so high that they’re not going to want to do it anyway, or were not going to make any money on it … It’s an incremental profit opportunity in these tougher times.”