B.C. seeks input into ventilation standards for new building code

Thermal Environmental Comfort Association Ventilation Committee members
Thermal Environmental Comfort Association Ventilation Committee members (left to right): Steve Savage, Terry Regier, David Hill, and Graham Finch.

Ventilation in many B.C. homes has been inadequate for years, says expert

This fall, B.C.'s Office of Building and Construction standards would like to talk to you. And they're planning to do it face to face.

"Call it old school, but we think going out and talking to people will give us a better read on how people are reacting, and help us make sure they understand the proposals," says John Nicol, energy projects team leader with the Building and Safety Standards Branch. "Plus we hope stakeholders who don't normally come out, heating, cooling and ventilation contractors, those people who design, sell, and install ventilation systems - will participate and share their experiences."

At the heart of the consultation plan are new ventilation standards proposed for the BC Building Code. Developed by TECA, the Thermal Environmental Comfort Association, the proposals aim to improve the ventilation effectiveness in new homes.

Read a summary of the new standards

Proposed changes provide continuous exhaust, makeup air, and improved distribution

Currently, the Building Code requires the operation of a home's principal exhaust fan on an eight-hour interval cycle or continuous operation. That will shift to a minimum requirement for continuous operation.

One or more air intakes will be required to ensure the home has a steady flow of fresh air drawn in from dedicated opening(s). Finally, the proposed changes require distribution of fresh air, particularly to bedrooms.

David Hill, a founding director of TECA and chair of its ventilation committee, says the proposals aim to cover other gaps as well.

"We've been very clear that ventilation is required for the health of the occupant and for the building," says Hill. "Why should people expect colds more frequently in the winter than the summer?

"Houses are typically closed-up in winter. When you wake up in the morning, you're stuffy. Twenty percent of society today is very, very sensitized to that environment, and today we understand this and can provide summer indoor air quality all winter long."

"The ventilation in many homes has been inadequate for years," adds Hill. He says smaller electric baseboard and hot water heated homes have faced challenges because they don’t naturally include moving air.

Today, he says, inadequate ventilation is showing up even in natural gas forced-air heated homes, because minimum furnace efficiency standards effectively eliminated the venting system that was previously required. Most single detached and duplex homes that are natural gas heated at least had year round house exhaust via their open chimneys.

"That was an unnoticed but continuous exhaust system we have enjoyed for years," he says.

Hill says there is a larger discussion at play about the appropriate sizing of ventilation, and says it's important to size the system correctly. "Over-ventilation is almost as bad as under-ventilation," he says. "It will bite you on the butt in January, compromising your comfort and hitting your utility bill."

Southern B.C. air leakage 'the worst'

"The current ventilation requirements were predicated on the standard airtightness of homes in B.C., which in the south coast has consistently been the worst in character," says Nicol. "With the mild climate, we've been able to get away with it. But if we're tightening up, we need to upgrade the mechanical ventilation requirements as well."

"If you've got two people sleeping in a bedroom, over the course of the night their breathing contributes several quarts of water to the air," says Nicol. "So moisture and carbon dioxide will both build up within that room. Without ventilation, condensation may develop which can lead to mould."

Opportunity to comment and learn

Revised energy performance requirements for new homes will not take effect until December, 2014, leaving time for consultation and for builders to prepare. TECA has also been invited to present the proposed standards at the educational forum of the Building Officials' Association of B.C.

But Hill says a challenge builders may face is not in understanding, or even implementing, the ventilation requirements. He says the learning curve may lie in sales.

"Typically the public will buy what they see. What they can't see, they have trouble paying for. Ventilation has always been a very difficult sell, and most builders who are market‑savvy will have some degree of resistance unless they have personally lived in a home that has effective ventilation and have developed the skill to convey its merits."

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