Windows and Health

As always, your dossier on windows was very informative. Below are a few other points to look for.

Canada Mortgage and Housing Corp. (CMHC) has found that plants and some hypersensitive people react adversely to the fact that the sun’s balanced, full-spectrum of colors is filtered by low-e glazing. That’s why some healthy-home designers only use clear glass on the south side, but efficient glazings on east and west façades and most-efficient glazings on the north side.

But all is not clear and this issue is far from resolved. CMHC is pursuing its research. Amory Lovins of RMI tells me his plants are growing very well in his Heat Mirror glazed greenhouse.

Canada’s National Research Council (NRC) is studying the effects of full-spectrum artificial lighting. Psychiatrists use it to treat people affected by the winter blues. Seasonal Affective Disorder (or SAD) is linked to unbalanced levels of melatonin, a mood-affecting neurotransmitter which also reduces tumor growth.

For now, NRC says full-spectrum lamps are too costly for the uncertain health and worker-performance benefits they provide. It seems they only help more sensitive individuals who aren’t exposed to sunlight daily. I personally use one (an EMF-shielded Ott Light) because I’m worried about the long-term effects of being zapped by my computer dozens of hours a week (EMF overexposure can significantly lower melatonin levels).

CMHC’s new 238-page report

Building Materials for the Environmentally Hypersensitive states that hypersensitive people may be affected by the odors emitted by PVC windows exposed to heat and sunlight. One can also ask if ABS windows emit butadiene styrene vapors, as do ABS plumbing and often-polluting styrene butadiene rubber carpet backing. Some toxicologists, such as Yves Allarie of Pittsburgh University, say plastic fires are faster, hotter and more toxic. “When in doubt, kit it out,” my soccer coach always said. I believe plastics should be used minimally indoors, but that some can be highly recommendable outdoors.

It should also be stressed that mold growth favored by condensation on poorly maintained wood windows not only makes them rot, but can also pollute indoor air with mycotoxins. Similarly, important mold growth can occur on walls and beneath carpets when frost on metal windows melts.

While I agree energy efficiency should be a priority, it is only one of many important factors. The Canadian Standards Association’s omnibus standard, A440, deals with all of them: airtightness, watertightness, wind, condensation and forced entry resistance, winter energy rating, ease of operation, installation, etc. CSA is also developing a cooling energy rating for summer performance.

Finally, extra cost and payback is a major concern of consumers. In Canada, it seems that one low-e glazing and an argon fill generally add 0 to 15% to the total cost of a window. Because times are hard for window manufacturers and demand for high-performance windows is much higher, some dealers actually give away such options—even insulated spacers, whose performance I would have liked to read about.

Most important, a good vendor should convince consumers that efficient windows first and foremost make houses much more comfortable and virtually eliminate glass condensation problems in airtight, well-insulated and well-ventilated homes.

André Fauteux, Editor

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Sainte-Adele, Québec