Healthy Indoors Magazine - USA Edition

HI February 2020

Healthy Indoors Magazine

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Page 48 of 58

Healthy Indoors | 49 series is trying to explore how to get it right more often. If you are a contractor, start offering BAD ASS HVAC as an option, if you are a homeowner, ask for BAD ASS HVAC. This article is going to focus on the importance of dehumidi- fication. Dehumidification of homes is a huge issue that affects air quality, your health, home durability, and much more that many realize. In our practice, we have found humidity to be remarkably hard to control. Humidity & Health Did you know we breathe 3000 gallons of air per day? Or that most high security prison inmates spend more time outdoors than we do? We and our families breathe at least a third of that air breathed inside our homes. Is it worth at least considering the quality of that air? Ken Gehring of Themastor, who invented the ventilat- ing dehumidifier, coined the term "green grass climate." If your grass stays green most of the year without watering it, why? Could it be because it rains a lot? That's mois- ture that needs to be controlled to provide a comfortable, healthy, and long-lasting home. If you're thinking "I live in a dry climate, I don't have to worry", you may be right, the risk is much lower. That said Bill Hayward of Hayward Score had his home make him and his family sick. Mike MacFarland of Energy Docs had a client with a very sick child that solving mold and moisture issues in a bathroom helped enormously. The more we learn, the more crit- ical keeping a house warm and dry becomes. Our practice, Energy Smart Home Performance, has over 40 Foobot air quality monitors in the field. Foo- bot measures temperature, humidity, dust (PM2.5), and chemical pollut- ants (tVOC). For more discussion on why we like those four measurements best, check out the Health Thief article from May 2018. VOCs are volatile organic com- pounds, which have boiling points close to room temperature. That means we are likely to be breathing them at room temperature, and particularly if it's humid. Many VOCs are essentially harmless like vinegar, cheese, or wine odors. But many others are harmful such as formaldehyde or chemicals in air fresheners, cosmet- ics, and cleaners. The first step is to reduce the number of these bad chemicals we bring into the house - look for "fragrance free" products as a start, but I don't know of any fool proof way to keep VOCs out of your home. The other challenge with VOCs is that they already exist in the building materials of your home, and in your furni- ture. While source control is best, it's surprisingly difficult to achieve. Which brings us to dealing with the VOCs that are al- ready in your home. If we want to avoid breathing bad stuff, one of the best ways to do that is to keep relative humidity inside our homes in the 30-50% relative humidity range. By watching these air quality monitors, we have repeatedly found that if we can't control humidity, we can't control chemical pollutants, which agrees with the research I have read. Speaking of research, Richard Corsi is one of the best indoor air quality researchers I know. He seems to have been the PhD advisor of every air quality researcher I work with as well. Corsi found that high relative humidity is di- rectly related to the release of VOCs. This turns out to be true for lots of other factors as well in- cluding dust mites, bacteria, viruses, mold, and more. If you haven't seen this ASHRAE chart, burn it into your mind now. The blue "Optimum Zone" should be 30-50% relative humidity in our experience. Maintaining 40-50% RH in cold climates during winter is a sure way to create condensation, which then leads to mold, mildew, and rot. If ever you see condensation inside your windows in winter, keep in mind there is probably condensation inside your walls that you can't see, feeding things you would prefer not to feed.

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