Healthy Indoors Magazine - USA Edition

26 | HOUSE WHISPERER —November/December 2017 Being an expert in Home Performance – a field that stud- ies the intersection and interconnection of insulation, HVAC, Energy Efficiency, and Indoor Air Quality – I know that in- doors and outdoors are very connected, particularly in the nicer months when we open windows while outdoor pollu- tion levels are often highest. Managing the quality of the air we breathe is a problem that needs a solution worldwide. By mid-2015, these IAQ devices were looking like they might have had the answer to the measurement problem, which meant that they may have been useful for helping to reduce those ugly statistics about air pollution. I started to beg, borrow, and even buy these devices. I first bought Foobot, Awair, NetAtmo, Hobo, and CO Ex- perts devices. Later I was given additional Foobots and a Speck. Dylos and Air Mentor 6 in 1 were loaned to me. After taking so much time to get to know these devices, the information they provide, and how they can be useful for improving lives, I decided to put some thought into cre- ating a framework for explaining what makes a really good consumer IAQ monitor and why. So which things do we really want to detect? How do we prioritize these things if we have to sacrifice one or more? Here's my list: 1. PM2.5 — Research is increasingly showing this is a major villain. The recent study about increased mental illness in kids bothers me a great deal. I'm concerned about my 3 year old because I live near a busy road. It's like smoking — it kills us slowly and causes sensitive in- dividuals varying degrees of discomfort. The WHO said it's our biggest single environmental health issue, so it's top of the list. I'd love a sensor that picked up smaller particles like PM0.5 as well. 2. VOCs — Volatile Organic Compounds can cause irrita- tion of the eyes, nose, and throat; headaches and nau- sea; and damage to the liver, kidneys, and central ner- vous systems. Some are suspected carcinogens. VOCs look to be the second most important pollutant from the studies I've read. 3. Temperature & Humidity — These two are usually cov- ered with one sensor. Damp buildings are causally linked to asthma in kids, and humidity and moisture are major health concerns. Contaminants can be affected by both temperature and humidity, so it's important to have these measured to look for correlations. For example, VOCs off-gas much more rapidly at higher humidity levels ac- cording to Dr. Richard Corsi of the University of Texas. Another example is that smog formation is often worst on the hottest days. Finally, mold becomes increasingly likely over 60% relative humidity. 4. Carbon Monoxide (CO) — This common byproduct of combustion replaces oxygen in our blood, causing as- phyxiation. Research is showing that low level carbon monoxide poisoning may cause depression, confusion and memory loss. If you have a furnace, gas water heat- er, gas dryer, gas range, gas fireplace, or any other ap- pliance that burns a fuel in your home, this is something to be aware of. Standard carbon monoxide detectors do not alarm at lower levels. Being an energy auditor, I see problems with CO quite frequently. In fact, my mom was recently poisoned by older furnaces. Particularly in lower income homes, colleagues have told me they've seen CO problems in about 50% of homes. I would like to understand carbon monoxide concentrations in client homes over time; unfortunately, none of the IAQ devices tested has this capability. 5. Carbon Dioxide — CO 2 is a good proxy for air fresh- ness in a home. Outdoor levels are around 400 parts per million (ppm). Berkeley Labs found that concentra- tions as low as 1000 ppm affect cognitive function, and levels in the 2500 ppm range have a substantial effect on decision making abilities. Even so, this is the least important item to measure because tVOC sensors pick it up indirectly and it will likely be controlled along with other pollutants through filtration or circulation. Would I like more? Of course! Every sensor adds cost, though, and these factors are probably enough to figure out how much you should be concerned about your IAQ, and if more steps are necessary. Sensors & Calibration I learned through both Foobot CEO Jacques Touillon and Particles Plus (a high end IAQ device manufacturer) CEO Adam Giandomenico that there are only a few sensors of each type on the market. To my knowledge, only Dylos manufactures its own sensors in the devices I looked at. For instance, Foobot, Speck, and Awair all use the same

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