Indoor Air Quality in Colorado: What to Test, What to Skip

The indoor air quality industry is a mess of legitimate science, semi-legitimate testing services, and outright sales theater. As a heating and cooling company that gets pulled into the conversation often, here is our honest take on what to actually test for in a Colorado home and what to ignore.

Worth testing for

Radon. The biggest single air-quality concern in Colorado, by a wide margin. Radon is a radioactive gas that seeps from the soil into basements and lower levels. Colorado is one of the highest-radon states in the country. A short-term radon test costs about $25 from any hardware store; a long-term test costs about $80. If the result is above 4 pCi/L, mitigation runs $1,200 to $1,800 and reduces indoor radon by 90 percent or more. We do not install radon mitigation systems but we will refer you to several local contractors who do.

Wildfire smoke during fire season. Colorado fire season runs roughly May through October, and the Front Range gets significant smoke days when the wind blows wrong. Particulate measurements during smoke events are real, the health effects on sensitive individuals are real, and a properly sized HEPA-grade filter on the central HVAC system makes a meaningful difference. We can spec a high-MERV filter for your existing system or, for severe cases, a standalone HEPA air cleaner running in parallel.

CO from gas appliances. Carbon monoxide leaks from a furnace, water heater, or stove are a real safety concern, and CO is undetectable without instruments. A combination smoke and CO detector on every floor of the house is the basic standard; we check existing detectors during every annual furnace tune-up and replace them when they hit their ten-year service life.

Worth knowing about, but rarely worth testing

Mold. Most homes have some level of mold spores in the air; this is normal and not a problem. The question is whether you have an active mold growth in the building, which is almost always the result of a moisture intrusion (roof leak, foundation seepage, HVAC condensate problem). The fix is to address the moisture source, not to "test for mold." Anyone who shows up at your door pushing mold testing without first asking about a known moisture issue is selling testing as the product, not solving a problem.

Allergens (pollen, pet dander, dust). A high-MERV filter and routine HVAC maintenance handle the bulk of routine allergens. Specialty allergen testing rarely produces actionable findings beyond "you have a cat" or "tree pollen is high in May." If you have allergy symptoms that change between rooms or between seasons, a conversation with an allergist is more useful than an air quality test.

Volatile organic compounds (VOCs). Common in new construction, fresh paint, new carpet, and certain cleaning products. The right answer is ventilation: open windows on warm days, run kitchen and bathroom exhaust fans appropriately, ensure the HVAC system has fresh-air intake. VOC tests are interesting but rarely change what you would do anyway.

Sales-pitch theater

Whole-house "purification" systems. UV lights in the ductwork, ionizers, ozone generators, "active oxidation" devices. The marketing is impressive. The peer-reviewed evidence is thin or actively negative. Some ozone-producing devices generate the very pollutant they claim to address. We do not install these and will not recommend them.

"Free" indoor air quality tests offered by HVAC vendors. Often these are loss-leader visits that produce alarming-looking reports designed to upsell expensive add-ons. The legitimate version is a $200 to $400 visit from an actual industrial hygienist with calibrated instruments. The free version is a sales call.

"Mold sniffer dogs" and other novelty inspections. The science is approximately zero. The cost is meaningful. Save the money.

The simple version

For a typical Colorado home, the minimum indoor-air-quality steps that actually matter:

1. Working CO detectors on every floor.
2. A radon test kit run for a few days, then mitigation if the reading is above 4 pCi/L.
3. A quality HVAC filter changed on schedule (MERV 11 to 13 for most homes; higher only if the system can handle the airflow restriction, which we can verify).
4. Working bathroom and kitchen exhaust fans, used appropriately.
5. Address moisture sources promptly when they appear.

That covers 95 percent of legitimate indoor air quality concerns in our market. If you have a specific symptom or concern that the simple version does not address, the next step is an actual conversation with an industrial hygienist or, for medical concerns, a physician. We are happy to point you at either.

If you want our honest take on a specific air-quality system you have been pitched, send us the brochure. We will tell you whether it is worth the price.

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