Learning Center / Efficiency
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How to Actually Improve Indoor Air Quality — Beyond the HEPA Marketing
Air quality is a stack, not a product. The best HEPA filter in the world can't fix a house that has a moldy crawlspace or 65% indoor humidity. Here's the order I walk homeowners through in Creedmoor.
What is indoor air quality?
IAQ combines four measurable dimensions: particulates (PM2.5, PM10), volatile organic compounds (VOCs), humidity (30–50% is the safe band), and biological contaminants (mold, dust mites, pollen). Each requires a different fix.
The hierarchy — cheapest, highest-impact first
- Source control. Vent bath fans outdoors, not into the attic. Encapsulate the crawlspace if humidity is high. Store paint and solvents outside the conditioned envelope.
- Filtration upgrade. A 4-inch MERV 11 or 13 media cabinet catches 90%+ of PM2.5 without choking your blower.
- Humidity control. In the Triangle summer, that's your AC. A properly sized AC pulls humidity as it cools. An oversized one doesn't.
- Ventilation. Modern well-insulated homes actually need mechanical ventilation. An ERV (energy-recovery ventilator) brings in outside air while transferring heat + humidity back to the outbound stream.
- Advanced (UV, ionization). Only after 1–4 are addressed. Adding an ionizer to a leaky, humid, dusty house is putting whipped cream on an untended garden.
Frequently asked questions
Do UV lights in HVAC systems work?
For coil sterilization (preventing biofilm on the wet indoor coil), yes — measured by dozens of studies. For whole-home air sanitization, the evidence is much weaker. Great supplement, poor standalone.
What humidity should my house be at?
30–50%. Below 30% you get static and dry skin; above 50% you get dust-mite explosion and eventually mold. Summer target in NC: 45%.
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