Alaska winters mean 8 months sealed indoors. Here's how to manage your home's air quality through the long season — from simple DIY steps to knowing when you need professional help.
From early October to late May, most Anchorage homes are sealed tight against the cold. Windows stay shut, air exchange drops dramatically, and your family breathes the same recirculated air day after day, week after week, for most of the year.
During that sealed period, everything your household generates indoors — CO2 from breathing, moisture from cooking and bathing, VOCs from cleaning products and furniture, particles from cooking and candles, radon gas from the soil below — accumulates without relief. Without active management, air quality in a sealed Alaska home deteriorates steadily over winter.
The good news: there are practical steps you can take yourself, and professional solutions for the problems that need more than a filter change. Here's both.
See the Action StepsAnchorage homes are sealed from October through May. That's a long time for indoor pollutants to accumulate without the dilution effect of natural air exchange.
EPA data consistently shows indoor air is 2–5 times more polluted than outdoor air. In Alaska's sealed homes during winter, this gap can be even wider.
Alaska residents spend approximately 90% of winter hours indoors. The air quality in your home matters more here than almost anywhere else in the country.
These steps require no professional help and can meaningfully improve your home's air quality through the sealed season.
Most Alaska homes ship with MERV 4–6 filters — these capture large particles but pass fine dust, mold spores, and allergens freely. Upgrading to MERV 11–13 dramatically improves whole-home filtration. Check first with an HVAC professional that your system can handle increased static pressure — some systems are not compatible with high-MERV filters without modification.
During Alaska's sealed season, filters load up faster than in summer. In a typical occupied home, MERV 11+ filters should be checked monthly and replaced at least every 3 months during peak winter. A clogged filter reduces both airflow and filtration effectiveness — the worst of both worlds. Mark replacement dates on your calendar in October.
Sleeping areas are where you spend the most concentrated time. Adding a HEPA air purifier in each bedroom specifically addresses particles (dust mite waste, mold spores, pet dander, PM2.5) that your HVAC filter may miss. Run it on continuous low-speed or medium-speed for best results. Our Alaska air purifier guide →
Alaska's extreme outdoor cold creates very dry air, but occupant activities (cooking, bathing, breathing) add moisture that can push indoor RH above 50% — the threshold where dust mites and mold thrive. Invest in a digital hygrometer ($15–25) to monitor humidity, and use exhaust fans consistently. If RH stays above 55%, investigate sources and consider a dehumidifier in problem areas.
Scented candles, air fresheners, strong cleaning chemicals, and aerosol sprays all introduce VOCs into your sealed home's air. Switch to fragrance-free cleaning products, eliminate scented candles (use beeswax if needed), and store volatile chemicals in attached garages rather than inside living spaces. These small changes meaningfully reduce chemical load in winter air.
On milder winter days (above 15°F), opening two windows on opposite sides of your home for 10–15 minutes provides meaningful air exchange without extreme heat loss. Even one good cross-ventilation event per week helps dilute accumulated CO2, VOCs, and moisture. Avoid ventilating during wildfire smoke events or extreme cold below -10°F.
Radon levels are highest during winter when homes are sealed. Alaska's geology elevates radon risk across much of Southcentral, and winter gives you the most accurate peak-exposure data. Short-term kits are available at hardware stores, or contact a certified radon professional — visit epa.gov/radon to find one.
Some IAQ problems require professional diagnosis and solutions. These are the signs it's time to call us rather than rely on self-help measures alone.
If household members experience headaches, fatigue, respiratory symptoms, eye/nose/throat irritation, or worsening allergy or asthma symptoms that improve when away from home, professional IAQ testing is the right next step. A HEPA purifier won't help if the problem is radon, a gas appliance issue, or hidden mold. Professional testing →
Mold visible on walls, ceilings, or around windows — or persistent musty odors — indicate moisture problems that require professional assessment. Cleaning visible mold without addressing the moisture source is temporary at best. We identify the source and recommend remediation and prevention strategies.
If you've never tested your Anchorage-area home for radon, winter is the best time to do it. Radon is the second leading cause of lung cancer in the US and is entirely invisible and odorless — you can't know your exposure without testing. Contact a certified radon professional — epa.gov/radon can help you find one in Alaska.
DIY tips help — but knowing exactly what's in your air is better than guessing. Our IAQ audit gives you professional data on your specific home's winter IAQ, and a prioritized action plan that goes beyond generic advice.
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