Why Your Indoor Air Quality Drops in Winter (And How to Fix It)

Sealed Up Tight — But at What Cost?

When temperatures drop across Central Iowa, we seal our homes as tight as possible to keep the cold out. Windows stay shut, doors stay closed, and fresh air circulation drops to near zero. While that's great for your energy bill, it's not great for your indoor air quality.

What's Actually in Your Winter Air?

A sealed-up home traps a surprising cocktail of pollutants:

• Dust and dust mites: With no fresh air flushing them out, they accumulate faster.
• Pet dander: Pets spend more time indoors in winter, increasing dander levels.
• Volatile organic compounds (VOCs): Cleaning products, paint, furniture, and cooking all release VOCs that concentrate in sealed spaces.
• Dry air: Furnaces remove moisture, and Iowa's winter air is already dry. Low humidity (below 30%) irritates sinuses, dries out skin, and makes you more susceptible to colds and flu.
• Carbon dioxide: A family of four in a sealed home can raise CO2 levels enough to cause headaches and fatigue.

Solutions That Actually Work

Whole-home humidifier: Maintains humidity between 30–50%, which is the sweet spot for comfort and health. It integrates with your furnace and requires minimal maintenance beyond seasonal adjustments.

UV air purifier: Installed inside your duct system, UV lights neutralize bacteria, viruses, and mold spores as air circulates. Particularly effective for families with respiratory concerns.

Upgraded filtration: Moving from a basic MERV 8 filter to a MERV 11–13 captures significantly more particles, including many allergens and fine dust. Some systems can accommodate MERV 16 or even HEPA filtration with modifications.

Energy recovery ventilator (ERV): This is the gold standard. An ERV brings in fresh outdoor air while recovering heat from the outgoing stale air, so you get ventilation without wasting energy. Ideal for tight, modern homes.

Trade Allies Heating and Cooling offers complete indoor air quality solutions for Central Iowa homes. Call (515) 669-4481 and breathe easier this winter.