How Indoor Air Quality Impacts Your Health During Cold & Flu Season

Cold and flu season hits every winter and so does stale indoor air. When temperatures drop, we shut the windows, crank the heat, and spend more time inside. That’s when indoor air quality really starts to matter.

According to the CDC, millions of people get sick with colds or flu each year, especially kids and older adults. While you can catch a cold anytime, winter is peak season, and poor indoor air can make it worse.

The good news? Improving your indoor air quality is one of the easiest ways to help protect your home this winter.

Why Indoor Air Quality Matters More in Winter

During colder months, your furnace runs more often and the same air circulates over and over. If your HVAC filter is dirty—or low quality—it can’t effectively trap:

• Viruses and bacteria

• Dust and dust mites

• Pet dander

• Mold spores

• Smoke and outdoor pollution

That means more irritants in the air you breathe every day.

Common Winter Indoor Air Pollutants

Here’s what’s typically floating around your home during cold and flu season:

• Viruses & bacteria – circulate longer in poorly ventilated spaces

• Dust mites – thrive in bedding, carpets, and furniture

• Mold spores – grow when humidity isn’t balanced

• Pet dander – builds up faster when windows stay closed

• Household chemicals & fragrances – linger in stagnant air

• Outdoor pollution – wildfire smoke, pollen, and smog still get inside

Not exactly what you want your lungs dealing with all winter.

Easy Ways to Improve Indoor Air Quality (That Actually Work)

1. Change Your Air Filter Regularly

Yes, a dirty air filter can make you feel sick. High-quality filters (like MERV 11 or MERV 13) help capture fine particles, allergens, smoke, and many bacteria before they circulate through your home.

Shop high-quality Aerostar furnace & HVAC air filters →

2. Use a Portable Air Purifier

Air purifiers or air scrubbers work best in smaller, high-use spaces like bedrooms or home offices. They’re a great supplement to your HVAC filter, not a replacement.

3. Let Fresh Air In (When You Can)

Even cracking windows for a few minutes helps flush out stale air before turning on your heating system.

4. Ventilate When Using Cleaners

If you’re cleaning or using chemicals, open windows and run exhaust fans. Better yet, switch to low-VOC or natural cleaners when possible.

5. Add a Few Indoor Plants

Plants won’t replace air filters, but they can help with humidity and overall air comfort. Just make sure they’re pet-safe.

Extra Protection During Cold & Flu Season

Clean air is only part of the equation. Don’t forget the basics:

• Wash hands frequently

• Clean high-touch surfaces

• Keep sick household members in one space when possible

• Consider masks when close contact is unavoidable

Think of clean indoor air as your first line of defense—not your only one.

Indoor Plants That Can Support Air Quality

Some popular options include:

• Spider plant

• Snake plant

• Peace lily

• Bamboo palm

• Boston fern

⚠️ Pet owners: Always check plant toxicity and keep unsafe plants out of reach.

Not Sure What Size Air Filter You Need?

Getting the right size matters more than most people realize.

How to measure your air filter correctly →

TL;DR

Winter = more time indoors + more circulating air. A clean, high-quality air filter is one of the simplest ways to help your home breathe easier during cold and flu season.