Health

10 Signs Your Home's Air Quality Is Poor

Indoor air quality can be up to 5 times worse than outdoor air — and we spend an average of 90% of our time inside. Your body often sends signals before the problem becomes visible. Here are the 10 most telling ones.

1. You Cough More When You're Home

Coughing in the morning when you wake up, or in the evening after a few hours at home, but it stops once you go outside? That's one of the most reliable indicators. The indoor air is irritating your airways.

2. Your Allergies Are Worse Indoors Than Outdoors

Counterintuitively, spring allergies can actually be worse inside your home: pollen gets in, builds up in carpets and ducts, and keeps recirculating. If your nose runs more at home than at the park, something's off.

3. Dust Comes Back Very Quickly on Furniture

You dust, and two days later there's a visible new layer? That's not normal. It's often a sign that your ducts are continuously releasing dust into the air, or that your system's filtration isn't strong enough.

4. Persistent Smells You Can't Quite Place

Musty, stale, chemical, pet — a clean home shouldn't smell like anything in particular. A stubborn odor that persists despite cleaning often points to a problem in the ducts, the air exchanger, or a hidden moisture spot.

5. Condensation on Windows in Winter

A little fog at -30°C is normal. Water running down, staining on the frame, or frost on the glass is not. It's a sign that moisture isn't being removed properly — often because of a poorly maintained or missing air exchanger.

6. Unexplained Headaches or Fatigue at Home

Volatile organic compounds (VOCs) released by furniture, paint, cleaning products, and even some building materials can cause headaches, nausea, and fatigue. If these symptoms disappear once you leave the house, it's worth taking seriously.

7. Black or Green Spots in Bathrooms or Ceiling Corners

That's probably mold. Even if you clean the visible spots, the spores are still circulating in the air. The cause is almost always a ventilation problem or excess humidity. A properly working air exchanger often solves 80% of the problem.

8. The Air Feels "Heavy" or Stale

You open a window and it feels like a completely different world? Your home isn't getting enough fresh air turnover. Either there's no exchanger, or it isn't working properly.

9. Dry Skin and Eyes in Winter

A bit of dry air in winter is normal in Quebec, but extreme dryness (chapped lips, tight skin, burning eyes) can indicate humidity levels that are too low — often caused by an HVAC system that dries out the air without compensating for it.

10. Your Pet Is Coughing or Sneezing

Pets are lower to the ground and closer to dust sources. A cat or dog that sneezes often, or a bird that seems to struggle breathing, can be an early indicator of an air problem you can't perceive yet.

What to Do If Several of These Sound Familiar

Start with the basics — and in this order:

1. Check your filters (change them at least every 3 months)
2. Make sure your air exchanger is working and clean
3. Have your ducts assessed
4. Monitor your humidity level (aim for 30–50% year-round)
5. Eliminate indoor pollution sources (chemical products, too many plants, rarely-cleaned carpets)

In most homes we visit, a simple, thorough HVAC system tune-up transforms air quality within a few weeks. It's rarely as complicated as people think.