The Hidden Challenge of Calgary Winters: Dry Air Inside and Condensation on Windows
When winter arrives in Calgary, homeowners often brace for subzero temperatures, snowbanks, and drafty entryways. What you may not expect is how much the cold — and dry — air affects your home’s interior environment.
Because cold outdoor air holds far less moisture, when that air is heated indoors it becomes very dry. As a result, many homes in Calgary experience indoor relative humidity well below recommended levels throughout the long winter months.
This dryness isn’t just a comfort issue — it can affect your health, your home, and even your windows. At the same time, some well-intentioned attempts to “moisturize” the air (e.g. with humidifiers) can go too far, leading to condensation, frost, and damage to glass, frames, and surrounding structures. For homeowners, finding the right balance is key.
Why Some Humidity in Winter Matters — and What’s at Stake
Health, comfort, and wellbeing
Dry indoor air can lead to dry or irritated skin, chapped lips, itchy eyes, sore throats, and aggravated sinus or allergy issues.
Cold, dry air may also worsen respiratory issues — and in theory may make it easier for some viruses to linger longer in indoor air.
For many, dry air means discomfort: static shocks, scratchy throats, dry coughs, and a generally less welcoming living space.
Beyond health, dryness affects the home itself: wood furniture, hardwood floors, door frames, window sills and trim can shrink, crack, warp or squeak when humidity is too low over extended periods.
The Case for Moisture — but Only in Moderation
Because of these risks, many homeowners turn to humidifiers or other ways to raise indoor humidity. That’s often a smart move — when done carefully. According to many building and health experts, a comfortable indoor winter humidity level generally falls between 30% and 40% (and up to 50% in milder conditions).
Within that range, you’re far less likely to suffer from dry-air symptoms — and woodwork, paint, and furnishings remain more stable.
The Other Side: Too Much Humidity — and Why It’s a Problem, Especially for Windows
As important as humidity is, more isn’t always better — and winter adds complexity. Because outdoor glass surfaces get extremely cold in Calgary winters, even modest indoor humidity can trigger condensation on windows.
Condensation isn’t just annoying. Over time, repeated moisture build-up can cause:
Mould and mildew around window frames, walls, and sills — a health risk, especially for those with allergies or asthma.
Structural issues: moisture may seep into wall cavities or attic areas, where it can condense within insulation or sheathing — potentially leading to rot or long-term damage.
Window-frame / sill deterioration, warping, paint peeling — especially if the frames are wooden.
Freezing or frost build-up on windows if condensation freezes — leading to ice, window sticking, or further moisture damage.
Because of this risk, many experts recommend adjusting your indoor humidity target depending on how cold it is outside — even if it feels dry inside.
Finding the Right Balance: Practical Tips for Calgarians
As a local glass service provider, we see many cases where windows suffer because humidity management was too heavy-handed — or too light. Here are practical guidelines to help homeowners strike a healthy balance through the winter.
Use a hygrometer. A simple humidity meter, placed inside your main living space, will show you the actual relative humidity (RH). Aim for 30-40% RH when it’s very cold outside; in milder winter weather you can approach 35-45% if your windows can handle it.
Adjust humidifier settings based on outdoor temperature. If it’s extremely cold (e.g. –20 °C or lower), consider lowering humidity output — even if the air feels dry. This helps prevent condensation and frost on cold glass surfaces.
Use ventilation wisely during moisture-generating activities. Cooking, showering, drying wet clothing — these add moisture. Run exhaust fans or open windows briefly after such activities to prevent localized humidity spikes.
Ensure good air circulation, especially near windows. Blocked vents, heavy drapes, or furniture pressed against windows can trap moisture. Allow airflow to help glass surfaces warm slightly and reduce condensation.
Inspect windows and seals. If condensation persists despite good humidity control, there may be issues with insulation, window seals, or thermal performance. In those cases, consider contacting a professional — especially if you notice persistent moisture, mold, or warping around glass or frames.
Why This Matters — and How It Ties Back to Glass Care
As a glass service company serving Calgary for nearly three decades, we at Around the Clock Glass Service know how often we get called for issues that stem not from a single accident — but from seasonal cycles of humidity and temperature stress.
Balanced humidity isn’t a luxury — it’s part of proper home care. When indoor air is too dry, you and your home suffer — from dry skin to cracking woodwork. But when too moist, the very windows and glass installations meant to bring light and comfort can become sources of mold, rot, and structural damage.
By monitoring your indoor humidity, adjusting it intelligently, and combining humidification with good ventilation and circulation, you can create a home environment that’s healthy, comfortable, and safe — all winter long.
If you ever notice condensation, frost, or moisture damage around your windows, don’t wait: contact us. We’ll inspect your glazing, assess insulation and seals, and help you protect one of your home’s most important assets.
