House humidity in winter: What should your home’s humidity be in Michigan?
If you’ve noticed your windows fogging up or your basement smelling musty during the winter, you're not alone. Michigan homes deal with a different kind of winter discomfort: moisture problems caused by too much humidity indoors.
Unlike drier climates, Michigan’s winters can be damp, with snowmelt, poor ventilation, and air leaks all contributing to rising indoor humidity. That leads to condensation, mildew, and a whole host of comfort and health issues if your home isn’t properly sealed or insulated.
Wondering if your home’s humidity is balanced? Call Ecotelligent Homes at (248) 291-7815 or schedule a home energy audit. We’ve completed more than 6,000 energy audits for homeowners in southeast Michigan since we started back in 2009.
Table of contents
What is humidity and why it matters in winter
Humidity is the amount of water vapor in the air. In the winter, we often think of dry air being the problem — but in Michigan’s climate, it’s not always that simple.
Cold outside air + poor insulation = condensation indoors
Older or poorly sealed homes can trap moist air in areas like basements or attic cavities. Combine that with cooking, showering, and breathing, and suddenly your humidity climbs — especially when ventilation is poor.
What should humidity be in your house in winter?
Aim for 30–40% relative humidity (RH) in your Michigan home during the winter. That’s the sweet spot for:
- Reducing condensation on windows
- Preventing mold growth
- Keeping wood floors and furniture in good shape
- Supporting comfortable, healthy breathing
Some smart thermostats might recommend up to 45%, but that’s often too high for older homes in a cold, wet climate like ours, especially when indoor temps meet freezing outdoor glass.
Signs your home’s humidity is too high or too low
Too low (< 30% RH):
- Dry skin or chapped lips
- Scratchy throat or frequent static
- Brittle houseplants
- Shrinking wood or gapping floors
Too high (> 40–45% RH):
- Foggy or “weeping” windows
- Musty smells in basement or closets
- Visible mold or mildew on walls, especially in corners
- Peeling paint or bubbling wallpaper
- Allergies or asthma symptoms worsening indoors
How excess humidity affects your home and health
In Michigan winters, it’s often too much humidity — not too little — that causes damage.
- Condensation inside windows can rot wood frames and ruin drywall
- Basement mildew is often a sign of poor air circulation and trapped moisture
- Increased allergens like mold spores and dust mites thrive in humid conditions
- Energy bills go up if your furnace has to work harder to dry and heat damp air
How to control humidity in winter
1. Use your ventilation the right way
Moisture builds up indoors from cooking, showering, and even breathing.
- Run your bathroom fan while showering — and for 15–20 minutes afterward
- Use your kitchen exhaust when cooking, especially when boiling or simmering
- If you don’t have fans or they’re underpowered, that’s a good place to start upgrading
2. Seal up air leaks
Cold Michigan air sneaks into your home through attic hatches, rim joists, plumbing penetrations, and old windows. This not only lowers indoor temps—it also causes condensation when that cold air hits warm, humid indoor air.
A blower door-guided energy audit from Ecotelligent Homes will pinpoint exactly where leaks are and how to seal them properly.
3. Seal ductwork leaks
Leaky ducts in attics or crawlspaces pull in humid outside air—especially if your system is unbalanced or the fan runs constantly.
- Return leaks suck in moist air
- Supply leaks create negative pressure, pulling more humid air into the home.
A duct sealing service can fix both, improving both humidity control and energy efficiency.
4. Upgrade your insulation and vapor control
Insulation keeps more than heat inside. It also protects your home from the temperature swings that cause condensation on walls, ceilings, and window frames.
- Use materials suited for Michigan’s climate (dense-pack cellulose, closed-cell spray foam)
- Ensure vapor barriers are installed in the right places — not trapping moisture where it doesn’t belong
5. Right-size and optimize your HVAC system
High airflow across the coil can reduce your system’s ability to dehumidify. A trusted HVAC professional can:
- Measure and adjust your airflow (target ~350 CFM per ton for dehumidification)
- Ensure the fan is set to auto, not on — so moisture doesn’t get re-evaporated after the cooling cycle
- Check refrigerant charge and coil temps, which also affect dehumidification
6. Monitor your indoor humidity
Get a digital hygrometer or a smart thermostat with humidity tracking. These can help you fine-tune your home’s humidity and identify problem areas.
Aim for 30–40% RH in winter to stay in the safe zone between “dry air discomfort” and “weeping windows.”
7. Use a dehumidifier when needed — but know its limits
If you’ve sealed up your home, improved ventilation, and still have moisture problems in the basement or certain rooms, a portable dehumidifier can help.
But remember — it’s a band-aid, not a cure. It treats the symptoms, not the cause.
Want to fix the source of humidity issues in your home?
Start with a home energy audit. We’ll help you identify where moisture is getting in — and how to stop it with proper sealing, insulation, and ventilation.
Don’t just treat the symptoms — fix the source. Schedule your home energy audit today or call Ecotelligent Homes at (248) 291‑7815. We’ll help you solve humidity problems for good.
Ecotelligent Homes
Since 2009, Ecotelligent Homes has completed more than 3,000 projects in Michigan. If you need help with new insulation, efficient HVAC, or abatement services, give us a call anytime: (248) 291-7815. Satisfaction guaranteed.
Got a project in mind?
Tell us about your project, and we'll send ballpark pricing in 2 minutes or less.