Why Is My House So Humid?

Humidity inside your home shouldn’t feel worse than the heat outside. But during a Michigan summer, it’s common to notice foggy windows, sticky air, or that damp feeling that never goes away. So, why is your house so humid, and what causes high humidity indoors?

The short answer is that more moisture is being trapped indoors than your HVAC system can remove. Air leaks, poor ventilation, or an air conditioning system that’s not working correctly can all exacerbate the issue.

When warm outdoor air carries water vapor into your home, it raises your relative humidity, and your system struggles to keep up.

Addressing Your Home’s Humidity Levels

Michigan isn’t humid all year, but summer is different. Moist air from the Great Lakes moves inland, raising the humidity level inside.

That air seeps in through air leaks or poorly sealed windows. When it mixes with poor ventilation or an overworked heating and cooling system, moisture problems appear quickly.

What Causes Excessive Moisture to Build Up?

If your indoor humidity feels high, your home may be allowing in too much moisture for your system to manage. That’s especially common in older homes in Kalamazoo.

Common causes include:

Air leaks around windows and doors
Plumbing leaks or moisture near the foundation
Poor insulation in crawl spaces or attics
Signs of mold and mildew, musty smells, or condensation

Is Your AC Unit Working Like It Should?

A properly sized air conditioning system helps remove excess moisture as it cools the air. But if your AC is short-cycling, undersized, or low on refrigerant, it won’t absorb moisture effectively. Clogged filters and dirty coils make it worse.

If the air feels cold but still damp, your HVAC system might need attention. A seasonal tune-up can restore airflow and help reduce excessive humidity in your living space.

Poor Ventilation and Outdated Exhaust Fans

Your kitchen, bathroom, and laundry room create some of the most humid air in your home. If your exhaust fans are weak, old, or not vented outside, they can’t keep up. This leads to moisture buildup, higher humidity levels, and an increased risk of mold growth.

Many Kalamazoo homes still rely on outdated fans. Upgrading them can move moist air out faster and improve the air inside your home.

Everyday Activities that Contribute to Humid Air

Daily habits can raise your humidity level without you realizing it, especially in homes with poor insulation or airflow:

Cooking without a range hood
Long, hot showers
Running a dishwasher or laundry
Drying clothes indoors
Using appliances that release moisture in the air or water vapor

Opening windows may seem like a fix, but during humid months, the outside air can add even more excess moisture. That’s why your house feels humid even when the AC is on.

How to Solve Humidity Issues

If your house feels damp or sticky all the time, your HVAC system may not be keeping up. High indoor humidity can compromise your comfort, increase energy costs, and even lead to mold growth.

According to the EPA, the ideal humidity range is between 30% and 50%. Once it exceeds 60, you’re more likely to encounter problems such as musty odors, warped materials, or mildew around vents and windows.

The fix doesn’t have to be complicated. Making a few smart adjustments can significantly improve the air quality inside your home.

Use cold air the right way

If your air conditioning system is too small or short-cycling, it may cool your house without actually removing enough moisture from the air.

Verify that your air conditioners are functioning properly

Old or undersized air conditioners may leave behind moist air, forcing your system to work harder than it should.

Install a whole-home dehumidifier

A dehumidifier pulls excess moisture out of the air in every room, lightening the load on your system and making your space feel more comfortable.

Seal air leaks and improve insulation

Fixing cracks and poorly insulated areas helps keep humid air out, allowing your system to run more efficiently.

Upgrade ventilation

New exhaust fans or mechanical ventilation systems bring in fresh air and push out stale, humid air, especially helpful in tight or older homes.

Get Help from a Kalamazoo HVAC Team

If your house still feels humid, R.W. LaPine has helped Kalamazoo homeowners solve humidity issues, lower energy bills, and improve air quality for decades. Whether you need a quick tune-up or a brilliant long-term solution, we’ll help you find the proper fix for your space.

Our certified HVAC technicians understand how to handle excess moisture in Michigan homes. If you’re tired of sticky air and inconsistent comfort, let us help you get back to breathable air.