What Causes High Humidity in a House? Your Questions Answered

Chances are you have many questions about humidity in your house if you live in a climate that experiences high humidity. What causes high humidity in a house?

High humidity in a house includes reasons such as the humidity level of the climate you live in and how well a house is ventilated during times of high moisture in the air. Bathrooms and kitchens that are not properly ventilated are major contributors to a higher level of humidity in a house.

What Causes High Humidity in a House? Your Questions Answered

We’ve put together a comprehensive resource to answer many of your questions about humidity in your house as well as what you can do about it.

What Causes High Humidity in a House?

Several factors can cause humidity to rise in a home, and it’s important to understand what causes high humidity in your house so you can address it.

Many common indoor sources of moisture can lead to increased levels of humidity in your homes such as cooking and bathing.

Studies have shown that we should maintain humidity levels in the home of between 30% and 50%.

Let’s take a look at things that can cause your in-home humidity levels to rise:

  • Improper Ventilation: When showering or taking a hot bath, it’s important to run your ventilation system to combat the increased moisture in the air.
  • Cooking: When you’re cooking, the water vapor causes humidity in the kitchen to rise rapidly, particularly when you are boiling or steaming vegetables. Turn on your over-the-stove fan when cooking to reduce humidity in your kitchen.
  • Doing Your Laundry: A washer and dryer create a large amount of moisture in the air. If you have a fan in your laundry area, you are strongly encouraged to have the running while doing your laundry.
  • Toilet: Leaking toilets or any other water leak can cause humidity levels in your house to increase. Where there is water, there is humidity.
  • Bathroom: Hot showers and baths contribute to high humidity in bathrooms causing condensation on the walls, windows, and other surfaces inside the home.
  • Wet Clothes: Air-drying wet clothing indoors causes the humidity levels to go up in a home.

Related Article: How Does Humidity Affect Furniture? Full Resource

Signs of High Humidity in Home

Humidity alone may not cause any physical symptoms, but humidity leads to the growth of mold and mildew. Mold spores become airborne and can cause an allergic reaction.

We also cannot overlook that high humidity can wreak havoc on the building structure of our homes, especially older homes that aren’t treated properly to withstand the effects of high humidity.

The following are signs of high humidity in a home:

  • Your home feels clammy and moist
  • Foggy windows
  • Mildew smell
  • Visible mold
  • Allergies become intense
  • Sweating rooftops
  • Rotting wood

Do Fans Lower Humidity?

Fans can make us feel some relief from high humidity, but are they helping the humidity problem? Do fans lower humidity?

A fan does not directly lower humidity but can help by circulating the air. Fans pull exterior, less humid air into a higher humidity area of a home lowering humidity by diluting the moisture of the indoor air with the less humid air from another area. Bathroom and kitchen fans pull humidity outside.

In a closed room, the total amount of water vapor in the air remains unchanged when you are using a fan. The amount of moisture in the air does not decrease when the air circulates.

Related Article: How Does Humidity Affect Hair? Show Your Hair Who’s Boss

Do Dehumidifiers Work?

A dehumidifier is a device that is meant to reduce the amount of moisture in the air and can be purchased in many retail stores. Do dehumidifiers work?

Dehumidifiers work by pulling warm air currents into the dehumidifier via a fan. Warm air is drawn into the machine and comes into contact with cold coils, causing the warm air to contract. Moisture from the air is trapped inside the dehumidifier, and less humid air is released back into the room.

Dehumidifiers can be extremely effective in lowering humidity levels in your home. Make sure that when you are looking at dehumidifiers you purchase one that is large enough to cover the area of concern.

You will likely need more than one dehumidifier; one for each room.

Bathrooms can be notorious for excessive moisture, but if you have a good, functioning fan in your bathroom, you shouldn’t need to put a dehumidifier in there.

Unless, of course, the climate you are living in produces a large amount of humidity. Then, of course, having dehumidifiers everywhere makes sense.

Remember that dehumidifiers are electrical appliances. So be sure to buy one that is safe for a bathroom.

Related Article: Does Humidity Affect Hardwood Floors? Protect Your Investment

Why Is My AC Not Removing Humidity?

You walk into your home and you notice something isn’t right. The cool, humidity-free feeling isn’t there. Why is my AC not removing humidity?

If you have an AC unit in your home that has stopped removing humidity, then something is wrong. There are a few things that could be causing the problem:

  • Dirty or clogged filters: If your home’s AC unit is not draining properly, and it has a lot of sediment buildup in the drain pan, the unit will be unable to remove humidity from the air. When you have a filter that is dirty or clogged, then this causes moisture to build up in the air instead of being removed.
  • Dirty evaporator coil or blower: If your home’s AC unit is dirty, then it cannot effectively remove humidity from the air. A dirty blower can cause the coils to overheat and the fans to slow down.
  • A clogged drain or overflow: If your home’s AC unit has a clogged drain or overflow, then this causes the unit to shut down, as it cannot drain water properly. This will inhibit the process of removing moisture from the air.
  • A plugged condensate drain: If your home’s AC unit has a clogged condensate drain, then this causes the unit to shut down because it cannot drain water properly.
  • A defective evaporator coil: If your home’s AC unit has a defective evaporator coil, then this causes the unit to shut down, as it cannot drain water properly. This in turn will stop the humidity from being absorbed by the air.

How to Reduce Humidity in a Room Naturally

We’ve all heard about how ACs and dehumidifiers can reduce humidity in our homes. Are the alternative ways to reduce humidity?

Ways to reduce humidity in a room naturally:

  • Reduce the time you are in the shower. Bathrooms are the biggest contributor to in-home humidity. Never take a shower or a hot bath without running the fan. The fan in your bathroom will pull the moisture outside through the vents.
  • Good in-home ventilation is one of the best ways to reduce high humidity levels in a home. If you have a window in the bathroom, open it while also running the fan during a hot shower. Do you have a window near the kitchen? Open it when you are cooking, while also running the fan above the stove. Portable fans will help to circulate the less humid air into the more humid areas of your home, reducing the overall humidity.
  • Reducing the number of house plants in your home can contribute to the reduction of in-home humidity. This one is tough, so it’s up to you.
  • Absorbing moisture from the air by using charcoal briquettes or calcium chloride in areas of your home that experience the highest levels of humidity. Charcoal briquettes used for barbecuing naturally absorb moisture from the air and can be placed in cute baskets to hide them. Calcium chloride is a powerful chemical found at hardware stores and also has the ability to absorb moisture.
  • Find and repair water leaks to cut down on the humidity in a home. Watch out for leaks under your sinks and also underneath your house. Cracked pipes can lead to dry rot in your floorboards and mold and mildew on your walls and ceilings.
  • Dry heat in a home is best for a home with high levels of humidity.
  • Vent your clothes dryer so it can properly eliminate the moisture from the drying clothes. Clothes dryers that do not have an efficient ventilation system to the outside will cause condensation will form on windows, walls, and ceilings. This condensation will lead to mold and mildew. If you do not have a dryer with a venting system, then opt instead to hang your clothes to dry naturally.
  • Solar air heaters are a wonderful way to help with high humidity. These effective heaters bring in outdoor air, warn it, dry it, and filter it before being introduced into the home.

Related Article: Humidity causes mold and health problems. An ERV system can reduce the humidity in your home significantly. What is an Energy Recovery Ventilator (ERV)? Ultimate Resource

How Do You Remove Moisture from Walls?

If you have a damp wall, then this needs to be addressed right away. Moist walls are a welcoming breeding ground for mold and mildew. This fungus is relentless and will grow quickly.

Excessively damp walls could lead to deterioration of the plasterboard, as well as spreading mold to neighboring insulation.

There are things you can do to dry out your walls and put an end to this problem.

Water Leaks Causing Damp Walls

Leaking pipes should be repaired immediately to stop the root cause of the damp walls. Once you find and repair the problem, then it’s time to address how to dry out your walls.

You may want to contact a professional who is an expert at locating leaky pipes in walls. This may be a more expensive approach yet would provide you peace of mind and less of a headache having to do it yourself.

Drain Excess Water in Walls

If you are dealing with more of a major leak, then chances are you will need to drain built-up water within the wall.

Checking to see if you have standing water in your wall that needs to be drained, you can drill a hole down low to see if water comes out.

If you have standing water within your wall, you will need to drill additional holes along the length of the wall for proper drainage.

Replace and Replace Damaged Plaster Board

Plasterboard that has been soaked in moisture for quite some time may need to be replaced.

Depending on the extent of the water saturation, it may be worth removing all wet drywall and starting fresh so as not to give the mold fungus a chance to grow.

Mold spreads quickly. And while you are waiting for your wall to dry, mold is likely to be blossoming within the drywall.

Small Damp Areas – Use Fans

If the area of your wall is relatively small, then using a couple of fans placed near the wall may be sufficient enough to dry out the moist area.

Fans provide much-needed air circulation to remove the humidity near the damp wall, which will assist in the drying process.

Related Article: What Happens if Indoor Humidity Is Too High?

Dehumidifiers are Recommended

If you live in a humid climate, or if the damp wall area is large, you will benefit from the use of a dehumidifier.

Dehumidifiers remove the moisture from the air, trapping the water inside of the machine, and returning dry air into the room.

Natural Ways to Absorb Moisture in the Air

There are things you can use that pull moisture out of the air that can be purchased at a local retail or hardware store.

  • Charcoal briquettes placed into a decorative basket to disguise them is an effective way to eliminate moisture and humidity from the air.
  • Calcium chloride can be purchased in large bags at your local hardware store and naturally absorbs water from the air.

More Tips

These additional tips may also help to dry out your walls:

  • Open windows for added air circulation, providing it’s not excessively humid outside.
  • Air conditioning units are great for removing humidity from the air in a home.

Related Article: How Does Humidity Affect the Building Structure of a House?


Trina Greenfield, Author
SmackDown Media LLC

About the Author:
Trina Greenfield, the owner of SmackDown Media LLC, is passionate about providing information to those interested in the air quality in and around their homes. Trina writes content about things she’s passionate about, such as safe, in-home air, educational platforms for children and adults, as well as all things family-related.