How To Control Humidity in Your Home

Avoiding mold and improving ventilation

Control Humidity In Home - Hoffmann Brothers

“What should the humidity be in my house?” is an important question that all too often gets skipped.

According to the Consumer Product Safety Commission, a humidity level between 30–50 percent is ideal. The Environmental Protection Agency (EPA) expands that just a bit and recommends 30–60 percent humidity levels.

Knowing when and how to control the humidity in your home can affect the comfort, health, and lifespan of your property, and the people (and pets) living within it.

What Is Humidity?

Controlling Humidity In The Home - Hoffmann Brothers

We often think of humidity as that heavy, wet, sticky feeling in the air when outdoor temperatures rise. What we don’t often consider is that humidity can also mean the lack of moisture in the air outside and inside. You know it when you feel it.

Whether we are trying unsuccessfully to get comfortable and sleep with the AC on high and a fan pointed straight at us in the summer, or we are inside wrapped in blankets with dry skin and chapped lips during the winter, humidity plays a large factor in both comfort and health.

Absolute vs Relative Humidity

There are two kinds of humidity: absolute and relative.

Relative Humidity = the amount of water in the air vs. how much water it could hold. This is the term you are likely more familiar with and the one you will use to gauge your home’s humidity level.

Absolute Humidity (g/m³) = the water mass in the air divided by the air mass in a room. In other words, it tells you the amount of water in the air.

Humidity and Your Home

This probably has you asking, “What should humidity be in the house in winter, summer and throughout the year? During the colder, winter months staying below 40% humidity is ideal, while in hot, summer months the average humidity should be between 30-45% (or below 50%, depending on your preferences).

Measuring Humidity Levels

One way to make sure your home is staying within the ideal humidity range is to invest in a hygrometer. This device measures the amount of moisture in the air. It is inexpensive and available at your local hardware store or, no doubt, plenty of places online.

A hygrometer can also come in handy as different areas of your home have various humidity levels (think: your basement, kitchen, and bathroom vs. bedrooms and living areas). For instance, areas like basements and crawl spaces tend to have higher moisture levels because they are susceptible to moisture and leaks from the ground below and around them.

Unfortunately, that also means they are susceptible to mold growth as these spaces have limited airflow and trap moisture. Having a home with too high or not high enough humidity levels can cause a number of problems for your property and your health.

What is High Humidity?

Anything over 50–60% could be considered high humidity, especially during certain seasons in certain regions. A sign that the humidity is (too) high in your home is moisture on the windows. This often happens during/after cooking, taking long, hot showers, and doing the dishes.

Common Consequences of High Humidity

Foul Odors
Mold, fungus, dust mites and rotting
Rusted and corroded metal
Ruined floorboards
Weakened floor joists
Condensation in your walls, which leads to structural damage and wood rot
Pests such as termites, carpenter ants, wood-eating beetles, and others that love rotting, moldy wood
Allergens and allergies
Respiratory problems
Sleep interruptions
Feeling lethargic, irritable, and generally unwell
Higher utility bills

How to Lower Humidity in House

Some helpful and even creative ways to reduce the humidity in your home include:

Running AC or furnace (Note: an oversized AC or one that is continuously running could increase the humidity)
Using your AC, exhaust, and ventilation fans (especially while showering and cooking)
Trusting your mini-split thermostat to automatically monitor and maintain a certain level of humidity without your constant manual manipulation. However, when you do have to step in, most can be controlled by an app or other smart home devices
Installing a Dehumidifier
- Whole House Dehumidifiers – These fit inside your furnace air handler and remove moisture from the air before it moves through your ductwork
- Portable/room dehumidifiers – Often a fit for basements
Sealing crawl space vents
Putting a plastic cover over crawl space dirt
Installing crawl space vapor barrier on walls and floors
Fixing leaky pipes (these only add moisture to the equation)
Insulating cold-water pipes
Cleaning gutters to avoid leaks inside, and directing downspouts 6 ft. away from the house
Taking cooler showers
Drying laundry on a clothesline outside (unless restricted by your neighborhood bylaws)
Moving moisture-releasing plants to a well-ventilated room or outside
Setting out a basket of charcoal briquettes (which are highly absorbent), then replace every 2-3 months
Opening a window
Adding storm doors, drapes, blinds, double / triple-paned windows, caulk, and weather strips to help insulate and separate your home from moist outdoor air
Leaving inside doors open for better air circulation
Using area rugs that can be taken up and washed often. In certain climates, if carpet is to be installed over a concrete floor, it may be necessary to use a vapor barrier (plastic sheeting) over the concrete and cover that with sub-flooring (insulation covered with plywood) to prevent a moisture problem.” (will add foonote: EPA)
Vacuuming and changing HVAC filter(s) routinely

What is Considered Low Humidity?

If the ideal range for relative humidity is 30–50%, anything below 30% is considered low, and comes with its own list of disadvantages to your home and health.

Without enough humidity in the air, you will notice a spike in:

Wood floors and furniture drying, cracking, shrinking/warping
Millwork and paint drying and cracking
Static electricity
Damaged electronics and musical instruments
Allergies
Asthma
Dry skin and hair
Chapped lips
Cough, wheezing, and other breathing problems
Interrupted sleep
Increased susceptibility to colds and respiratory illness (viruses and germs thrive in this kind of environment)

How to Increase Humidity

What do you do when you need to know how to increase humidity in a room? First, it is helpful to know that the benefits of increasing the humidity levels are not insignificant. On top of relieving the above-listed symptoms of low humidity, snore relief is also a perk of more balanced air quality. This is huge for the person snoring getting better quality sleep and for partners trying to escape the freight train noises coming from the next pillow!

Some useful and creative ways to increase the humidity (and your comfort) include:

Installing a Humidifier – Modern models automatically sense and maintain humidity at around 45% as well as prevent bacterial growth.
- Whole house humidifiers are installed directly inside your furnace and help add moisture through your home’s ductwork with the help of a humidistat.
- Portable/room humidifiers come in warm and cool mist and are great for bedrooms and living areas.
Opening the dishwasher after its last rinse cycle and letting the steam escape into the air rather than use the dry cycle.
Simmering a pot of water on the stove
Air-drying laundry inside – Your permanent press load is perfect for this.
Letting hot bath or dishwater cool before releasing the plug
Using a fine-mist spray bottle to spritz the air every hour or so

FAQ’s About Humidity Control

What Is Relative Humidity?

Relative Humidity is a measurement of the amount of water in the air vs. how much water it could hold. This is the number you use to gauge your home’s humidity level.
What Causes High Humidity In a House?

The top causes of humidity in the home are showering, boiling water, and drying clothes inside as well as ventilation and insulation issues. Using a whole house humidifier offers a great solution.
What Do You Do If Your Humidity Is Too High In Your House?
Some ways to remove moisture from your home include adding a:
- Dehumidifier to your home or “wettest” rooms
- Boston Fern or similar plant that removes moisture rather than adding it to the air
Can Humidity Make You Sick?

Yes. Humidity and poor indoor air quality may cause, contribute, or increase the likelihood that you will have infections, lung cancer, asthma, heatstroke, and heart problems. Too much humidity can make you feel lethargic, irritable, and generally unwell on top of making it hard to sleep and get good rest. Too little humidity can cause dry skin, chapped lips, cough, wheezing, other breathing problems, scratchy throats, nasal discomfort, and snoring.