When considering home health, indoor air quality is typically at the top of the list of concerns. And even then, it’s still not on a lot of people’s radars! One issue even further down the home maintenance task checklist is indoor humidity and the importance of keeping it at just the right level.

Think about it! When’s the last time you thought, "Huh, I wonder what the moisture content in my home’s air is?" Chances are that it doesn’t pop into your head that often. You’re not alone! This issue isn’t exactly a hot topic in society.

That being said, it should be. This component is integral to ensuring your home is a safe indoor environment and doesn’t suffer from issues like microbial growth.

With that in mind, here’s everything you need to know about indoor humidity and how to increase and decrease it as needed.

What Should the Indoor Humidity Level Be?

That’s the golden question!

indoor humidity

The ideal humidity level in a home should be between 35 and 50 percent. Too high or too low humidity indoors can not only cause wellness issues but also problems with the health of the home as well. 

When the humidity is too high, it can cause microbial growth, poor indoor air quality, and structural issues in the building. However, you also don’t want it to be too dry indoors! That can lead to adverse health reactions and structural issues like wood separation.

Ideal humidity should be maintained not only for comfort but also to maintain a safe indoor environment that promotes ongoing wellness.

The Mold and Humidity Relationship

Mold can grow at a relative humidity level of 60%. Keeping that level below this threshold can ensure that fungus among us doesn’t turn your home into a toxic hazard zone.

Why We Should Avoid Mold Indoors?

While mold is an important element in nature, it can turn our homes into health hazards. As a colony grows, it releases microscopic spores and fragments into the surrounding areas. Some species of mold also create microscopic toxins called mycotoxins when threatened. Interestingly, while mycotoxins are regulated in our food products, there are no acceptable levels in our homes.

The difference between mold growing indoors and outdoors is the space these particles have to disperse throughout. Thanks to modern building practices pushing for net-zero energy efficiency, there’s minimal airflow between indoor and outdoor environments. This means that the majority of the particles released by the colony will remain inside and continue to build up. 

The Health Aspect

The hazardous part of the equation is due to the size of the particles in question. Measured in a unit called microns, mold particles are all able to be inhaled, ingested, and absorbed into the body. The more time someone spends in a home with an issue, the more particles will enter the body. 

A common misconception is that since mold is everywhere, it’s not a big deal in our homes. While it’s true that completely avoiding exposure to these particles is impossible, the volume of exposure is the problem. In an everyday situation where low levels of spores or toxins make their way into the body, the body will tag them as foreign invaders and send the immune system to get rid of them ASAP. 


Microbial growth in a home is not the same situation. Instead of a manageable number of particles, the body is facing an army of them every time the person is inside the building. Eventually, the immune system can get overloaded and/or malfunction, leading to a long list of chronic adverse health reactions. It can also work in relation to autoimmune conditions such as Aspergillosis, Chronic Fatigue Syndrome, and Mast Cell Activation Syndrome. 

A few common symptoms of exposure include:
  • Brain fog
  • Chronic fatigue
  • Hair loss
  • Migraines and headaches
  • Muscle and/or joint pain
  • Skin issues such as rashes
  • Digestive problems 
  • Allergy and cold-like reactions
  • Anxiety and/or depression
  • Mood swings

The tricky aspect of exposure is that no two people respond the same way. One person in a home with mold under the carpet may have the occasional digestive issue, while another may develop 20 seemingly random symptoms. This makes diagnosing the problem difficult if medical professionals are unfamiliar with the impact environmental exposures can have on health.

Much more research is needed to understand better how toxic indoor environments can impact health, but there are a variety of factors that make it a difficult subject to nail down. Genetics, species of mold, presence of mycotoxins, presence of bacteria, the volume of exposure, and immune system status can all play a role. For example, those with compromised or developing immune systems are at greater risk of developing symptoms faster and to a greater extent. 

Protecting our bodies from a bombardment of microscopic particles should be at the top of everyone’s wellness plans. A piece of this puzzle is knowing how to prevent mold growth by maintaining the correct indoor humidity levels.

Pro Tip: Invest in a Hygrometer


EVERY home should have a hygrometer (or multiple) to monitor indoor humidity levels in real-time. 

If the humidity tips too far in either direction, you can quickly take steps to remedy the situation and get your home back into balance. Mold can grow in as little as 24-48 hours, so time is of the essence when it comes to home health.

With that in mind, here are steps you can take to influence your indoor humidity and ensure it remains in the sweet spot of 35-50%.

How to Decrease Indoor Humidity

When it comes to mold, decreasing indoor humidity is at the top of the list. Again, too high, and it can allow that fungus among us to grow. This issue can be especially difficult during those warm summer months or in high-humidity areas, so make sure to pay attention to that hygrometer and actively work to keep your home safe.

Steps to decrease indoor humidity include:

  1. Use the air conditioner
    Your air conditioner helps reduce indoor humidity because it replaces warm, humid air with cooler air that has less moisture content. Another piece of this puzzle is changing the air filters on time and maintaining the HVAC system so that the air conditioner can run properly.
exhaust fan
  1. Focus on airflow in high-moisture rooms like the kitchen and bathrooms
    While showering, turn on the exhaust fan and crack a door or window. This will help replace all of the moisture-rich air with dryer air from outside the room. Leave this on for 30 minutes after finished. For kitchens, use the exhaust fan while cooking or crack a window.
  1. Cleaning up spills and pooled water ASAP
    Standing water can contribute to humidity inside, so avoid these situations as much as possible to keep these levels low.
  1. Avoiding leaving wet clothes
    Again, reducing moisture is key. Dry clothes immediately after washing, but avoid hanging them up inside. This can increase indoor humidity.

  2. Fix any leaks
    Leaks can create excessive moisture in a home, which increases the humidity as it evaporates into the air.
  1. Ensure that doors and windows are sealed properly
    This will help prevent the transfer of temperature and humidity between the indoor and outdoor environments, which may have very different moisture levels.
  1. Invest in a dehumidifier 
    These machines help pull moisture from the air, helping to keep the moisture content at an appropriate level. Dehumidifiers can be used year-round in rooms that are prone to mold growth, such as kitchens and bathrooms, which get bombarded with water throughout the day. If these areas don’t have adequate ventilation or it’s difficult to keep the indoor humidity low, these are a great option to ensure they remain as dry as possible. Whole-home dehumidifiers are also a fantastic addition to a home to help ensure high humidity levels from the outdoors do not increase the humidity level inside, particularly during those warm, humid spring and summer months.
decreasing indoor humidity
  1. Do not open windows and doors when it’s raining
    During the warmer months, especially, the outside humidity level can remain fairly high. Keeping windows and doors closed will help prevent that moisture-rich air from coming inside.
  1. Keep those gutters clean
    Improperly installed gutters or a lack of maintenance can allow for moisture intrusion into the home. The more moisture there is, the higher the indoor humidity will be.
  1. Ensuring there’s adequate insulation
    Top-notch insulation that is installed correctly will help maintain temperatures inside and prevent wide fluctuations in humidity.
  1. Increasing air circulation throughout the home
    Opening doors throughout the home and turning on fans can help prevent humidity from settling in one area. 
  1. Reduce carpeting
    Carpets can retain moisture, increasing the levels within your home. Reducing this material will help avoid this scenario.

Collectively, these steps will help ensure that the moisture content in the air doesn’t get high enough to allow for microbial growth, cause structural issues, or negatively affect your health. Consider it a winning hat trick!

How to Increase Indoor Humidity

While it may seem like we want to keep the lowest possible humidity to prevent mold growth, that can negatively affect our home's health. As mentioned, it can trigger adverse health reactions and a long list of structural issues. Not to mention, a super dry home is just uncomfortable!

With that in mind, if the hygrometer shows that levels are plummeting, take action quickly to resolve the issue. Wintertime and locations with constant low humidity will make this a constant battle but it’s one you can absolutely conquer!

Steps to decrease indoor humidity include:

  1. Ensure that doors and windows are sealed properly
    Again, this will help prevent the transfer of temperature and humidity between the indoor and outdoor environments, which may have very different moisture levels. 
increasing indoor humidity
  1. Cook on the stovetop often
    The steam created by cooking can help increase the overall moisture content in the air.
  1. Lower the heat
    This helps avoid drying out the air too quickly, which can decrease the humidity in the home.
  1. Open the bathroom door while showering
    This will let all of that steamy air out into the rest of the home, and it also helps prevent mold in the bathroom.
  1. Air-dry clothes indoors
    As the clothes dry, the moisture will evaporate into the air, increasing the indoor humidity.
  1. Place dishes of water near heat sources
    The heat from the sources will cause the water to evaporate, adding moisture to the air. Make sure to empty and clean them daily to prevent microbial growth.
  1. Invest in a humidifier that has a humidistat
    Humidifiers will help add moisture to the air, but it’s important to make sure that they’re not adding too much. A humidistat will help avoid this issue by turning the machine off once the ideal humidity level has been reached. Proper maintenance should also be done so that the machine doesn’t allow for microbial growth, which lowers the indoor air quality. 

Opting for a few of these steps throughout your home can help ensure that the moisture content of the air doesn’t drop too low and start causing issues.

This is a Journey

puzzle pieces

Home health is an ongoing process. Think of it like a puzzle! Every piece will eventually come together to create a healthy home that promotes your wellness. Indoor humidity just happens to be a piece of that puzzle!

Still Have Questions?

A member of our team is here to help!  Click on “Get Started ➤” below to book a consultation with a member of the HOMECLEANSE team. We have a few quick questions that will help us put together a roadmap to solve or prevent all of your mold problems.

Two minutes of your time could lead to better health for you and your family.


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