What Is The Ideal Indoor Humidity For Your Home?

Humidity control in your home is important all year round. You might not know it, but humidity levels play a vital role in the health, safety, and comfort of you and your family. 

Sometimes, the humidity in your home isn’t right. It can be too high or too low. Both can range from being mildly uncomfortable to unbearable and damaging. 

This article discusses the ideal indoor humidity levels, how to measure it, how to manage it, and why humidity is so important! So continue reading to learn more!

a hygrometer on the windowsill

What Should The Humidity Be In Your House?

The humidity in your home is the amount of water vapor in the air, generally considered in correlation to temperature — the level of water vapor the air can hold changes as the temperature fluctuates. 

Humidity levels that are consistently too high or low can cause varying issues within your home, so maintaining the recommended level is imperative. The ideal relative humidity (RH) level for your home depends on the time of year, temperature, and a few other things. 

However, generally speaking, the humidity level in your home should fall somewhere between 30 and 60% RH for ideal comfort and safety. 

The EPA recommends indoor humidity between these percentages to reduce mold growth and the spread of pathogens like COVID-19

Info: Humidity levels above 60% RH promote germ, fungal, and mold growth, and levels below 40% RH allow pathogens (like viruses) to suspend in the air and spread easier. 

However, the best level for you may be somewhat different based on specific factors, like the outdoor conditions, maintenance of your home, and any health concerns. 

What Should The Humidity Be In Your House in Winter?

a person cleaning condensation on the walls

The ideal indoor humidity generally falls between 30 and 50 percent during the winter months. 

You’ll likely notice a difference in humidity levels during the winter, especially if you live in a cold climate. 

Info: Colder air cannot hold as much moisture as warm air, so cold air is usually dryer.  

However, during the winter, your home is susceptible to condensation forming on various surfaces in your home. The warm, moist air within your home can form condensation on cold surfaces throughout the house, like windows and doors. 

This happens because the cold air cannot hold as much moisture as warm air. So, it’s best to maintain a lower indoor humidity during the winter to avoid condensation. 

Why should you care about condensation? Condensation might seem harmless, but mold can grow if your windows constantly have moisture. Obviously, you don’t want mold in your home!

Note: Even if mold doesn’t pop up, the condensation can still be problematic. Over time, the moisture can leak down into your window casements and damage them. Rotting wood, soggy drywall, and an expensive repair bill probably aren’t on your Christmas list. 

What Should The Humidity Be In Your House in Summer?

On the other hand, the ideal humidity percentage bracket for summer temperatures looks different than in the winter months. The perfect indoor humidity is between 40 and 60 percent in the summer. 

Note: Unlike the cool temperatures gripping the air in the winter, the summer air is much warmer and can therefore hold more water vapor. Your home is considerably more susceptible to mold forming on various surfaces during the summer. 

A similar situation to winter condensation may occur. For instance, if you have your air conditioner on full blast and it’s unable to dehumidify the air adequately, you may have issues with condensation. 

This is especially problematic in areas with high outdoor humidity levels. If you live in Florida, Mississippi, Louisiana, west Texas, or anywhere in the Southeast U.S., watch out. You may need a dehumidifier to help keep your humidity low. 

Because objects in your home, like windows, walls, furniture, etc., hold heat, your cold AC blasting on them may cause condensation to form on them due to high humidity levels. 

How To Measure Humidity In Your Home

a person holding a hygrometer

Indoor humidity gauges or hygrometers are an excellent way to monitor relative humidity levels in your home. These devices are generally inexpensive, so you can purchase several gauges without spending too much money. 

Some home thermostats measure RH, too, so check your thermostat. For battery-powered RH gauges, make sure that you position them in different areas of your home. 

Note: Humidity levels can vary from one room to the next, so monitoring the levels in different rooms is essential. 

For example, basements tend to be more humid than other rooms since it’s cooler, and moisture from the ground can seep through basement walls.

If the humidity is drastically different in one area of your home than in another, you’ll need to find a solution to maintain a consistent level. For example, it may be 50 percent in one room while under 30% in another area. 

In these cases, a portable dehumidifier will become your knight in shining armor to protect your home from the evil humidity that dares to set foot in your territory. 

What Should Humidity Be In a House with Air Conditioning?

a person turning on the AC

Even with air conditioning, the humidity levels should be within the same range we mentioned earlier — between 30% and 60%. One of the functions of air conditioners is to remove excess humidity from the air as the system conditions it. 

However, you may deal with excessively high humidity levels if the system isn’t operating correctly. 

For example, if the AC unit is short-cycling, which is a common problem with oversized units, it won’t have enough time to remove moisture from the air in the rapid cycles adequately. 

Or, if the fan runs continuously, you may notice high humidity levels. When the fan constantly runs, the evaporator cooling coil cycles on and off to maintain a consistent temperature in your home. 

When the coil is cool, it cools and dehumidifies the air when water from the air condenses on the coils.

If the fan remains on while the cooling function is off, then the fan blows the moisture from the coil back into your house. Switching the fan to ‘Auto’ can correct this issue.

Why Should You Care About The Humidity Levels?

a cleaning professional removing mold

Humidity is an important thing to monitor in your house. Why? It can negatively impact your health and damage your home.  

Health Issues

Extreme humidity levels in your home can wreak havoc on your health. When the humidity is too low, you run into issues associated with dry air. 

Dry air can cause you and your family to have dry skin, a dry nose and throat, and an increased risk of catching a cold. 

Studies confirm the correlation between humidity levels and the survival of influenza and COVID-19 viruses in the air and on various surfaces. The virus’s survival rate increases, becoming more contagious in lower humidities.

On the other hand, high humidity levels aren’t beneficial for your health either. High humidity often goes hand in hand with high temperatures, which creates a deadly combination. 

When the humidity level is too high, sweat can’t evaporate as quickly, interfering with your body’s natural mechanisms to cool itself (thermoregulation through evaporative cooling). 

Your risk of heat stroke and heat exhaustion is heightened with this combination, not to mention additional problems, like dehydration issues, muscle cramps, fainting, fatigue, etc. 

But, assuming you have air conditioning, your chances of heat stroke are slim to none. 

Individuals with asthma or other respiratory issues often struggle with high humidity levels. In addition, people may have problems with dermatitis and other skin-related issues if the indoor RH levels are too high. 

Comfort Levels

Extreme humidity levels also put a damper on your overall comfort levels. 

When the air is too dry, you may have difficulty breathing. On top of that, the associated health issues, like dry skin and a dry nose and throat, create an uncomfortable experience. 

When the air is too moist, particularly in the summer, you’ll have a balmy environment in your home. If you have an air conditioner, the air in your home may be cool, but the excess humidity will make the air feel clammy and uncomfortable.

Biological Pollutant Problems

Aside from comfort and health issues, extreme humidity levels can create a problem with biological pollutants. This includes unwanted visitors like mold, fungi, bacteria, viruses, and dust mites. 

In addition to the unwelcomed guests, these pollutants can cause flare-ups in individuals with respiratory health problems. 

If mold takes a firm root in your home, the spores may blow around your house when the AC runs. While inhaling any type of mold spores isn’t good for your health, some types of mold can cause worse health issues than others. 

A few of the characteristic symptoms of mold inhalation or contact include allergy-like symptoms, including skin rash, headaches, lung irritations, eye irritation, etc. 

Plus, improper RH levels let airborne viruses prosper. This means if you don’t maintain the RH levels to safe levels, it will be much easier for contiguous viruses to spread around your home. 

How To Manage Humidity Levels

Since humidity levels can cause all sorts of issues for you and your home, maintaining consistent levels within the correct bracket is imperative. 

There are a few ways you can control humidity levels in your home, including dehumidifiers, humidifiers, and more. 

Winter Humidity Management

stainless steel pan boiling water on the stove

During the winter months, when the air is dry and cold, you may struggle with issues associated with low humidity. 

To combat low RH, consider incorporating a humidifier. You can buy humidifiers of varying sizes at many different stores. These devices simply require you to fill the water tank, and then they release water vapor or steam to increase moisture levels in the air. 

Since many people have an easier time breathing with more humid air, humidifiers can be a great addition to any space where you spend a lot of time (bedroom, living room, etc.).

Depending on your needs and preferences, you could add a portable room humidifier or a whole-house humidifier. 

Here are other ways you can tackle humidity levels during winter:

Boil Water 

Aside from a humidifier, there are other ways you can increase your home’s indoor humidity levels. One of which is boiling water. As the water heats up and evaporates, it releases moisture into the air. You can also leave the lids off when you’re cooking. Also, try to use the microwave less. Instead, use the stovetop. 

Take A Hot Shower 

Shower steam can help with low humidity as well. 

When you take a hot shower, open the bathroom door and keep the shower curtain open. This allows the humid air to move into the main parts of your home, helping to tackle dryness issues. You can even use a fan to help circulate the moist air to other rooms in your home. 

Set Out Water Pans And Hang Dry Laundry 

If you don’t want to boil water on your stovetop or run a humidifier, there are a few ways to boost the indoor humidity for free. 

Fill a pan or vase with water and set it near heating vents or on the top of a radiator. The warmth from the heating system will help the water evaporate quicker. 

Toss a few things in the water for pleasant scents in your home, like citrus peels, essential oils, or vanilla. 

Another great way to humidify your home for free is to hang dry your laundry. By allowing the laundry to line-dry, the evaporated water from the clothes contributes to the humidity in your home. Bonus: you save money by not using the dryer!

Summer Humidity Management

a technician installing an exhaust fan

During the summer, high humidity plagues many homes. When the air becomes too humid, you’ll run into varying problems associated with the excess moisture in the air. 

So, to tackle this issue, consider incorporating a dehumidifier.

Dehumidifiers can be standalone units or incorporated into your central heating and air conditioning system. These devices work by drawing air from the surrounding area into the system via a fan. 

As the air passes through the dehumidifier, it comes into contact with the system’s cooled coils. The coils utilize condensation to remove moisture from the air. The collected moisture stays on the coils before dripping into the dehumidifier’s reservoir. 

Once the moisture is removed from the air, it collects in a tank that you can empty (or connect to a continuous drain line). 

Note: Consider purchasing a two-in-one system if you have issues with high humidity in the summer and low humidity in the winter. You can buy dehumidifier-humidifier combos that package the same functions of the individual units into a single system. 

Alternatively, you could purchase a three-in-one system that functions as a dehumidifier, humidifier, and air purifier. These systems may be a good idea if you have health or allergy sensitivities in your home. 

Like central heating and cooling, many HVAC systems come with a whole-house dehumidifier. So, in the summer, when the air is too humid, the system automatically removes excess humidity from the air, leaving you with a comfortable, cool environment. 

Like winter humidity level management, there are other ways you can deal with high humidity levels: 

Install Exhaust Fans 

Exhaust fans are a standard fixture in kitchens and bathrooms. They work great for removing excess humidity in space. You may have one above your stove, where boiling pots of water add to the humidity in the kitchen. 

And your bathroom probably has one in the ceiling to help remove moisture from the air after a hot shower. 

Turning on the exhaust fan allows the system to pull hot, warm, moist air from your home and release it outside. This helps ensure your home remains comfortable. 

Add Indoor House Plants 

If you enjoy having houseplants, you could invest in a few. The plants absorb water vapor via the stomata in the leaves, which transfers the moisture to the roots. This is great for reducing excessive humidity levels in your home.

They are a great alternative to dehumidifiers for small spaces, as they do a great job of pulling excess moisture from the air and using it for growth. Plus, house plants add ambiance and decor to your home, making it more welcoming and pleasant. 

Conclusion

Given the importance of humidity levels in your home, maintaining between 30% to 60% RH is imperative. 

Extreme humidity levels may wreak havoc on your health, comfort, and home, so investing in the appropriate humidifying or dehumidifying measures is a good idea. 

Whether you decide to incorporate these functions into your central heating and cooling or simply carry around a portable unit, you’ll likely notice a difference almost immediately. From more comfortable sleep to better health and home safety, it’s a win-win all around. 

About The Author

Jonathon is a mechanical engineer with over ten years of experience in the HVAC industry. He has hands-on experience with all types of HVAC systems.

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