What Is the Ideal Humidity Level for Your House?

HVAC Logo IconBy HVAC.comJuly 31, 2023
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While most homeowners pay close attention to the temperature inside their homes by adjusting their HVAC systems accordingly, some forget the importance indoor humidity levels play in keeping their families comfortable and protecting their homes from damage.

Most people find a relative humidity level between 30 and 50% is most comfortable. To achieve desired humidity levels, many homeowners install portable or whole-house dehumidifiers and humidifiers.

Ideal Humidity for Home

Between 30 and 50% humidity

Seasonal changes and the climate where you live play crucial roles in your home’s humidity level, but the ideal atmosphere is below 50% average humidity.

As the moisture level in the air increases, you may begin to feel hot and sticky. An increase in moisture levels can also affect certain health conditions, like asthma and allergies, making it difficult to breathe.

Meanwhile, when the air is dry, meaning the humidity level is too low, you may experience dry skin, an irritated throat, or itchy eyes. A lack of moisture can also cause your wood floors or furniture to warp or crack. A simple tool can help you avoid the home and health issues that arise from too much or too little humidity.

How to Measure Indoor Humidity

If you want to measure your home’s humidity you’ll need a hygrometer. A hygrometer is used to measure the humidity level in your house. This small tool can be placed in a living space that’s a good distance away from a bathroom or kitchen where moisture is created. You’ll also want to avoid placing it near doors and windows to ensure the reading isn’t skewed by rain, sunlight, or other weather conditions.

You can buy a digital hygrometer online or at a local big-box store. It will monitor your home’s moisture level so you can be proactive about creating a relaxing environment. 

Ideal Indoor Humidity Levels by Outdoor Temperature

What is a good humidity level for your home? The ideal humidity level for your home may change as the seasons change and outdoor temperatures fluctuate. Certain areas of the country, especially those in the South, typically experience higher humidity levels.

The chart below offers a good place to start if you’re trying to create a comfortable atmosphere.

Outdoor temperatureOptimal indoor humidity level
Higher than 50°FMax. 45%
25°F to 50°FMax. 40%
0°F to 25°F30% – 40%
-20°F to 0°F20% – 30%
Below -20°F15% – 20%

Maintaining Ideal Relative Humidity Levels in the Home

The best tools to keep relative humidity at ideal levels in your home year-round are whole-home humidifiers and dehumidifiers. These systems are integrated into your home’s heating and cooling system and automatically adjust their performance based on the humidity level in your home. Utilize a humidifier in winter months when air is naturally drier, and a dehumidifier in the summer when air naturally carries more moisture.

Portable humidifiers can also help add moisture to a room, alleviating dry skin and preventing damage to wood floors or furniture. 

Problems Caused by Low Indoor Humidity Levels

Dry indoor air can be just as bothersome to your comfort and health as high humidity. Too little moisture may result in:

  • Worsening of asthma and allergy symptoms. Cold and flu viruses may spread more quickly, and you may be more prone to sinus infections. You may suffer from dry skin, chapped lips, and dry air passageways.
  • Increased energy bills as you crank up the heat to stay warm after the dry air pulls moisture from your skin.
  • Cracks and damage to wood flooring, trim, and even framing around windows and doors. Wood, building materials, and furniture are robbed of their moisture when the air is dry.

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FAQs on Optimal Humidity Levels

What is the perfect humidity for home?

Although the perfect humidity for a home is subjective, the Consumer Product Safety Commission recommends a humidity level between 30-50% for comfortability, and the Environmental Protection Agency makes the same recommendation. This means that the air contains 30-50% of the maximum possible moisture that it otherwise could. Keeping it in this range helps prevent the growth of harmful mold and mildew and the presence of dust mites.

What causes high humidity levels?

The top causes of high humidity in the home are showering, boiling water, and drying clothes inside. If you often have high humidity in your home that is not caused by any of these, you might need to have your home’s ventilation and insulation inspected. There could be gaps or cracks that are allowing for air exchange with the outdoor air.

What is relative humidity?

Relative humidity refers to the amount of water in the air compared to the amount the air can hold at a given temperature. If the relative humidity is 50%, the air is only holding about half the amount of moisture it’s capable of holding at that temperature.

How do I increase the humidity in my home?

One of the most effective ways to increase the humidity level in the house is with a whole-house humidifier or a portable humidifier, depending on your needs. If you live in a dry climate, like many states in the Southwest Region of the U.S., installing a whole-house humidifier to your heating and air conditioning system is a good investment to consider.

How do I decrease the humidity in my home?

To lower your home’s humidity level, you need to reduce the amount of moisture in the air. A whole-house dehumidifier is likely the best way to accomplish this task if you regularly battle high indoor humidity. You’ll also want to change the filter in your heating and air conditioner system as recommended (usually every 60-90 days) and have the unit inspected each year for needed maintenance.