Humidity is an important factor in the comfort, efficiency, and health of a home and its occupants. Getting the levels just right is essential for creating a comfortable and safe indoor environment. Home Comfort Services is here to provide a clear breakdown of the science behind humidity, the ideal ranges to aim for, and practical ways to maintain proper levels throughout the year.
The Science of Humidity
Humidity refers to the amount of moisture present in the air. Water molecules don’t chemically bind to air molecules. Instead, they occupy the empty spaces between them. The warmer the air, the higher its kinetic energy and the space between its molecules. As a result, warm air tends to hold more moisture than cold air. You may have noticed that summer air feels heavier and more humid, while cold winter air tends to feel dry and crisp.
Relative vs. Absolute Humidity
Humidity is often described as absolute or relative humidity. Absolute humidity refers to the actual amount of water vapor in the air, regardless of temperature. It is expressed as grams of water vapor per cubic meter of air (g/m³). Relative humidity, on the other hand, expresses how much moisture the air is holding compared to how much it could hold at that same temperature. It is expressed as a percentage to reflect how close the air is to becoming saturated.
To put this into perspective, an absolute humidity of 15 g/m³ would translate to a relative humidity of about 63% at 78°F. Increase the temperature to 95 degrees Fahrenheit, and that same 15 g/m³ would represent only about 38% relative humidity. The moisture content has not changed, but the air’s capacity to hold moisture has increased, which lowers the relative humidity.
For that reason, relative humidity is the more practical measurement for understanding indoor comfort. It reflects how the air feels based on influencing indoor factors such as temperature, rather than simply indicating how much moisture is present.
Seasonal Behavior of Indoor Humidity
Indoor humidity does not remain constant throughout the year, even when your home’s moisture sources stay the same. As stated, temperature shifts from season to season change the air’s capacity to hold water vapor.
Warm summer air can hold far more moisture, and indoor spaces often feel more humid. Air conditioning helps remove some of this moisture, but homes can still experience elevated humidity during long stretches of heat or rain.
Winter brings the opposite challenge. Cold air holds very little moisture because its lower kinetic energy reduces the space between its molecules. This leaves less room for water vapor. If you heat already dry air, it becomes even drier.
Transitional seasons, like spring and fall, tend to be more balanced. However, they can still produce swings in humidity as temperatures fluctuate. A mild afternoon may raise indoor humidity, while a cool evening can cause it to drop again.
Ideal Indoor Humidity Ranges
The ideal indoor relative humidity range, regardless of the time of the year, is 30% to 60%. This level strikes a healthy balance by supporting comfort and well‑being while also preventing moisture‑related problems.
What Happens When Indoor Humidity Is Too Low
Low humidity is any level below 30% relative humidity. When the air becomes this dry, it can lead to several issues.
Respiratory Issues
The human body relies on moisture for nearly every respiratory function. The air passages and lungs are lined with a thin film of water that protects delicate tissues, supports smooth gas exchange, provides lubrication, and helps trap and remove pathogens. When humidity drops too low, this protective moisture layer begins to evaporate more quickly.
The first signs often appear in the nose, where debris becomes more noticeable because mucociliary clearance is impaired. As the airway lining dries, the fragile cells become inflamed. Symptoms such as a sore throat and a persistent dry cough begin to develop. If this dryness continues, the lining can crack, which may lead to minor bleeding and increased vulnerability to respiratory infections.
Extremely dry air can also collapse the alveoli, which is a condition known as atelectasis. Alveoli are responsible for gas exchange in the lungs. This means you’ll begin to suffocate while still breathing air. This is especially common among individuals who already have respiratory sensitivities.
If there are people in your household with asthma, chronic obstructive pulmonary disease (COPD), or allergies, low humidity can make their symptoms worse. You’ll often notice more coughing, wheezing, and even shortness of breath.
Skin and Eye Irritation
The skin relies on a stable moisture barrier to stay functional, supple, and comfortable. When the air is too dry, moisture evaporates more quickly from the skin, leading to tightness, itching, flaking, and irritation.
The eyes also suffer a similar response. The tear film that keeps the eyes lubricated evaporates more quickly in dry air, which can create a gritty or burning sensation.
Damage to Property
Wood, books, electronic equipment, and many other household materials are also affected when indoor humidity drops too low. For instance, wood flooring, cabinetry, doors, and furniture can shrink, warp, or develop small cracks in prolonged dry air. On the other hand, the fibers in books, photographs, and documents can lose flexibility. This increases the risk of curling, cracking, or permanent distortion. Low humidity can also contribute to static electricity buildup, which can be very harmful to sensitive electronics.
Impacts of High Indoor Humidity
Humidity levels above 60% promote mold and dust mite growth and can cause a range of property-related problems. The excess moisture in the air will seep into material, settle on surfaces, and create conditions that support structural deterioration.
You’ll notice rusting on metallic equipment in your home, including your HVAC system. Wood floors, furniture, and structural beams can warp, swell, and rot. Paint and wallpaper may start to bubble, peel, and then separate from the wall.
Mold and dust mite growth will trigger allergies, asthma, and other respiratory illnesses. High humidity also causes the air to feel heavy, clammy, and sticky, making it difficult for your body to cool itself through evaporation. This can lead to heat exhaustion and, in some cases, heat stroke.
Maintaining Optimal Humidity
You can maintain optimal humidity levels in your home by installing both a dehumidifier and a humidifier. Choose units that integrate directly into your HVAC system, since these provide the most consistent and efficient control throughout the entire home.
A dehumidifier removes excess moisture from the air, whereas a humidifier adds water vapor when the air becomes too dry. These systems have built-in hygrometers, meaning they’ll automatically monitor indoor humidity and adjust their output to maintain your set range. Some smart thermostats for HVAC systems can also read indoor humidity levels and coordinate with your dehumidifier and humidifier to improve indoor air quality.
Proper ventilation also plays a key role in maintaining stable humidity. Kitchens, bathrooms, and laundry rooms generate significant moisture, which can accumulate quickly. Exhaust fans, fresh‑air intakes, and well‑sealed ductwork can help move humid air out of the home and bring in cleaner, drier air when needed.
Contact Home Comfort Services for More Information
Let our experts help you manage humidity issues in your home. Our technicians will assess your indoor environment, identify the sources of moisture imbalance, and recommend the right combination of equipment to keep your home comfortable. We are ACCA (Air Conditioning Contractors of America) and EPA certified, and we hold an A+ rating with the Better Business Bureau. You can trust that we’ll provide honest guidance, high‑quality workmanship, and solutions that are tailored to your home’s unique needs. Call Home Comfort Services today for professional humidity control in Grand Junction, CO.
