Can You Lower Humidity by Running the Air Conditioner?

Excess humidity can cause many problems, such as mold growth, musty odors, structural damage, and an unpleasant muggy feeling. That’s why it’s important to control humidity if you hope to improve indoor air quality and home comfort. 

The ideal relative humidity level is between 30 to 50 percent. Summer is typically the hardest time of year to stay within this range. Fortunately, running the air conditioner can help. 

After all, air conditioning doesn’t just cool your home—it also lowers humidity. Here’s a look at how this works, along with tips to control indoor humidity levels. 

How Air Conditioning Removes Humidity 

Contrary to popular belief, your air conditioner doesn’t add cool, dry air in your home—it removes heat and humidity. The process requires refrigerant, which absorbs heat and moisture effectively from the indoor air. Here’s how it works: 

• Indoor air rushes through the ductwork and passes over the evaporator coil containing cold refrigerant. 
• The refrigerant absorbs heat, and the moisture in the air condenses on the coil. 

• The condensation drips into the condensate pan below the evaporator coil and drains away. 
• Cooled, dehumidified air blows back into your home. 

Tips to Lower Humidity 

Running the air conditioner may be enough to bring the relative humidity below 50 percent in dry climates. But if high humidity is still a problem in your home, try these tips. 

Ventilate Properly 

Run the exhaust fan in the bathroom, kitchen and laundry room when you shower, cook and wash clothes. Spot ventilation removes humidity at the source to keep these rooms more comfortable. You can also open a window when it’s mild outside to let in fresh air. 

Wipe Up Standing Water 

Wet shower tiles, kitchen counters and laundry room floors raise indoor humidity and may promote mold growth. Wipe up standing water promptly to prevent these problems. 

Run a Dehumidifier 

If you struggle with high humidity in the summer, consider installing a whole-house dehumidifier that runs in tandem with your air conditioner to make every room more comfortable. A whole-house unit can even operate independently of the AC to remove humidity on mild days without running the air conditioner. This technique saves you money and prevents that “cool but clammy” feeling. 

Set the AC Fan to Auto 

The condensation that collects on the evaporator coil needs time to accumulate and drip away. If you run the air conditioning fan constantly, the moisture will blow back into your home. That’s why it’s better to set the fan to “auto” so it only runs when the AC compressor turns on. You should be able to adjust this setting easily on your thermostat. 

Change the Air Filter Regularly 

A clogged filter traps dust and debris and may harbor mold growth if it becomes wet. This introduces moisture and mold spores into your home every time the AC turns on. Change the air filter once a month or as recommended by the manufacturer to lower indoor humidity and improve air quality. 

Adjust the Fan Speed 

Optimizing the fan speed can be tricky. High airflow helps the AC keep up with cooling demand on the hottest days, but this may cause shorter cycles that prevent effective dehumidification. Work with an HVAC technician to help you choose the right fan speed for your comfort needs. 

Check the Cleanliness of the Evaporator Coil 

A grimy coil can’t cool and dehumidify efficiently. If your AC is having trouble reaching the desired temperature, contact our HVAC specialists to inspect your cooling system and check the cleanliness of the evaporator coil. Cooling and dehumidifying performance should improve as a result. 

Check the Refrigerant Charge 

Low refrigerant can impair your air conditioner’s ability to do its job. Left unchecked, serious issues such as a frozen evaporator coil or compressor failure could occur. Only a qualified HVAC technician can fix refrigerant leaks and recharge the system as needed, giving you another reason to schedule an AC tune-up. 

Replace Your Air Conditioner 

If your home has consistent comfort problems and your air conditioner is getting old, it could be time for a replacement. Choose a new AC unit with advanced features, such as a thermal expansion valve (TXV) and variable blower motor. A TXV delivers the precise amount of refrigerant based on the air temperature, and a variable blower motor adjusts the fan speed to meet demand. Both features improve cooling and dehumidifying performance. 

Control Indoor Humidity with Service Experts Heating, Air Conditioning & Plumbing 

If you decide it’s time to install a whole-house dehumidifier or replace your air conditioner, Service Experts Heating, Air Conditioning & Plumbing can help. Our HVAC services are designed to maximize home comfort and energy efficiency for your long-term satisfaction. To ask questions or schedule a visit from one of our qualified heating and cooling technicians, please contact us today.