Can You Lower Humidity by Running the Air Conditioner?

Excess humidity can cause various problems, like mold and mildew, musty odors, structural issues, and an unpleasant muggy feeling. That’s why it’s necessary to manage humidity if you want to increase indoor air quality and home comfort.

The perfect relative humidity level is about 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 only cool your home—it also lowers humidity. Here’s details of how this works, along with recommendations to adjust indoor humidity levels.

How Air Conditioning Eliminates Humidity

Contrary to what you might think, your air conditioner doesn’t add cool, dry air in your home—it takes out heat and humidity. The process requires refrigerant, which stores heat and moisture effectively from the indoor air. Here’s the process:

  • Indoor air moves through the ductwork and passes over the evaporator coil containing cold refrigerant.
  • The refrigerant soaks up heat, and the moisture in the air condenses on the coil.
  • The condensation flows into the condensate pan under the evaporator coil and drains away.
  • Cooler, dehumidified air flows back into your home.

Tips to Decrease Humidity

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

Ventilate Correctly

Turn on the exhaust fan in the bathroom, kitchen and laundry room when you shower, cook and wash clothes. Spot ventilation eliminates humidity at the source to keep these rooms comfortable. You can also open a window when it’s milder outside to allow in fresh air.

Wipe Up Standing Water

Water on shower tiles, kitchen counters and laundry room floors raise indoor humidity and could stimulate mold spores. Dry any standing water promptly to prevent these problems.

Use a Dehumidifier

If you grapple with high humidity in the summer, consider installing a whole-house dehumidifier that operates in tandem with your air conditioner to make every room more comfortable. A whole-house system can even operate separately from the AC to remove humidity on more temperate days without using the air conditioner. This approach saves you money and doesn't leave you with that “cool but clammy” feeling.

Flip the AC Fan to Auto

The condensation that collects on the evaporator coil needs time to build up and flow away. If you use the air conditioning fan constantly, the moisture will blow back into your home. That’s why it’s more effective to adjust the fan to “auto” so it is only running when the AC compressor switches on. You should be able to adjust this setting easily on your thermostat.

Replace the Air Filter Consistently

An obstructed air filter traps dust and debris and can harbor mold and mildew if it becomes wet. This introduces moisture and mold spores into your home every time the AC is running. Exchange the air filter once a month or as suggested by the manufacturer to reduce indoor humidity and enhance air quality.

Fine Tune the Fan Speed

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

Clean the Evaporator Coil

A filthy coil can’t cool and dehumidify efficiently. If your cooling is having trouble maintaining the preferred temperature, contact our HVAC specialists to maintain your cooling system and clean the evaporator coil. Cooling and dehumidifying performance should improve as a result.

Confirm the Refrigerant Charge

Low refrigerant can impair your air conditioner’s ability to carry out its job. Left ignored, severe issues such as a frozen evaporator coil or compressor failure can occur. Only a qualified HVAC technician can fix refrigerant leaks and recharge the system as necessary, lending you another reason to schedule an AC tune-up.

Exchange Your Air Conditioner

If your home has constant comfort issues and your air conditioner is getting old, it may be time for a replacement. Select a new AC unit with modern features, including a thermal expansion valve (TXV) and variable blower motor. A TXV offers the exact amount of refrigerant based on the air temperature, and a variable blower motor adapts the fan speed to meet demand. Both features increase cooling and dehumidifying effectiveness.

Balance Indoor Humidity with Service Experts Heating & Air Conditioning

If you believe it’s time to install a whole-house dehumidifier or upgrade your air conditioning, Service Experts Heating & Air Conditioning can help. Our HVAC services are tailored to improve home comfort and energy efficiency for your long-term satisfaction. To share questions or arrange a visit from one of our experienced heating and cooling technicians, please contact us today.