Why Is My House So Humid with the AC On?

Excess humidity can make the summer heat all the more uncomfortable. Inland Empire homeowners use air conditioners and heat pumps not only for cooling but also to help control indoor humidity levels.

However, your home still may suffer from excess airborne moisture while running the cooling system, leading you to wonder why your house is so humid with the AC on.

Why Is My House So Humid with the AC Unit On?

High indoor humidity can be frustrating, especially when your air conditioning system seems to be running like normal.

Here are some reasons why your home might seem so humid:

1. Outdoor Humidity Levels are Very High

When humidity in the outdoor environment is very high, it becomes more difficult to control indoor relative humidity levels. This is most common in the middle of summer, but the occasional spike in humidity can happen during other seasons as well.

During times like these, it’s typical for an air conditioner to struggle not only with cooling, but also dehumidification. When outdoor temperatures and humidity levels decline and indoor humidity levels return to normal, you’ll know the extreme conditions were likely to blame. Even so, you can try to get some relief at present by reducing heat gain in your home so your air conditioner doesn’t have such a large cooling load to tackle.

2. You’re Using the Wrong Fan Settings

Air conditioners dehumidify the air as they cool it – the process of extracting heat from the air lowers air temperature, causing water vapor to condense and become too heavy to stay suspended in the air. Thus, the air pushed through your vents by the blower fan and motor when the air conditioner runs is cool and less humid. 

You can also run your blower fan and motor when the air conditioner is off, which provides constant air circulation throughout the home and HVAC system – but no cooling. Because the air conditioner is on, the air coming out of your vents feels muggier. Many homeowners assume the air conditioner is running because air is blowing out of the vents, but it’s actually just the blower and the air conditioner is off. 

Don’t run your blower around the clock when humidity levels are high, as it could be the answer to why your home is humid even though the AC is running. It’s easy to mistake the blower for the air conditioner running, as the blower is housed inside the indoor cooling system unit. At your thermostat, switch the fan setting to AUTO so the blower only runs while the air conditioner is on.

3. Frozen Evaporator Coils

The evaporator coil inside the indoor cooling unit can freeze during the summer, causing the home to feel more humid. Ice and frost on the coil surface prevent the refrigerant within from absorbing heat to lower air temperature and remove moisture from the air. Frozen coils are caused by issues such as a dirty air filter, a clogged condensate drain, blocked condenser unit, and low refrigerant levels. 

When coils freeze, you need to turn the air conditioner off until they have thawed. Look for issues that could be causing the coils to freeze up. Check the filter and replace if needed and clear away debris from the outdoor unit. Call a licensed HVAC contractor for air conditioner repairs to clear condensate drain clogs, find and fix refrigerant leaks, and recharge the system with refrigerant to prevent frozen coils in the future.

4. Dirty Condenser Coils

Another reason homes can become too humid is due to dirty condenser coils in the outdoor unit. These coils allow refrigerant to release heat absorbed from indoor air into the outdoor environment. When dirt and grime collect on the surface of the coils, this buildup blocks heat transfer and prevents refrigerant from doing its job. When refrigerant cycles are disrupted, the air conditioner won’t be as effective at removing humidity from the air.

Cleaning the coils will stop this problem. Condenser coil cleaning is commonly included in AC maintenance tune ups, so schedule one if you haven’t already this year.

Working with a team of experienced technicians, like the ones at Sanborn’s, can determine the root cause of your cooling issues and provide you with the necessary AC repair.

Do I Need AC Services if My Home Feels Too Humid?

Scheduling air conditioning services is, in fact, the most effective way to restore your home to comfortable humidity levels. If your home remains uncomfortably humid despite the AC running, it might indicate a variety of issues.

Ignoring high humidity levels can lead to more serious issues, including mold growth, which can affect your health and damage your home. Regular maintenance and timely repairs can help prevent such problems, keeping your AC system running efficiently. If you notice persistent humidity, unusual odors, or a musty smell, it’s a clear signal to call in a professional to inspect and service your air conditioning system.

Taking a proactive approach can save you from costly repairs and improve the overall comfort and safety of your home.

Air Conditioner Repairs in the Inland Empire Area

If your home is experiencing warm air or high humidity levels, you might be in need of air conditioner repairs. The professional technicians of Sanborn’s Air Conditioning & Heating find system flaws that cause high indoor humidity and perform repairs to keep your home comfortable.

Contact us today to schedule our Redlands HVAC services, including air conditioning repair, to address all your AC needs.