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. Sanborn’s Air Conditioning & Heating explains issues that can cause high humidity in your home and what to do to correct them.

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

If you’re wondering why your house is so humid even though the air conditioner is running, the excess indoor humidity you feel could be caused by any of the following issues:

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. Current conditions are certainly contributing to this problem as Southern California experiences record-breaking heat and humidity during the heat wave.

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 air as they cool the air – 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. Your HVAC technician can also perform this service when you call for air conditioner repairs.

Air Conditioner Repairs in the Inland Empire Area

If your home feels humid and you’re wondering why your cooling system isn’t properly controlling humidity levels in your home, you may be due for air conditioner repairs. The licensed California air conditioning system repair 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 air conditioning repair service.