Home Humidity Issues In The Summer

Humidity is the amount of moisture in the air inside your home, and keeping it in the right range is one of the easiest ways to stay comfortable and protect your house. When indoor humidity climbs too high, you get that muggy, sticky feeling along with real problems like mold, condensation, and added strain on your HVAC system. San Diego’s climate is mild, but coastal air and summer heat can still push indoor moisture past healthy levels. Here is how to tell where your home stands and what to do about it.

To prevent mold and keep your home comfortable, the EPA recommends an indoor humidity level between 30% and 50%, with 40% to 50% being the sweet spot for most homes. If you are noticing more pests, condensation on the windows, or mold, there is a good chance your humidity is higher than it should be. You can measure it with an inexpensive tool called a hygrometer, or ask your HVAC technician to check during your next maintenance visit.

The EPA recommends keeping indoor relative humidity between 30% and 50%, with 40% to 50% being the comfort sweet spot for most San Diego homes. Below 30%, the air feels dry and static. Above 60%, you risk mold, condensation, and that heavy, muggy feeling. Use the chart below to see where your home falls.

You can check your levels with an inexpensive hygrometer from any hardware store, or your Same Day technician can measure it during a maintenance visit. If your home consistently reads above 50%, your air conditioner or ventilation is the first place to look.

Your house feels humid when more moisture is entering the air than your AC and ventilation can remove. Everyday activities like cooking, showering, and running the dryer release water vapor, and a large number of houseplants adds even more. Your air conditioner is the biggest factor: when it is sized correctly and well maintained, it pulls moisture out as it cools, but a unit that is too big, too small, or overdue for service leaves the air feeling damp. Poor ventilation makes it worse by trapping that moist air inside. In coastal San Diego, ocean air and the summer marine layer can also raise indoor humidity, so year-round attention pays off.

High humidity inside your home can cause a range of problems, from personal discomfort to serious mold problems, both superficially and at the structural level of your home. Humid air can exacerbate allergies, asthma, and breathing issues. If mold is resulting from the humidity, you may be looking at additional complications from toxic mold and mildew, which can make you sick.

Humidity can also adversely impact your major appliances, causing them to run poorly or inefficiently, and in some cases contributing to early burnout.

Here are some other issues caused by high indoor humidity levels:

There are several ways top manage high humidity during the summer months to leave your home feeling cool and comfortable!

An air conditioner is one of the best defenses against home humidity in the summer, provided it is the right size for the space and is maintained properly. A certified HVAC specialist can help you determine if your unit is too large, or too small, or what type of maintenance may need to be done if you’re having humidity problems along with central air.

After air conditioning, a dehumidifier may be the second-best method to remove moisture from the air in your home. 

You can also try changing your behaviors to reduce the causes of excess humidity – like long, hot showers, running the dryer frequently, lots of stove-top cooking, and keeping a lot of plants in one location of the house. Running fans is always recommended when cooking and showering, since the added circulation will help to spread out the humid air.

Want to learn more about home humidity levels, or have your home tested to see where you stand? Our professionals are happy to help with questions, servicing, and much more, call (619) 762-3014 to schedule your appointment.

High indoor humidity usually comes from a mix of everyday moisture and how your AC is running. Cooking, hot showers, laundry, and houseplants all add water to the air, while an air conditioner that is oversized, undersized, or overdue for maintenance fails to pull that moisture back out. In coastal San Diego, the summer marine layer and ocean air push outdoor humidity indoors as well. If levels stay above 50% for days at a time, your AC or ventilation is the first thing to check.

Use a hygrometer, an inexpensive moisture meter sold at any hardware store, and place it in the room that feels most humid. Many smart thermostats display indoor humidity too. Aim for a reading between 30% and 50%. If you do not have a meter, condensation on windows, musty smells, and sticking doors are reliable signs that humidity is running high.

The target stays in the EPA’s 30% to 50% range year-round, but most homes sit toward the lower end in winter and the higher end in summer. In San Diego’s mild climate, summer is when humidity is most likely to climb past 50%, so that is when a well-maintained AC or dehumidifier matters most. During a dry, cool stretch, levels under 30% can make a home feel dry and static.

Yes. Mold can begin to grow when indoor humidity stays above about 60% for an extended period, because the excess moisture settles on walls, windowsills, and other surfaces. Keeping humidity in the EPA’s recommended 30% to 50% range is one of the simplest ways to discourage mold, dust mites, and the musty odors that come with them.

Run your air conditioner. A properly sized, well-maintained AC removes moisture as it cools and is the quickest fix for most San Diego homes. Pair it with exhaust fans while cooking and showering, and add a dehumidifier for rooms that stay damp. If humidity stays high even with the AC running, the unit may be the wrong size or due for service.

Need expert help deciding or ready for an installation? Contact Same Day today! Our experts are always happy to help. With the right system, you’ll enjoy better efficiency, lower utility bills, and your home may experience less humidity!