How Does Humidity Impact HVAC Performance?

As part of our range of air quality services, Sky provides humidifier/dehumidifier installation. Too much or too little moisture in the air can not only make your home uncomfortable. It can affect the performance and condition of your HVAC system. Air conditioners work to remove humidity from the air, but moisture levels can still have an impact. We’ll take a look at exactly how your AC is affected by higher or lower humidity in your house.

Impact of High Humidity on Your AC

An oversized air conditioner won’t run long enough, so moisture remains in the air. That’s one reason you need the right-sized unit. Single-speed air conditioners can have humidity control problems; leaving the fan on without the AC can also result in moisture issues. If there’s negative air pressure, too much air will be vented and more outside air will be drawn in, increasing indoor humidity if it’s muggy outdoors.

The humidity in your home should generally be below 60%, and ideally between 30% and 50%. At higher humidity levels, the following issues can occur:

• The air conditioner struggles to maintain the desired temperature, increasing wear and tear.
• Uneven cooling, which means some rooms will be warmer or cooler than others.
• An increased risk of requiring repair for a preventable AC issue or breakdown.
• Mold or algae can grow inside ducts, reducing indoor air quality and increasing the risk of allergies, respiratory issues, and other health effects.

Signs of High Humidity

The signs you need to lower the humidity in your house include:

• Condensation on windows or mirrors.
• Musty odors or visible mold.
• Damp spots on walls or ceilings.
• The house feels warmer than it is.
• Your skin feels moist and clammy.
• The basement is unusually damp.

How Low Humidity Can Affect Your HVAC System

If your home is too dry, the system can be overworked just as it can be due to high moisture content in the summer. Your home can become uncomfortable, while a harder-working system can lead to higher energy bills. Straining your HVAC system is only effective at increasing the amount you pay each month and the odds of needing major repairs. 

Low humidity also affects your well-being. Dry air can lead to dry, cracked, or chapped skin and lips. If you wake up each day with a dry, scratchy throat, then there may be a moisture problem in your home. There may also be an increase in static electricity and related shocks. Throughout most of the cooler months, indoor humidity should be kept at around 30% to 40%; the only exception is when it is below 0℉, in which case you should aim for below 25%.

What to Do If Your HVAC System Has Been Affected by Humidity

You can correct humidity-related issues and avoid more serious damage by having your AC tuned up. This can improve performance and extend operating life. Changing the air filter and cleaning out the duct system can improve air quality dramatically. 

Also, take measures to address the underlying problem. These include adjusting the settings on the HVAC humidifier (if applicable) and running the AC for a short time to reach and maintain proper temperature and humidity levels. Other factors can affect moisture content in the air, which can be addressed by: 

• Insulating condensation-prone pipes.
• Fixing leaks in your plumbing.
• Properly ventilating the kitchen and bathroom.

Contact Sky Heating & Air Conditioning

Our qualified, dedicated team knows how important indoor air quality is in Portland-area homes. If your home has humidity issues and you want to lower humidity in your house, we can provide high-quality dehumidifiers; if necessary, we can also provide efficient humidifiers. Other air quality solutions we offer include electronic air cleaners, UV air treatment systems, and whole-house air purification systems. Call 503-673-9083 today to learn more.