This is an important topic when it comes to air conditioning. Homeowners are often confused about how their ACs affect indoor humidity. People know that high humidity makes hot weather feel much worse, but don’t often know exactly why or what an air conditioner does to alleviate the problem.
The short answer is that an air conditioner can make you feel cooler, but not because it significantly lowers humidity in the air. An air conditioner does have some dehumidification properties, but not enough to make a difference or be considered an actual dehumidifier.
Humidity makes heat feel worse—it doesn’t raise the amount of heat
Here’s a quick primer on why humidity can make a hot day feel unbearable. The term “relative humidity” refers to the amount of moisture in the air. At 0% relative humidity, there’s no moisture. At 100%, there is too much moisture for the air to hold it; in other words, rain. When relative humidity is higher than 60%, the moisture in the air is enough that it makes it harder for the human body to expel heat through the skin by perspiring. More heat is trapped inside the body, making a person feel hotter. So when it’s 85°F outside, you’ll feel as if it’s around 93°F if the relative humidity level is high. The outdoor temperature is still 85°F, but it feels hotter.
How an air conditioner helps—and how it doesn’t
The main job of an air conditioner is to remove heat from the air inside a building. It evaporates refrigerant to do this, and this absorbs heat along its refrigerant coil. Going back to our last example, if it’s 85°F in your house, you can set the thermostat to 78°F (a recommended energy-saving temperature) and the air conditioner will remove enough heat from the air circulating through the house to drop the temperature by 7°F.
What the AC doesn’t to is significantly alter humidity levels. If the indoor humidity is high enough that it’s making you feel 8°F hotter, then no matter how low you set the thermostat, you’ll still feel that 8°F difference. The 78°F thermostat setting will feel like 86°F. You can keep lowering the thermostat to cool off, but that’s putting immense strain on the AC and wasting power.
We mentioned that the AC dehumidifies—just not much. When refrigerant evaporates in the refrigerant coil, it also causes some moisture in the air to condense along the coil. This won’t make a noticeable difference during a day when relative humidity is above 60%, however.
What you can do
We wouldn’t have this post up if we didn’t offer air conditioning service in Cincinnati, OH to help out. The best way to battle high summer humidity in your house is with a whole-house dehumidifier. This is a device our technicians can install into the HVAC system. It works in conjunction with the air conditioner to lower relative humidity to a balanced level around 45% without interfering with the cooling system and making the air too dry. Get in touch with us to learn more about whole-house dehumidifiers.
Work with Bartels Heating & Cooling “For a Comfortable Way of Life.” Serving Hamilton, OH and the surrounding area.