Cleaner Indoor Air

Running the A/C may seem like the obvious choice to feel more comfortable during the hot summer months. But for many homes, cool comes with an unwanted side-effect. The air feels heavy, skin feels clammy, and too much humidity is left in the air. As air conditioners become more efficient, they do their one job better: they drop the air temperature quickly. Their secondary benefit of dehumidification is lessened and this leaves a significant amount of moisture trapped in the air.

Air at any given temperature has a maximum amount of water it can hold before it becomes saturated and starts to condense. I call this the soda-can effect. If you take a cold can of soda and set it on a countertop, it usually doesn’t take too long to start showing beads of water on the outside. This is because the air temperature at the surface of the can has dropped to the saturation level, water condenses and forms droplets. The opposite is true with heat. When you raise the temperature of air, its capacity to hold water significantly increases, and you can turn that liquid water on the soda can back into humidity. Think of how a hair-dryer works. Warm air passes over liquid water and the water evaporates, drying your hair.

The maximum amount of water that air at any given temperature can hold can be determined and compared to the amount of water that it currently holds. This is called Relative Humidity, read as a percentage, because it’s the current humidity relative to the maximum amount it can hold. As air temperature goes up, relative humidity goes down, and vice-versa.

When we look at what’s inside a home, most things, including people, need a relative humidity somewhere between 30% and 60%. Somewhere in the middle, around 45% to 50%, we can maintain conditions that won’t lead to common conditions like mold, mildew and even dust mites. But also won’t lead to the ill-effects of air that’s too dry, itchy skin, shrinking, splitting woodwork, etc..

Dehumidifiers, such as our Aprilaire 1700-series, work to maintain conditions in your home, relative to the temperature that you keep your house. So, the warmer the air temperature, the easier it is to maintain a lower relative humidity. The benefit of this is the energy savings of running your A/C less, as you don’t have to keep your home as cool. You’ll feel comfortable even at higher temperatures. By keeping your summertime temperature 3° higher, you can save an estimated 20% on your energy bill. Lower costs, more comfort? What’s not to like?