Heat, Humidity and Mold
The Dollar Stretcher
by Gary Foreman

Elizabeth has set up a pretty good challenge for herself. She lives in the hottest, wettest portion of the country. Since she's in a condo she can't line dry her clothes outside. Plus, she's allergic to mold. But that doesn't mean that she has to throw in the towel. There are things that she can do to control the temperature, humidity and her budget.

Let's begin by analyzing the problem. Summers in Atlanta are hot and humid. That's a given. We know what temperature is, but what is humidity? Weather.com defines humidity as "the amount of water vapor in the air."

And, according to the EPA, moisture in the air encourages the growth of mold. They suggest keeping indoor humidity between 30 and 60% to control the growth of mold.

How do we do that? As Elizabeth pointed out, her air conditioner reduces humidity. It's part of the process of cooling air. But an air conditioner is expensive to run.

That brings us to the dehumidifier. According to Wikipedia, a dehumidifier is "a household appliance that reduces the level of humidity in air."

They are built very much like an air conditioner. So it's not a cheap appliance to run. Elizabeth shouldn't be surprised if her dehumidifier costs between $25 and $50 a month to run (it would be less in a dryer climate). Still, that's cheaper than running an air conditioner.

Dehumidifiers are rated based on how many pints of water they can remove in 24 hours. Elizabeth will probably need something that will remove about 17 pints per day.

Many dehumidifiers include a humidistat that will automatically shut it off when the proper humidity level has been reached. She may need to buy a hygrometer which measures relative humidity. Electronic ones are available for less than $30.

One other tool that could help Elizabeth is a fan. Even if she doesn't have ceiling fans, a table or floor fan will do. Moving air feels cooler than standing air. That's because the moving air absorbs more heat from your skin.

Now that we understand our tools, let's put a strategy together for Elizabeth. First, the dehumidifier will cost less to run than the air conditioner. So she'll want to set it to run any time the relative humidity is over 50%.

Keeping a fan going in the room that she's in will allow Elizabeth to set her air conditioner at a higher temp. Eighty is not uncomfortable if there's air moving in the room.

Elizabeth asked about keeping the fan on the air conditioner running constantly. That's probably not the best answer. The central AC motor will use more electricity than the smaller motor on a ceiling or room fan. The only exception would be if the central air conditioner fan was equipped with a filter that's good enough to remove pollen from the air. Then it could be worthwhile to consume the extra electricity.

There are a couple of other things that Elizabeth can do to help. Use exhaust fans in the bathroom and kitchen. Especially when you're showering or using steam or boiled water to cook food.

Better yet, don't generate the extra moisture. Shower at the gym and save those steamed/boiled recipes for the winter months.

Drying her clothes at home is probably not a good idea unless she has an outdoor balcony. What she saves at the laundromat, she'll spend running the dehumidifier.

Elizabeth can accomplish what she wants. Yes, it would be easier in other parts of the country or in a home where she could dry clothes outdoors. But reasonable use of a fan, dehumidifier and air conditioner should allow her to control humidity and temperature without sweating her budget too much.