The right humidity level is really important during the heating season.



Relative humidity is an important factor for several reasons. It affects how comfortable we feel. If it's too dry, we can't seem to get warm no matter how high we set the thermostat. It can affect the ability of some folks to breathe. Humidity levels also affect the cost of heating because lower humidity levels require higher temperatures in order for us to feel comfortable.

If you're bothered by frequent colds or allergies, your house may be too dry. And excessive humidity can result in unwanted mold growth along with damage and discoloration of window sills, walls, and other building components.

So for a number of different reasons people pay more attention to the indoor relative humidity levels during the heating season.

A lot of folks don't really know what relative humidity is. A simple but non-scientific explanation is that it is the amount of water vapor in the air.

A common method of measuring indoor humidity is to buy a little devise at your local hardware store to tell you what it is. These devices are designed to sit on a table or shelf and are about three inches square in size. They usually sell for less than $20.

My personal experience with these devices is that they are often inaccurate when compared to a commercial indoor air quality meter. The ones I tested were not off by a couple of percentage points. They were off by a lot!

This same device often includes a "comfort zone" which is supposed to indicate at what temperature and relative humidity you will feel comfortable. There is a quick, free, and accurate method to evaluate your indoor humidity. It won't give you the relative humidity in percent, but it will indicate if you have too much or too little humidity. Remember that mold loves excess humidity. Too little and you're going to be uncomfortable.

I have tested this method against the commercial indoor air quality meter I use and found it to be quite accurate in indicating when the humidity level is too high or too low.

So what is this method? It simply requires you to look for two things.

First, look at your windows. Moisture on your windows means the humidity is too high. We're not talking one or two drops. We're talking about enough moisture so it runs down the glass and forms little puddles on the window sill. When you see this, it means your humidity is too high! If you continue to maintain this high humidity level, you are encouraging mold growth by providing the perfect environment. It will happen.

You may discover water forming on the windows in one area of your house, but not in another. For example, your bathroom window has water frequently forming on the sill while other windows in the house remain dry. Too much humidity in your bathroom may be the result of not running the exhaust fan long enough after a bath or shower. The rest of the house is ok.

So now you know how to determine if there is too much humidity in your house. What about too little?

To determine if it's too dry, you look for another simple, yet accurate indicator. Static electricity. Do you get static electric shocks when you walk across the carpet and touch something metal? Is it impossible to comb your hair without having several strands stick straight out? Do you need a ton of hair spray? Does the cat's fur stick out when you pet him?

These are all signs that it's too dry in your house. You need more humidity.

Now that you know how easy it is to check, you never need to wonder about your indoor humidity level. You'll know almost instantly if it's too humid or too dry. You don't need to buy a thing, and the results are almost instantaneous and quite accurate!

Copyright (c) 2008 Jon Dacken