What level should I set my humidifier to?

Leave your humidifier off.

As a home inspector in the Stillwater MN area, I see a lot of whole house humidifiers. They are the boxes on the side of the furnace. They have a few low-voltage wires attached, and a thin water line. Somewhere, usually near the thermostat or attached to the furnace, is a small box that is about the same size and shape as a thermostat. It will have a dial that offers high, medium or low.. That box is the control for the humidifier. The way it works is simple; when the moisture in the air drops below a certain level (set by the dial- stay with me here), a valve opens up, letting a small amount of water to run down an evaporator pad. The air moving through the furnace picks up the moisture, increasing the humidity in the house. Sounds good, but hold on.

Dry air has been blamed for loose floorboards, nosebleeds and static electricity. Bringing moisture in the air does indeed reduce those problems. The problem is, moist air CAUSES some problems, too.

High levels of moisture in the air can cause frost on the windows in the wintertime, leading to decay of window parts and damaged walls, including insulation. Have you ever seen stains on the lap siding that look like the house has been crying? Sometimes, you can see actual icicles coming right off the siding in the winter. This could be the result of ice dams, where water runs down the inside of the walls. It could also be a result of very high moisture levels in the house. Remember science class? (me neither) Heat goes to cold, moisture goes to dry.  Moisture can also lead to high levels of mold. Certain kinds of mold grow when relative humidity is 55% or higher. Bedbugs? 65%.

If you’re like me (and I know I am!) you’ll see that the problems outweigh the benefits.

There are some alternatives.

If someone is sick, and sleeping is easier when the air is moist, there are small vaporizers that can be used at night and turned off during the day.

Some musical instruments react poorly to low moisture levels. They can crack and warp. Sometimes pianos cannot be tuned properly because the low moisture has caused the sound board to warp beyond repair. Good news; There are products that can be installed in the piano itself that will help control moisture levels, although they are not cheap; $600. for that reason, make sure you need one by buying a hygrometer for about $10, and try keeping a leafy plant nearby first. I found an interesting article by someone named Ask Andy.) Why, oh why did the Andy family name their kid Ask? I’d hate to see HIS therapy bill!) Click: Mr. Andy talks about moisture

AprilAire makes a sophisticated device that takes into account the outside temperature and self-adjusts. You can learn more by clicking AprilAire Whole House Products