Dealing With Dry Air

Question

My house gets so dry in fall and winter that static electricity sparks. I have
seen so many humidifiers in stores, I get confused. What type is best and can
one really lower my utility bills?-Dan T.

There are hundreds of models of humidifiers ranging from $20 to $200, so your
confusion about which to buy is understandable. The effectiveness of each design
does vary significantly depending on your specific home and needs.

Indoor air that is excessively dry can be as much of a problem as air that is
overly humid. For example, harmful bacteria and viruses can thrive in your home
in very dry conditions, while dust mites and molds thrive in very humid conditions.
Large seasonal indoor humidity level swings can seriously damage the house structure,
furniture, cabinetry, etc.

Running a humidifier to maintain a comfortable and healthy indoor environment
can lower your heating bills overall in several ways. When the indoor air is
too dry, moisture from your skin evaporates at a very rapid rate even though
you are not aware of the moisture loss.

This evaporation lowers your skin temperature. With properly humidified air,
you can often set the furnace/heat pump thermostat a few degrees lower to reduce
your heating bills and still feel comfortably warm. Also, if your house is overly
dry, the lumber framing may shrink during the heating season. This allows cracks
to form and gaps to open, which increases cold outdoor air leakage into your
house.

When selecting a humidifier, first determine the moisture output capacity (gallons
per day) of the model you need. Although this is somewhat dependent on your
climate, a newer airtight, 2,000-sq.-ft. house typically needs about 5 gallons
per day, and a loose one needs about 10 gallons per day to maintain an adequate
humidity level.

Once you determine the proper moisture output capacity, you must select among
the various humidifier designs available -evaporative, steam mist (vaporizers),
warm mist, cool mist, and ultrasonic. Each humidifier design has particular
advantages depending on your specific comfort and health needs.

Evaporative models, where a quiet, low-wattage fan draws the room air through
a wet wick or filter, typically have the greatest moisture output, up to 13
gallons per day (gpd). Select one with a tank housing and wick materials that
are antibacterial. These designs are also easy to clean out.

Hot steam mist humidifiers are effective. Since they boil the water, most microorganisms
are killed and no hard water deposits (white dust) are emitted. Steam mist designs
use more electricity than other fan-only designs and they do not self-regulate
the humidity level. Although the multiwall housing stays cool, the steam outlet
may hurt a child’s hand.

A warm mist design combines a hot steam mist with a cooler airflow for safety.
It uses the most electricity of all the designs to boil the water and for the
fan. Ultrasonic humidifier designs vibrate the water at high frequency to introduce
moisture into the room air. These use little electricity, but can create the
white dust like a cool mist model.

Cool mist designs use little electricity and are safe around children. There
are many variations, but basically, a spinning impeller picks up water from
the reservoir and slings it into a screen to create a fine mist. In hard water
areas, this can create a fine white dust near it and it does not kill or filter
out microorganisms like a steam mist model.