James Dulley
Detroit Free Press (Freep.com)
Sunday, February 3, 2008
Dear Jim: My children have allergies to mold. I want to make my house more airtight for better energy efficiency, but I heard this can exacerbate mold problems. What safe efficiency improvements can I make?
- Karla S.
Dear Karla: People often think mold-ridden indoor air is the price one has to pay for greater energy efficiency. Actually, making your house more energy efficient can positively affect air quality.
Mold spores are a unique indoor air-quality and health issue because they can come from outdoors or indoors. With many allergens, such as pollen, the source is outdoors and an efficient airtight house keeps them outdoors. Mold spores can live and breed in your house. Bring in some spores on your shoes, flowers, etc., and they reproduce indoors on a damp surface.
First, test your house for mold. Several laboratories offer home test kits. For a viable test, you grow house test samples in a petri dish.
At IMS Laboratory, it costs about $10 for the kit. If you find growth, they charge about $35 more to analyze the mold types. Some types of mold cause few problems while others are quite toxic.
A better test is a so-called nonviable test where the sample is analyzed for many types of mold. This test costs $75. If there are dead spores in your sample, the nonviable test finds them. The viable test would miss them because the dead spores would not reproduce, but live ones may still be in your house.
Setting your heating thermostat lower saves energy and can slow mold growth. At a lower indoor temperature, less moisture content is needed in the air for comfort. This may reduce dampness. Installing more energy-efficient windows in high-humidity areas, such as the kitchen, cuts condensation. Window condensation can drip and saturate a wall or baseboard.
Installing a central air cleaner on your furnace/air-conditioning duct system removes more mold spores than a standard 99-cent fiberglass filter and raises energy efficiency. By keeping the heat exchanger surfaces cleaner, they transfer heat more efficiently.
Sealing the return air-duct joints saves energy by drawing the air from rooms, not from inside musty walls or attics. Sealing them also keeps mold spores from being drawn into the ducts. Gorilla tape or spread-on sealing compounds work well to seal leaky joints.
It is difficult to completely rid a house of mold spores once they are established. They can stay dormant for a long time. One EPA-registered mold-control liquid by Concrobium (www.concrobium.com) encapsulates existing mold spores on surfaces so they cannot reproduce and inhibits growth from new spores brought indoors. To treat large areas, Home Depot rents foggers for applying this product.
The following companies offer home mold-test kits: Home Health Science, 877-276-8250, www.moldcheck.com; IMS Laboratory, 877-665-3373, www.homemoldtestkit.com; Prolab, 800-427-0550, www.prolabinc.com, and Tennessee Mold Consultants, 865-558- 9772, www.tennesseemold.com.
Send inquiries to James Dulley, c/o Detroit Free Press, 6906 Royalgreen Drive, Cincinnati, OH 45244 or visit www.dulley.com.