Permanent Link: http://ufdc.ufl.edu/IR00002363/00001
 Material Information
Title: Moisture Control in Your Home, Part 1: The Basics
Physical Description: Fact Sheet
Creator: Lee, Hyun-Jeong
Publisher: University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS
Place of Publication: Gainesville, Fla.
Publication Date: 2007
Acquisition: Collected for University of Florida's Institutional Repository by the UFIR Self-Submittal tool. Submitted by Melanie Mercer.
Publication Status: Published
General Note: "First published: January 2007."
General Note: "FCS3256"
 Record Information
Source Institution: University of Florida Institutional Repository
Holding Location: University of Florida
Rights Management: All rights reserved by the submitter.
System ID: IR00002363:00001

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FCS3256 Moisture Control in Your Home, Part 1: The Basics1 Hyun-Jeong Lee and Virginia Peart2 1. This publication combines, updates, and supersedes FCS3042, FCS3211, FCS3212, FCS3213, FCS3239, FCS3244, and FCS3245. This document is FCS3256, one of a series of the Department of Family, Youth and Community Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. First published: January 2007. Please visit the EDIS Web site at http://edis.ifas.ufl.edu. 2. Hyun-Jeong Lee, assistant professor, and Virginia Peart, former associate professor, Department of Family, Youth, and Community Sciences, Institute of Food and Agricultural Sciences, University of Florida, Gainesville FL 32611. The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean Effective moisture control is an important part of home maintenance. Too much humidity can result in mold growth and indoor air quality problems and can cause allergic symptoms in some people. Mold can also damage your valuable possessions and can even harm the structure of your house. Mold spores need three things in order to grow: moisture, nutrients, and warm temperatures. Many mold experts agree that the most effective way to control mold growth is to control moisture. But how does moisture enter our homes? How can we find out if our homes are dry enough to be free from mold? And how can we control moisture in our homes? nHow Moisture Gets In Moisture can enter your house from the outside, either as liquid or as air. When moisture is in the air, we call it vapor. Water vapor can come into your house through any opening: doors, windows, and even small cracks and crevices. We cannot see or touch the vapor until it changes into liquid. We also produce moisture inside our houses through the activities of daily living. Each person produces about three pints of water every day just by breathing. In addition, we create indoor moisture through cooking, dishwashing, showering, and doing laundry. Leaks and plumbing problems can also produce moisture. Research done by an insurance company cites washing machine hoses, shower tile grout, and water heaters as the top three sources of water damage in homes (Lankarge, 2003). Measuring the Moisture In order to understand moisture issues, we need to understand relative humidity (RH). RH is an important measurement to know because it tells us how moist the air is. When relative humidity reaches 100%, water vapor in the air changes into liquid water. This is called condensation. When condensation settles on surfaces such as floors, walls, ceiling, or furniture, mold can grow. There are two things that affect relative humidity: the amount of moisture in the air, and the temperature of the air. RH increases when the amount of water vapor in the air increases or when the air temperature drops. To understand why a drop in a


Moisture Control in Your Home, Part 1: The Basics 2 temperature can increase relative humidity, we need to know that there is a maximum amount of water vapor that air can hold before the vapor starts to condense. This maximum amount changes as the air temperature changes. The warmer air is, the more moisture it can hold. The colder air is, the less moisture it can hold. You can easily measure the RH in your home using a moisture or humidity meter. You can buy a small and inexpensive one ($10-$50) at your local hardware store. Experts recommend keeping indoor humidity below 60% RH. Ideally, it should be between 30% and 50%. Controlling the Moisture To control moisture problems in your home, you must find and eliminate the sources of the excess moisture, and you must dry up existing water and moisture. Otherwise, your moisture problems will keep recurring. Look for the Source of the Problem Find out where the moisture is coming from. Is your plumbing leaking into walls, ceilings, or floors? Are stopped-up drains causing standing water? Check washing machine hoses, shower tile grout, and water heaters for leakage. One mold expert says that these are the top three sources of water damage in houses, based on research findings by an insurance company and an insurance council (Lankarge, 2003). The expert recommends that homeowners check these three areas once a month. Check for any excessive air leakage. If outside air can flow into your house, outdoor moisture also can flow into your house. Windows, doors, electric outlets, and window air conditioning units all can leak moisture into your home. Leaky windows are easily noticed because water will stream down the window. The windowsill may also be rotten because of the leak. Weatherstripping and caulking may be needed. Check your air conditioner. Make sure that the filter is not clogged and that the evaporator cooling coils are not iced over. Look for water that may be flowing back into the room (for instance, from the condenser of a room air conditioner). Remove Moisture Build-Up Once corrections have been made, a clammy house can best be dried out by heating and cooling by turns. Turn on the heat. Use a high temperature setting (80F) so the unit will not cycle off too often. This will draw moisture out of the furnishings. Then follow with air conditioning. Use a low setting (65F) so the unit will not cycle off too often. Allow the air conditioning to operate for two or three hours before resetting to normal. If the moisture level is still not sufficiently reduced, repeat the heating/air conditioning cycle. Prevent Future Moisture Problems To minimize the risk of future moisture problems, follow these guidelines when opening windows, using exhaust fans, and using air conditioning. Before opening your windows to bring in outside air, check the weather report to find out the predicted dew point or forecasted nighttime low temperature. If this will be 55F or below, natural ventilation can be used. Use exhaust fans for short periods for odor and moisture removal. Remember, though, that during humid weather, outside air may hold more moisture than inside air. Ten minutes of fan operation will remove most of the moisture from the air after bathing or showering. During humid weather, run your air conditioning regularly rather than opening windows. Use the slowest air conditioner fan speed available on your air conditioner. For More Information


Moisture Control in Your Home, Part 1: The Basics 3 For more information on moisture control, refer to FCS 3257 (Moisture Control in Your Home, Part 2: Room by Room Tips). References Kansas State University Agricultural Experiment Station and Cooperative Extension Service. (1995, September). Controlling mold growth in the home. Author. Lankarge, V. (2003). What every home owner needs to know about mold (And what to do about it). New York: The McGraw-Hill Companies. U.S. Environmental Protection Agency. (2001, March). Mold remediation in schools and commercial buildings. Washington, DC: Author.