Ask the contractor: Indoor humidity a likely cause of window condensation
Originally Published: April 5, 2012 9:56 p.m.
Q: What is window condensation? - Ed in PrescottA: Window condensation is a real pain in the glass! YCCA receives a number of calls on what causes surface condensation on windows. Most people are quick to blame the manufacturer. The answer to this question does not relate to condensation caused by seal failure; this addresses glass and frames.Windows do not create the moisture for condensation; they are a product of their environment. Condensation occurs on windows when warm, moisture-laden air comes in contact with a cold surface like a metal frame or glass and the dewpoint is reached. Factors that contribute to the likelihood of window condensation include the climate or outdoor environmental conditions; the indoor relative humidity through the window; whether window shades or curtains are closed for a long time during cold weather; and the Condensation Resistance Factor (CFR) and the window's ability to resist condensation. The CRF is a number between 0-100. The higher the number, the greater the resistance the window has for condensation.Window condensation can be a sign of excessive indoor humidity. It is important that you control indoor humidity levels, which should not go above 40 to 45 percent. In cold weather, you need to lower the humidity levels to prevent condensation. Often, humidifiers are set in the fall and never adjusted for times of cold weather. High humidity can be caused by humidifiers, plants, aquariums, lack of kitchen or bath exhaust fans, wet crawlspaces and basements, or poorly vented dryer exhausts.It is important when it comes to buying windows that you do not opt for cheap products. It is also important to remember that the type of frame is as important as the glass and the low-e coatings. Pay attention to the type of frame, glass configuration and spaces. Selecting the wrong window technology for the given climate can be a costly mistake.Yavapai County Contractors Association (YCCA) is a professional association representing licensed, bonded and insured contractors, suppliers, distributors and business entities. Call YCCA for information on hiring a contractor at 778-0040. Submit questions to firstname.lastname@example.org or through www.ycca.org. The 34th annual YCCA Home Garden Show is coming to Tim's Toyota Center in Prescott Valley, May 18-20. Admission is free.