ASK A BUILDER
By CCHRC Staff
The “Ask a Builder” series is dedicated to answering some of the many questions Fairbanks residents have about building, energy and the many other parts of home life.
Q: I’ve read LED lights perform well in cold temperatures. What about in Alaska?
Absolutely. LEDs are generally pretty tough. They are shock and cold resistant. In fact the colder it gets, the better they perform. When it comes to outdoor lighting at extreme temperatures, some fluorescents can suffer from performance losses when compared to their use inside. Currently, LEDs are popular in lowlight applications such as pathway lighting or for task lighting such as workbenches, nightlights, flashlights and other devices where incandescent bulbs have traditionally been used. Because small incandescent bulbs are the least efficient, they are perfect to be replaced by an LED.
When it comes to the lighting industry in general, changes are coming along quickly. Prices are coming down on LEDs and fluorescents, and they are being better designed to work in different environments. If you are looking at buying an LED light for outdoor use, get one with a good warranty. The bulbs may last a long time, but there are other components in the light that may not fare as well.
Q: What is the difference between EPS and XPS foam?
Both are similar chemically and both are made from polystyrene, but the manufacturing process is different. Expanded polystyrene (EPS) foam, also called “bead board” is what you would find in coffee cups.
It is manufactured using small plastic beads that are expanded and fused together in a mold. Extruded polystyrene (XPS) is blue or pink, hence it is also called “blue board” or “pink board.” It is also made using polystyrene beads, but they are liquefied rather than expanded and then a blowing agent is added to force the liquid into a form. This process also creates a skin on the surface of the foam.
XPS is slightly more resistant to water vapor than EPS. EPS, generally has an R-value of 3 to 4 per inch, whereas XPS has an R-value of about 5 per inch. No matter what type, the R-value will be printed on the packaging or the board itself.
It is often assumed that the blue or the pink foams are the only ones you would want to use “below grade,” such as in your basement or a damp environment. The truth is both products will work as long as they are strong enough or dense enough to handle the stress in the place they are going to be installed. For example, many insulated concrete forms are made with EPS foam. These forms always go below grade. No matter the case, consult the product manufacturer information, which is usually available where you purchased the foam. Also, judge the prices in relation to the R-value you are getting, and get a product that is rated for your application.
Alaska HomeWise articles promote home awareness for the Cold Climate Housing Research Center (CCHRC). If you have a question, e-mail us at akhomewise@cchrc.org. You can also call the CCHRC at (907) 457-3454.