Lorna Fear's blog

Insulation Problems

Recently I bought a camera that can see whether and where a home is insulated. This camera is so cool! It overlays visible-light and infrared images (no, you can't see through anything) and it has a 5-inch display. It can detect temperature differences of .07 degrees centigrade, yes seven hundredths of a degree! In addition, I can burn a report to CD using my tablet PC.

I became interested in infrared technology for building science applications after I'd talked to the fourth or fifth person who spent many thousands of dollars replacing all their windows with dual pane models, yet saw almost no difference in energy use. That's most likely because their walls have no insulation. In California, builders large and small didn't insulate walls until recently. We don't have extreme temperatures so insulating anything but the attic was considered unnecessary.

In most homes, only 25% of the wall space is dedicated to windows. And dual pane windows reduce heat loss by just 30 to 50%. Each standard-size window costs about $400 installed so that's an extremely poor cost/benefit ratio. They do make your home less drafty and more quiet, but reduce your energy use? Hardly, when your walls are not insulated. One woman I spoke to had spent almost $30,000 to replace her old windows. The sad thing is, she's disillusioned and may not install any more energy efficiency upgrades.

I'm not sure which energy agency it was, but one of them estimated that over half the California homes built before 1960 still have no wall insulation. Many others have been remodeled, and perhaps an addition got insulated. But with our homes changing hands so often, we don't have much reliable information.

I can say for sure that adding insulation is surprisingly reasonable (please note I have no interest in any insulation company). For saving money, it probably beats any other energy upgrade you could install. Our built environment does as much damage as our cars, greenhouse gas wise, and now we can confidently go about solving the problem. I'm so excited this technology made it out of the military and into our hands! For that, I've been told we have a bunch of guys from Honeywell to thank.

Ho-Ho-HO!

Lorna Fear
Certified Green Building Professional (Advanced)

Thermal imagers have been used by the military and manufacturing facilities for a long time. Recently, they've been refined and specialized for building science applications and I just bought one. It's loaded with report software and using my laptop, I can burn a CD real time.

These imagers reveal temperature anomalies so you can see where a building leaks or is infiltrated by air and where it traps moisture. Having this information is crucial if a homeowner is going to make improvements in the right order. There is definitely a correct order for some projects. Here's an example.

Have you heard the horror stories about dual-pane windows? In the Q&As that follow my talks on How to Go Green without Going Broke, I certainly have! People are spending $15,000 and more to replace all their old windows, without getting more than a two-dollar reduction in energy bills.

Dual panes can't save energy unless your walls are insulated (this doesn't apply if you live in a fishbowl/Eichler). They can make rooms less drafty and quieter, but the warm air will still find its way out the uninsulated walls, like it always has. NOTE: replacing a window with dual panes reduces that window's heat loss by 50% or less. And because windows typically account for only 25% of a wall, the cost/benefit ratio is not that attractive.. As part of a whole house upgrade or new construction, dual panes make a lot of sense -- and they're the law. But before you decide to replace all your windows with dual pane products, determine whether and how well your home is insulated.

Until recently, that's been difficult to do. Now, a thermal imager can show you where and how badly your home leaks. You can also identify areas of potential mold growth. Some pest control companies are using them now, because thermal imagers can detect the presence of termite nests as well.