Letters: January/February 2012
Diagnosing an IAQ Problem
I read your article in Home Energy and thought I would try to contact you about a problem ("Safe Air at Home" Sept/Oct '11, p. 6).
I had a contractor (not a blown—insulation specialist) install Owens Corning Attic Cat loose—fill fiberglass last spring in the two exterior walls of a room that I am planning to use for a home office. After the insulation and before painting the drywall (paint = Behr Premium Plus Ultra paint/primer combo), I smelled an odor that has persisted for several months even with the windows open continuously. Just after completion of the room refinish, I tried working in it but became lightheaded after several hours and noticed some teeth gnashing. There does not appear to be any additional dust present (that is, same level of dust that accumulates in the other rooms, which isn't a problem). I have moved the office to a different room. I have read that odors from VOC related to fiberglass insulation can cause lightheadedness and teeth gnashing, and can take some time (amount not specified) to dissipate. However, as winter approaches, the smell persists, so it's time for action, as I don't want to leave the windows open in that room all winter, and it would be good to use the room for its intended purpose.
I am thinking the best course of action is to
- rip out the drywall on the two exterior walls;
- collect and dispose of the insulation;
- do a thorough vacuuming (perhaps two or three passes) of the exposed exterior wall cavity, carpet, and other interior wall surfaces and ceiling;
- let the room set (with cavity exposed) for a couple weeks and see if that takes care of the odor; and
- refinish the exterior walls using some type of less—toxic insulation material.
- Does that sound like a good approach?
- Should I first try to find an environmental consultant with a VOC sensor to check if the odor corresponds to something that may be emitted by the fiberglass insulation (and related binder)?
- Any other advice?
Thanks for any help you can provide.
— Joel Neymark P.E. J. Neymark & Associates Golden, Colorado
Author A. Tamasin Sterner replies:
Thanks for contacting me. I feel for you.
Without seeing your house, I can only guess what is going on. These are my suggestions:
- Get the material safety data sheet (MSDS) for the materials used in your home, including the Sheetrock, and see if there are warnings about exposure and ventilation suggestions.
- If you determine that the best solution is to remove what was installed, I think your approach sounds reasonable. Just protect yourself.
- If you choose to reinsulate, spend a day with the materials before installing them to see how you feel and react to the materials.
Another idea you could consider is this: Put the room under slight pressurization. Supply air to the room and don't allow much air to leave the room. This should push air into the walls and to the outside (under the best circumstances), and that will ventilate the walls. Keep the room dry while you do this so you don't push moisture into the walls as well.
Another thought is this: Was the paint moldy? What does the odor smell like? You may be dealing with a mold problem, which means you have moisture in the walls.
Good luck, and please let me know what works for you.
The Down—Low on Downlights
Here is a question for the experts. My house was built in 1912, and it is generally as leaky as a sieve. However, I had recessed—can downlights put in the kitchen about 20 years ago. They take a 100W incandescent flood. When it is installed, the surface of the bulb is about flush with the outside edge of the can. Today I couldn't find any regular floods, so I bought a 90W halogen flood instead. I notice that when this flood is installed, the surface of the bulb is recessed about 2 inches inside the can.
So my question is, Will this create excessive heat inside the can (I believe that halogens are hotter than regular incandescents.)? Or in other words, should I switch this bulb out before I burn my house down? Thanks for any advice that you can provide.
—In the Dark About Halogens
Home Energy editor Jim Gunshinan replies:
That is a great question. Since recessed—can lights are so prominent in homes, new homes especially, and since these can lights are notorious leak sites, the topic comes up frequently for discussion on the Home Energy Pros web site and other sites.
When we had our home retrofit in 2007, while the house was depressurized with a blower door, the contractor had me put my hand below a recessed—can light in our living room. It felt like my hand was in front of a powerful fan! Lots of air was coming from the attic into my house. The fix was to put a foam board box around the fixtures in the attic, to seal the can light fixture, and to insulate it so that we wouldn't be losing heat into the attic from the light. But when we turned on the lights after that (incandescent downlights), after an hour and a half the lights switched off. There is a safety feature in new downlight fixtures—a thermal cutoff switch. Instead of our house burning down, when the temperature in the light fixture reached above a certain temperature (194°F), the lights switch off.
We replaced the incandescents with cool CFL downlights, and that fixed the problem.
If you have leaky downlights, then you probably won't have problems of heat buildup. If they are sealed and insulated, you should have problems—lights turning off but not the house burning down!
The CFLs work well. They don't dim as smoothly as the incandescents and the light is not so bright. We kept an incandescent light in one can because we need a brighter light, but we don't use that light for long. I understand that there are pretty good, and cool, LED downlights available now and the prices are falling as I write this. Last I checked, you could purchase a dimming LED flood for about $40. LED downlights could be a very energy—efficient and economical choice.
Hope this helps!
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