Reduce electric bill by installing radiant barrier in attic?

[cute fuzzy bunny]

Tell me about replacing the recessed lights. I have a bunch of them and they're open on top to the attic, and from what I read they'll catch fire if you cover them with insulation or block the vents. The only thing I saw involved building a sheetrock box about 2' per side and a foot or two tall to put over the top of the can in the attic.

I guess you could use an enclosed can and specify CFL lights only for that fixture, but everything I read about covering or insulating the recessed cans screamed about fire dangers.

I was actually going to remove them, and either put in a regular light fixture or fill the holes with sheetrock and insulate it, then relocate the wire to the center of the room and install a ceiling fan.

But if theres some easy way to replace the cans with closed, insulate-able ones, I'm interested.

[cute fuzzy bunny]

As an aside on our energy saving maneuvers, we replaced our old aluminum double pane windows with insulated low e vinyl ones, added r4 of foam insulation under the new stucco, and replaced last years 9seer a/c with a 15 seer.

Our july electric bill this year with all those improvements and similar weather was 25% lower.

Only thing I'd like to do is some attic insulation, but i've been holding off as having a dozen recessed fixtures full of vent holes that I'm not supposed to put insulation within a foot of sort of makes stacking more insulation up there pointless.

[lets-retire]

CFB--Lowe's and Home Depot have cans made to allow insulation to cover them. I put them in my last house I did renovations to.

[Leonidas]

Quote:

Originally Posted by cute fuzzy bunny Only thing I'd like to do is some attic insulation, but i've been holding off as having a dozen recessed fixtures full of vent holes that I'm not supposed to put insulation within a foot of sort of makes stacking more insulation up there pointless.

Three ways to deal with that.

1. Get a roll of chicken wire and make an exclusion zone around the cans to keep insulation from touching.

2. Buy fixtures that are designed to be in contact with insulation. "IC"

3. Buy fixtures that are designed to be in contact with insulation and which don't leak air. "ICAT"

I'm cheap and the attic was hot, so I used some chicken wire I had laying around in the garage from a school project.

[ls99]

CFB FWIW, in our kitchen are 8 recessed cans, non-insulation contact type. I did not want to go thrugh the hassle of changing them, but wanted to eliminate airflow to attic.

At Lowe's found bathroom light covers for recessed fixtures. These have glass in the frame and gasket around the rim. Pop out the old director insert, put in place rim with glass and gasket.
Ergo, no more airflow to attic. Also replaced incandescent with CFL.

Even DW likes it!

[unclemick]

Quote:

Originally Posted by Leonidas Three ways to deal with that. 1. Get a roll of chicken wire and make an exclusion zone around the cans to keep insulation from touching. 2. Buy fixtures that are designed to be in contact with insulation. "IC" 3. Buy fixtures that are designed to be in contact with insulation and which don't leak air. "ICAT" I'm cheap and the attic was hot, so I used some chicken wire I had laying around in the garage from a school project.

I used to walk 300 ft or so up the drive to HWY 90 and shut off the electricity outside the meter at the first power pole.

Electricity like sanity is overrated. You really don't need electricity in the Louisiana swamp.

Alas - those were the days - first I upgraded the whole house fan from 1/4 to 1/2 hp, got rid of penetrating light fixtures - 4 and 8 foot flourescent lights(for times when I turned on the juice).

Then later a window A/C - downhill ever since.

heh heh heh - now in my old age(65) I watch on PBS (like last night) a guy from Iowa built a log cabin in Alaska and live their 35 yrs. In A/C on cable yet - oh how fall I've fallen from frugal. Heck I don't even know what kind of insulation is in my attic!

[soupcxan]

Quote:

Originally Posted by cute fuzzy bunny Tell me about replacing the recessed lights.

I replaced mine with 6-inch Commercial Electric insulation-rated (IC), airtight, new construction cans from Home Depot. The benefit of replacing the fixtures (as opposed to just putting chicken wire or a drywall box around them) is that you can actually bury them in insulation (which I did). Getting cans that are rated "airtight" will also help prevent the flow of heat/cold from the unconditioned attic to the living space. I have read that if you leave even a small uninsulated gap around the fixture (from chicken wire or whatnot), you will greatly reduce the efficency of the total attic insulation. So you're better off getting IC fixtures and burying them. The pack I bought contained both the fixtures and the baffle/trim, which I think also needs to be IC-rated. There is no requirement to use a CFL in these fixtures - they're made to take up to a 75W incandenscent bulb which is what I'm using. Since you have access to the attic, you can buy the cheaper "new construction" fixtures (versus the "remodel" fixtures).

Replacing the fixtures didn't take any particular skill, just time and patience. Our house's wiring is modern so it was easy to untwist the wires and pop them into the new fixtures' quick-connect fittings. One concern, if you have older wiring, is that it may not be rated to be covered in insulation (there is some wiring specification that the light fixture instruction referred to). The only difficult parts of the job were:

1) working in the attic heat
2) maneuvering through the existing insulation
3) getting access to the fixtures that were installed close to the exterior walls, because the slope of the attic limited overhead clearance to wrestle the existing cans out.

The link below is very similar to what I bought, although the interweb concensus is that Halo is a better brand than Commercial Electric (don't know why, my CE's are fine so far). If you have a lot of fixtures to replace, I've heard you can get a better deal at a commercial supply store rather than Home Depot/Lowe's.

http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100096552&N=10000003+9 0016+501111

[Leonidas]

Quote:

Originally Posted by unclemick Electricity like sanity is overrated. You really don't need electricity in the Louisiana swamp.

I got to say that if I lived in the swamp without AC during August I wouldn't have to worry about an excess of sanity either! You're a manly man for being able to do it.

Quote:

Originally Posted by unclemick Then later a window A/C - downhill ever since.

Don't negate the importance of a refrigerator and ice. One must have cold beverages to maintain sanity.

Quote:

Originally Posted by soupcxan The benefit of replacing the fixtures (as opposed to just putting chicken wire or a drywall box around them) is that you can actually bury them in insulation (which I did).

I'm cheap and balked at the price, but mostly I was reluctant to spend any more time in the attic in July than I had to. July worked because I had my slaves sons home from school and they were helping. I was a tad skeered of inciting a mutiny if I prolonged their time on the job during the heat to stop and do electrical work. I think I'll revisit this issue in February.

[HFWR]

Quote:

Originally Posted by Leonidas I think I'll revisit this issue in February.

I noted the temp in my attic yesterday afternoon: 140F!

Jeez, Louise...

[eridanus]

Quote:

Originally Posted by HFWR I noted the temp in my attic yesterday afternoon: 140F! Jeez, Louise...

During the day, my attic temp is about 25-30 degrees warmer than the outside temp. It cools off pretty quickly at night, leading me to believe that I have enough passive air flow (2 turtle vents, 5 gable vents, and vented soffits). I also think there's some serious leakage from the house due to sheetrock repairs I've been doing. Cooled air goes into the walls and into the attic. I'm going to finish most of those repairs this weekend (I hope).

[boutros]

One thing that I did that no one has mentioned was glue batt insulation to the attic access panel so that when we close the attic access it forms a better seal against leaking air. You could even improve upon that by using weather stripping around the edges .

[cute fuzzy bunny]

Good info. I've never installed or changed a recessed light before. I didnt know they had insulation friendly versions and oddly enough, the stuff I read up on didnt mention replacing the non insulation friendly versions with different ones.

I do have one of the sealed ones over the tub in the master. I'll have to snoop around home depot and see if I can buy covers for the rest of them.

[hogwild]

Here are two options that a syndicated radio home improvement show suggests for recessed lights:

1. If they are the non-IC type, simply purchase a $1 or $2 dollar styrafoam minnow buckect and put a bead of calk around the rim and place over the fixture.

2. Replace the bulb with one of those new flourescent type that look like the regular spot light type but enclose a flourescent bulb.

I guess a third option would be do both.

[soupcxan]

Maybe I'm just being impatient, but I expected to see a huge reduction in my A/C usage the day after I installed the extra cellulose insulation. No such luck. I guess the benefits from increasing attic insulation from R-35 to R-49 are more subtle.

The suggestions to jury-rig non-IC rated light fixtures with inverted buckets or styrofoam coolers makes me nervious. If a fire were to start smoldering in your attic, you'd probably not realize it until it was too late. The using chicken wire or roof flashing to keep the insulation away sounds like a safer approach, but then you're still going to have air leaks through the light fixture and some uninsulated drywall (which is like, what, R-0.5?).

[Patrick]

Quote:

Originally Posted by hogwild Here are two options that a syndicated radio home improvement show suggests for recessed lights: 1. If they are the non-IC type, simply purchase a $1 or $2 dollar styrafoam minnow buckect and put a bead of calk around the rim and place over the fixture. 2. Replace the bulb with one of those new flourescent type that look like the regular spot light type but enclose a flourescent bulb. I guess a third option would be do both.

If you do 1 you better do 2. I'm surprised any reputable home improvement show would suggest this. The reason the cans are vented is to allow heat to escape. By gluing a bucket over it, you will be trapping that heat against a flammable (styrofoam) material. Not too bright (so to speak). By changing to a CFL, you might reduce the heat production enough to prevent your styrofoam bucket from catching on fire. Good luck.

[cute fuzzy bunny]

I already have CFL's in there, and I see that the models I have will turn off the power to the bulb if theres an overheat.

What I think I might try as a quick temporary thing is to remove the bulbs and stick some of the metal tape I use on ducts over the vent slots and openings and then put the bulbs back in. That'll at least eliminate open air transfer although the metal in the cans would still conduct.

Pretty much free except for a few hours work. Some of the lights I have attic access to get on top of them. Several others are in a ceiling area about 25' up and no attic access. A bunch more are in the ceiling in the first floor...I dont think theres any insulation there and I can feel a little bit of a draft when I changed the bulbs.

What's probably the worst thing is that when I run the whole house fan, I get hot attic air shooting out and around the bulbs, along with plenty of dust. Pretty much no bueno.

[hogwild]

Styrofoam will not melt below 464 degrees F. There should be plenty of air clearance between the can and the styrofoam bucket. The air will not reach that temp. That is unless your house is on fire.

[Patrick]

Quote:

Originally Posted by hogwild Styrofoam will not melt below 464 degrees F. There should be plenty of air clearance between the can and the styrofoam bucket. The air will not reach that temp. That is unless your house is on fire.

Are you sure? Let's try it on your house.

But seriously, if you are contemplating doing this, at least use a non-flammable container like a galvanized steel pail. Still, you might get some pyrolysis of any wood that might be in the area.

[cute fuzzy bunny]

I wonder why theres a code on this then, since fiberglass insulation and cellulose have fire points as high or higher than 450 degrees.

The stuff I saw suggested a box made from drywall as wide as the distance between the studs on either side of the can, at least 4-6" taller than the can and 2-3' long. Seemed like a lot of work. But drywall doesnt burn very well and thats enough space to let any heat buildup disperse.

[samclem]

Quote:

Originally Posted by cute fuzzy bunny The stuff I saw suggested a box made from drywall as wide as the distance between the studs on either side of the can, at least 4-6" taller than the can and 2-3' long. Seemed like a lot of work. But drywall doesnt burn very well and thats enough space to let any heat buildup disperse.

Regardless of the opinion of the well-respected radio gabber, I don't think an expanded polystyrene enclosure around a light is safe or that it meets code.

Drywall (gypsum board, etc) is interesting stuff. Not only does it not burn, but it does a fantastic job of resisting the transfer of very hot temperatures. (much better than the same weight of metal, cement, etc). That's because it has a lot of water bound up in it. As the drywall heats up from the flame, it cannot get above 212 deg F until all of this water is boiled off. That usually takes a lot of time, and is one of the primary reasons that drywall (with appropriate detailing and attachment schedules) is favored for fire-rated walls.

Cuts easily, looks good with paint on it, and makes your structure more fire resistant. Not a bad deal for 40 cents per square foot.