Has anyone actually painted their roof white?

Salanis wrote: The added benefit of having fresh hops for brewing does not hurt at all either.

Yes officer, it is technically... but the "hemp" keeps the atttic cool

Why not set the AC to 82 degrees and just go nude in the house? Depending on your own thermal comfort envelope alot of money can be saved by changing the thermostat and your clothing. Also a white roof won't be too much fun in the winter. Are you trying to save money or be more comforable?

Giant Purple Snorklewacker wrote:

Salanis wrote: The added benefit of having fresh hops for brewing does not hurt at all either.

Yes officer, it is technically... but the "hemp" keeps the atttic cool

an officer would be able to tell the difference by the smell

imirk wrote: Why not set the AC to 82 degrees and just go nude in the house? Depending on your own thermal comfort envelope alot of money can be saved by changing the thermostat and your clothing. Also a white roof won't be too much fun in the winter. Are you trying to save money or be more comforable?

Save money, but I'm not going to make myself uncomfortable to do so. That's why I want to improve the efficieny of the house.

I'm not going to do like I did when I was a broke college student who left the heat at 60 and wore layers of clothes.

the biggest difference i've seen so far, and it was a big one, was when i went to a programmable thermostat.

i keep the place fairly warm to begin with, but i have mine to go up to 83 during the day, and start cooling down to 77-78 at about 4:30 before i get home.

my electric bills have gone from 130-140/month in the summer to 70-100/month. the biggest savings has been in the winter, the electric furnace isn't the most efficient, so the bills were insane before, like close to 400/month, which have come down to 140-170/month last winter.

nicest part is that i can adjust the thermostat from my phone or online via the alarm system, so if i forget to turn it down before i go out of town, i can just change it from the airport.

When we had our roof installed last year, we inquired about the efficiency difference between a white roof and a darker colored roof and every single roofer said there was no notable difference in attic temps or energy efficiency. That said, there were incentives on the white roof shingles from both the manufacturers and federal government. We still chose a different color.

BTW, we've been doing the same kinda stuff here... our home was built in 1976. New windows are out, but we've upgraded the a/c to a 22 seer unit which cut $100 off our summer electric bill. Going to CFL saved another few dollars a month. Efficient appliances too. Any little bit that helps.

Paint the back half of the roof white. I doubt the neighbors witll complain much, and then add a roll-out system for black plastic to cover the white for the winter! Especially with the temps you get. Debbie Downer note: I would really check with the homeowner's policy for the proper type of fire-proof/resistant paint. I do echo all others with the attic fan. I remember as a kid, before the days of central air, we had a huge one in the attic, with moveable vents to open in the second floor hall. Sucked all the hot air out of the house, and was great at night to bring in the cool air. It was a little noisy from all the air moving, but come bed time, we turned it down to low, and it did the job. With a bit more insulation, and the attic fan, you should see a definite improvement. And sealing up all the little cracks helps a ton, too.

darkbuddha wrote: Going to CFL saved another few dollars a month.

In the winter an incandescent bulb is 100% efficient.

Strizzo, if the AC running non-stop from say 9am to 6pm and the house gains temp. I can't imagine letting the house warm up dramatically like that during the day.

z31maniac wrote: Strizzo, if the AC running non-stop from say 9am to 6pm and the house gains temp. I can't imagine letting the house warm up dramatically like that during the day.

This might be a part of your problem, if your AC system is undersized then it is forced to work harder than it's peak efficiency zone, like when they did the comparo between the 900cc and 1.3L mini some years ago and the more powerful 1.3L got better millieage because it wasn't as stressed.

At my previous gig in commercial/utility scale solar power I had to learn a lot about roofing. The systems would have to live on host roofs on big box stores for 20 years and removal to re-roof isn't feasible. Our roofing manager decided to experiment with white coatings w/ also purported to effectively "reset" the roof warranty start. He had about a dozen 5 gallon pails shipped to my attention, which I had neither the space, time or inclination to test.

'Til the flat torch-down membrane roofs on the back 1/3 of our 60 year old house and garage started looking pretty rough.

I brought home a couple pails and slathered all the flat areas w/ a couple coats. The back half of the kitchen and the office, both became way more hospitable on hot days. The garage interior temp dropped by 5-8 degrees.

If you've got uninsulated black flat roofs the white stuff works. For that matter, the cheap silver stuff works fine too, and it's dirt cheap.

I can sell you window film for an easy fix for the suns heat gain in side www.btropical.com

tuna55 wrote:

darkbuddha wrote: Going to CFL saved another few dollars a month.

In the winter an incandescent bulb is 100% efficient.

Depends on where you live I suppose... here in Florida, I'm often still running the a/c during the winter.

imirk wrote: Why not set the AC to 82 degrees and just go nude in the house? Depending on your own thermal comfort envelope alot of money can be saved by changing the thermostat and your clothing. Also a white roof won't be too much fun in the winter. Are you trying to save money or be more comforable?

If you've got good insulation, your roof will be white in the winter anyway

No, but I did hear one about a guy who painted his house black with pink shutters.

z31 what kind of siding do u have. even last month my electric bill was only 120 and thats on a 1800 sq foot house

Brick home.

imirk wrote:

Giant Purple Snorklewacker wrote:

Salanis wrote: The added benefit of having fresh hops for brewing does not hurt at all either.

Yes officer, it is technically... but the "hemp" keeps the atttic cool

an officer would be able to tell the difference by the smell

Smells different, looks different. They're in the same family, but not the same genus. By comparison that means those plants are about as closely related as we are to gorillas.

Salanis wrote:

imirk wrote: an officer would be able to tell the difference by the smell

Smells different, looks different. They're in the same family, but not the same genus. By comparison that means those plants are about as closely related as we are to gorillas.

Well if you put it that way ... there are some people I have a hard time differentiating from gorillas.

I think this mean we need to find a white boy with dreadlocks, give them some hops, and see how they react.

I have friends who had their black 3 tab roof replaced with a white vinyl sheet roof a few years ago. Their house was very uncomfortable in summer and now it is much, much nicer.

tuna55 wrote:

darkbuddha wrote: Going to CFL saved another few dollars a month.

In the winter an incandescent bulb is 100% efficient.

Well, so is a CFL. But in the summer, the CFL isn't using a bunch of energy unnecessarily negating your efforts to cool the house. Even if it's not hurting anything in the winter, in the summer the incandescent wastes energy twice, once in the bulb and then again in your A/C. I concede that it may have been a joke, but this is a foolish argument.

I am a Certified HERS Energy Rater. Part of what I do is home energy improvement analysis- meaning I try to offer improvement recommendations based on what the actual payback period is of the improvement.

Let me bust a few myths.

Windows: This is the BEST improvement for new construction (most cost effective), but the ABSOLUTE WORST for most remodels. Most people in the industry won't tell you that. Why? Because it is also the highest profit item of all the energy improvement options. I make a lot of money installing windows- you won't.

Air leakage: This is almost always the MOST cost effective improvement you can do. But doing it right means a lot more than just shooting great stuff into every crack you can find. It would be worth hiring someone to do a little testing and prove the improvements. There are 3 primary tests- a blower door test, a duct leakage (aka duct blaster) test, and infrared imaging. Expect to pay several hundred dollars for each of the tests. The best version would be done by a Certified Rater, and include tests before and after the improvements. These tests will pinpoint the exact areas of leakage in your house, quantify them, and enable you to evaluate the cost effectiveness of them. Without real tests, it's just internet conjecture and BS.

Roofers recommendations on light colored roofs: They lied. Light colored roofs DO reflect heat and reduce the radiation gain in measurable amounts. Why would they lie? Because light colored roofs are hard to install without defect, and guaranteed to be a headache and a lot of callbacks for a roofer. They don't get paid more for them, so they would rather not do them. HOWEVER, this will only be cost efffective if you are replacing your roof anyway.

Painting a shingle roof: this sounds like a really bad idea. Think of it like painting the beach. It won't last, and it might accelerate the wear on your roof. What you would be trying to do with this is reduce the radiated heat gain, and there is a better way to do it.

Reflective heat barrier: This is the best method of reducing radiated heat gain in a retrofit. It is a reflective foil product that you can attach to the underside of your roof decking from the attic. It is fairly inexpensive, and DIY user friendly. You will also reap the benefits even if you only do half the job (unlike insulation).

Undersized AC system: Houses are more efficient if the AC system is slightly undersized, particularly in humid climates. The more frequent cycling will control the humidity better, which reduces the effective load.

Insulation: generally a very good dollar return, but ONLY if air infiltration is addressed. Here's the deal- insulation gives thermal mass, but it DOES NOT stop air leakage. If you take a nice sized chunk of pink fiberglass insulation and blow through it, the air will blow through. Point made. The insulation acts like a filter, but it does NOT stop the air leakage. Drywall, plywood, foamboard, taped joints, caulk, and wood blocking are all methods to stop air leakage. Lots of insulation without good air leakage measures is like a big fluffy coat with no buttons.

Relocating ducts inside the conditioned space: This is kind of big. Can be difficult, but sometimes easier than it sounds. Here's the deal... your duct system leaks. Badly. Unless every joint is sealed with mastic (not duct tape), and 95% of ducts are not. If you see mastic on the joints of the insulation wrap around the ducts, then you've got a crappy job. It's supposed to be UNDER the insulation on the joints of the actual metal duct. Let's assume your ducts are in the (unconditioned) attic, and you've got a supply leak in the attic. Your blower pulls 1000 cfm out of the conditioned space through the return ducts, and the supplies leaks 20% into the attic. Your blower is STILL going to pull 1000 cfm out of the house, even though it is only putting back 800 cfm of your conditioned air. The house will have negative pressure, and the missing 200 cfm will be pulled in through various leaks (cracks, bathroom fan, range hood, clothes dryer, etc.). If you seal the leaks in the supplies, the system won't need to pull 200 cfm of unconditioned air in through the various points of entry. Relocating the ducts (after sealing) may be as simple as moving the insulation so it is over the ductwork instead of under it.

Well, there are a few points to get you started.

Josh wrote:

tuna55 wrote:

darkbuddha wrote: Going to CFL saved another few dollars a month.

In the winter an incandescent bulb is 100% efficient.

Well, so is a CFL. But in the summer, the CFL isn't using a bunch of energy unnecessarily negating your efforts to cool the house. Even if it's not hurting anything in the winter, in the summer the incandescent wastes energy twice, once in the bulb and then again in your A/C. I concede that it may have been a joke, but this is a foolish argument.

Well the incandescent bulb isn't filled with mercury, and doesn't require all of the nasty environmental concerns that go along with manufacturing something that is filled with mercury. It's not that much of a joke.

In california I think there is a law that if you have a flat roof it has to be painted/foamed white. A flat roof is a very poor roof design and also pretty popular in my area. After a big storm you see all the flat roofs with 3-4" of water on them and if you don't have a sump it will stay that way.