Don't want to do it myself because I'm LOLrich.

I would like to take suggestions on companies you have used and your experiences. I'm lining up some bids but it appears that some use the foil and some use the paint. I've read the paint is not as efficent as foil so I'd like to hear about the price differneces.

Thanks.

Correct. The paint is not as good as the foil but beware as there are different levels of radiant barrier paint. Some are really inexpensive and some go for like $600/5gal. Check what the percentage is of each type of product and then compare costs to make your decision.

Pay for insulation first, duct sealing second BEFORE you think about radiant barriers. There are energy efficiency items you can do that have better bang for the buck that radiant barriers do.

I would also add to have the attic checked for proper ventilation. If you do not have the correct air flow in the attic, the radiant barrier won't help as much as it should.

^ who would you get to so this?

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Don't want to do it myself because I'm LOLrich

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Real LOLriches live in houses that came with it.

^^^ Good point. I'm really LOLazy.

In my first house, I had the techshield foil installed when we built so I don't know how much it was actually saving me.

Does anyone have any real life data of the savings you have realized from adding radiant barrier?

PS... I want to add radiant barrier mainly because Tom Tynan says that is the first thing to do followed by added insulation.

It will definitley make your home more comfortable and save you money as well. Most clients that we add it to on remodels have told us they save between 15%-20% on their heating and cooling portion during the peak summer months.

Having more fiberglass insulation blown in the attic is also fairly inexpensive as well.

anyone know how long that paint is good for? I have a few gallons in my garage that the contractor left in my garage. It was 2 or 3 years ago and I am not sure if it is even still good.

If not, how do I dispose of this?

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I would also add to have the attic checked for proper ventilation. If you do not have the correct air flow in the attic, the radiant barrier won't help as much as it should.

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I would like to know who you would get to check this as well.

Also, what would be the average temp expected in an attic in Houston during the summer? Would getting a temp give me an idea of anything?

I think if you have the attic properly venilated you can expect it to be within 10-15 degrees of outside ambient air temperature. I read this somewhere and am not sure where that was.

I am not sure the best person to talk to for checking air flow. I had some roofing contractors come by the house to give bids on adding ridgevent, but they spoke to my wife and not me and the meetings ended up not being very productive. However in talking to her about what each one said, I would reccomend S&I residential, www.siresidential.com/#!roofing. He seemed to somewhat understand what I was wanting done and said he could come back later to check air flow from the soffitts. He is based out of Houston but came to College Station for an estimate.

Had EAS out to do a free quote.
I have a 2 story house.

The guy went into all my attic spaces and ran some calcs. He calculated my ventalation and said I did not need to add or do anything. He mentioned that you need more intake than exhaust to create a slight positive pressure in your attic to force airflow out. He said you need about 8 - 10% more intake than exhaust.

They were offering 15" free insulation and I currently had 12". So I am essentially getting the needed insulation for "free".

My final quote on a ~1200 sq ft attic was $1700.

He expects my pay back to be about 3 years.

Payback won't be that fast. My energy bill did not go down between 2010 and 2011...of course, we did not have 45-days of 100°+ weather in 2010 like we did in 2011. Also, 30-days in a row of no rain.

I checked my AC energy use each night and it was running 13+ hours during those long dry spells. The few times it did rain, it ran 6-8 hours.

I guess my point is, it is definitely saving me money since my electrical use changed very little, but it was a lot hotter in 2011 than it was in 2010 and 2009. Also a lot less rain which has an evaporative cooling effect on your house. But not $1,700 in basically 12-months....(when you figure how much you run the AC in the summer over 3-year)

My attic was unbearable hot in the summers if I had to go up there for any reason before I installed the radiant barrier. Last summer, I put a thermometer up there a few days and randomly checked it and it was about the same as outside temp. I had one installer quote me $2K to install but I’m not LOL Rich and DIY for ~$350 from atticfoil.comd (check out their web site to get good info. on how it supposed to work).

Also, I think superspek will be along shortly to tell you it's which craft, junk science and will shorten your roof life, all of which he is wrong about. A&M did a study several years ago which showed it did nothing to the roof life (and roof manu. will not void your warranty if you install it) and does in fact help save on energy costs (Honestly, I have no idea why he's got such a beef with it - other than maybe he or some friends have been screwed over by some installers).

[This message has been edited by agracer (edited 6/11/2012 3:10p).]

Thanks for the reply agracer.

There are a lot of factors in the savings you obtain... A/C age/seer rating, how cold you run your house, etc.

Right now I'm estimating that I use about $300 a month between May - October so about $1800 a year. If I can save 20 - 25% I can save about $400 - $450 a year so my calculated pay back I estimate is more like 4 - 5 years.

The guy did say the coating they use is 80% efficient against radiant heat where as the foil is 97% but can be problematic if not installed correctly.

Either way, I plan on staying in my current home for at least the next 10 - 15 year so I think it's a go for me.

Thanks for the reply agracer.

There are a lot of factors in the savings you obtain... A/C age/seer rating, how cold you run your house, etc.

Right now I'm estimating that I use about $300 a month between May - October so about $1800 a year. If I can save 20 - 25% I can save about $400 - $450 a year so my calculated pay back I estimate is more like 4 - 5 years.

The guy did say the coating they use is 80% efficient against radiant heat where as the foil is 97% but can be problematic if not installed correctly.

Either way, I plan on staying in my current home for at least the next 10 - 15 year so I think it's a go for me.

Runnning. The reason EAS gives away the "free" insulation is that it is

1. cheap
2. does 90% of the heat reduction in the attic.

don't waste your money on the radiant paints. They don't payback.

Look at the cost of just the insulation and do that only.

The radiant foil works good, but I am not quite sure on the payback.

[This message has been edited by chocolatelabs (edited 6/11/2012 8:30p).]

Thanks chocolate. Do you have a source of data to show insulation does 90% of the work?

chocolatelabs analysis is incorrect that insulation does 90% of heat reduction in attic.

Attic rise in temperature due to radiant heat from the exterior, not from rising air inside the home. The radiant paint or foil product will both pay for themselves and you will have a noticable difference in comfort level of the home.

Now if chocolatelab was talking about spray foaming your entire roof decking and sealing the attic, then it will cut out the radiant heat, but you are going to pay about $1.40/sqft of attic decking (think of it as square foot of shingles that you have on your roof and you will be pretty close), plus will have to close your soffit vents, and add a fresh air intake on your HVAC system. Those costs will probably not pay themselves back any time soon

[This message has been edited by DaybreakAg (edited 6/11/2012 8:46p).]

What I was saying is that the insulation does 90% (rough guess) of the heat reduction when you install insulation and radiant paint.

I stand by my statement that radiant paints don't work. Look it up and you will see. They aren't a true radiant barrier.

The energy savings claims by radiant paint companies like EAS are overstated.

I will run an energy model on my house and show the savings after I get back from colorado.

there are lots of sites that claims paints work and claim only the foil works. Got to dig hard to find out the truth.

http://energystar.supportportal.com/ics/support/KBAnswer.asp?questionID=14468

although the radiant paints may provide some benefit, they don't payback and aren't the best choice to spend your money on. There is a reason they throw in the "free" insulation.
check out figure 5
http://www-esl.tamu.edu/docs/terp/2007/ESL-TR-07-02-01.pdf

My advice is to add either blow in or spray foam insulation on the decking.

[This message has been edited by chocolatelabs (edited 6/11/2012 9:39p).]

Radiant Paints don't work? That is a pretty blanket statement from a person who has not experienced it first hand or has just been trying to justify a stance without facts. The research is there and a quick google search on "Radiant barrier paint v. Foil" will yield enough articles to make your head spin. All articles point to foil being the better of the two and no one is arguing that at all, but both products do work.

To be technical, there is not such thing as a radiant barrier paint because by definition a "radiant Barrier" must have a rating of 0.1 emitting no more than 10% and reflecting at least 90% of thermal radiation.

Now the best paints will only reflect about 78% and the foil product will get you +95% so there is a difference but also a cost difference as well.

I put the sherwin williams product on a home a lived in 4 years ago and did not add insulation to the attic. My energy bills were cut by almost 30% in the summer months as compared to the previous years with the billing contract with my energy provider staying the same. There is a reason that radiant barriers are sold and it is not some marketing hoax. Both products will yield savings and pay for themselves.

Investing in either product is a good idea. If your attic is scorching hot, your AC is going to work double time. Do you realize how much temperature loss you get from the plenum to the registers do to the heat around your R-6 or R-8 flex ducts in the attic? Drop the temperature in the attic by reflecting the radiant heat away and your system is going to work more efficiently and the save you money.

Does adding more insulation also help? Of course it does but not in the same purpose as reducing radiant heat and attic temperature. We can discuss adding insulation and its values but that should be a separate topic.

If you really care;

The model discussed in the Economic Evaluation of Insulation/Radiant Barrier Systems is Here. Basically, the model is accurate to < 5% of the test cases it was compared against.

Also; a Catolog of the digital library has all the publications. Type “radiant” into the search box and you’ll find several publications (including the two I linked above) about radiant barrier systems.

Basically, energy savings are between 15-30% a year depending on the start case (new construction, R level of attic insulation, installation method of radiant barrier). The heat gain on the shingles is less than 1% according to all data I found.

So they do reduce heat loads in the attic, thereby reducing heat loads dumped into your house from the ceiling (one study showed a 60% reduction) and on the ducts in your attic saving you money.

And the foil does work better than the paint as it’s emissivity is <0.1 where as the paint is much lower (like <0.3 which does not technically qualify as radiant anything). See here

EDIT: Fix Links

[This message has been edited by agracer (edited 6/12/2012 12:54p).]

Agracer. links aren't working, but work maybe blocking me.

Daybreak. I agree with you that radiant barriers are a good idea and yes you want to get your attic temp lower. No dispute on that.

I amended my statement and said that radiant paints don't payback. I also know they aren't a true radiant barrier because of the emissivity.

Your 30% savings is interesting because it differs from other studies that I found.

the paints don't perform as well once they get dusty is another factor.

My whole point is that I don't think "radiant" paints have a good payback, and to look for other alternatives first.

Hey if you got a 30% energy reduction that is great. Not what I see, but maybe it worked for you.

We may just have to agree to disagree. :-)

Daybreak,

since you are in the housing industry, have you ever used this product.

http://www.heatbarriersystemsinc.com/productinformation/

Chocolatelabs,

I have not used that specific product, but about 7 years ago we used something similar on remodel. A couple purchased a home and the techshield roof decking delaminated and we put something that looks very similar to that product in its place. I cant remember the name of it and would have to do some digging to find it.

Now the building wraps and behind siding applications is something I am not familiar with. I know that reseach shows that a radiant barrier OSB (same as roof decking) has no added effect when applied as sheathing. The website you provided is pretty vague on the information.

I'll read up on it and make some calls to my suppliers and vendors to find out more about it.

While researching this for my own home, I cam across a product called radiant barrier chips. Basically once you have you insulation level you spray these aluminum chips over your insulation to act as the radiant barrier.

They claimed to have more success without insulation in the attic then with it because the insulation traps and stores heat. This is really somewhat of a contraversial claim in that most would argue that you need more insulation, but they showed, at least in Arizona, that you don't need it at all. If you have ever actually stuck your hand in the attic insulation at 7pm, you will notice that it is still hot and is storing heat.

I would at least reccomend in googling "Radian Barrier Chips" to learn more about this method. To my knowledge it hasn't caught on in Texas and it might be worth looking into more.

Some of those studies I linked discuss the use of radiant barrier and insulation levels and effectiveness of the two products together.

We're in the very early planning stages of building a new home. I have been looking at a lot of "green" building info to try and get an idea of ways to make the house as energy efficient as practical. One of the things mentioned for our climate (outside Austin) is a sealed attic with insulation at the roof deck/rafters with polyurethane spray foam. Is this something that can be done in conjunction with a radiant barrier?

No if you spray foam and seal the attic, the radiant barrier will not be necessary (it will be rendered useless) and you will be wasting money at that point.

If you spray foam the rafters, make sure they adjust the HVAC system to have a fresh air intake that is sufficient for the home, make sure they do not install attic vents (air hawks or ridge vents) and make sure they do not install perforated soffit.

I have a house (new) with spray insulation. They installed the pre-drilled eave wood. With the spray foam, it just filled in the holes. Would have been better without the holes, but not the end of the world.


One thing, if you care about it, that radiant barriers do is block radio signals to your house. So, if you have an antenna in the attic, it won't work anymore if you put up the foil/metal.

Something to ponder.

~egon

AggieFromArkansas

There are some ways to combine a radiant barrier and a full foam encapsulated attic. You will need to have "raised" type roof that creates an airspace. Tile, or some metal roofs work, or you can do a double-roof deck system like this: www.radiantbarrierguru.com/combining-radiant-barrier-with-spray-foam-insulation/

We've been looking at the standing seam metal roofs as well. That works better as far as a radiant barrier and insulation?

Update - Had EAS out to install today. The crew completed the job in 2 hours. My appt was from 12 - 2 but they got their first job done early and called to see if I could let them come early.

The did a very good job and the tech applied a nice even coat and he crawled into places and applied it where I didn't think a human could fit. The additional insulation was added and they did a nice clean up job. Both techs were very nice.

I'll provide updates over the summer to see what kind of differnece this might make on my electic bill.

Nice!

Running with the Bulls said:

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Update - Had EAS out to install today. The crew completed the job in 2 hours. My appt was from 12 - 2 but they got their first job done early and called to see if I could let them come early.

The did a very good job and the tech applied a nice even coat and he crawled into places and applied it where I didn't think a human could fit. The additional insulation was added and they did a nice clean up job. Both techs were very nice.

I'll provide updates over the summer to see what kind of differnece this might make on my electic bill.

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After a 12 year data collection period, what is the conclusion?