Had Efficient Attic Systems/Home Depot come out and take a look at our new house and make some recommendations for making the attic space more energy efficient. Curious to get some feedback/opinions on the recommendations and price.

Insulation - attic currently has 8-12 inches of the white blown-in insulation, but it has been pushed around alot from running wires/cable/etc. Recommendation is 20" of insulation throughout the attic.

Solar Attic Fans - we have 2 large turtle vents in the attic, without fans, so currently it relies on air flow coming through the soffit vents and up through the turtle vents. Don't have alot of breeze/wind up here in NW Austin, so it seems like hot air probably just sits in my attic most of the time. Recommendation is to install 2 solar-powered attic fans on each of the turtle vents to suck the hot air out of the attic.

Radiant Barrier - doesn't have it. Recommendation is to add it. Pretty straight forward.

Altogether, the price tag comes out to $2900. I could put it on my HD card and pay it off over 12 months with 0% interest. However, the wife is wanting new floors in the house, so gotta win that battle.

Insulation seems like a no-brainer. Anyone had the radiant barrier or attic fans installed? How much of a difference/cost-savings did you see? Would you guys pull the trigger on these recommendations for this price?

I'm no expert but this is what I've gathered from my own research:

Insulation - this is the most common solution and probably the most affordable. you could probably do this yourself for blown-in. there is a thread on this forum about this right now.

Solar Attic Fans - attic fans are great and solar is just the newest technology. you could also install electric fans with a switch hidden in a closet (my dad's house is like this).

Radiant Barrier - I've heard these are great if you buy the house with them, but IMO, they aren't worth the investment.

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Altogether, the price tag comes out to $2900. I could put it on my HD card and pay it off over 12 months with 0% interest. However, the wife is wanting new floors in the house, so gotta win that battle.

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$2900 sounds like a great price, even from HD. I would still get a second quote. I've done the 0% 12-month thing with HD and it worked out great, as long as you pay it off of course.

How big is the house. 2900 does not sound terrible. Did they itemize? I upgraded insulation last year for about $550 - about the same upgrade you described for about 1800-2000sf of attic floor. The fans are somewhere in the $200 - $500 price range for you or I buy. Depending on your roof slope, installation is not that hard. You have to decide if whatever is left in the price for the radiant barrier is worth it. Personally, I love the built in tech shield stuff, but am not as big a fan of the paint.

If they do the fans, make SURE they confirm proper inlet openings in the soffit. If they don't the fans will pull from the house (this is bad) and will die sooner. I would tell them I expect this to be part of the job/quote.

As long as you have realistic expectations, you should be okay. If they sold or you are expecting some hugely noticeable reduction in your bills, you may be disappointed. In my experience you should expect 5 - 10% improvement - if that. Keeping in mind that it is REALLY hard to quantify. Any improvement can be a positive thing, but the ROI may be a while.

I should also mention that the roof is going to need to be replaced in the next year or two. Was a known quantity when we bought the house, and was reflected in the sales price.

Would it be better to hold off on anything other than adding insulation for now, and then adding some ridge vents and such when we have the roof replaced?

Insulation is a no-brainer. 20" should be R-60 and is good. Make sure they install soffit baffles. It's not a bad idea to install extra soffit vents if you don't have that many; I actually have replaced all of my soffits with continuous HardiSoffit and put a baffle in each bay.

THE FOLLOWING IS PERSONAL OPINION (although I feel it's validated and backed up by "Science!" :

I don't feel that electrical attic fans are a great improvement. The problem with them is that if they're not properly sized to the attic space and the free air that's available, they force air conditioned air up out of the house. I'd rather contract a roofer or architect to actually calculate and properly balance a more passive system. The other problem is that they've got parts to maintain. If you get one with a battery so that it works after dark (when you're trying to sleep in a sweaty house with the A/C running full blast), you've gotta make sure that the battery is still good. The bearings on the fans themselves can blow in hot, dusty environments and cause things to seize up, which can be a fire hazard. Hard wired (AC) attic fans can also be a fire hazard. I see a lot of fire reports where the fire was attributed to an unmaintaned one. It's sort of a big maintenance item, and I don't think they should be installed without considering how often you're going to check on their operation.

However, the good point about the solar attic fans is that they do the most important thing for cooling your attic: They cause air changes, which reduces the difference between the outside temperature and the attic temperature.

You can do the same with turbines in most cases. The trick, again, is to have baffled soffits with enough air coming in and then have enough air going out the top of your roof from the turbines. Turbines or turtles should only be on one side of your roof, not both. If you increase your soffit air space and add turbines, plug up your gables.

As far as radiant barrier goes -- you'll see a LOT of people who are huge fans of it. I have a couple of serious problems with it. First, it reflects some of the heat back into your house. Ever seen one of those shiny mylar emergency blankets? Yeah. Second, it reflects the radiation it receives (UV, IR, etc.) right back through the roof decking, and heat helps to break down the roof decking faster. There haven't been any real studies on this that I can find except short term studies done by manufacturers (which are about worth the paper they're written on) which says that it doesn't heat up the surface of your roof, but a little exploration with an IR thermometer will tell you otherwise. Third, depending on how they install it, it may really reduce the amount of air that's moving around in your attic. It is correct that it will reduce the temperature in your attic. My question is, "at what cost?" ... we don't really know, and the same thing with no downsides can be done using ventilation alone.

A better alternative is, when it comes time to, replace your roof surface with an energy-star rated one ... most of them look just like normal roofing shingles, but have integrated materials that reflect the heat of the sun back out.

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As long as you have realistic expectations, you should be okay. If they sold or you are expecting some hugely noticeable reduction in your bills, you may be disappointed. In my experience you should expect 5 - 10% improvement - if that. Keeping in mind that it is REALLY hard to quantify. Any improvement can be a positive thing, but the ROI may be a while.

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This pretty much sums up any of the options you go with (or all of them). Sure, it's good to plug gaps in doorways and windows, but when you start putting down serious money on this kind of stuff, you can't expect a drastic or immediate ROI. It might help with resell, but because of a slow, long ROI, I haven't done any of the things you're looking to do on my own house.

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This pretty much sums up any of the options you go with (or all of them). Sure, it's good to plug gaps in doorways and windows, but when you start putting down serious money on this kind of stuff, you can't expect a drastic or immediate ROI. It might help with resell, but because of a slow, long ROI, I haven't done any of the things you're looking to do on my own house.

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This is a good tactic to take if you're at the bottom of the market or you're flipping, but I think if you're planning to hold the house for 5+ years, you will definitely see an ROI from doing it. And even if you're in those market areas in an area where things are moving slowly, if you think you might want or need a quick sale, having already done the window replacement and other energy improvements to the house will help your house sell faster because buyers seem to prefer houses where these things have already been addressed.

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if you think you might want or need a quick sale, having already done the window replacement and other energy improvements to the house will help your house sell faster because buyers seem to prefer houses where these things have already been addressed.

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+1

This probably covers both "flippers" and "nesters" as far as a reason to update.

Honestly if you KNOW you will be replacing the roof. Save the money on the radiant barrier part and when you do the roof spend it to have them install new decking with the barrier built in. This will work MUCH better than any retrofit method. Or do as speck said and invest in a higher end shingle that does the same type of thing.

I have seen a lot of concern along the lines of what speck said about shingle life but also no real conclusions. We should know in a about ten more years around here. Most all new houses around here have the built in barrier. Even with that concern, I would get the built in - shingles rarely live to old life here anyway due to hail. As someone who goes into many attics, I have absolutely no doubt in my mind that good radiant barrier systems combined with good ventilation make a HUGE difference in attic temps.

I also agree with him on the powered fans. I have installed them in past houses and seen no noticeable difference - and I made sure they had enough inlet air (what a crappy dirty job that is.)

Again, with your added info about the roof, if it were me, I would probably only do the insulation now. Maybe add turbines myself. But wait for the major stuff until the roof gets replaced and do it right with ridge vents (if the house allows them) and adding new radiant barrier decking at that time.

Oh and definitely get more quotes. EAS will not probably be the best price.

[This message has been edited by Absolute (edited 7/20/2011 3:37p).]

Check and see if you have baffles installed. If you do, then buy atticcat from owens corning at home depot. Its 29.97 for 65 sq ft (R-30). If you decide to go that route, 4-5 hours of work with a friend and you save $1800+ after tax.

if you are replacing the roof soon wait on all of it.

replace the roof, put in massive soffits (real soffits with 2" holes) and a ridge vent, radiant decking, passive turbines properly space, attic tent, and tons of good insulation. solar screens for the house. done.





[This message has been edited by cclearman (edited 7/20/2011 11:41p).]

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Save the money on the radiant barrier part and when you do the roof spend it to have them install new decking with the barrier built in. This will work MUCH better than any retrofit method

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At quite a premium too boot. That will NEVER pay for itself and is a waste of $$. The radiant barrier is a good ROI since it lowers the attic temperature where you AC unit is operating, not to mention the heat load on the space right below your attic. Also, EAS puts in the spray in stuff which is NOT a radiant barrier. It also will not work near as well as the foil. http://texags.com/main/forum.reply.asp?topic_id=1825971&forum_id=61

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Insulation - attic currently has 8-12 inches of the white blown-in insulation, but it has been pushed around alot from running wires/cable/etc. Recommendation is 20" of insulation throughout the attic.

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If you have any kind of DYI interest, then DYI. Home Depot or Lowes will let you borrow the machine if you buy x-bags of insulation. It’s a pretty easy project to do.

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Altogether, the price tag comes out to $2900. I could put it on my HD card and pay it off over 12 months with 0% interest

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Why in heavens name would you finance something like this? It ads very little value to your home and the payoff is YEARS away. Your wife is right, if you’re going to finance then do the floors.

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Solar Attic Fans - we have 2 large turtle vents in the attic, without fans, so currently it relies on air flow coming through the soffit vents and up through the turtle vents. Don't have alot of breeze/wind up here in NW Austin, so it seems like hot air probably just sits in my attic most of the time. Recommendation is to install 2 solar-powered attic fans on each of the turtle vents to suck the hot air out of the attic.

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I seriously doubt these guys carefully calculated how much air flow you need and will fully balance the ventilation system once it’s installed. More than likely you will suck cold air out of your house around your attic stairs, lights, outlets in walls, etc. up through your attic and push it outside. See my thread above. The guys who quoted mine said I did not have enough ventilation. Well, guess what. After I put in the radiant barrier myself, my attic is very near outside temperatures and I my turbines spin pretty much all the time. Even with no wind, the heat rising out of the space goes out the vents via chimney effect and I can fell the air moving near the turbines in the attic. I’d say it works just fine.

[This message has been edited by agracer (edited 7/21/2011 2:42p).]

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Why in heavens name would you finance something like this? It ads very little value to your home and the payoff is YEARS away. Your wife is right, if you’re going to finance then do the floors.

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If it is 0%, then why not? Let's us go ahead and purchase without having to drop our savings by $3k to do so, and spreads out the cost over time, while keeping the overall cost the same. I would much rather shell out $250/month and not impact our savings than shell out $3k, and then have something unexpected happen.

Regardless, we have decided to just wait until we replace the roof. Too many alternatives that seem like they will give as much if not more ROI. We will probably go ahead and do the insulation ourselves though. Home Depot rents the machine for free if you buy 10+ bags. We will need about 15 bags for our attic space, so looking at about $500 after taxes to add another 10-12 inches of insulation in our attic.

You might check the prices to have the insulation done - just for kicks. When I did, it was only about $100 more to have it done. I figured that was worth it, not to have to haul the stuff, do half a day's work and all that goes with it. I had to shop around a bit, but found a pretty good price. all that from someone who HATES paying others to do things I can do. I had also waited till it was pretty hot in May and did not want to be messing around in the attic at that point in the year.

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Save the money on the radiant barrier part and when you do the roof spend it to have them install new decking with the barrier built in. This will work MUCH better than any retrofit method

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At quite a premium too boot. That will NEVER pay for itself and is a waste of $$. The radiant barrier is a good ROI since it lowers the attic temperature where you AC unit is operating, not to mention the heat load on the space right below your attic. Also, EAS puts in the spray in stuff which is NOT a radiant barrier. It also will not work near as well as the foil. http://texags.com/main/forum.reply.asp?topic_id=1825971&forum_id=61

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Like I said -- some people believe in the foil, but I PERSONALLY don't because I don't see how it fits into the building system. (We all know that the spray in stuff really doesn't work.)

The decking is $2 more/sheet than normal decking; it's the labor you're paying for when re-roofing using it.

Instead of using the decking, consider applying a Cool Roof shingle. That will get you ROI without a huge investment. Another way to get ROI is to apply a similar product that's actually a Cool Roof Stone Coated Steel roofing product -- not only do you get a cooler roof, but you get almost complete protection from hail (worth a big homeowner's insurance discount) and a 50 year warranty.

[This message has been edited by superspeck (edited 7/22/2011 12:05p).]

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Like I said -- some people believe in the foil, but I PERSONALLY don't because I don't see how it fits into the building system. (We all know that the spray in stuff really doesn't work.)

The decking is $2 more/sheet than normal decking; it's the labor you're paying for when re-roofing using it.

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And yet data and personal examples have shown time and time again that the foil works just fine. It lowers the temperatures in your attic significantly. It put less stress on your AC system if it's in the attic. It lowers the heat load in your house. It pushed the heat UP and out of the roof. Why is this so hard to understand?

And why would you replace ALL of the roof decking when replacing the shingles on a roof? Sure, replace a few rotten ones or bad ones, but why would anyone spend that much extra money? It's not just labor, it's all the material as well. Again, it will never pay for itself vs the foil.

"And yet data and personal examples have shown time and time again that the foil works just fine. It lowers the temperatures in your attic significantly. It put less stress on your AC system if it's in the attic. It lowers the heat load in your house. It pushed the heat UP and out of the roof."

I agree it does most of those things, but I disagree about the pushing the heat up and out of the roof. It sounds nice, but a majority of the radiant heat is absorbed by the internal structure before fully exiting the attic. So, it keeps your attic cooler, but cooks the backside of the roof etc [it would be like placing aluminum foil onthe inside of a tent facing a campfire. True, the inside of the tent will be more managable, but the integrity of the tent goes to **** because of the stress from the added heat.

My fathers construction company in Houston in conjunction with DW homes, did a RB test for 2 houses (one with and one without). They placed radiant barrier in one with r -19, and they placed only r-40 in the other. After a year, they replaced the roof of both houses as was planned. The house with r-19 nd radiant barrier had visible heat damage while the properly drafted attic with r-40 was clean.


[This message has been edited by CSTXAG2015 (edited 7/22/2011 1:25p).]

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And yet data and personal examples have shown time and time again that the foil works just fine. It lowers the temperatures in your attic significantly.

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See my repeated objection to foil, repeated in nearly every thread on this forum about it -- we don't know what it's long-term cost is to the roofing material, and I don't think it's good. Reflecting the heat out is a brilliant idea that will have long-term benefits for your home, but we don't yet know what all the costs of that are to the things on the surface of the house or even surrounding homes.

Example: In the Great White North, vinyl siding is very popular, as popular as Hardi is down here. As houses have been built closer together and low-E windows have been required by code, they've found that the reflection of the Low-E windows will actually melt the vinyl siding and window frames/jackets on adjacent houses. Like a boy scout with a magnifying glass and an ant nest... Oops. Unintended consequence!

You reflect the energy using the tin foil hat on the inside of your roof, but where does it go? Think about it... What didn't get absorbed coming in through the roof in the first place gets bounced back up through the roof, some of which gets absorbed on the way. If you don't think that's a lot of heat, go stand outside with some of that radiant foil and reflect it back up into your face. You'll sunburn in like ten minutes.

Again, there have been LOTS of informal experiments (I've done my own) about the use of radiant barriers, but there doesn't seem to be an academic or scientific peer-reviewed paper that looks at the issue.

I agree completely that the foil decking is NOT a great solution for a retrofit, a) because of the need for an airspace and rain jacket layer, and b) because of the cost. Hence my suggestion of the Cool Roof products that either are or look exactly like standard stone coated asphalt shingles. The premium is not that much. The insurance discount for the stone coated steel is nice and helps with the return.

Keep the radiation on the outside of the house, don't let it in at all. Especially if you're re-roofing.

Oh! Oh! Oh! From this month's Fine Homebuilding, in an article called "A Crash Course in Roof Venting", excerpted from a class taught by Joseph Lstiburek of Building Sciences (Ph.D P.Eng), -- FH # 221, Pg. 72) -- "Shingles that are installed on unvented roof assemblies operate at slightly higher temperatures, roughly 2F to 3F warmer than shingles on vented assemblies. This can reduce their service life by roughly 10%."

Testing with an IR thermometer, I found that a house that had radiant foil in the attic showed roof surface temperatures about 10 degrees higher than an identical neighboring house (same construction dates, same shingle make model and batch) without radiant barrier. Wonder how much of a service life difference THAT'S worth?

And that was back in March. Wonder what it's like now in July/August?

Guess what, the space gets hot as hell regardless. It either heats the entire attic, or just the portion up high. By keeping it high, you contain the heat and lower the load on your AC system. An without a cost comparison of energy savings vs. loss in service life of the roof, it's all speculation anyway. At this point, I haven't seen any hard data to suggest that the foil is going to decrease the life of my roof by enough of a margin to justify not putting it in.

The venting also matters. Obviously if you just put up the foil and don't properly vent the space it will heat the roof system (although, without a properly vented roof you're screwed either way).

EDIT: Super - I understand what you're saying, but as I noted above, from what I've read and understand (as a ME PE with HVAC experience) I believe I will see a larger benefit from an energy savings stand point than I will loose in roof life.

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operate at slightly higher temperatures, roughly 2F to 3F warmer than shingles on vented assemblies. This can reduce their service life by roughly 10%.

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2°F = 10% loss in service life. I'd like to see how he comes to that conclusion.

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Testing with an IR thermometer, I found that a house that had radiant foil in the attic showed roof surface temperatures about 10 degrees higher than an identical neighboring house (same construction dates, same shingle make model and batch) without radiant barrier. Wonder how much of a service life difference THAT'S worth?

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Nothing. Random observations of data under uncontrolled conditions are a bit meaningless. What time was it when you checked each roof, what direction was the roof facing, color of roof, angle of roof, etc....

[This message has been edited by agracer (edited 7/29/2011 12:48p).]

I knew I'd seen this somewhere.

http://www.rimainternational.org/technical/tb103.html
Obviously not an unbiased source. I also saw mention that the DOE has done tests that show roof temp. only increase 2-5°F and virtually all roof manu. will not void a roof warranty if you have or install radiant barrier.

Look, A&M says it's OK as well
http://blog.ufpi.com/blog/go-green---energy-efficiency-in-your-home/texas-am-university-study-gives-thumbs-up-to-radiant-barrier-insulation

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The use of a Radiant Barrier System in conjunction with enhanced venting does not increase either roof shingle or roof sheathing temperatures. In fact, these temperatures are slightly lower than those measured during Standard Venting tests. The lowest temperatures were measured during the Full Venting tests.

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As I said, the venting has to be done correctly along with the radiant barrier.

[This message has been edited by agracer (edited 7/29/2011 1:26p).]