I just wanted to put up a rough data point on cost and return on investment on a foam insulation project. We just finished up a 2200 sf remodel for myself. We used closed cell on the entire envelope of the house (no need to discuss the open vs. closed cell)
Foam cost me $6000 more than cellulose. Our August electric bill was $100. August was a warm month here in central Texas-I was astonished. One of our previous houses was about the same size and average about $250/month. Based on this data point, we will be saving about $150/month on heating and cooling, roughly $1800 per year.
This savings creates a return on investment of 3.3 years for insulation on this project.
I just wanted to share a data point with you all. I am very excited about it and man is that house quiet with the exception of a three year old and 1.5 year old screaming and running around.
Bruce
Replies
Good for you!! MY brother-in-law did the same thing and now the same boiler he'd been using with the old smaller house is too big! He's replaced it with a water heater! (not to mention the energy savings)
The only thing better would have been a house built of SIP's or ICF's
Here's why,
Every 16 inches or so you have a stud with a low R value rating.. much lower than insulation. In a lot of places those studs are doubled and tripled up which could give you 4 1/2 inches of wall where there is effectively no insulation.
Because SIP's or ICF's don't use studs anyplace you have effectively 20% greater insulation. Even with the walls the same thickness.
Now to be fair it'slikely not going to give you a full 20% reduction in energy costs, instead the numbers of windows and etc. will still have a big impact but I do feel confident in another 10 or 15% reduction..
Thanks Frenchy,
I just wanted to get a bit of solid data out there as possible.
Bruce
I agree with your conclusions!
I too am anxious to spread the word about the value of foam..
So I risked reprinting stuff I've said many times before.
<<<<
So I risked reprinting stuff I've said many times before. >>>>
what ... you considered the risk for 2 nanoseconds ... or was it 3 ?Mike Hussein Smith Rhode Island : Design / Build / Repair / Restore
Be nice Mike
i was being nice
i like frenchyMike Hussein Smith Rhode Island : Design / Build / Repair / Restore
Mikes' sensitive on the subject of foam He's invested elsewhere..
i probably install about 500 bf of foam a year on averageMike Hussein Smith Rhode Island : Design / Build / Repair / Restore
250 sq.ft? 2 inches thick? pretty small houses..
I don't know about the ROI for our foam but ...
We altered/added on and went from a moderately-insulated 1600 SF house with a 1964 gas boiler/window A/C units to an extremely well-insulated (foam in walls, fiberglass in roof) house of 5600 SF plus radiant heated garage of 690 SF plus electric-heated outbuilding of 350 SF, with new WM boiler/indirect-fired water heater and 2 x SEER 15 A/C units and our bills only went up around 25% (at 3.5 x the SF), and that's not taking into consideration the dramatic increases in energy costs over the last few years.
The foam also increases the structural rigidity and sound transmission - a lot.
I'm a believer.
Jeff
Edited 10/14/2008 10:42 am ET by Jeff_Clarke
I'll add my experiance as well.
I doubled the size of my house (5500sq.ft.) and tripled the number of windows (to 76) my new home built with SIP's &ICF's (foam panels and foam concrete forms)
using my same exact furnace My energy costs went from $500 a month down to $200 a month in the cold of the winter and last summer I needed to run A/C less than 10 hours total!
When it's chilly outside my house is 20 degrees warmer. When it's warm outside my house is 20 degrees colder..
without any thing running..
"When it's chilly outside my house is 20 degrees warmer. When it's warm outside my house is 20 degrees colder.."
That's exactly the way I would put it.
And with the ERV running, never better ventilated either.
Jeff
You say you will save $1,800 a year, based on your August savings. I don't know the finer points of your climate, but won't your shoulder months water down your annual savings?
If August was a warm month and you saved $150, wouldn't your savings in October be a small percentage of that?
Jon Blakemore
RappahannockINC.com Fredericksburg, VA
It seems like we run the AC 8-9months of the year and then run heat about 2 months of the year-so while it may not be 100 degrees 12months, it seems like we are always conditioning the air.
While this will impact overall return calculations, it seems to be a feasible period for the ROI.
Bruce
Jon,
Big picture please!
We're not accountants.. what we need to know is what sort of potential savings are possible?
Exact numbers are impossible to determine.. we don't know temps in the future we don't know prices in the future. a finely tuned number today is meaningless next year or in the foreseeable future..
So let's take your example (which while valid denies the big picture look needed) let's assume a savings of Say $1500 annually if next summer is hotter or winter colder won't that impact more than the differance?
If energy costs appreciate or inflate won't that affect the calculations?
Is the payback going to be 3 1/2 years or 7 years? Does it matter? I mean really matter? Homes exist an average of 58 years last I read before they are dramatcially remodeled or demolished. That's a long time to save money!
How much will he and future owners save because of his superior insulation? Well, more with it than without it..
Frenchy,When it's my money being spent, I want good numbers. Maybe you don't feel projections are worthwhile, but I think they're indispensable.Sure, temps may change. And energy costs may go up or down. But good data will always be a platform that you can make educated decisions based on.Saving money is not the goal for me. I want to save the most amount of money I can for whatever I'm willing to invest. It doesn't matter if my investment is time, materials I already own, cash, bartered items, etc. I want to get the most for the least.I like SPF. If you have a good applicator, you can get a very nice product. On the other hand, I like using cellulose and the airtight drywall approach. Is foam better then cellulose/ADA? I don't know if I can make a blanket judgement.I can, however, tell you that we built a house this year with cells and ADA and achieved an air infiltration rate about equal to another house in the area that used SPF. Both houses were tested by the same energy star technical advisor.I believe that I saved thousands of dollars and got a similar result. Would you agree, if my anecdote is correct, that I got the better deal?
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Assuming all the facts to be correct and knowing nothing about metigating circumstance that's correct..
Now I know that sounds like a lot of double talk but frankly it's needed..
For example what would your numbers have been if you'd constructed with either SIP's or ICF's on that site? In that exact size and style house?
You don't know! All you know is one way.. However to be fair I only know the way I did mine..
Further we both entered our construction with a decision made.. Looked as I'm sure you looked but we both arrived at differant conclusions!
For example on raw materials price alone I found SIP's to be cheaper than similarly done stud walls. Not to mention the ease of simply erecting a panel compared to constructing a stud wall, erecting it, and then insulating it.. Yet doubters question my numbers in spite of my willingness to show all my receipts..
As for energy costs going up or down? Frankly you missed the boat with that statement.. When in your lifetime has any energy cost materially gone down? Oh the spot markets may fluctuate but you have to admit that trend has always been up.. (if not I'd buy all that 8 cent heating oil my dad used to get) <grin>
Since you do not accept global warming as likely I cannot convince you either that weather patterns do not foretell good things regarding future weather patterns.. So I won't attempt to try..
In the end we're left with the debate of which is the superior insulation for the dollar..
I do know that a flaw in the weather sealing of celluliose can cause water to invalidate any R value at all while a similar flaw in Foam will have no effect at all. (note I've avoided long term issues which really are subject to debate).
I like the recycled nature of celluliose compared to the oil based formulation of foam plus inevitably there will be waste with a foam insulated house there isn't with a celluliose house..
Given all of that I choose to select foam and I've recieved a real cost benefit even if it hadn't been cheaper..
"For example what would your numbers have been if you'd constructed with either SIP's or ICF's on that site? In that exact size and style house?
You don't know! All you know is one way.. However to be fair I only know the way I did mine.."
I did get quotes on SIP's. I did not consider ICF's. The SIP package would have cost me about $5,000 extra (that's taking everything into account). Maybe there are places to get them cheaper, but I could not find them.
"As for energy costs going up or down?"
That's not the point. As you yourself said, it is next to impossible to quantify exactly how much energy costs will go up over the long run. Still, good data is the best bet to make a good decision.
"I do know that a flaw in the weather sealing of celluliose can cause water to invalidate any R value at all while a similar flaw in Foam will have no effect at all. (note I've avoided long term issues which really are subject to debate)."
This has been discussed before. I will choose to base my opinions on my own experience along with those who have blown truckloads of cellulose insulation (including the many cell fans on this forum).
Jon Blakemore RappahannockINC.com Fredericksburg, VA
SIP's have been used since WW2, true as freezer panels but since the late 70's in home construction as well. If cellulose was superior to foam freezer panels would be made with cellulose. Keeping a freezer cold is a serious cost consideration. Here in Minnesota our winters are colder than the inside of most freezers!
I was asking what your energy savings would have been with the use of SIP's or ICF's but it's good that you brought up the additional cost of construction..
Frankly if it really were an apples for apples comparison, that is the same number of homes built with SIP's that are stick built, there would be a cost savings in construction of SIP's...
For several reasons..
First you effectively are buying factory built panels and there are efficiencies in a factory there aren't on a typical construction site..
Second, the time to assemble panels (with experience) is dramatically less than the time to hand build a stick frame.
Third material costs for 2x4's& 2x6's etc. are dramatically higher than OSB and foam in large volume.
But to be fair That's not the situation! 98% of all homes built are built with traditional stick building.. Understandably since so many contractors have massive experience and investment in stick building. They know the tricks and short cuts so well it's standard fare not something requiring great thought and anticipation.
Only after I was more than 1/2 way thru my construction did I find a short cut which eliminated about 60% of my assembly time.. and years after I was done with my panels did I see a tool which would have easily cut another 20% of my time off. Cheap simple tool that caused me to go... Duuhhhhhh!(and slap my head)
So once contractors do enough homes for there to be a fair comparison in construction, that $5000 premium you spoke about would more than disappear..
Then we would be faced with pure energy cost comparisons. With enough volume to do real back to back cost comparisons.. Until then it's really going to be laboratory results and anecdotal experience.
Even lab results at this point tend to be meaningless since the results are always affected by who pays for the testing..
As to energy costs going up or down that does matter!
If we can be exact enough to predict energy usage than higher costs equate to a faster return on investment.
A simple example, if costs double the time required to reach payback is cut in half..
As to the moisture effects on cellulose the pure fact is that sometimes flaws occur and when it does you do lose any energy savings.. You won't with foam.
Finally,
You made a point of those who support cellulose on this board. Wow! that's like saying all the republicans like McCains performance and all the democrats like Obama's. I know of no contractor who does exclusive SIP construction on this web site. I do know a few who actually blow cellulose for a living which might tend to make them biased.
There is no way I'm going to be able to sell you foam.. your home is built.. But the fact that panels are 200% stronger than stick built should have some impact on future builders.
My energy savings are anecdotal, but very real to me. I have great comfort at a annual cost that is thousands of dollars cheaper than a smaller house with cellulose as insulation..
just wanted to share a data point with you all. I am very excited about it
Details!
Is this slab-on-grade? Insualted at the ceiling or to bottom of roof deck? A/C (& ducts) inside conditioned space or not? A/C on plain stat or setback? Setback in actual use or not? Zoned hvac?
August was a bit wetter than normal in Austin this year (or we were more dry). September may be the critical month to plot your changes against.
This month (October) will also be critical for your tracking of costs. It's been a mix of mild and both over and under normals. What that also entails is that it's the month (March is the other) where the least precise numbers come into play. This from having windows open, and humidity rather than temperature causing occupants to not follow the "normal program" for stat use.
I case you can't tell, I've done this before, just not to my house (owner is poor and a deadbeat, after all <g>). Using a setback stat can really help your savings; but, you may then need to find a really, really, really, sharp person to wire you in a "logical or" humidistat into the a/c side of things. (The "or" needs to cope with humidity needs during nominal heating season, as well as cooling--get 10-12 extra folk in the house over the holidays when it's only 45-55 outside, and you need cooling.)
CapnMac,
I have not had a chance to reply to your post, but will do so this weekend
Bruce
but will do so this weekend
10-4.
Data is always good.Occupational hazard of my occupation not being around (sorry Bubba)
Here are some more details
Original structure built in 1948, approx 900 sf, stone facade, concrete strip footing around perimeter about 2' below grade with concrete piers about 8' o.c. throughout dirt crawlspace.
Gutted and took off roof of house. pour additional strip footers to support internal walls and poured a 3" slab across entire to seal off dirt. Also beefed up perimeter strip by creating 2' tall beams between piers to support 4x6 rim joist for upward expansion of house.
Added 400 sf to first floor and 900 sf second floor.
All wall framing is 2x4 with closed cell foam filling entire cavity. Roof is 2x12 rafters (got a screaming deal on some Doug Fir when the house crunch was starting) I was originally going to use cellulose, but I convinced my cellulose guy to buy a foam rig. So he did. Rafters are also filled so 11" of closed cell.
Totally sealed envelope. We have a 3 Ton 18.5 seer lennox ac with variable speed. Multiple returns throughout the house. We also have a 4" fresh air intake on return side and I have a 4" that dumps conditioned air into the crawl space and exit the crawl through a dryer type vent at the other end to keep the crawl space "fresh"
All water heaters and ac components are in the conditioned envelope.
Windows are all lowE
Tstats are highly programmable so I let my wife do that. I still have not figured out the flashing 12:00 on my VCR. My three year old probably could. We can run the system so we cool or heat up or down or both and return up or down or both.
Let me know if you have any other questions.
Bruce
Edited 10/19/2008 8:09 am by Hiker
Only thing that stands out is:
have a 4" that dumps conditioned air into the crawl space
Which, you may find that's more than needed. You might need a backflow damper on the c/s "exhaust" you have installed. Which you might try changing to a pure gravity system of a 4" duct from attic to c/s. This might save you needing to open 1-2" of effective duct to the attic (but, adding conditioned air to the attic generally works better in our climate than into the c/s).
The other thing you may run into, with 3 tons available, is not enough system run time. This is where a humidistat can be crucial, as it gives an additional "on" parameter. With a 3t plan, you may need to mostly close most of the registers, just to get the system to run long enough to get up to speed.
This is hard for the average tech to balance, too--they are so used to having the ducts run through 130-140 attics, and pushing that bollus of air into the house that then needs cooling. You no longer have that condition.
Try and track everything if you can. Get a $10-15 radio shack thermometer and put it near the attic access. That will let you track temps in both spaces. Another thermometer is really needed next to the stat, too, if only to work out what stat temperature you need to set for a given actual ambient. Jotting the max/min numbers into a spreadsheet, then plugging in your monthly electrical use can let you track actions to results.
Just 2 degrees setback when no one is at home is about a $50/month savings as is. Whether you will now need it may wind up the question.
Will be cool to see as you report it.Occupational hazard of my occupation not being around (sorry Bubba)
The crawlspace is about 1200 sf and I like the idea of keeping air moving in the space-but you may be right about it being too much. The supply is dampered at the plenum.
The unit is a variable speed which allows the unit to run at 1/2 speed and allows for longer run times.
As far as collecting data. I leave a key out for you and help yourself. As much as I am interested in overall performance, I would rather play with girls.
Let me know next time your in Austin, we can grab some lunch and maybe drag Blue along.
Bruce
I leave a key out for you and help yourself.
Nah, then I'd have to bring 'graphs and thermocouples and all the rest, which would then requite bookeeping and invoicing and the like <g>
As much as I am interested in overall performance, I would rather play with girls.
Yeah, well. have to keep Austin Wierd somehow <g>
Let me know next time your in Austin, we can grab some lunch and maybe drag Blue along.
Aw, we have to draw Tom in from out of the hinterlands, too <g> Was scheduled to wander over to Medina this Saturday, which takes me through Austin, but that's off for now. If I head that way, you (among others) will hear of it. Tough part is picking a spot, I'm about equally in need of Artz, Stubbs, County Line, or Threadgill's at this point, and that's leaving Chui's & EZ's and some other places out of the mix, too (like the Rudy's spin-off burger joint over off 183).
Hmm, maybe what's needed is we all go over to San Marcos and get Blownonfuel squared away--Gristmill being just down the road and all <G> . . . Occupational hazard of my occupation not being around (sorry Bubba)
Now that I am having a craving for BBQ and a burger, we'll catch up.
Bruce
that I am having a craving for BBQ
I will not, then, bring up the drive-through joint across 35 from San Marcos that has really good chopped beef samitches <g>Occupational hazard of my occupation not being around (sorry Bubba)
Having the actual UNITS rather than just the dollars will help a lot. And having the degree days for the two months.
And having the degree days for the two months
Well, it will need to span more than a couple months; it will also require a "translation" paradigm for the difference between stat temp and the degree-day "normal" too.
CDD are measured (IIRC) from 75--but, for 8 hours a day over the summer the setback on my stat is 83; lowest the stat gets set to is around 78 (any colder and I get into aclimmatation problems). Same difference in winter, if closer for me--HDD is indexed to 65, my stat sets back to 60, and maxes around 70 for three hours a day,
So, it's a juggling game--performance versus actual ambients get measured in dollars, generally. How that tracks versus published DD, only really helps across regional, climatic, boundaries. And, even then, loses something in translation.
My approach to both CDD & HDD has to be different from, oh say, Splintie's. December highs for me (and Hiker, mostyl0 will be in the low 60s--get 8-10 people in the house, and you need dehumidification, then cooling (2800btuh for 8) just from them hanging around. Hiker's climate over in Austin does have the advantage f being about 10-15% drier than mine, though.Occupational hazard of my occupation not being around (sorry Bubba)
"that house quiet with the exception of a three year old and 1.5 year old screaming and running around."
Wasn't in the budget to get them foamed too?
Sounds of two little girls laughing, screaming and giggling=priceless
How many inches of the foam did you use?
See post 27
Thanks, that thread got me thinking. I can tell the foam/cellulose debate is the hot topic!
As with most decisions on your projects, there are many viable options which are a function of budget and personal goals for the project. I do lots of remodels with cellulose, but I am leaning to closing the attic spaces to make the entire envelope conditioned due to conditions here in Texas.
Best of luck and ask many questions.
Bruce