peterswet
New Member
Posts:59
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| 16 Dec 2011 02:40 PM |
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I have a potential client who is determined to use durisol and has asked if I would be interested in the job..... Im now in the process of researching the system and am wondering if any of you good folks have opinions or observations about this wall system you would care to share?
Id appreciate any insight y'all might have
regards
Peter |
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Chris Johnson
Advanced Member
Posts:878
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| 16 Dec 2011 07:21 PM |
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It's heavy...compared to ICF, expect your build to be slower |
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| Chris Johnson - Pro ICF<br>North of 49 |
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BrucePolycrete
Advanced Member
Posts:524
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| 16 Dec 2011 08:50 PM |
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There is a thread or two on this forum that addresses Durisol. It has its fans, but I do not believe it is a mainstream product.
It's really not much different than building with CMU. You lay the block, pack the cores and add rebar as required. |
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Ray Gladstone
New Member
Posts:97
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| 16 Dec 2011 08:56 PM |
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Durisol has a very annoying website, It's written for search engines, not humans. Try reading it -- it sounds like it was written by robots for robots. Shows disrespect for their human customers. I question their intent.
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peterswet
New Member
Posts:59
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| 16 Dec 2011 09:06 PM |
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@Ray....
LOL I too find their website offensive,,,,, hard to navigate and glean info, Ive attempted to sway my customer to eps forms but she wants the breathing wall and hygroscopic properties . Im not all that fussed on what Ive seen .... but I do like to try different things.
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TexasICF
Advanced Member
Posts:622
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| 16 Dec 2011 10:36 PM |
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Wall Absorbs moisture from the air? Wood does the same thing -- exchanging significant water with inside air. |
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peterswet
New Member
Posts:59
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| 16 Dec 2011 11:00 PM |
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@ Texas
The company claims that humidity of the home is maintained at an ideal level by the blocks ability to absorb and release humidity, apparently no vapor barrier is required as the wall "breathes", Customer intends to parge interior with a clay product.
I look at the design, similar to cmu's in that there are webs molded integral to the interior and exterior surfaces making me think there must be quite a bit of thermal bridging as the block is cement and wood particles. They claim an R value of 21 or so .
They also coment on the positive aspects of having the thermal mass "exposed" to the inside living space claiming its a more effective than the thermal mass eps constructed block
More reading to do........... |
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TexasICF
Advanced Member
Posts:622
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| 17 Dec 2011 09:41 AM |
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Posted By peterswet on 16 Dec 2011 11:00 PM
@ Texas
The company claims that humidity of the home is maintained at an ideal level by the blocks ability to absorb and release humidity, apparently no vapor barrier is required as the wall "breathes", Customer intends to parge interior with a clay product.
I look at the design, similar to cmu's in that there are webs molded integral to the interior and exterior surfaces making me think there must be quite a bit of thermal bridging as the block is cement and wood particles. They claim an R value of 21 or so .
They also coment on the positive aspects of having the thermal mass "exposed" to the inside living space claiming its a more effective than the thermal mass eps constructed block
More reading to do........... Well hmmmm. Even if this exchange actually happens - and I know that it does with wood I don't believe there is really any value to it. It may have worked pre-AC but today we AC with tighter or minimal air infiltration to have smaller units that run longer to maintain target humidity inside. Virturally, all ICF homes have initial temporary high humidity because of wood, sheetrock etc. drying out and have less avenues (due to tightness) to do so than your conventional less tight home. I believe you are correct regarding R-value. Actual R-value is much lower. It will be higher than CMU though because their cement includes the wood particles. However, the claim is similar to that of a wood builder saying his cavity R-value is the R-value of his wall. The IECC now states explicitly that foam inserts in the CMU will no longer count toward R-value. I am glad they finally closed that loophole as it really helping the ICF industry today. Previously, you could put a very high R-value in the cavity and it simply didn't really make much of any difference -- unless you really just wanted to check the box. Virturally all the heat is shorted through the path of least resistance. ORNL does say that thermal mass to the inside performs slightly better than ICF but those that hang their hat on that are not reading the small print. In order to make this claim you need the same mass and the same R-value. In this case you have neither. If you compare this system to your typical 6" core ICF wall, you have much less mass -- perhaps 40-50% overall (with some smaller percentage of that to the inside) -- and much less R-value -- perhaps 50% (with a smaller percentage of that to the outside). I am willing to concede that R-22 continuous insulation -- all to outside (5 1/4" thick) with a solid 6" thick mass of concrete all to the inside will outperform a 6" ICF core wall in some climates (according to ORNL). Regards. |
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peterswet
New Member
Posts:59
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| 17 Dec 2011 10:06 AM |
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Re insulation inserts, they have roxul type inserts in half the cavity of their block which IMHO would weaken the wall as it halves the amount of concrete for mass and strength
I suggested sheeting the exterior with 2 inch eps as this to me would give a real thermal break and still allow for the hygroscopic and thermal mass properties she is choosing this block for.
P |
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arkie6
Veteran Member
Posts:1453
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| 17 Dec 2011 12:07 PM |
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Posted By peterswet on 17 Dec 2011 10:06 AM
Re insulation inserts, they have roxul type inserts in half the cavity of their block which IMHO would weaken the wall as it halves the amount of concrete for mass and strength
I suggested sheeting the exterior with 2 inch eps as this to me would give a real thermal break and still allow for the hygroscopic and thermal mass properties she is choosing this block for.
P
That sounds like a better idea to me. If using the 10" wide block, that would result in a 12" wide wall. What is she using for the homes exterior? |
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toddm
Veteran Member
Posts:1152
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| 17 Dec 2011 05:28 PM |
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Have you no shame, TexasICF. For thermal mass to work there's no need for any insulation. All you need is enough mass that fluxes of heat during the day and cold during the night ebb and flow in the wall without penetrating. Obviously, putting the mass in an EPS sandwich significantly reduces its ability to react on a 24-hour basis. I thought you'd quit spinning stories when we found this ORNL study paid for by the ICF trade group and then buried when it concluded that the mass effect in ICF is piddling. http://www.ornl.gov/~webworks/cppr/y2002/pres/114086.pdf
OP, dynamic benefit of mass, or its ability to buffer diurnal temperature extremes, only works if the daily average is comfortable or comfortablish. Obviously again, it works best in a dry climate with great extremes in daily temperatures, such as the desert southwest. In any climate, it stops working when the thermometer drops below 70 degrees and stays there. In other words, no one here can know how well durisol will work until you tell us where it will be used
Your client is correct that an open celled block will buffer humidity. Again, this is climate specific. The midAtlantic has been so wet this year, that my AAC house isn't buffering squat. |
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ICFconstruction
Veteran Member
Posts:1324
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| 17 Dec 2011 06:14 PM |
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Here in MN we have many days in the spring and fall that we could use heating and cooling in the same 24 hour period. I believe the thermal mass (concrete) in an ICF is a big benefit at those times.
I don't see the point in the wood fiber blocks when there is typical ICFs and composite ICFs (recycled eps and cement). |
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| Brad Kvanbek - ICFconstruction.net |
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peterswet
New Member
Posts:59
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| 17 Dec 2011 06:40 PM |
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The proposed dwelling is in Nova Scotia, within sight of the Atlantic ocean, The wintertemps fluctuate from 10 deg centigrade to - 20 degrees notwithstanding windchill
Regarding the effectiveness of the eps sandwich thermal mass, Im certainly not an authority but my footing to eave nudura build is far more comfortable and consistant in temperature fluctuation than my stick built R20 2X6 house.
P
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toddm
Veteran Member
Posts:1152
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| 17 Dec 2011 07:14 PM |
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ICFconstruction: Durisol IS a hybrid ICF. And, while MN has spring and fall days when DBMS works, it would work better with mass exposed to the interior than it does with conventional icf. You can dispute ORNL but ICFA already paid for and participated in a study to set the record straight from its point of view, and it didn't.
OP, as ICFconstruction suggests, mass saves energy during the shoulder seasons, when you might run AC at 5 p.m. and heat at 4 am in a low mass house. In high summer or dead winter, R value is R value, period. ORNL developed multipliers in some climates to adjust annualized r value for the thermal mass gains you might expect in summer and fall. Nova Scotia isn't one of them, but Climate Consultant has local weather data and will help you evaluate energy strategies incorporating ORNL's mass work: http://www.energy-design-tools.aud.ucla.edu/heed/ My guess is that the Atlantic is already buffering your diurnal temp swings quite nicely.
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TexasICF
Advanced Member
Posts:622
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| 17 Dec 2011 09:03 PM |
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Posted By toddm on 17 Dec 2011 05:28 PM
Have you no shame, TexasICF. For thermal mass to work there's no need for any insulation. All you need is enough mass that fluxes of heat during the day and cold during the night ebb and flow in the wall without penetrating. Obviously, putting the mass in an EPS sandwich significantly reduces its ability to react on a 24-hour basis. I thought you'd quit spinning stories when we found this ORNL study paid for by the ICF trade group and then buried when it concluded that the mass effect in ICF is piddling. http://www.ornl.gov/~webworks/cppr/y2002/pres/114086.pdf
OP, dynamic benefit of mass, or its ability to buffer diurnal temperature extremes, only works if the daily average is comfortable or comfortablish. Obviously again, it works best in a dry climate with great extremes in daily temperatures, such as the desert southwest. In any climate, it stops working when the thermometer drops below 70 degrees and stays there. In other words, no one here can know how well durisol will work until you tell us where it will be used
Your client is correct that an open celled block will buffer humidity. Again, this is climate specific. The midAtlantic has been so wet this year, that my AAC house isn't buffering squat. Toddm, The ORNL report I was referring to is talking specifically about the value of mass and where it is positioned relative to the insulation -- e.g between the foam like ICF or inside or outside like the various hybrids. Several posts about this. Lab folks like me know that in order to show if whatever (in this case mass) helps or hurts you need to keep other variables (in this case insulation) constant. For clarity, you can't change the mass of the car and the fuel at the same time and try to learn something. Regarding this particular link: This is a 10 year old report that isn't really aligned with the discussion -- yet it is worth reading. Here are my comments: R15 ICF? -- never heard of an ICF with an R value that low -- R-20 is about as low as they go - even back then. Attic BAT ? This is a bit like a screen door on a submarine. If a potential customer insists on BAT in the attic, I tell them that ICF may not be for them. To compare an ICF wall to stick without closing the attic is a bit like making the strongest link on a chain stronger and expecting a different result. 2 AC tons for 1000 square feet? -- Typical ICF is 50% of this amount. The report even states explicity that the test cases had too much tonnage. I have houses (mine included) that operate at 25% of this amount. Blower door test with Attic BAT? Lets just say that if ICF was absolutely PERFECT-- what would you learn from this test if you didn't close up the attic? You don't learn anything about the relative performance of ICF and stick when you "leave the lid OFF" -- a screen door on a submarine. The fact that it takes ICF much more than 24 hours to "react" to the temperature change is exactly where the value is of ICF resides. We ICF folks want the greatest delay possible. In fact, this even works when Mother Nature quickly goes from 40 degrees to 10 degrees (both significantly below set point). The longer it takes for the building to "know" somethings happened outside the better. I appreciate your helping me make his clear. Regards. |
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ICFconstruction
Veteran Member
Posts:1324
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| 17 Dec 2011 11:58 PM |
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I think it is a benefit to have insulation between the thermal mass and the living space. Think how slow the response time to warm a house would be if there was 6" concrete walls that had to heat up. It is bad enough in the winter when I have my programmable thermostat set to start warming the house and everything in it in the morning. |
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| Brad Kvanbek - ICFconstruction.net |
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toddm
Veteran Member
Posts:1152
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| 18 Dec 2011 10:27 AM |
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So, TexasICF, if it was such a rotten test, I assume that Insulating Concrete Forms Association asked for its money back and fired the execs responsible for commissioning it, eh? And set up a test that would show what ICF can really do....
Yes, ICF would buffer the odd blue norther; Ergo its modest mass effect. But if you want mass to work for you, you'd want it to buffer temperature swings that happen every 24 hours because, well, they happen every 24 hours.
ICFconstruction: I am confident that UCLA's Climate Consultant will tell you that more insulation is the biggest bang for your energy buck in MN. At which point you should ask what are you getting from concrete energy efficiency wise that spray polyurethane couldn't do for far less money?
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BrucePolycrete
Advanced Member
Posts:524
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| 18 Dec 2011 12:48 PM |
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Toddm, I guess from your perspective, it's a good thing that energy efficiency isn't all ICF has going for it, eh? Silence, fire resistance, and the sense of well being that you get from living and working in a robust and high quality environment count for a lot. Add energy efficiency and it's a big win. Let me leave you with this thought: If your heating and cooling costs $45 per month in an ICF house and $41 in a wood house with spray foam insulation, who really cares about the 4 bucks a month? GIANTS are coming on in 15 minutes. |
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narcszm
New Member
Posts:14
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| 18 Dec 2011 02:14 PM |
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toddm,
I read that decade-old report you posted, and it's really an amateur comparison. While the method is sufficiently scientific, the results are quite expected, given the selective use of ICF vs. wood construction in a residential structure. As TexasICF points out, having a partial ICF construction envelope significantly reduces the efficacy of insulated construction techniques and methodology. You don't have to be a student of science (which you appear not to be) to understand that a chain is only as good as its weakest link, and having such high intrinsic air turnover through a structure completely invalidates the concept of thermal mass leverage.
Your perception that somehow a structure must also perfectly react over a 24 hour period over an entire calendar year also bears witness to your partial understanding of thermal mass utility in a climate-controlled environment. And, your preconception that thermal mass and insulation are completely unrelated further exposes your fractional knowledge of basic thermodynamics and sustained heat transfer among various medium. In order to contribute to an insulated environment, a thermal mass simply needs to be able to store and dissipate energy. It is unlikely in a reasonable-cost structure to have a sufficiently high mass to completely remove the need for heating and cooling systems, but as the saying goes, every bit helps, and having any amount of thermal storage capacity in a structure is better than none. As you and others have pointed out, the climate in which the structure is built will certainly affect which thermal storage techniques and capacities would yield the greatest result. That does not change the fact that a well insulated home with a reasonable thermal mass will contribute the the efficiency of the climate control system many days of the year, regardless of where the structure is built.
Lest you continue to call others out on their experience and knowledge, I would highly advise you pick up a book or attend some classes at a junior or community college that offers courses in physics and science so that you can better comprehend the discussions on this forum.
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TexasICF
Advanced Member
Posts:622
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| 18 Dec 2011 03:32 PM |
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Posted By toddm on 18 Dec 2011 10:27 AM
So, TexasICF, if it was such a rotten test, I assume that Insulating Concrete Forms Association asked for its money back and fired the execs responsible for commissioning it, eh? And set up a test that would show what ICF can really do....
Yes, ICF would buffer the odd blue norther; Ergo its modest mass effect. But if you want mass to work for you, you'd want it to buffer temperature swings that happen every 24 hours because, well, they happen every 24 hours.
ICFconstruction: I am confident that UCLA's Climate Consultant will tell you that more insulation is the biggest bang for your energy buck in MN. At which point you should ask what are you getting from concrete energy efficiency wise that spray polyurethane couldn't do for far less money?
I'm not saying the report is bad. But I do think narcszm is correct and its really an amateur comparison. I was on the ICFA board of directors a few (more recent) years ago and I didn't know that they (we) had anything to do with the report. Interestingly enough, I contributed 20 ICF houses to the recent MIT study on ICF which was a bit more thorough. I was very careful to provide only sealed attic ICF homes. This wasn't hard since I regularly tell all potential customers to avoid putting a "screen door on a submarine". Unfortunately, I found out later that many of the 20 or so additional houses provided by other distributors/installers (at least that I was aware of) were mostly ICF with BAT attic. To my knowledge they performed blower door tests on 10 of the 20 I provided. The report is still quite positive. Anyway...
Regarding what are you getting from concrete energy efficiency wise that spray poly could do for far less money? ----. I know a guy in the mountains of Colorodo thats done some basic informal tests with unoccupied homes ICF and not and those that freeze and those that don't etc. You might be surprised to know that with the heat turned off ---- even after equilibrium is reached (where it's been really cold for a while) the ICF homes are still substantially warmer than the non-ICF homes. How is this possible? As you know, heat always travels from hot to cold so the insulated walls are being heated by the earth. This thermal wiking or coupling is quite valuable and cannot be provided by foam. Regards.
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