Your answer to trading on ignorance is 'No! Yo Momma!' Really, TexasICF?

Posted By sharter on 13 Sep 2012 07:32 PM
Dana,

My main point is that 6.5" of EPS is a well-known commodity and should get 25-27R or so depending on quality\density. So saying R30 by including the rest of the wall system seems reasonable to me.

AFAIK, bad press that ICF gets regarding rvalue is related to using the "effective R value" argument about thermal mass, and not cheating by a couple r values by air film or other BS. The thermal mass effect only helps to average the temperature out over the course of a day, so under the right conditions (cold nights, hot days) it works and was abused by sales to exaggerate the rvalue. So I totally get calling the sales department on BS and half-truths.

For stucco, their chart said .13R which is nothing really as I think they would have just round up to R30 anyway. They could have said insulated siding instead and got and additional R3. I agree though that the true rvalue of stucco is probably better than .13 due to the air gap between it and the EPS.

So cost:benefit EPS currently wins factoring in air infiltration and other factors (at least for exterior layer of insulation) but there are better insulatators out there. I would rather pay more for ICFs that had better insulation and that weren't as thick, since that extra insulation cuts into floor (or roof) space, requires bigger window\door bucks, makes me question fastening ability due to shear load, and thus costs as well. I'd love to see a polyurethane ICF that gets R6\inch instead. Maybe a good price:value combination would be a bimodel polyurethane exterior and cheap EPS on interior since we cut into the interior insulation anyway for wiring etc and I don't think rvalues really matter as much on interior. Better yet, ignoring cost, if interior ICF had structural supports or made out of something else altogether such as EPS+portalnd I'd go for that even if the rvalue goes down -- that way I can hang cabinets, curtain rods, pictures, drywall, etc. without having to find strips. Yeah the blocks wouldn't be reversible but who cares.

In the future, look at aerogel. R10 or more per inch and is translucent. Translucent walls and roofs so free daylighting. Where we want windows we'll have cameras with head-tracking digital projections. That would be awesome anyway...

They counted the air films a R1.5, so that's probably enough to more than make up for any under-rating of the stucco.

I'm not saying that the wall as a system won't perform something like R30 at an average lower-48 US climate. But their silly charts were suggesting a steady-state R36  in a hot climate based on VERY dubious (& erroneous) R-values for the foam.  While dynamic issues might render R36ish performance in a hot climate, the foam-R in their charts (which I linked to, but won't again), is well below the stated values. They should be arguing their case on the facts (the dynamic factors), rather than  bullshi'...nola.  The facts really are good enough, so why make stuff up?

The next time I read "EPS is R4.5 per inch, and (x) inches that make R(y)" expect the same rant from me.  EPS has among the LEAST-constant R-values across temperature of any commonly used building insulation (with the only other contender for the title being low density fiberglass), and in cooling dominated climates R4.5 per inch is a gross exaggeration of1.5lb EPS performance- it'll only average about R3.5/inch on the hottest side of the house (or in a roof assembly) on the hottest day of the year in TX or AZ.  Yes, EPS is R4.5 inch at a 40F average temperature within the insulating layer, but +10F isn't an average annual temperature in any of the lower 48, and that's what it takes with a 70F interior.

I'm good with estimating R30 whole-wall performance for colder US climates though. In Fargo ND the mean January temp is about +5F so even ignoring dynamic effects the R4.5/inch average is probably going to hold, and as an assembly it'll do better than R30 when it counts the most.

I've been waiting for well over a decade for aerogels to become a cost-effective solution for residential building apps, but I'm not holding my breath. There are a couple of residential daylighting/skylight products out there that would make sense for daylighting in cooling dominated climates, since the solar gain is quite low and the R value quite reasonable, and the aerogel becomes a diffuser element for shadow-free lighting. (They're pricey, but quite nice!) The commercial versions will likely drive that market for the time being though.

The R4 aerogel stud-edge strips for metal studs in commercial apps may be cost effective in some places, but not in most residential apps. I don't expect to see it as a primary building insulation within my lifetime.

6.5" EPS = 100R baby! (footnote:absolute zero and in a vacuum lol)

Dana, yeah there should be a standard rvalue calculation. At least two numbers - one for higher temps (summer or cooling dominated) and one for cool temps (winter or heating dominated). Aka MPG for cars (highway, city, combined, electric equivalent, etc).

Posted By Lbear on 13 Sep 2012 09:04 PM
EPS; once the density and thickness is known, becomes an easily attainable R-Value. ICF's don't have much "wiggle room" when it comes to determining R-Values. Putting aside the thermal mass effect, once you know the forms parameters, determining R-Value of the EPS is pretty straightforward.

Now, with stick frame, there are so many variables at play that determining a true R-Value is not as easy to do. The quality of the lumber, the stud spacing, the headers, framing around doors, corners and windows, paying attention to details, sealing, caulking gaps, vapor barriers, insulation types (cellulose, spray foam, EPS, fiberglass), quality of installers, attention to properly filling wall cavities, air barriers, thermal bridging, and on and on...

With that being said, exaggerated claims are very prevalent in the stick frame and the stick frame insulation industry. Yet I don't hear the same outrage and "fact checking" against stick frame that ICF brings. The minute someone mentions ICF the insane asylum doors open and the patients come out, log on the internet and begin posting on GBT. The visceral hate that is sometimes present on this forum against ICF makes me question what is really behind the people and their positions.

I have been accused of being employed by the ICF industry. Which is not only a complete and utter lie, it shows the personal attacks and disgusting hate that is present on this forum by a few people. If you dislike ICF, fine don't use it, but don't go around making personal attacks against people. Discuss and debate it but don't make false allegations against people and personal attacks.

Each building method has its pros and cons. Some building methods are better in some climate areas than others.

I've said my 2 cents...

Show me an example of a "very prevalant" exaggerated claim on stick frame being made on this site (or in a manufacturer's literature.)  I'm sure there are tract-builders that are full of BS who haven't a clue how to build an efficient house, but that's not a typical poster here.

The ORNL and others have very good standards for evaluating "...true R-value.." of any given stud spacing & framing as well as what performance to expect at any given quality of construction of those assemblies.  The deficiencies of low-density fiberglass and the likelihood construction errors of batt insulation are widely discussed & evaluated in the building-science world as well as on this site- nobody get's a pass on exaggerated claims.

If you're going to refer to something as "...true...", be prepared to back it up with something better than demonstrably false or misleading R values.  Facts matter.  Pretending that the R-value of EPS is constant is misleading, especially when the constant asserted is so removed from the average that would would be expected in the climates for most of the readership on this forum.

I'm not accusing YOU of anything beyond than perhaps not reading the spec closely/critically enough.  I'd hold the manufacturer responsible for their marketing literature though.

I've stated before (even in this thread), I like EPS, and I like ICF, but I despise piles o' marketing poo of the ilk Amvic put up to support their numbers. (Hell, even I could make their case better for them, and without flights of fancy around what's factual!)

Posted By sharter on 14 Sep 2012 02:54 PM
6.5" EPS = 100R baby! (footnote:absolute zero and in a vacuum lol)

Dana, yeah there should be a standard rvalue calculation. At least two numbers - one for higher temps (summer or cooling dominated) and one for cool temps (winter or heating dominated). Aka MPG for cars (highway, city, combined, electric equivalent, etc).

In the EPS world they seem to standardize on 40F and 75F as the two points, but it's not exactly linear.  People seem to fixate on the 40F number 'cuz it looks so good, but that's no more legitimate than using the 100F number which would look pretty bad. 

In a roof in a cooling dominated climate the 100F number would be more appropriate though.  (On an 85-90F AZ day the finish roofing or a sun-baked wall can easily run ~125F, and with a 75F interior you'd have 100F average, so the performance would be close to the 100F performance of EPS, give or take the non-linearites in the curve.  At 100F Type-II EPS is running about R3.75/inch, well shy of the 40F number everybody loves to quote, but not too far removed from R4/inch.  On the non-sunny sides the walls would still be averaging a bit under R4/inch, but that would still be a pretty reasonable estimate.

In a US climate zone-5 type location with a 30F winter mean-temp, with a 70F interior temp the performance of EPS @ 50F R- is relevant.  That's about R4.3/inch- a bit closer to the number everybody seems to love, but still less than 10% from R4/inch.  For exterior insulating sheathing up to about half the total R  (including the exterior half of a symmetric ICF) it's legit to estimate at R4.5/inch performance in that climate, but not for a SIP, (or the interior half of an ICF.)

IIRC ASTM C 518 tests use the average measured U-factor at 75F +/- 30F to determine an R-value-  that's how low-density batts get labeled, and that's how EPS gets labeled. (Ever wonder how 2" EPS sheet goods get labeled R7.8? It's the lower high-temp performance bringing down the average.)  Building designers who care about performance know the difference though. R19 batts only measure R19 in a test-fixture, at a full 6-1/4" of loft. (~R3/inch) Compressed into a 5.5" wall cavity they're only performing at R18 (R3.25/inch) over the ASTM range, and worse beyond that range (in both directions.)  In attic apps where an R-19 batt has no top-side air barrier it's convective losses are huge, and it's doubtful that makes R16 (R2.6/inch) across the ASTM range, and at peak summer/winter temps it can struggle to hit R12 (~R2/inch @ 6.25 ").  But with a topside air-barrier they perform a lot better, and as long as the delta-Ts are within the ASTM test range it'll perform pretty close to label, if installed well. But that's why the low-density batt is everybody's straw-man argument when pissin' & moanin' about real world performance vs. labeled performance.  There are applications where a low density batt can be a "right" solution, but those aren't usually as primary insulation in high performance wall or attic apps.  (Isolating radiant floor zones from rooms below and acoustic dampening come to mind.)

Quad-Lock has higher R-Values for a long time now. The step from R-22 up to R-30 only runs about $0.60/sqft. Pretty small increase in total job cost for the increased R-value. We use 4" on the outside and 2" on the inside, making better use of the thermal mass. I agree, when you get up into R-45 and above, it gets very costly. The Arizona area sees as much R-value interest as the high Mountains as the high temperatures are sustained for long periods. I have a dealer that did the high sun load walls in R-30, and the low sun load walls in R-22. Made a great improvement for little extra $$. You want to see something wild, look at our R-53TMO. 10" on the outside, 2" on the inside!

In most EPS apps it gets estimated using 10cents/sq-ft/R installed-cost.

The R8 step-up from R22 to R30 for 60cents/ft is 7.5 cents/ft/R, but I'm guessing that's material only. In some systems the labor would be identical, which would be a comparatively cheap upgrade, in other systems you have to factor in the additional labor too. Even with the easy-slip-in panels you're probably still looking at closer to 10 cents/ft/R as an installed price.

I do LIKE the concept of adding R on the sun-loaded sides only in that climate- it overcomes the de-rating curve of EPS where it counts the most without burning budget where it doesn't matter!

Up to about R40 whole-wall with stick built, standard-studs w/cellulose + exterior rigid foam, with the sheathing detailed as part of the primary air barriersystem tends to be a bang/buck sweet spot, but sometimes o.c. foam comes in under dense-packed cellulose these days. (In my market spray foam has become VERY competitive compared to 5 years ago.) On the same houses, up to ~R22 ICF is usually somewhat more expensive than insulating the foundation from the interior, but from a "time is money" point of view ICF is still likely to be a net win. But to make the jump to all-ICF (rather than stick-built) @ R40 you're paying a premium for the thermal performance, but you're getting more in other terms. On even higher-R walls a double-wall + cellulose approach comes in at about half the installed cost $/sq.ft/R as EPS or iso.

Why about Phase Displacement?

During summer the goal of any wall system is to slow temperature penetration of that wall so that the daytime high temperature only reaches the interior when the outside temperature is at a low temperature that the heat can be driven out by ventilation.  According to BuildingScience and ORNL, the target Phase Displacement is 10 to 12 hours. Wall systems that perform the best are materials with low thermal conductivity but which also have a high specific thermal storage capacity (ie - ICF).

So while EPS drops it's R-value in summer, in an ICF home there is a lot of gain in the concrete thermal mass that more than makes up for the R-Value drop of EPS in summer temps. Yet, it is not mentioned. Why not?

So while all this talk about R-value is straightforward when talking about stick frame, not so with ICF and the thermal mass of concrete.  As we all know and agree, concrete takes a long time to respond to temperature changes. So on a typical Arizona/Texas/Colorado day from morning to night, during a hot Summer day, the outside temperature may fluctuate by 30 degrees or more, yet indoors there is hardly any change in an ICF home. This has been tested and verified by ORNL, Building Science and host of other agencies besides Portland Cement.

This is another area where ICF walls simply trounce most wall systems. The thermal mass of concrete very nicely smoothes out those outside temperature fluctuations through the day, keeping the home comfortable. Insulation alone has a shorter and worse thermal mass but good resistance. Yet this highly insulated building would conceivably be subject to overheating in the summer with such diurnal swings, whereas an ICF building would fair a lot better.  So 'Phase Displacement' or the amount of time it takes for a temperature difference outside to make its way inside, is benefited by ICF and its concrete walls.


The question stands, how do you assign a R-value to this Phase Displacement/Thermal Mass phenomena? Sure, one can crunch the EPS data and get an R-Value. Yet when it comes to the thermal mass of concrete some people wrongly and with bias disregard it and claim it adds no value. Yet science and studies show otherwise. Where some of the experts stop short is how do you quantify the thermal mass to get an approximate R-Value rating?

And so the debate continues...

how do you assign a R-value to this Phase Displacement/Thermal Mass phenomena? ... some people wrongly and with bias disregard it and claim it adds no value.

You don't - R value is a different measurement for a different thing. It would be like trying to assign a R value to cheap electricity. And sometimes thermal mass reduces energy use, often it has no effect and sometimes it increases it (ie, has negative value). Which one depends on far more than just climate.

Posted By jonr on 14 Sep 2012 10:59 PM

how do you assign a R-value to this Phase Displacement/Thermal Mass phenomena? ... some people wrongly and with bias disregard it and claim it adds no value.

You don't - R value is a different measurement for a different thing. It would be like trying to assign a R value to cheap electricity. And sometimes thermal mass reduces energy use, often it has no effect and sometimes it increases it (ie, has negative value).

ORNL believes otherwise and does assign it a value:

Effective R-values and Dynamic Benefits for Massive Systems (DBMS)

Complex walls cannot be analyzed using simple one-dimensional tools. The methodology applied for dynamic thermal performance evaluations of complex massive wall systems needs to be able to thermally analyze complicated geometries and material configurations.

A new measure of the wall thermal dynamic performance is proposed by ORNL - Dynamic Benefit for Massive Systems (DBMS). The thermal mass benefit is a function of the material configuration and climate conditions. To enable wall performance comparisons, the R-value Equivalent for Massive Systems is used. The R-value equivalents for massive walls are obtained by comparison of the thermal performance of the massive walls and light-weight wood frame walls.

Dynamic thermal performance of massive walls is also a function of climate. The most favorable climate for application of the massive wall systems is in Phoenix. Relatively worst location for these systems is in Minneapolis (especially for less insulating walls). Thermal mass benefits are a function of the material configuration and the climate.

(2)

where:	: DBMS - Dynamic Benefit for Massive Systems,
	mReqv - R-value equivalent for massive wall, and
	R- steady-state R-value.

ORNL Thermal Mass Calculator Dynamic R-Value Equivalent for an ICF 2.5" EPS x 6" concrete x 2.5" EPS in a Phoenix Arizona climate netted a R-value equivalent of R-38.

ORNL Thermal Mass Calculator

Exposing the 6" concrete to the interior with a 5" EPS exterior showed a Dynamic R-Value equivalent to R-53.

Utilizing a 3.25" EPS x 6" concrete x 3.25" EPS showed a Dynamic R-Value of R-43.

No, Lbear, the debate does not continue. ORNL did iits DBMS work in the 1980s in part to rein in extravagant mass-effect claims (by many wall system manufacturers and not just ICF it should be noted.) Since then, Apex, Rastra, durisol, and other compostie ICF systems have used ORNL's work to publish mass-enhanced or effective R values for specific climates that pass muster with the Federal Trade Commission. Conventional ICF manufacturers have not. The testing they do proves up simple R value. The reason is because DBMS measures the ability of a wall to buffer high and low temperatures ON A 24-HOUR BASIS. Arizona is the perfect locatiion for mass effect because of the daily extremes in the high desert. Here is Rastra's testing:
http://www.rastra.com/ThermalPerformance.html

Soi here are two questions for you, Lbear.. If ICF delivers R38 in Phoenix, whiy do manufacturers claim R22 (ish)? If they don't, whiy should we believe you?

> how do you assign a R-value to this
> ORNL believes otherwise and does assign it a value:

Nope, unlike you, ORNL adds "equivalent" to make it clear that it's not a R value. DBMS is the value you want.

Guys please dont' point to Rastra marketing materials and call them tests. If they pass the muster of the trade commission you might go ahead and point to the test results.

Most ICF manufacturers will publish 2 numbers in their detailed spec sheets. One is listed as a steady-state R-Value (R-22) and the other is a Dynamic R-Value equivalent, sometimes referred to as an Effective R-Value. But being the 2nd number is region dependent, the number cannot be advertised the same for everywhere so either an average is displayed or simply stated as R-30 or greater. For areas like Arizona that number will be R-38 or better.

The point is that ORNL, along with other researches have determined that ICFs have a benefit due to their concrete thermal mass and that this benefit cannot be calculated using simple one-dimensional rating tools as would be with stick frame insulation. ICF walls are viewed as complex massive wall systems and they require a different approach and hence the development of the dynamic performance and R-Value Equivalent by ORNL.

So for people building in Arizona using a 2.5" x 6" x 2.5" ICF wall system. Stating that the wall performs with a Dynamic R-Value Equivalent of R38 is an accurate and factual statement.

With that being said, a 2-story home design that utilizes ICF walls and then incorporates a slab-on-grade, in addition to having a 2nd floor using InsulDeck flooring with has exposed concrete to the conditioned space of the entire 2nd floor. The thermal mass benefit of such a design makes for a design that would see tremendous dynamic benefit from both the walls and floors due to the thermal performance of these massive concrete systems. The thermal mass that is exposed on the 1st floor and 2nd floor of this 2-story residential would amplify the performance & comfort of that home. Although a tile floor can produce a thermal mass effect, an exposed concrete slab on both floors has a much larger gain.

Posted By Dana1 on 14 Sep 2012 03:05 PM

Show me an example of a "very prevalant" exaggerated claim on stick frame being made on this site (or in a manufacturer's literature.)  I'm sure there are tract-builders that are full of BS who haven't a clue how to build an efficient house, but that's not a typical poster here.

The ORNL and others have very good standards for evaluating "...true R-value.." of any given stud spacing & framing as well as what performance to expect at any given quality of construction of those assemblies.  The deficiencies of low-density fiberglass and the likelihood construction errors of batt insulation are widely discussed & evaluated in the building-science world as well as on this site- nobody get's a pass on exaggerated claims.

98% of stick frame builders never factor in the thermal bridging of wood, assembly techniques or how different insulation (fiberglass, loose vs dense packed cellulose, etc) impacts the true RValue of a wall system. I've run calculations on the ORNL RValue calculator using stick frame in numerous configurations like 2x4 vs 2x6 vs 16" oc vs 24" oc, with cellulose filled cavities and exterior foam.

There have some here who posted numbers on stick frame wall systems that never accounted for thermal bridging and/or they used higher realms of RValues that seemed questionable. I read the post, maybe mention something in passing, but do so in a friendly matter. I don't go koo-koo or start foaming at the mouth like some do when ICF RValues are brought up. I'm not saying you are one of those people but just making an observation that you might not be seeing. When people's family members are being personally attacked over the ICF issue, I notice a silence from most people. No reprimand, no rebuke. That's troubling to me. People do get passes on exaggerated claims and remarks.

The timber industry is no saint, they have their exaggerated claims and questionable practices. The FTC went after cellulose companies because of false energy claims and false & misleading product advertising.

Moderating & characters aside. One can crunch the numbers and get the RValue of EPS down to the tenth. Which is fine but to fair I believe one should use at least the ORNL research and calculations for ICF in regards to the thermal mass and its dynamic benefit. If they researched it and believe it deserves a classification, then one can use it without crying conspiracy or foul. So one can say that when building an ICF home in a region like Texas or Arizona, they can have a wall assembly that has an Equivalent or Effective R-Value of R38, and say so without rioting in the streets and personal attacks or being called a liar. This is not a Portland Cement study, it was done by ORNL.

in Arizona using a 2.5" x 6" x 2.5" ICF wall system... Dynamic R-Value Equivalent of R38 is an accurate and factual statement.

I disagree. It depends on a lot more than just Arizona. For example, a fixed interior temperature reduces it. So does the use of thermostat setback. It's complicated enough that it's not accurate to state such a value except perhaps for "average households" or "according to the ORNL method" (which is overly simplistic).

thermal mass and its dynamic benefit.

Even ORLN will say that in some places it has no benefit and increases energy use.

On the other hand, I'll say that "R value" has a few dependencies too - temperature, convection effects, etc.

Interesting jonr - any convection at all and r-value approaches zero. Which is part of its limitation. The other limitation is radiation.

Lbear, kindly link the detailedl spec sheets that cite DBMS and mass enhanced equivalent r values for ICF.

Your climate specific explanation is hooey, BTW. Rastra, linked above, has no trouble publishing and advertising equivalent r values for the climates modeled by DOE2, and most building inspectors have no trouble accepting them. Mine took Wash DC as representative for my building permiit. I repeat, if ICF manufacturers won't tell the world and the FTC that Phoenix is R38 why would we believe you?

For starters, there is no one DBMS for ICF. It varies with foam thickness. As figure 8 in this ornl document suggests, the less foam the better in phoenix. In DOE simulations, the best performing icf wall was R5 on either side. R25 was the worst. http://www.ornl.gov/sci/roofs+walls/research/detailed_papers/thermal/index.html (Click on "Potential Energy Savings" in the left column.) Save your pixels TexasICF; everyone knows a simulation does not require an R5 ICF in the real world. We are not as dumb as you think.

Interesting: You keep pointing to mass walls. AAC and most hybrids are not mass walls so why keep pointing to these charts? Perhaps we should discuss ASHRAEs definition of exactly want constitutes a mass wall? AAC is not. I don't mean to be aggressive but you can't just pick a chart and place your wall system in it.