Good day

I have a potential client who has heard of and wants to run in wall heating inside of his ICF, a la in floor heat.  He has mentioned running it on the inner side of the icf, so basically running his lines horizontally each course all the way up the wall.  He will also be connecting it to a geo thermal system and putting in 3 zones.  Has anyone else seen/heard/done this?  Unless there is a good reason not to do this he is going to do it, but we thought we would see what kind of feedback we got from this forum.

Thanks in Advance

Are you planning on removing the interior insulation? If not, he will be spending money to heat the concrete FIRST before it even has a chance to try and heat the interior.

Now if you want to run it on the interior surface of the ICF, then furr the wall and rock it, that's a possibility, but you need to review the extra finishing costs.

Heat rises....I don't understand the logic of why he wants to put it in the wall??

bbicf - Your client is very correct in his thinking. By using a "lop-sided" ICF (2" EPS - 6" Concrete core with 20mm ID Pex tubing - 10mm MgO2 Board); along with using the area underneath his basement (or slab foundation) as a "heat storage", he would create a "supercharged ICF" (adding veins and arteries to the ICF wall so to speak). Concrete is by nature a solid thermal mass; and if supplied with a continues water temperature of let's say 60 F (Free energy from the earth below the building), this concrete wall will maintain that temperature. This has been done in Europe since 1996.

Robinnc... If Heat rises than why is it colder on Mt. Lemmon (9000ft) than in Tucson AZ? Heat seeks the cold - but does not necessary rise!

Hot air rises! Very different than heat.

Thanks DOnnerwetter
So what you are saying is that what should be done is basically a half ICF system so that the inside wall is not actually insulated with eps foam.  How would you recommend doing that, I would have to use a knowckdown system and attach the MG02 board instead of the other icf side.  Do you know where I can get some more info on this.

bbicf
More info can be found at the following website www.Isomax-terrasol.eu (click english flag in upper left hand corner for english). We will be starting our next installation in Philadelphia later on this year and will be keeping this forum posted on our progress.

Where are you located and how soon is your start date? Please PM me - might be of further assistance. Have taken this "Dog and Pony" show on the road before :)

Heinz Horn
Terrasol Technologies USA

In a typical ICF the insulation is equal on both sides of the concrete. so half the heat would leave the house. I would be a pain to install, and would weaken the walls and would inhibit concrete flow.

Sounds like a bad idea, put it in the floor.

ICFconstruction

I will agree with you that installing the 20mm Pex could be somewhat of a Pain; however one must also consider the advantages. The drywall is hereby totally eliminated (at least on all exterior walls). Concerning a weakening of the wall; this would be to such a minor extent that it would be (In my humble opinion) a non-factor. Regarding concrete flow (after placing and pouring the retaining wall for the city of Burbank power and water - (I have never seen that much steel in a wall in my life - barely had room for the concrete); this also is a minor factor (we have used a cellular concrete for many years in order to increase flow while maintaining 3000+ PSI).

If I remember correctly, it takes 1Kcal (1000 calories) to heat 1 liter of water 1 degree C. Why not use the free energy below the building to at least help out? Even using conventional ICF's - while heat loss (and Heat Gain as well) would be equal on both sides; is it not the goal of this system to achieve a constant inner wall temperature regardless of exterior temperatures ( a so called micro enviroment or temperature barrier)?

Lastly, I value your expertise and comments greatly; however, this is one of the rare times that I must respectfully disagree with you.

Hello Everyone this is the architect in Philadelphia trying out this new system. My firm Stimulant Design www.stimulantdesign.us is a hybrid architecture and technology firm who researches sustainable design, installations, and manufacturing processes. (not much on our website as it is being reconstructed) Our projects will be soon online within this forum. please respond, react, and enjoy the dialogue. We are in this thing together and any input will be taken into consideration.

From our understanding this system is completely counter intuitive to the traditional heating approaches whether it be in geothermal, solar, or high efficiency systems. Ours focus is to combine several systems into one super efficient (super insulated system).

I think you and Donnerwetter are talking about different technologies.  If I understand correctly, your client wants, essentially, to make radiant walls sort of like this:

<http://www.fccplanterm.com/eng/index.htm> You must click on the Planterm button on the left side.

This product is basically 1/2" drywall with closely spaced 1/8" tubing and 2" of styrofoam all laminated together.  It is used on walls or ceilings.  I have a sample in my office if you are interested in a picture of it.  The web site is not to clear in English.  I have been to the Permasteelisa factory and seen it work in a cooling mode installed in a ceiling.  It was impresssive. 

Donnerwetter will place PEX inside the concrete to keep it at a uniform temperature.  I am a bit skeptical about this concept...not that it can't work, but I am concerned about the complexity of the plumbing and whether the energy sources/uses balance out.  To me, this concept is viable if ALL the insulation is on the exterior.

Bruce

In my opinion its a horrible idea. All of the time and money spent by making your walls 'radiant' could be spent upgrading the shell of the home to a higher R value which would net you far better energy savings results. I mean come on people, wake up! To even motion the idea that your walls 'need' radiant heat to counter their 'lack' of thermal resistance (keeping the 'heat' in the conditioned space of the home) should be a plain SLAP in the face! Get those walls up to a higher R-value, face your living room windows to the south, throw up a nice masonry fireplace to hold some thermal mass from the intake of daily sunlight and call it a day.

I know that Integraspec (integraspec.com)does have the application your looking for which is ecf (exposed concrete face) mainly seen in elevator shafts or for higher fire rating. However I am with the others on this one for taking out one side of the insulation of the systeme is completely beside the point of the icf sandwinch. But if that is what he wants then so be it. I would try to explain the situation but simply in an informational matter to try and talk some sense towards this inquire.Good luck.
Cheers.

Hello all. I wanted to respond to the conversation a little more in depth rather then my brief introduction yesterday. Our firm has been researching construction typologies for several years and the systems we are discussing exist. I am considering installing it on a few projects in Philadelphia. The main problem with the thinking is that we as Americans are stuck in our calculations of R Values in a wall and or roof, windows, etc. This throws that idea out the window.
It proposes that to not focus on the R-value rather the thermal mass and like thagreen mentions it is a factor whether the system is able to maintain a balance or not. I am looking closer into this personally prior to installation, however the results I am seeing prove that this is possible. bbicf if you wish to discuss further these results I am not complete allowed to share all the technology at this time as there are some proprietary components that my be of use to you.

all an one last thing... what about cooling the system. this has been on my mind for a while and it seems to me if we begin a cooling system with in a unit / wall section there would be condensation? Does any one else have any ideas about this?

Aside from being airthight an icf system, from footers up to rafters is connected to the ground is it not? Therefor the ground always being approx 11 deg. there should be some sort of temp. conductivity in the concrete core. This being said, the amount of work and materials will not offset the price of a smaller than usual a/c unit to bring the indoor temps to comfort level. Another point to which the icf systems are the best envelope on the market as of now and don't need be tampered with. You know what they say, if it ain't broke don't fix it!!
Cheers!

I am with thagreen on this one. ICF without the sandwich is like using your bathtub as a boat. It can be done, but it's pretty silly considering the alternatives.
Such as: Apex, Rastra and the other composite forms; AAC; stay in place forming systems such as E-Wall; Certainteed's insulating systems for cast in place; tilt up; shotcrete; CMU. There are more than enough ways to put mass on the inside and foam on the outside in climates where it makes sense to do so. That leaves a far bigger chunk of the U.S. where traditional ICF is a great system just as it is.

I'm along the thinking that while this can be done, but why would you? If the client is a recently retired AIG Executive with a lot of cash and that's what they want to do, then the contracter will LOVE him. I would think that the added expense to do what he has planned is going to be huge with very little return! Your ICF wall is going to be filled with rebar and now piping for the radiant wall?

If it were me, I would consider the additional cost of the radiant wall (and the geothermal - depending on the size of the house) and look to see about investing those dollars in windows, tankless water heater, maybe solar, etc.

Gentlemen

It seems that the single greatest concern is COST. Certainly a valid concern. However may I propose that we all evaluate and consider the following - Let's say for discussion sake - the average 2000 sqft (say 50ft X 40ft X 10ft) Home.

A.) Total exterior wall space needing drywall on the inside (minus 20% for windows and doors)
= 1440 sqft. Labor and material to install (excluding taping, sanding) = ?????

B.) Initial cost of geothermal, heat pump, wind and/or photovoltaic = ?????

C.) yearly operational cost of geothermal, heat pump, wind and or photovoltaic = ?????

The Passiv House standard in Europe is anything less than 40Kw/h/m2/year (correct me if I am wrong) to heat and cool (including Hot water) a building. Documentation confirming Buildings using such a system (in locations in all climate zones - i.e. Poland, China, Japan, Germany, Luxembourg, Spain - just to name a few) confirms usage equal to; and in most cases far less than the European Passiv Haus Standard - at an initial cost quite competitive (in some cases less) with far less operational costs.

I am sure that we can all agree that "Efficiency = cost and performance" (or as I was once told "Is the bang worth the Buck). In 1991 the ICFA had 12 primary members; ICF's were vertially unheard of; and building inspectors told us "To build with wood...like everybody else does". It is my humble opinion that today; as well as in the near future, ICF - as THE EXTERIOR WALLING SYSTEM, is the most efficient system available. We just propose to enhance it - not replace it!

P.S. renangle...Regarding AIG execs....after their 90% taxes are applied; they might be looking for a job....heard some are working for $1.00/year :). By the way I love tankless water heaters. We had them installed in our houses in Germany over 3 years ago and they work GREAT!

The following paragraph is quoted from this ORNL paper:
http://www.ornl.gov/sci/roofs+walls/research/detailed_papers/thermal/index.html

"Comparative analysis of sixteen different material configurations showed that the most effective wall assembly was the wall with thermal mass (concrete) applied in good contact with the interior of the building. Walls where the insulation material was concentrated on the interior side, performed much worse. Wall configurations with the concrete wall core and insulation placed on both sides of the wall performed slightly better, however, their performance was significantly worse than walls containing foam core and concrete shells on both sides"

Figure 5 from the same report is shown below.

The DBMS is a dimensionless number that really only useful for comparison.  What this tells me is that a wall with interior concrete and external insulation (INTMASS) outperforms a conventional ICF in all climates.

Remember, this report deals heavily with the famous 'equivalent R value'.  I think we have Dr. Kosny to thank (or blame) for that term.

Bruce