autolake
Registered Users
Posts:5
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| 03/05/2007 3:30 AM |
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I was just wondering if anybody has more insight on the "ALL WALL" system. I am considering building with icf's and bumped into the all wall system. With that system the foam is placed on the interior and the concrete is on the inside and outside. The manufacturer states that this is more effective, more durable and thermal mass is therefore better utilized. It seemed to make sense to me. Their website is link
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Scott McIntosh
Registered Users
Posts:6
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| 03/06/2007 2:59 PM |
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It looks like a good system, but they sure do a lot of jumping up and down and screaming.
check out link It may give you some answers.
Scott |
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slenzen
Registered Users
Posts:163
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| 03/06/2007 3:50 PM |
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in that article it shows ICF reducing the most for energy cost but sandwich walls reducing the size of HVAC unit needs more. why is that?
I am curious why they didnt include wood SIPS in the comparisons.
What is the best source for the most independent information comparing all types of building systems? ORNL, PATH or ??? |
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slenzen
Registered Users
Posts:163
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| 03/06/2007 4:29 PM |
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| Wonder what kind of thermal transfer they have in the concrete beam areas. No thermal breaks there that I can see. |
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Scott McIntosh
Registered Users
Posts:6
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| 03/06/2007 6:06 PM |
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I found this site without even trying, www.cfawalls.org/news_press/cfa/2001/01_thermalstudy.htm
simular study without the HVAC discrepancy.
Like I said, it looks like a good system, but...
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slenzen
Registered Users
Posts:163
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| 03/06/2007 7:34 PM |
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Thanks for that link Scott. It was helpful. Now we need a study to factor in the costs of construction for each of the methods and see where the best value for overall performance lies to determine the sweet spot of cost vs. performance. I may not want to pay a premium for the top system that may only have marginal increases in efficiency.
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Opus
Registered Users
Posts:51
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| 03/06/2007 9:07 PM |
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The steel studs that hold this wall together go from one side to the other creating a large thermal leak . This decreases the effectiveness of the insulation by 50% to 80%. This is the same problem as with the Hurricane Proof Roof System and all the other systems that have steel running from one side to the other without a thermal break. In Flordia where thermal mass works much better than in other climates these systems can work , especially if you reduce the other big energy loss, air infiltration. My question is why would you want to use such a system when there are systems with thermal breaks where the steel is? They will ALWAYS PERFORM BETTER!For more information on thermal losses in buildings go to the Building Science Corperation site and download the PDF on Thermal Control in buildings : http://www.buildingscience.com/documents/digests/bsd-011-thermal-control-in-buildings/?topic=/doctypes/digest .
Clif |
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autolake
Registered Users
Posts:5
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| 03/07/2007 3:46 PM |
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| I sure do appreciate the feedback on the the "All Wall" System as well as links. I am also considering "precast". |
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slenzen
Registered Users
Posts:163
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| 03/07/2007 6:16 PM |
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Autolake, where are you building? I am in MN and considering various methods including precast as well.
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autolake
Registered Users
Posts:5
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| 03/08/2007 2:50 PM |
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Slenzen,
It seems like we are a little removed from each other. I am going to be building in South Carolina (Outside Charleston). I currently reside in Mass. Are you planning on building soon. I'm looking out about 18 months myself..
The more I read the closer I am to building with precast. It seems like it's one of the best alternatives. One of my concerns with icf's is with the quality of the people doing the pours. What if the walls aren' properly braced? How can you assure that the concrete being delivered meets the specifications ordered.
Seems precast has a controlled enviroment with optimum conditions as well as offering quick set-up. You can go to the factory and inspect your panels before it is delivered. I'm still considering other methods, but am seriously leaning to precast. My next hurdle is to find a qualified architect local to where I am building to modify my plans as well as incorporate "Passive Solar" design.
It's nice to have a great forum such as this have people learn from each other.
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James Eggert
Registered Users
Posts:1001
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| 03/08/2007 7:42 PM |
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The amount of misinformation posted on thermal breaks is appalling to me. Even though I do not use this particular system, ANY metal strapped wall ENCASED IN A CONCRETE THERMAL MASS will not lose 50-8-% of it's effectiveness. And the building science link posted does not say that either!!
Yes, metal has a "measureable" thermal loss when used in a generic style ICF; it's doubtful that a person could feel it no matter which brand! |
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Take Care
Jim
Design/Build/Consulting
"Not So Big" Design Proponent |
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walltech
Registered Users
Posts:469
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| 03/08/2007 7:46 PM |
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Your concerns of being properly braced all comes back to your choice in a ICF installer! If you don't do your due diligence in finding someone with a reputation you will end up with a pour sub-contractor no matter what product you build with. As far as the concrete goes, most reddi-mix plants are computer batched. We have poured over 1000 pours and still haven't ran into a poor batch of concrete.
Dave |
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James Eggert
Registered Users
Posts:1001
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| 03/08/2007 9:03 PM |
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Dave
Good Points! |
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Take Care
Jim
Design/Build/Consulting
"Not So Big" Design Proponent |
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icfblocks
Registered Users
Posts:265
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| 03/09/2007 12:24 AM |
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| Just finished an ICF job in Aiken, SC. It had 5' deep stem walls, 13' first floor, with a 12' 6" second floor,all with ICF's. Be glad to have you look at it. Th owner lives in Charleston. It's on a Polo development near Aiken, SC. |
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Thanks,
Tom
www.advbuildingtech.com |
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Opus
Registered Users
Posts:51
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| 03/09/2007 12:54 AM |
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What misinformation is that Jim? I did not say that the wall will perform 50% to 80% worse -- but the INSULATION WILL! A steel C channel every 24" through insulation is always going to reduce the ability of that insulation to prevent heat flow by 50% to 80%. That is not the same thing as the overall performance of the wall system itself. Having thermal mass on both sides of the insulation does not change the thermal properties of the insulation ,and steel has constant thermal properties that do not vary based on where it is. Having thermal mass on both sides can change the Delta T greatly. The amount of heat flow depends on the Delta T, the temperature difference between one face of the insulation and the other face. Having thermal mass on both sides of your insulation will only moderate the Delta T. A lower Delta T means a lower amount of heat flow. In some climates thermal mass can lower the Delta T a great deal. In Florida on some days it could be possible for the Delta T is such a system to be 0. In that case it would make no difference whatsoever what you use for insulation. In a very cold climate where the high temperature is below freezing it is going to make a big difference. If your outside thermal mass is keeping its face against the insulation at 20 degrees and you want to keep your inside thermal mass at 70 degrees facing the room then the steel C channels in such a system are going to make a large difference. To understand how a wall system is going to perform you need to look at what you are asking it to do .What you are asking it to do in any given situation is to minimise the heat flow at some Delta T. The greater that Delta T the worse the insulation with the steel running through it is going to perform. If you are asking the insulation to do very little then this could be a great system. If you are asking your insulation to deal with a large Delta T then this system is going to perform mush worse that one with no steel thermal bridges.Thermal mass is very climate dependant in its effectiveness and without climate information no one can say how a complex system will perform. A person might not be able to feel the difference, but by using a far more sensitive instrument such as the wallet I'm sure the difference could be felt. Thermal breaks are an important part of stopping heat flow. If you want to understand how this particular system will work then look ate the climate you are putting your thermal mass in and then look at the Delta T you are asking the insulation to deal with. In most climates this kind of system will be less effcient that a similar one with no thermal bridging. How much worse depends again on the Delta T. How important that difference in effciency is remains a personal decision. I myself am counting on energy prices going up and payback periods getting shorter. I don't know where you got your engineering degree that you would think this is misinformation, but where I studied this is very basic stuff.
Clif |
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James Eggert
Registered Users
Posts:1001
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| 03/09/2007 9:50 AM |
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Let me simplify, because I'm not trying to argue the basic point at all. That is not my way!
Yes, metal stud walls with batt insulation is a very poor assembly. I agree with you!
No, metal studs with eps insulation and a subsequent concrete thermal mass is not a fair comparison to the metal stud/batt insulation assembly!
You are using scare tactics and inuendos. That is my point. Once again, I agree with you that metal studs and batt insulation is poor, very poor. But it is important that you compare fairly when we look at these products. I don't use the all-wall, I'm only looking at it from a practical end result!
I think we want the same result, build better than we did years ago! |
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Take Care
Jim
Design/Build/Consulting
"Not So Big" Design Proponent |
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Opus
Registered Users
Posts:51
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| 03/09/2007 7:23 PM |
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First of all I don't remember comparing metal studs with bat insulation to this "All Wall" system. I was pointing out that the effective R value of the insulation in the system will suffer because of the design . It doesn't matter if it is fiberglass or cellulose or some kind of foam. If you run that amount of steel through any kind of insulation you will cut the R value of that system by 50% to 80%. That is not a scare tactic or inuendo. That is a fact of science. I am not trying to misinform anyone. Quiet the opposite. I am saying educate yourself so that when some manufacturer tells you his new system is the best thing since flying pigs you will know the facts. If you will look at the Oak Ridge National Laboratory site ( http://www.ornl.gov/sci/roofs+walls/AWT/Ref/prefab.htm ) you will find actual tests on 3 different concrete systems with 3 inches of concrete on both sides of 2 inches of foam. The system with steel and concrete thermal bridges has a clear wall R value of 4.6. The system with steel thermal bridges in limited locations has a clear wall R value of 7.6 . The wall with no thermal bridges ( thermomass system) has a claer wall R value of 10.5 . So the wall that is similar to the All Wall system has a clear wall R value of only 44% of the better designed wall. I think that is about as fair a comparison as you will find and it backs up what I have been saying. I don't think the engineers at Oak Ridge are trying to misinform or scare anyone. I have no control over what someone infers from what I say. I am simply trying to state the engineering facts as clearly as I can. Actual testing at oak Ridge backs up what should be obvious to an engineer. In cold climates you need more than thermal mass. You also need insulation. This All Wall system might have some good points but energy effciency in cold climates is not going to be one of them. By the way if you should see me gluing feathers to a pig please do not infer that pigs can fly or that we now need to be afraid of them. Its only a cross dressing thing the barn yard animals have been into lately.
Clif |
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Opus
Registered Users
Posts:51
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Opus
Registered Users
Posts:51
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| 03/09/2007 7:40 PM |
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OK .Try going to this page: http://www.ornl.gov/sci/roofs+walls/ Then click on hot box tests on the left. Then click on prefabricated concrete panels. The three systems I am talking about are at the bottom of the list, Metal connectors, metal and concrete, and thermomass.
Clif |
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autolake
Registered Users
Posts:5
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| 03/10/2007 1:53 PM |
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I sure am glad I happened on to this forum. I am learning a great deal and there has been excellent feedback. I have now rethought the "All Wall" system and know more what to look for in other applications. Thanks again for the great links.
I am new to this and am trying to do the best system possible. |
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