Re: Exotic steel stud shapes

ThermaChannel — Thu, 02 Jul 2009 15:29:55 GMT

Hello Bud,

Thanks for taking the time to read the Oak Ridge report. That is pretty dense information. How we break it down for architects is that the test showed up to a 16% improvement in r-value for that wall assembly by simply using our 1/2" deep stud design --and we would like to point out that we used high-performance framing of 24" oc framing, which has less steel in the wall overall. By using standard 16" oc framing, there are more studs in the wall, more steel, and therefore more thermal bridging. Our percentage of improvement over the standard stud would have been higher than 16% on a percentage basis had we framed at 16" oc.

So, the r-value of our 1/2" design, for that wall assembly, showed an r-value of 11.12, or a 16% improvement over that same assembly using standard studs. So the effectiveness of ThermaChannel was demonstrated. From there, there are many assemblies, and we could not possibly test them all at Oak Ridge. You can read about this more easily in our short brochure on our website.

An industry standard for commercial walls, 6" deep, with 2" of exterior rigid insulation is r-14, I believe. That is a calculated value, so if you actually tested that assembly, it might not even perform that well. So, when we look at r-11.1 for our oak ridge results for the 1/2" deep ThermaChannel studs, with r-19 batt insulation and 1/2" gwb, that is an "actual" r-value, since it was tested. Truly to compare the two, one would have to use the same method for both assemblies: either use mathmatical calculations for both, or do actual hot-box test for both.

In short, our figures are always conservative.

We have had professional energy modelers take the information from Oak Ridge and calculate the building's performance. For example, my partner and the inventor of ThermaChannel also works as an architect in a firm. They designed a building using standard framing and batt insulation. We asked the energy modelers to calculated the energy use/savings if the building were designed with ThermaChannel steel studs. If it has employed our 1/2" deep flange stud, they concluded that that same building would have saved 3-4.7% of it's overall annual energy use. A huge savings, with zero maintenance, over the life of that building. 3% was in Arizona (hot clime), 4.7% was in Minnesota (cold). I'd like to point out as well, that that building was designed with 16" oc framing, while our data was calculated from 24" oc framing. We need to recalculate the savings, using ThermaChannel data for 16" oc framing. Something we are pursuing currently. The results will be even higher energy savings.

ThermaChannel can still be combined with exterior rigid insulation for an even higher-performing wall assembly. We just don't have the data yet to say exactly what that would be.

In response to wood framing, we mainly look at steel framing for commercial construction. At first we did not think we would have enough thermal benefit to compete with wood framing for low-rise residential construction, where wood is common. However, we are starting to think that we will have enough. Currently working with energy/mechanical engineers on this.

Condensation: our designs lower the delta T (I hope I am speaking correctly, I am businessman versus an architect like my partner is), thereby evening out the temperature differential in the center of the cavity versus the wall or stud temperature. This helps condensation issues. It also greatly or completely reduces "ghost marking". For those who don't know, ghost marking is where that temperature differential creates minor condensation on the wall surfaces which over time pic up dirt, striping the interior and exterior walls where the studs are. In that case, it is mainly a cosmetic, maintenance issue.

Your last question, there are few new steel stud shapes. Our is the only one that addresses thermal bridging at the flange or wall surface. It is patented, so no one else can do this. Others all cut out the web of the stud, which has other issues. Yes, though, it would be of great value for providers of new studs, such as our company ThermaChannel, and others, to develop formulas and information for architects to making it easier to compare and specify with confidence new products of higher performance. We are working on it. (We are also seeking investment...)

Thank you again for your keen interest. Please look at our brochure on our website, and e-mail or call me directly any time. Contacts there.

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Re: Exotic steel stud shapes