Posted by daestrom on September 10, 2006, 4:02 pm
>>>
>>>> Since steel is not a good thermal conductor (it's a diffuser) it's uses
>>>> are good in enviormentally friendly "geen homes." Since one can reduce
>>>> electricity dependence up to 60% with the use of steel in the frame of
>>>> the structure, solar powered configurations don't have to work as hard!
>>>> At Tri-Steel we have 8 ft spans which allow for maximun spacing for
>>>> wiring and placement of panels. check us out at Tri-Steel.com We do
>>>> customs, but also have over 200 floorplans to choose from in which
>>>> solar power can be utilized.
>>>
>>>Just how is Steel [1% carbon]
>> k = 25 Btu/h-ft-F
>>
>>>not a better conductor of heat than say WOOD [fir]
>> ... 0.063, 400 times less conductive
>>
>>>or concrete???? [1:2:4 stone mix]
>> ... 0.79, 32 times less conductive.
>>
>> Nick
>>
> Thank you for the real numbers Nick. There is science and then
> there is belief. Those that believe would never let those science
> and proof numbers get in the way of their beliefs.
The thing to remember is that steel has a higher thermal conductivity than
wood or concrete, the thermal conductivity alone is not the final
determination. Because steel is much stronger, a steel 2x4 is has a much
thinner cross-section than a wooden 2x4. And it is thermal conductivity
times the area, divided by the length that determines the overall heat
transfer coefficient (i.e. R-value). So a very thin sheet of steel folded
appropriately for ridgidity has a very small cross-section and is thus has a
higher R value. It may be '2" ' (actually 1.5) on the face, but the heat
must flow through a thin (1.2mm ??) webbing to get to the other 'face'.
daestrom
>
Posted by nicksanspam on September 10, 2006, 9:50 pm
>>>>Just how is Steel [1% carbon]
>>> k = 25 Btu/h-ft-F
>... Because steel is much stronger, a steel 2x4 is has a much thinner cross-
section than a wooden 2x4. And it is thermal conductivity times the area,
divided by the length that determines the overall heat transfer coefficient
>(i.e. R-value). So a very thin sheet of steel folded appropriately for
>ridgidity has a very small cross-section and is thus has a higher R value.
>It may be '2" ' (actually 1.5) on the face, but the heat must flow through
>a thin (1.2mm ??) webbing to get to the other 'face'.
Got numbers?
Nick
Posted by SJC on September 11, 2006, 12:01 am
>>>>>Just how is Steel [1% carbon]
>>>> k = 25 Btu/h-ft-F
>>... Because steel is much stronger, a steel 2x4 is has a much thinner cross-
> section than a wooden 2x4. And it is thermal conductivity times the area,
> divided by the length that determines the overall heat transfer coefficient
>>(i.e. R-value). So a very thin sheet of steel folded appropriately for
>>ridgidity has a very small cross-section and is thus has a higher R value.
>>It may be '2" ' (actually 1.5) on the face, but the heat must flow through
>>a thin (1.2mm ??) webbing to get to the other 'face'.
> Got numbers?
> Nick
I think the point was made even without numbers. It is when you
get comments like "thermal diffuser" that I think you need hard numbers.
If you look at the web site the orginal poster suggested one part says:
Does the Steel Transfer Heat & Cold?
Yes. Insulation companies performed energy efficiency tests on steel framing
and found that when a steel home is insulated properly, the transfer can be
reduced or eliminated.
http://www.tri-steel.com/Buyer/FAQ.asp
So much for "geen homes"...
Posted by Biff on September 11, 2006, 12:17 pm
Steel doesn't grow on trees capturing solar energy.
Posted by Jeff on September 11, 2006, 2:39 pm
Biff wrote:
> Steel doesn't grow on trees capturing solar energy.
>
The first *commercial* use of steel in shipping came as the high quality
woods necessary for construction became rare and expensive. These were
hybrids, with steel ribs and wooden sides. Not a good design! Or so I
seem to remember hearing...
Steel stud construction has it's own economic reasons and needs
special techniques to get around the thermal breaks in the skin. We need
to transition to all steel houses that will keep us warm in summer and
cool in winter...
Jeff
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>>>> Since steel is not a good thermal conductor (it's a diffuser) it's uses
>>>> are good in enviormentally friendly "geen homes." Since one can reduce
>>>> electricity dependence up to 60% with the use of steel in the frame of
>>>> the structure, solar powered configurations don't have to work as hard!
>>>> At Tri-Steel we have 8 ft spans which allow for maximun spacing for
>>>> wiring and placement of panels. check us out at Tri-Steel.com We do
>>>> customs, but also have over 200 floorplans to choose from in which
>>>> solar power can be utilized.
>>>
>>>Just how is Steel [1% carbon]
>> k = 25 Btu/h-ft-F
>>
>>>not a better conductor of heat than say WOOD [fir]
>> ... 0.063, 400 times less conductive
>>
>>>or concrete???? [1:2:4 stone mix]
>> ... 0.79, 32 times less conductive.
>>
>> Nick
>>
> Thank you for the real numbers Nick. There is science and then
> there is belief. Those that believe would never let those science
> and proof numbers get in the way of their beliefs.