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[email protected] trader4@optonline.net is offline
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Default High Efficiency gas furnace..



On Jan 26, 5:25 am, wrote:
wrote:


... if the metal is a good conductor, eg steel with 50 Btu/h-ft-F, with
poor airfilm conductances on both sides, eg 5 Btu/h-F-ft^2, thinner steel
won't help much. How much, in this case, starting with 0.050" steel?


Heh, don't try to obfuscate the facts by spewing a bunch of calcs as
usual, trying to cover up...


It's 300-year-old physics :-) What's the answer to this simple problem?


Still no clue? Rewrite the steel conductivity as 50 Btu-ft/h-ft^2-F...


Still stuck? Try 600 Btu-inch/h-ft^2-F.


Another clue: the thick steel conductance is 600/0.050 = 12,000 Btu/h-F-ft^2.


And if we halve the thickness, it becomes 24,000 Btu/h-F-ft^2. Wow!So the steel thermal resistances are 1/12K and 1/24K h-F-ft^2/Btu.


Now what do we do with resistors in series?




Try shoving them up your ass and get back to us on how many fit.