re: heat transfer plates
13 dec 2003
>>you might make 19 btu/h-ft^2 with 95 f water and 19/(5(95-65)) = 0.127
>>feet of 5 btu/h-f-ft fin-tube pipe per square foot of floor, ie 1 $32
>>8' length of fin-tube per 63 ft^2 of floor, vs about 2 sheets of filler
>>board, 64 ft^2 of aluminum, 96 ft of pex and more labor...
>hmmm...interesting. i thought finned tube baseboard had to run at much
>higher temperature in order to get the heat output, but then the fins do
>create a large surface area for heat transfer.
they move more heat with higher temp water, but the basic thermal
conductance in slow-moving air is about 5 btu/h-f per linear foot.
speed up the air with a fan or a "closet convector" and the thermal
conductance will increase.
>so you suggest using fin tube baseboard instead of radiant floor?
sure. you might put it under the floor for more of a radiant floor
feeling, and possibly add a few holes in the floor to let some warm
air flow up near the center of the house and let some cool air flow
down near the perimeter.
>i picked up yunus a. cengel's "intro to thermodynamics and heat transfer" at
>the college library so i can kick some numbers around myself.
you might also look at the graphs on some fin-tube web sites.