Asked by James
The thermal conductivity of fiberglass batting, which is 8.9 in thick, is 8.6 10-6 BTU/(ft °F s). What is the R value (in ft2 °F h/BTU)?
The R value is 24 ft^2 Fh/BTU. How do I get this answer?
The R value is 24 ft^2 Fh/BTU. How do I get this answer?
Answers
Answered by
drwls
R is the reciprocal of the amount of BTU of heat transfered across 1 ft^2 in 1 hour with a temperature difference of 1 F.
1/R = 8.6*10^-6*3600 s*(1.0 degF)/(8.9/12 ft)
R = 24 ft^2*degF*h/BTU
1/R = 8.6*10^-6*3600 s*(1.0 degF)/(8.9/12 ft)
R = 24 ft^2*degF*h/BTU
Answered by
James
Thank you!
Could you write out just the basic equation that you used?
Could you write out just the basic equation that you used?
Answered by
James
The equation I found in my text book doesn't mention time being a factor when calculating R.
I have R= L/k
where L is length and k is thermal conductivity.
I have R= L/k
where L is length and k is thermal conductivity.
Answered by
Mr. Polopotato
37