units help: si to english (heat xfer convection coefficient)?

[eber]

i'm a little unsure of the units. i need to convert W/m^2 K to english units. what i'm stuck on is the K part. is that going to be in R or F in english units?

or even better, anyone have a link for conversion?

or even a value in english units for natural convection heat xfer coefficient? i have one here as 5 W/m^2 K.

thanks in advance.

 

[Martin]

yes

 

[minendo]

K will go to F. m^2 goes to ft^2, W goes to BTU.

 

[rgwalt]

Originally posted by: minendo
K will go to F. m^2 goes to ft^2, W goes to BTU.

It depends. If you are going to multiply the unit by a temperature difference, then you can use F. If you are going to multiply the unit by an absolute temperature, then you need convert to R. Fortunately, Rankine (R) is the absolute temperature reference for the F scale, so there really is no difference in converting to R or F from K.

R

 

[eber]

thanks. arrgh ok i see. i found something. so it's (btu)/h*(ft^2)*F? or does BTU have time already?

argh damn english units!

 

[minendo]

Originally posted by: rgwalt

Originally posted by: minendo
K will go to F. m^2 goes to ft^2, W goes to BTU.

It depends. If you are going to multiply the unit by a temperature difference, then you can use F. If you are going to multiply the unit by an absolute temperature, then you need convert to R. Fortunately, Rankine (R) is the absolute temperature reference for the F scale, so there really is no difference in converting to R or F from K.

R

Just based my response off of everything we did in my thermo course.

 

[rgwalt]

Originally posted by: minendo

Originally posted by: rgwalt

Originally posted by: minendo
K will go to F. m^2 goes to ft^2, W goes to BTU.

It depends. If you are going to multiply the unit by a temperature difference, then you can use F. If you are going to multiply the unit by an absolute temperature, then you need convert to R. Fortunately, Rankine (R) is the absolute temperature reference for the F scale, so there really is no difference in converting to R or F from K.

R

Just based my response off of everything we did in my thermo course.

You are right in this case, but my point is that when doing unit conversions you need to be mindful of what you are using the unit for. For instance, in the ideal gas equation you multiply temperature by the gas constant R. If you know the SI units for R, but not the english units, you need to convert temperature from Kelvin to Rankin because the ideal gas equation is based upon an absolute temperature scale.

R