Simple Unit Conversion Question

[sandbanana]

If I have units with degree Fahrenheit in the denominator can I cancel it with degree Rankine without a problem? Or do I need to use F + 459.xx to clear it?

does 1/F cancel with R?

I believe 1/F and R can cancel one to one, right?

\frac{\frac{Btu}{hr*ft^2*F}*\frac{ft^2}{}}{\frac{l bm}{hr}*\frac{Btu}{lbm*R}}

The above is unitless following my thinking.

[chroot]

The Fahrenheit scale and the Rankine scale use the same-sized degree, but they have a different starting point. You should convert all the temperatures to the same scale before cancelling them. If you do not, you'll end up getting an answer with the right unit but wrong numerical value. To convert from degrees Fahrenheit to degrees Rankine, add 459.67.

- Warren