To calculate the power in a fluid with a flow, the following formula is applied:

$$P = \Delta T \rho c_p \times flow$$

$\Delta T$ can be entered as both Kelvin and Celsius. But what if I want to use Fahrenheit? Is there any formula for this?

Reason is I'm making a web application that calculate some stuff. I have full unit support. I live in Europe so we always use Celsius or Kelvin. But, are americans using fahrenheit for calculations in general? If not, then maybe I can skip it all together.

  • $\begingroup$ Multiply by 5/9 $\endgroup$ – Mike Dunlavey Jan 31 '14 at 14:22
  • $\begingroup$ Thx for answear! Haven't added the feature yet in my app but it will be available in next version. Here's my app btw, sizepipe.com. $\endgroup$ – Joe Jan 31 '14 at 18:57
  • $\begingroup$ Looks cool! Good luck. $\endgroup$ – Mike Dunlavey Jan 31 '14 at 20:34

Given that the conversion from Celsius to Fahrenheit is given by:

$$T_F=T_C\cdot 1.8+32$$


$\Delta T_F=T_{F_2}-T_{F_1}=T_{C_2}\cdot1.8 +32 -T_{C_1}\cdot1.8-32 = \Delta T_C\cdot1.8 $

Or, to be used in that case,

$$\Delta T_C = \frac{\Delta T_F}{1.8}$$

So the formula becomes

$$P =\frac{\Delta T_F}{1.8} \rho c_p \times flow$$


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.