thermal expasion of air

j.osborne

how can i calculate the pressure change of air based on temperature change?
i have 1 cu ft of air at 15 psi and the temperature raises 100 degrees f. what is my end resulting air pressure psi?

Dave_23

PV=nRT

PV=nRT

Mike T., Swampeast MO

Because air behaves as an ideal gas you can use a simple equation:

P1 * V1 / T1 = P2 * V2 / T2

P = pressure

V = volume

T = temperature

Have messed this up. Pressure, volume and temp must be kept on the same relative scale.

zeke

You must use absolute temps in the gas equations. The 70 deg F = 460+70 =530 R and the 170 F is 630 R. Also the pressures must also be absolute, psia not psig.
psia= psig +14.7

Mike T., Swampeast MO

Thank you. Made it even worse and removed the calculations. Sorry.