Figuring heat exchanger's surface temp

  • Thread starter Thread starter TuomasO
  • Start date Start date
  • Tags Tags
    Heat Surface
Click For Summary
To calculate the surface temperature of a heat exchanger heating a room, the equation P = εσAT^4 is used, where P is the heating power, ε is the emissivity, σ is the Stefan-Boltzmann constant, A is the surface area, and T is the temperature. The attempt to solve for T using T = (P/σA)^0.25 results in negative surface temperatures, indicating an error in the power value used. It is suggested that the reported heating power P may not reflect the total heating power of the radiator. Additionally, the interaction between the heater and the room must be considered, as the room also radiates heat back to the heater. Accurate calculations require a correct understanding of these thermal dynamics.
TuomasO
Messages
1
Reaction score
0

Homework Statement


Calculate surface temp of heat exchanger when it's heating the room with the known power of P. Room temperature T is also known, as is the heater surface area A. ε ≈ 1.

Homework Equations


P = εσAT^4 is what I've been trying to use.

The Attempt at a Solution


I've been trying to solve this with T = (P/σA)^0.25, but that's giving me negative surface temps which clearly can't be correct. I'm guessing the reported heating power P can't be the actual total heating power of the radiator, but I haven't been able to figure out how to go at it.
 
Physics news on Phys.org
Your equation is not correct. If the heater radiating heat to the room, then the room is also heat to the heater.
 

Similar threads

How long does it take to heat a vessel?
  • · Replies 41 ·
2
Replies
41
Views
6K
Calorimetry Lab Analysis (predict specific heat of unknown metal)
  • · Replies 54 ·
2
Replies
54
Views
9K
Problem with refrigerator and radiator
  • · Replies 3 ·
Replies
3
Views
2K
Why is the Stefan-Boltzman formula for this problem like this?
  • · Replies 10 ·
Replies
10
Views
3K
Power Radiated From a Copper Cube
  • · Replies 3 ·
Replies
3
Views
921
Radiating sphere inside spherical shell - heat transfer
  • · Replies 8 ·
Replies
8
Views
3K
How Does Newton's Law of Cooling Affect Heat Loss Calculations?
  • · Replies 2 ·
Replies
2
Views
2K
Heat sink - calculating temperature at the base
  • · Replies 34 ·
2
Replies
34
Views
6K
Spec'ing the power of heater for an atypical heat exchanger problem
  • · Replies 22 ·
Replies
22
Views
4K
How much time will it take to heat water
  • · Replies 1 ·
Replies
1
Views
1K