Enter the cross-sectional area (m^2), the flow speed (m/s), specific heat (kJ/kg-k), temperature difference (K), and the density (kg/m^3) into the Waste Heat Calculator. The calculator will evaluate the Waste Heat. 

Waste Heat Formula

The following formula is used to calculate the Waste Heat. 

Qwaste = A * V * p * Cp * T


  • Qwaste is the Waste Heat (kW)
  • A is the cross-sectional area (m^2) 
  • V is the flow speed (m/s) 
  • p is the density (kg/m^3) 
  • Cp is the specific heat (kJ/kg-K)
  • T is the temperature difference (K)

To calculate the waste heat, multiply the cross-sectional area, flow, density, specific heat, and temperature change together.

How to Calculate Waste Heat?

The following steps outline how to calculate the Waste Heat.

  1. First, determine the cross sectional area (m^2).
  2. Next, determine the flow speed (m/s). 
  3. Next, determine the density (kg/m^3). 
  4. Next, gather the formula from above = Qwaste = A * V * p * Cp * T.
  5. Finally, calculate the Waste Heat.
  6. After inserting the variables and calculating the result, check your answer with the calculator above. 

Example Problem:

Use the following variables as an example problem to test your knowledge.

cross sectional area (m^2) = 4

flow speed (m/s) = 30

density (kg/m^3) = 100

specific heat (kJ/kg-K) = 1.21

temperature difference (K) = 2.5

Qwaste = A * V * p * Cp * T =  ?