There are two types of heat sources are known, one is resulting in the internal heat load on the conditional area and the second one is resulting in an external heat load.
Heat sources which result in an internal heat like heat conduction through the glass, walls, etc. Heat sources which result in an external heat load, heat from any source added in the air after it leaves a space.
The heat load formula is given as,
Heat load = Q = m × Cp ×ΔT
Q = Heat load (kW)
m = mass flow rate (kg/s)
Cp = specific heat (kJ/kg K or kJ/kg oC)
ΔT = change in temperature (K or 0C)
Determine the heat load in the electric convector in which the rate of mass flow is 5.45 and Cp is 1000 and the enthalpy is from 21.5 to 26.55.
M = 5.45
Cp = 1000
T1 = 26.55
T2 = 21.5
Substituting in the formula
Heat load , Q = m ×Cp ×ΔT
Q = 5.45 x 1000 x (26.55 – 21.5)
Q = 27522.5 W
Determine the heat load if the specific heat is 200 and enthalpy change from the temperature 31.5 to 26.55 and M is 4.45.
M = 4.45
Cp = 200
T1 = 31.5
T2 = 26.55
Substituting in the formula,
Heat load, Q = m × Cp ×ΔT
Q = 4.45 x 200 x (31.5 – 26.55)
Q = 4405 W