Energy Balance Calculator

Calculate sensible heat, latent heat, total heat duty, and power requirements for process heating and cooling operations.

Inputs

Mass Flow Rate

kg/hr

Specific Heat (Cp)

kJ/(kg·°C)

Inlet Temperature

°F

Outlet Temperature

°F

Heat of Phase Change

kJ/kg

Phase Change Mass

kg/hr

Tab to move between fields

Results

Sensible Heat

114,950 kJ/hr

Total Heat Duty

114,950 kJ/hr

Latent Heat0 kJ/hr

Power Required31.93 kW

How to Use This Calculator

Enter the Mass Flow Rate in kg/hr of the process stream.
Enter the Specific Heat (Cp) in kJ/(kg·°C): water = 4.18, air ≈ 1.005, oils ≈ 1.8–2.1 kJ/(kg·°C).
Enter the Inlet and Outlet Temperatures in °C to define the sensible heat duty.
If a phase change occurs (condensation, vaporization), enter the Heat of Phase Change in kJ/kg and the Phase Change Mass in kg/hr — set to 0 if there is no phase change.
Read the Total Heat Duty in kJ/hr and Power Required in kW to size heaters, coolers, or heat exchangers.
Compare Sensible Heat and Latent Heat contributions to understand which dominates the design.

How the result changes with Outlet Temperature

Outlet Temperature	Sensible Heat	Total Heat Duty
-80	-219,450 kJ/hr	-219,450 kJ/hr
220	407,550 kJ/hr	407,550 kJ/hr
580	1,159,950 kJ/hr	1,159,950 kJ/hr
880	1,786,950 kJ/hr	1,786,950 kJ/hr

What each input means

Mass Flow Rate: Mass flow rate of the process fluid in kg/hr.
Specific Heat (Cp): Specific heat capacity of the fluid. Water is approximately 4.18 kJ/(kg·°C).
Inlet Temperature: Temperature of the fluid entering the heat exchanger.
Outlet Temperature: Desired temperature of the fluid leaving the heat exchanger.
Heat of Phase Change: Latent heat for phase change (e.g., 2260 kJ/kg for water vaporization). Set to 0 if no phase change.
Phase Change Mass: Mass flow rate undergoing phase change. Set to 0 if no phase change occurs.

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Mass Flow Rate = 500, Specific Heat (Cp) = 4.18, Inlet Temperature = 25, Outlet Temperature = 80 = 6 input(s) provided
Calculate Sensible Heat
Sensible Heat
114950 = 114950
Calculate Total Heat Duty
Total Heat Duty
114950 = 114950
Calculate Latent Heat
Latent Heat
0 = 0
Calculate Power Required
Power Required
31.931 = 31.931

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