Calculate condensate return, steam supplied, steam not returned, or makeup water from a simplified steam mass balance in kg, g, lb or tonnes.
Condensate Return Formula
The calculator uses a simplified steam system mass balance. It assumes that steam supplied is accounted for by condensate returned plus makeup water. Steam not returned is usually close to makeup water when other losses, blowdown, and measurement differences are ignored.
SS = CR + MW
CR = SS - MW
SNR = SS - CR
MW = SS - CR
- SS = steam supplied
- CR = condensate return
- MW = makeup water
- SNR = steam not returned, consumed, or lost
The calculator lets you enter any three values and solves for the missing fourth value. It converts all entered values to kilograms before applying the formula, then converts the result back to the unit selected for the missing value.
- Condensate Return: calculated as steam supplied minus makeup water.
- Steam Supplied: calculated as condensate return plus makeup water.
- Steam Not Returned: calculated as steam supplied minus condensate return.
- Makeup Water: calculated as steam supplied minus condensate return.
Condensate Return Reference Values
Condensate return is often reviewed as a percentage of steam supplied. Higher return usually means less makeup water, less water treatment demand, and less heat lost from the system.
| Condensate Return Rate | General Interpretation | Typical Meaning |
|---|---|---|
| Below 50% | Low return | Large steam use to process, drain losses, leaks, or poor recovery |
| 50% to 75% | Moderate return | Some condensate recovery, but losses may still be significant |
| 75% to 90% | Good return | Most condensate is recovered and reused |
| Above 90% | Very high return | Common in closed or well-managed systems, if measurements are accurate |
The calculator supports these mass units:
| Unit | Equivalent in kg |
|---|---|
| 1 g | 0.001 kg |
| 1 kg | 1 kg |
| 1 lb | 0.45359237 kg |
| 1 tonne | 1000 kg |
Example Calculations
Example 1: Calculate condensate return
You supply 10,000 kg of steam and add 2,000 kg of makeup water. The condensate return is:
CR = SS - MW
CR = 10000 - 2000 = 8000 kg
The condensate return is 8,000 kg.
Example 2: Calculate makeup water
You supply 5,000 lb of steam and return 3,750 lb of condensate. The makeup water is:
MW = SS - CR
MW = 5000 - 3750 = 1250 lb
The makeup water is 1,250 lb. In this simplified balance, steam not returned is also about 1,250 lb.
FAQ
Is makeup water always equal to steam not returned?
Not always. In a simplified mass balance, makeup water is close to steam not returned because any steam or condensate that does not come back must be replaced. In a real boiler system, boiler blowdown, venting, leaks, sampling, and measurement error can make the two values different.
Can this calculator be used for flow rates instead of total mass?
Yes, if all inputs use the same time basis. For example, you can treat the values as kg/hr, lb/hr, or tonnes/day as long as every value is for the same period. The mass balance works the same way for consistent flow rates.
Why does the calculator reject a negative result?
A negative result means the inputs do not fit the simplified balance. For example, condensate return cannot be greater than steam supplied if makeup water is being calculated as steam supplied minus condensate return. Check the units and the entered values before recalculating.