Expansion Tank Sizing Calculator
The Expansion Tank Sizing Calculator finds the required tank volume for a hydronic system from its water volume and temperature swing. Example: for a 300 kW chilled-water system (≈2400 L) over a 7→35 °C swing, Required tank = 30.21 L, Water expansion = 14.16 L, Max pressure = 400 kPa (per ASHRAE 2023 HVAC Systems & Equipment Ch.12).
How it works
Computed from your inputs per ASHRAE 2023 HVAC Systems & Equipment Ch.12.
Worked example (HVAC & Cooling)
Inputs: a 300 kW chilled-water system (≈2400 L) over a 7→35 °C swing.
| Result | Value |
|---|---|
| Required tank | 30.21 L |
| Water expansion | 14.16 L |
| Max pressure | 400 kPa |
Computed live by WorkHive's calculation engine; standard: ASHRAE 2023 HVAC Systems & Equipment Ch.12.
How to use this calculator
- Enter the figures for the duty you are sizing: the worked example below uses a 300 kW chilled-water system (≈2400 L) over a 7→35 °C swing.
- The calculator returns Required tank, Water expansion, Max pressure, computed per ASHRAE 2023 HVAC Systems & Equipment Ch.12.
- Check the worked example to confirm the method matches how you would do it by hand, then run your own numbers in the interactive tool.
FAQ
What is a expansion tank sizing calculator?
The Expansion Tank Sizing Calculator is a free online tool that computes finds the required tank volume for a hydronic system from its water volume and temperature swing. It shows the formula and a fully worked example so you can check the method, not just the number.
How is it calculated?
The result is computed from your inputs following ASHRAE 2023 HVAC Systems & Equipment Ch.12. The worked example on this page shows a real computation with real numbers.
Is the calculator free?
Yes. WorkHive's engineering calculators are free to use, no sign-up needed for the tools. WorkHive is a free, offline-first maintenance platform built for Philippine industrial plants.
Run it on your own numbers
Open the interactive Expansion Tank Sizing Calculator in WorkHive: free, no sign-up needed for the calculators.