Expansion Tank Sizing Calculator
Static · formula-only · worked example computed when this page was built · no live data
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, at 15 m static head, 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. Anything the worked example does not state uses this calculator's standard default; the interactive version shows every input and lets you change it.
Worked example (HVAC & Cooling)
Inputs: a 300 kW chilled-water system (≈2400 L) over a 7→35 °C swing, at 15 m static head.
| Result | Value |
|---|---|
| Required tank | 30.21 L |
| Water expansion | 14.16 L |
| Max pressure | 400 kPa |
Computed by WorkHive's calculation engine when this page was built; standard: ASHRAE 2023 HVAC Systems & Equipment Ch.12.
How to use this calculator
- Read the worked example. It uses a 300 kW chilled-water system (≈2400 L) over a 7→35 °C swing, at 15 m static head and shows every number in the method.
- Follow the formula with your own figures: it returns Required tank, Water expansion, Max pressure, computed per ASHRAE 2023 HVAC Systems & Equipment Ch.12.
- To compute interactively, open the Expansion Tank Sizing Calculator inside WorkHive's free Engineering Design suite (link below). It runs the same method with your inputs.
FAQ
What is an expansion tank sizing calculator?
The Expansion Tank Sizing Calculator is a free online tool that 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 is free: this worked example is open to everyone, and the interactive calculator runs inside the free Engineering Design suite after a free sign-up (your work is saved to your account). 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, and a free sign-up saves your calculations, BOMs and scope-of-works to your account.