# Expansion Tank Calculator

What expansion tank size do I need? Use our calculator to estimate the size of the hydronic expansion tank require for heating system.

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The expansion tank in the heating system is used to maintain the pressure in the system at a stable level. Our calculator allows you to estimate the volume of the expansion tank based on the volume of coolant or capacity of the equipment. Recall that the optimal pressure in heating systems of private homes – 1-2 bar. Theoretical basis of the calculation:

Vtank = (Vsum × e) / ((Pmax - Po) × (Pmax + 1))

• Vsum – heating System Volume;
• e – volumetric coefficient of expansion;
• Pmax – maximum pressure;
• Po – initial pressure.

## What expansion tank size do I need?

1. Enter the volume/power of your heating system.
2. Choose a type of coolant
3. Enter the coefficient of expansion of the fluid.
4. Enter the initial pressure.
5. Enter the maximum pressure.

## Water expansion coefficient

 °С Coefficient of expansion °С Coefficient of expansion 0 0.00013 65 0.0198 10 0.00027 70 0.0227 20 0.00177 75 0.0258 30 0.00435 80 0.0290 40 0.00782 85 0.0324 50 0.0121 90 0.0359 55 0.0145 95 0.0396 60 0.0171 100 0.0434

## Water-glycol mixture expansion coefficient

 °С Glycol, % 0 10 20 30 40 50 70 90 0 0.00013 0.00320 0.00640 0.00960 0.01280 0.01600 0.02240 0.02880 10 0.00027 0.00340 0.00660 0.00980 0.01300 0.01620 0.02260 0.02900 20 0.00177 0.00480 0.00800 0.01120 0.01440 0.01760 0.02400 0.03040 30 0.00435 0.00740 0.01060 0.01380 0.01700 0.02020 0.02660 0.03300 40 0.00780 0.01090 0.01410 0.01730 0.02050 0.02370 0.03010 0.03650 50 0.01210 0.01510 0.01830 0.02150 0.02470 0.02790 0.03430 0.04070 60 0.01710 0.02010 0.02320 0.02630 0.02940 0.03250 0.03870 0.04490 70 0.02270 0.02580 0.02880 0.03180 0.03480 0.03780 0.04380 0.04980 80 0.02900 0.03200 0.03490 0.03780 0.04070 0.04360 0.04940 0.05520 90 0.03590 0.03890 0.04170 0.04450 0.04730 0.05010 0.05570 0.06130 100 0.04340 0.04650 0.04910 0.05170 0.05430 0.05690 0.06210 0.07290