Result
Preliminary calculation: This tool is for quick sizing and information. In real projects, load calculation, selection and commissioning require engineering calculations and a site survey. Results are approximate values.
Formula
V [L] = Q_stage [kW] × t [s] / ( ρ [kg/L] × cp [kJ/kgK] × ΔT_band [K] )Frequent on-off cycling of the compressor (short cycling) causes wear. If the water volume in the system is sufficient, no additional tank is needed. In the volume calculation, the total water volume including pipes, fan coil/coil bodies and manifolds is taken into account; sections isolated by closed valves should not be counted.
- The need decreases with multi-stage or inverter chillers
- Tank inlet/outlet should be connected so that the flow does not short-circuit
- Tank insulation is necessary for condensation and heat loss
Frequently asked questions
Why is a buffer tank needed?
By increasing the system volume, it prevents the compressor from cycling on and off frequently and improves control stability.
Is a tank necessary in every system?
No. If the water volume is sufficient, or if the chiller has variable capacity, an additional tank may not be needed.
Where do I find the minimum run time?
In the chiller manufacturer's technical documentation; the default value in this tool is an example.