Water-side calculator
Reheat · flow · pipe size
Sizing a whole system? These sums are built into the Heat Loss Calculator, worked from the design loss. Homeowner? The ten-second size check.
Cylinder reheat time
Flow rate from a duty
Copper pipe for the duty
| Copper | ΔT 5 K | ΔT 7 K | ΔT 10 K | ΔT 20 K |
|---|---|---|---|---|
| 15 mm | 2.7 kW | 3.8 kW | 5.5 kW | 10.9 kW |
| 22 mm | 6.0 kW | 8.5 kW | 12.1 kW | 24.1 kW |
| 28 mm | 10.2 kW | 14.2 kW | 20.3 kW | 40.6 kW |
| 35 mm | 15.7 kW | 22.0 kW | 31.4 kW | 62.9 kW |
| 42 mm | 23.2 kW | 32.5 kW | 46.4 kW | 92.8 kW |
| 54 mm | 39.4 kW | 55.1 kW | 78.8 kW | 157.6 kW |
EN 1057 copper bores at 0.9 m/s, water at 4.186 kJ/kg·K. Sizing guidance — an index-circuit calculation still rules a real system.