Building water equipment calculator
From floors and flats: controller, pump, pressure tank and settings.
Floors
4
Flats
8
An estimate for typical residential buildings, about 3 m per floor.
Controller
PM821-8
Pump type
Peripheral pump
- Power
- 1–1.5 hp
- Pressure the pump must reach
- head over 32 m, about 3.2 bar
Why this suggestion: For a small building with the tank level with or above the pump; low flow, good pressure.
Pressure tank
80–100 L
Tank pre-charge: 1.5 bar
Controller settings
- Stop pressure (F1)
- 3.2 bar
- Start pressure (F2)
- 1.7 bar
- Circuit breaker
- C10 – C16
The pump type is general advice; compare the head on the pump nameplate with the figure above.
Free selection adviceHow we calculate
- Each floor is taken as about 3 m.
- The stop pressure F1 is the height ÷ 10 plus 2 bar, and F2 is 1.5 bar lower.
- The pump head must exceed the building height plus 20 m; every 10 m of head is about 1 bar.
- The pressure tank pre-charge is about 0.2 bar below F2.
- The number of floors decides the controller model and pump power: 1 to 4 floors take PM821-8, 5 to 10 floors PM821-16. The number of flats decides the pressure tank size.
- If you enter the pump's nameplate current, it decides the controller model: up to 8, 16 or 25 A.