The right booster set comes down to two numbers: the building's peak water demand (flow, m³/h) and the total head needed to reach the highest point of use at sufficient pressure (metres). The number of pumps, casing pressure and control panel follow from these two values.
Contents
- What You Need to Know First
- How Do You Find the Flow (Q)?
- How Do You Calculate Total Head (Hm)?
- Read Flow and Head Together on the Pump Curve
- How Many Pumps Do You Need?
- Casing Pressure: 10, 16 or 25 Bar
- How to Read the ASN Model Code
- What to Watch on the Suction Side
- What Affects the Price of a Booster Set?
- Frequently Asked Questions
What You Need to Know First
Booster set selection starts with a few facts about the building and its pipework:
- Building type and size: Residential, school, hospital, hotel or industrial; number of units and wet rooms.
- Height: Vertical distance between the pump and the highest point of use.
- Water source: Tank or mains? Is the tank above or below the pump?
- Required pressure: How many bar are needed at the highest point?
- Redundancy: Can the supply stop if a pump fails?
How Do You Find the Flow (Q)?
Booster set flow comes from peak instantaneous demand, not daily consumption: the draw created by taps and appliances that may be open at the same time. Not every tap runs at once, so the pipework design applies a simultaneity calculation.
If there is a design, take the flow from it. If not, send us the building type and the number of units and wet rooms and we will review it with you. For conversion: 1 m³/h is about 16.7 litres per minute.
Daily consumption sets the tank volume instead; see our water tank sizing guide.
How Do You Calculate Total Head (Hm)?
Total head is the height needed to lift water to the highest point, overcome pipework losses and deliver the required pressure there. It is written in metres of water column:
Hm = static height + pipework losses + pressure required at the highest point − pressure on the suction side
Roughly, 1 bar equals 10 metres of water column. Here is an example for a 10-storey building, with the booster set in the basement and the tank water level 2 metres above the pump:
| Item | Example value |
|---|---|
| Static height (pump to highest tap) | 32 m |
| Pipe, valve and fitting losses | 6 m |
| Pressure required at the highest point (1.5 bar) | 15 m |
| Suction side (tank above the pump) | −2 m |
| Total head | 51 m (about 5 bar) |
The values above only illustrate the method. Real losses depend on pipe size, length and flow and should come from the mechanical design.
Read Flow and Head Together on the Pump Curve
A pump cannot deliver its highest flow and highest head at the same time: head falls as flow rises. Selection therefore means making sure the point where your calculated flow and head meet sits on the pump's operating curve.
Aquasan booster systems reach flows up to 500 m³/h and head up to 160 m (Aquapump catalogue p.5). Check the tables on the product pages for a model, or send us your values.
How Many Pumps Do You Need?
The number of pumps depends on how total flow is shared and on whether you need a standby.
- Single pump: For small and medium facilities. With no standby, a pump failure stops the supply.
- Double pump: Pumps run in sequence as demand requires and change duty after every run. While one is being serviced, the other keeps supplying water.
- Triple pump: For high-capacity facilities with varying demand; pumps cut in stage by stage.
- Variable speed set: Holds pressure constant in high-flow buildings such as hotels, hospitals and shopping centres.
Casing Pressure: 10, 16 or 25 Bar
Casing pressure is the highest pressure the pump casing can withstand, and it is chosen according to the highest pressure the booster set will create. The Aquasan ASN series comes in 10, 16 and 25 bar casing pressures (Aquapump catalogue p.6).
In the example above the working pressure is about 5 bar. The calculation must also allow for the pressure the pump delivers against a closed valve; taller buildings need a higher casing pressure.
How to Read the ASN Model Code
Aquasan booster models carry a code that shows the pump series and capacity (Aquapump catalogue p.6). Example: ASN-F 80-06.
| Code | Meaning |
|---|---|
| ASN | Pump name |
| F | Added if variable speed |
| 80 | Nominal diameter of the discharge inlet |
| 06 | Average flow of the pump |
The leading number in the product tables shows how many pumps the set has: the double pump table lists models as 2 x ASN 80-1005.
What to Watch on the Suction Side
The suction side of a booster set matters as much as the discharge side. On Aquasan TS EN 733 pumps, maximum suction lift is 8 metres, liquid temperature is 20–60 °C and ambient temperature is up to 40 °C (Aquapump catalogue p.6).
- Where possible, install the tank above or level with the pumps.
- Fit a level float switch so that the pumps stop when the water runs out.
- The set is for clean liquids that are not abrasive and contain no solids or fibres (p.5).
What Affects the Price of a Booster Set?
A booster set has no single list price; the cost depends on flow, head and equipment. The main factors are:
- Number of pumps and motor power
- Casing pressure (10, 16 or 25 bar)
- Panel type: fixed or variable speed
- Pressure vessel and additional equipment
- Scope of installation and commissioning
Send us the building type, number of floors, water source and any design flow through the quote form and we will prepare a suitable set and price.
Frequently Asked Questions
How many metres of water is 1 bar?
About 10 metres of water column. This shortcut is used in head calculations.
What pressure does a 10-storey building need?
It depends on floor height, pipework losses and the required pressure. In the example in this guide, total head is 51 metres, or about 5 bar; recalculate with your own building's values.
How many pumps does an apartment block need?
That depends on peak flow and whether you want a standby. Where redundancy matters, a double pump set is preferred, so the supply continues if a pump fails.
Why are booster set prices not listed?
Because the price depends on flow, head, the number of pumps, casing pressure and panel type. We quote for each project once we have the details.
Who should select a booster set?
Final selection should rest on the flow and head values in the mechanical design. If there is no design, send us the building details for a preliminary review.
Get a quote for your project
Share the building type, number of floors, water source and any design flow; our team will reply with a suitable booster set or expansion tank.