Designing the optimal water boosting system
To ensure constant water pressure in larger commercial or multifunctional buildings means making some key decisions at the earliest stages of design. As no two systems are alike, a range of factors need to be taken into account, however there are some basic questions that can help you make the right choice for each particular application.
Choosing the right solution:
Initially, just two factors will help you to design the right system - the height of the building and the load profile. This information will help you to develop the best design philosophy on whether to consider a single booster system, or in the case of a taller or more complex structure, a zone divided booster system. Getting this decision right will mean the building will receive equal water pressure to all floors without wasting energy – even under fluctuating consumption. A great starting point.
Why choose an intelligent boosting solution?
The intelligent solution: A zone divided system
Single booster system
The simplest way to achieve equal tap water pressure on all floors is by producing excessive pressure – and then removing it again.
Having just one booster set delivering water to the whole building leads to significant pressure differences in the system. The boosting station in the basement has the pump power to overcome the pressure head loss of a system that reaches all the way to the top floor. But this also means that the tap water pressure at the lower floors far exceeds an acceptable level. This requires pressure relief valves to be installed in order to remove excessive pressure. In other words, not only do you need to invest in additional components, you’re also removing the pressure you just spent energy on producing.
Zone divided system
The intelligent way to boost water is to produce the pressure needed at each floor – no more, no less.
By dividing a tall building into booster zones, you can define the flow and pressure needed at each zone. Sizing each booster to meet your exact demands is then an easy calculation in Grundfos Product Center. With each booster now pumping at the exact speed required, the effect on energy consumption is clear: there is no more energy waste from reducing overpressure, and the pumps perform for the load profile of each zone. Our booster sets intelligently adapt to demand, eliminating the need for pressure relief valves – all while ensuring reliable and efficient operation at all times.
Single booster vs. zone divided:
Exactly how significant is the benefit from choosing an intelligent system? We calculated the energy consumption of two different designs for a booster system for a 20-story hospital to find out.
We used Grundfos Product Center to size booster applications for a hospital with 800 beds and a water consumption of 300 m3/year per bed. The allowable tap pressure is 2.5 to 4.0 bar and the building and floor height is 80m and 4m respectively. With 60% of the water consumption occurring on the first storeys, a single booster system consumes 106,530 kWh/year. The zone divided solution uses only 72,937 kWh/year – 31.5% less.