Sizing to selection: Top tips for specifying pressure boosters
As building operators across the nation join the push for sustainable infrastructure development, ensuring energy and water efficiency in both retrofit and new build applications is crucial. Steven Walker, technical sales manager at Wilo UK, outlines the top tips for specifying a potential solution – cold water booster sets.
Launched in January, the 10-Year Infrastructure Strategy is central to the government’s aim of driving productivity and economic growth.[1] While prominent healthcare, educational and housing infrastructure delivery plans are outlined, the overarching ambition of accelerating to net zero by 2050 means that any approach must be taken in a ‘sustainable’ manner. But how exactly can this be achieved?
While there may not be a singular, standout answer here, ensuring energy and water efficiency is one of several components of sustainable infrastructure delivery. With building operators also responsible for complying with a host of building regulations, including the Standard Assessment Procedure (SAP) and Primary Energy Rating (PER), there is a growing need to incorporate products capable of making crucial gains.
Fortunately, cold water booster sets can deliver constant pressure at every extraction point throughout high-rise or large commercial buildings, all while being energy efficient and helping to achieve compliance with building regulations. With that said, what are the top tips for specifying booster sets?
Define the application
First and foremost, start by defining the application’s requirements. Understanding the type of building and usage requirements, for example, allows for the expected water demand and peak usage times to be determined. Calculating estimated water demand could be as simple as outlining the total number of outlets within a building, including taps, showers, toilets and other water-consuming appliances, against how many occupants are expected to inhabit the property.
Operators are advised to measure the vertical distance between the water source and the highest point in the building to provide sufficient pressure. Wilo’s SiBoost range, for instance, incorporates booster sets suited to a host of different applications.
It’s just as important to check whether a building requires multiple pumps for redundancy, which guarantees water supply even if one pump fails, and if the booster set tank in question includes appropriate backflow prevention devices. Wilo’s SiBoost, Sce and PC collections include a complete set of backup control functions, ensuring redundancy and preventing interruptions in the water supply should one pump fail. This also allows for maintenance without shutting down the entire system.
Size matters
Another top tip for specifying booster sets is to make sure the pump arrangement is correct for the building, especially as the market’s current offerings can differ significantly. For example, single-pump systems are simpler and less expensive, while twin-, three- or four-pump systems offer redundancy and can handle higher flow rates. Older style fixed-speed pumps may cause fluctuations in pressures at varying demand, which is not ideal, and can be more costly to run and maintain, whereas pumps with a variable speed drive can automatically adjust their speed and output on varying demand, optimising energy efficiency and providing more consistent pressure.
The chosen booster set must also be compatible with the building’s available power supply (1ph or 3ph) to avoid any issues with existing cabling. The power consumption of the pumps and controls may also be a consideration, and newer, high-efficiency sets will help to reduce operational costs and a building’s overall carbon footprint. Wilo can carry out lifecycle cost checks to build a profile and provide estimated power savings in the event of upgrading to modern units.
Boosters within Wilo’s SiBoost 2.0 range and Si Boost PC range incorporate efficient EC motors with energy efficiency class up to IE5 – the highest rated motor efficiency currently available – alongside innovative pump hydraulics and pressure-loss optimised manifolds, and with a range of control options available to suit user needs. This underlines how the boosters have been engineered to minimise running costs and capital outlay.
Wilo’s SiBoost 2.0, Sce, and PC ranges do just that, all while possessing the level of functionality required for most applications. This functionality includes the ability to connect to building management systems, which allows building owners and facilities managers to check and control the pump’s operation remotely and monitor pressure and flow rate, along with maintenance requirements. It also features an ‘external off’ function that allows it to be switched off should there be a failure in the building’s water supply, helping building operators minimise damage from water leaks as soon as they are reported. The units also have their own low water protection built into the booster set suction manifolds to measure inlet pressure and to switch the unit off until water levels are restored.
Once the application has been defined, the pump type chosen, and the power supply considered, operators should make sure the pump can draw water from the source without cavitation. Cavitation occurs when vapour bubbles form in the pump’s low-pressure areas and then collapse in higher-pressure areas, causing pitting and erosion on the impeller surfaces, leading to reduced efficiency and eventual failure. This can be checked with Wilo during the selection phase.
Safety first
A crucial safety feature that must be accounted for is controlled fill. If a building was to lose power and residents continued to empty water from the pipework, this could increase the risk of the pipework bursting, causing significant damage.
Control fill ensures a gradual and regulated reintroduction of water into a booster set, using timers and reducing pump speeds to help prevent sudden surges in pressure, which could again damage pipes, valves and fittings. This also helps to limit the mechanical stress on pumps and motors. Without this, the physical shock in the pipework could result in a shock equivalent to ten times the actual pressure output of the pump set. When specifying booster sets, it’s therefore essential to consider this function. Hydraulic surge protection is especially important in buildings with temporary power or new builds due to the increased likelihood of incomplete or untested systems, unpredictable usage patterns and new pipework containing trapped air, which can amplify pressure spikes when water flow starts or stops suddenly.
Ones to avoid overlooking
A commonly overlooked task when specifying pressure booster sets is reviewing maintenance requirements. Firstly, the booster should be easily accessible to technicians responsible for regular maintenance and any repair works. Filters and strainers should also be incorporated into the system to protect the pump from debris and sediment, subsequently preventing blockages and reducing overall wear and tear.
Once installed, operators are encouraged to develop a comprehensive maintenance schedule centred around regular inspections and servicing of the booster set. Key tasks include regularly checking the expansion vessel air charge, ensuring all check valves are still operating as they should and that none are passing, and checking the control panel for any previous alarms or messages.
The noise levels of the pump and controls must also be considered, especially those in residential or sensitive areas. Noise can be a significant issue, so buyers should look for booster sets designed to operate quietly or consider extra noise-reducing measures.
A helping hand
It’s highly recommended to consult with a pump specialist or engineer to ensure the booster set is properly sized and selected for the specific application. They can evaluate the discussed factors, such as flow rate, pressure requirements and system compatibility. Decision makers should keep detailed records of the booster set specifications and installation and maintenance procedures. Documentation is crucial for troubleshooting, future maintenance and guaranteeing compliance with any regulatory requirements.
Selecting a reputable manufacturer with a proven track record of quality and reliability, such as Wilo, can ensure the chosen booster set will consistently perform at its peak for years to come. Wilo has worked with the country’s largest housing associations, hospitals, and accommodation providers to gain the necessary experience required to help any business guarantee sufficient water pressure in a sustainable manner.
