© Photo | Diamond Light Source

Make it quick

At Diamond Light Source, it is not just light that moves quickly. The upgrade to effi­cient EC fans for cooling sensi­tive tech­nology also progressed at the speed of light

Every year, Diamond Light Source, a synchro­tron in the British county of Oxford­shire, hosts around 3,000 scien­tists researching highly complex projects (see box) in areas like medi­cine, archae­ology, mechan­ical engi­neering, biology or chem­istry. They all use light emitted by the elec­trons that are sped around the research facility’s massive storage ring at nearly the speed of light. “Cutting-edge research happens here every day, so it is impor­tant for us to always keep the tech­nology up to date as well,” says Lee Walters, Main­te­nance Manager at Diamond Light Source. “Effi­ciency is an impor­tant factor here.” So he was all ears when Phil Taylor, Global Strategic Accounts Manager at air-condi­tioning special­ists Stulz, suggested upgrading the existing cooling units for the sensi­tive elec­tronics to achieve a signif­i­cant energy saving.

This is how the synchro­tron works

mag214_beschleuniger_EN_700pxDiamond Light Source is a particle accel­er­ator based in Oxford­shire, England. The synchro­tron accel­er­ates elec­trons to speeds approaching the speed of light, creating extremely bright light beams that can be up to 10 billion times brighter than sunlight. Researchers use this like an extremely fine micro­scope. To generate the light, an elec­tron gun first fires elec­trons out into an accel­er­ator, where the parti­cles are heavily accel­er­ated. As soon as they reach the required speed, the elec­trons are shot out into the 560 metre storage ring. As the light hurtles through the ring, magnets agitate the beam, further increasing the bright­ness of the light. A range of labo­ra­to­ries connected to the ring divert the light from the storage ring to use it for various exper­i­ments. Over 500 staff, together with 3,000 visiting scien­tists every year, conduct research into areas such as medi­cine, nanotech­nology, archae­ology, engi­neering and envi­ron­mental science.

Great poten­tial


The light beam is directed through the particle accel­er­ator by magnets. The elec­tronics control­ling these magnets are cooled by CRAC units using EC fans from ebm-papst

The pair met with James Cooper, Product Manager at ebm-papst UK, at the high-tech research facility to pin down how much poten­tial existed. They exam­ined 27 CRAC (computer room air-condi­tioning) units installed by Stulz. Instead of a server room, they cool the elec­tronics used to control the magnets that convey the light beam through the storage ring. The units were previ­ously all fitted with belt-driven AC fans. Together with his part­ners, James Cooper came to the conclu­sion that switching to RadiCal® EC fans would be worth­while. “We esti­mated poten­tial for savings of around 39 percent,” says Cooper, “to fully convince the customer, however, we were initially commis­sioned to upgrade a single CRAC unit in a test run.” This task was carried out by ebm-papst together with the installer Cinque Energy Solu­tions.

Tailored instal­la­tion

Success against the clock: James Cooper from ebm-papst, David Japp from Cinque Energy Solu­tions, Phil Taylor from Stulz and Lee Walters from Diamond Light Source

The main chal­lenge here was the small instal­la­tion space in the CRAC units. “These sit on a solid concrete base, so it was impos­sible to assemble the EC fans in the base as usual,” explains Phil Taylor. Working together with the installer, ebm-papst devel­oped a special metal frame that allowed the fans to be installed in the units, despite the tight area. In addi­tion, the housing posi­tions the fans at the right angle to ensure the best air flow through the cooling unit. ebm-papst UK manu­fac­tured the special housing at its own produc­tion facility to allow the customised solu­tion to be imple­mented quickly.

Green light for upgrade

The test run began as soon as the tech­ni­cians from the installer completed the upgrade of the first unit, with posi­tive results. The energy saving exceeded esti­mates by almost five percent. One of the most impor­tant things for the oper­a­tors of Diamond Light Source here was keeping the temper­a­ture constant in the tech­nical space to be cooled. In order to ensure this, the EC fans are fitted with a 0-10 V controller that is easy to operate. This allows all units to be adjusted indi­vid­u­ally to the require­ments of the spaces. The test run also revealed further poten­tial for improve­ments: “We were able to further opti­mise the air flow by enlarging the hole in the housing beneath the fans,” recalls Cooper. The test run and the extra effi­ciency improve­ments were enough to convince the deci­sion-makers at Diamond Light Source to give the green light.

A race against time


The tech­ni­cians completed the upgrade to EC fans in just two weeks

The upgrade team were now faced with a daunting schedule. The fans could only be replaced during the synchrotron’s brief off-line period, giving the team from the installer just 14 days to retrofit the remaining 26 cooling units. The tech­ni­cians there­fore worked in two teams of three on the upgrade. To minimise delays, ebm-papst deliv­ered all 54 EC fans directly to the CRAC units. The first task was to remove the old belt-driven AC motors. The installers then open-up the base plate using a special cutting tool to improve the air flow, before fitting the indi­vid­u­ally adapted RadiCal® centrifugal fans from ebm-papst. After restoring all the connec­tions and adjusting the manual speed controller, the system upgrade was complete. Working along this proce­dure, the tech­ni­cians went from one unit to the next so that all CRAC units were fully func­tional when the system was started again.

One of our staff now always gives the system a hug to check if it is actu­ally running. Previ­ously that was obvious, due to the heavy vibra­tions and the noise.

Lee Walters, Diamond Light Source

Using the RadiCal® fans, Diamond Light Source now saves 55 percent of the energy used in daily oper­a­tion compared to the old AC fans. This repre­sents an annual CO2 reduc­tion of 46 tonnes. Oper­ating costs are also reduced, with Diamond Light Source spending 40,000 euros less per year thanks to the upgrade. “These are some impres­sive results. Another posi­tive is that the upgrade work did not affect the oper­a­tion at all,” says Lee Walters. Aside from the high energy saving, Diamond Light Source also bene­fits from signif­i­cantly reduced vibra­tion and noise following the upgrade. This is an impor­tant improve­ment, espe­cially given the sensi­tive high-tech equip­ment. Walters: “One of our staff now always gives the system a hug to check if it is actu­ally running. Previ­ously that was obvious, due to the heavy vibra­tions and the noise.”


RadiCalThe RadiCal® centrifugal fans with back­ward-curved blades stand out by halving the noise level and signif­i­cantly reducing the energy require­ment. These improve­ments are made possible by an aero­dy­nam­i­cally opti­mised impeller made from fibre­glass-rein­forced plastic. The motors in RadiCal® low-pres­sure centrifugal fans have been minia­turised and are much more compact than their prede­ces­sors. With the current dimen­sions, easy and trouble-free replace­ment of existing AC solu­tions is possible at any time.

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