Founded in 1946 to tackle the energy crisis and advance nuclear technology, today, Harwell Campus, in Oxfordshire, is home to a federation of leading science and technology organisations and facilities. With an array of buildings that vary in age, structure and purpose, management of these premises and the associated infrastructure comes under the auspices of the Science and Technology Facilities Council (STFC).
Building R89, which is described as business critical, was built at the turn of the century and is operational 24/7. However, it had become apparent that the four original chiller units were coming to the end of their life. Consequently, this presented a risk of unscheduled failure, which may have impacted on the building’s functionality. As this was an intolerable position for STFC, it was agreed that replacements should be installed, as part of a phased and planned programme of works. The first phase, which was the replacement of two of the chillers was completed in 2020.
Southern Maintenance Solutions UK ltd (SMS) had already successfully completed a smaller chiller replacement on another building on the Harwell site, when they were approached by the STFC about undertaking the second phase of the work on Building R89. Martin Lambourne, project manager for SMS, explains more about what was required; “There was a lot of preparation and planning involved to ensure that we would be able to complete the removal, install and commissioning in the four weeks that we had available. Prior to the removal of the old chillers, we needed to check the existing flow rates, ensure that the water was clear of any viral or bacterial infection and recover the refrigerants. Each of the two chillers that were being decommissioned contained approximately 160kg of refrigerant, that was disposed according to the latest guidelines.”
Before the removal of each chiller unit, the SMS team also recovered the existing water, approximately 1800 litres in each, which is treated with glycol to prevent it freezing. This was stored in bowsers, specifically hired for the duration of the contract and then introduced back into the new chillers once installed. Existing cabling was also made safe and the BMS connections made good.
The new Airdale chillers are 10m long and 3m high and weigh approximately 9 tonnes. Thanks to technological advances, these new turbo chillers, which have been integrated into the existing BMS, are far more efficient.
Martin Lambourne said, this was a complex refurbishment, and it was critical that the work that takes place in this building was not disrupted at any time. SMS has since been appointed to undertake several other chiller replacements across the STFC site as well as the refurbishment of five boiler rooms.