Chilled beams add to cooling capacity for Nationwide headquarters

Chilled beams have been used in the headquarters of Nationwide at Swindon to supplement the cooling capacity of an older VAV system with minimal structural work and disruption. The solution was designed by consulting engineers Building Management Technology to meet increased cooling loads. The Croft Campus was purpose built over 10 years ago. The increased use of IT at workstations and reduced dependence on paper storage have led to more people working on each floor. The result has been an increase in cooling loads that the existing VAV system could not handle. Roger Lott of BMT explains, ‘Nationwide wanted enhanced cooling, as well as improved reliability for its business-critical systems — all to be achieved without structural alterations. However, with limited riser and plant-room space available, we could not simply extend the VAV system. Instead, we decided to make better use of the spent chilled water coming from the air-handling units serving the VAV system.’ This chilled water is passed through Krantz high-capacity chilled panels suspended from the floor plate above the ceiling. One floor plate is being evaluated this summer, before a decision is made to continue with the rest of the building. The chilled panels can meet 35% of the maximum cooling load, which is a requirement all year round. The VAV system is used less throughout the year, while the overall cooling capacity is increased. BMT initially considered using chilled-ceiling units laid into the ceiling, but the number of units required would have left no access for maintaining the VAV system. Fewer high-capacity chilled beams are required, and they are suspended close to the slab, leaving space below for access to other equipment in the ceiling. The chilled panels themselves have no maintenance requirements. rs@krantz.uk.com

Related links:

• www.d4s.co.uk