In a move to reduce energy and life cycle costs, the Royal Academy of Arts (RAA) in London has replaced ageing air conditioning and humidification plant with Defensor Mk5 humidifiers and Hitachi Samurai chillers from Walter Meier (Climate UK). The products were specified by consulting engineers Peter Deer Associates Ltd (PDA), in conjunction with John Ellis, the Royal Academy’s Environmental Consultant.
“The existing direct expansion (dx) cooling system and Defensor Mk3 steam humidifier had reached the end of their useful life and were no longer able to ensure the close environmental control required to protect the exhibits in the galleries,” explained John Pengilly of Peter Deer Associates. “In replacing them, we took the opportunity to improve energy efficiency and cost of ownership as well as increasing the resilience of the system.”
The two RCUE40CLG Samurai condenserless chillers, which are enclosed in stainless steel enclosures on the roof, serve up to four of the RAA’s 20 galleries through chilled water coils in two new air handling units per gallery. Similarly, one Mk5 humidifier in each air handling unit injects steam into the supply air to maintain the relative humidity to within +/- 5% of the set point.
Although the air in the galleries is conditioned 24 hours a day, improved air distribution design within the galleries has allowed reduced air volumes to be used while maintaining the required conditions. This has enabled the RAA to reduce its energy costs, above and beyond the inherent efficiencies of the new plant. In addition, the increased reliability and longevity of the chilled water system, compared to the previous dx system means that maintenance costs are also reduced.