Turbomiser chillers from Klima-Therm cut energy use for National Library of Scotland
Energy use at the National Library of Scotland’s main site in Edinburgh fell by 11.4% during the summer following the installation of Turbomiser chillers from Klima-Therm to replace aging R22 chillers. The previous chiller plant was not monitored for energy consumption, but sub-metering has now been installed throughout. Greater savings are expected during the cooler winter period as the result of the use of free cooling and improved efficient of Turbomiser chillers at part-load.
The library sought the help of the Carbon Trust to develop a carbon-management plan. An important element was to harness the efficiency of the variable-speed Turbomiser chiller to deliver low-cost, low-carbon cooling for its archives and reading rooms as part of a major plant-replacement programme.
Jack Plumb, estates manager at NLS, says, ‘I had the opportunity to visit a Turbomiser installation at a local hospital while attending a conference in Ottawa. I was extremely impressed by its performance.’
He also saw Turbomiser in action at the National Archives in Kew, with documented energy savings and low servicing and maintenance costs.
The chosen solution was based on a free-cooling approach that had been successfully used at another site of the National Library of Scotland to achieve significant energy savings.
The new installation has two water-cooled 300 kW chillers using R134a. They are linked to a free-cooling system to provide chilled water to air-handling units. The free-cooling circuit harnesses the air-blast cooler and the condenser circuit, routed through the heat exchanger to provide chilled water to the low-loss header.
A BMS calculates the demand for chilled water and the current status of the various chilled-water batteries in the AHUs.
The chillers were delivered in sections and assembled in the basement plant room.
Looking to the future, there is the possibility of replacing R134a (GWP 1300) with HFO 1234ze (GWP 6) — future proofing against changes in legislation.
Following the success of this project, the NLS team plans to install Turbomiser chillers at its Causeway site in Edinburgh when the existing chillers have come to the end of their working life.