A recent high profile installation at the Hilton Hotel at London’s Stansted Airport highlights the outstanding performance of the Turbomiser chiller and validates the claims made.

A key design consideration was maximising energy savings in order to minimise running costs. With only one existing machine on site, a further important requirement was to ensure chiller replacement caused as little disruption to the hotel as possible.

With careful project management and a flexible approach,Turbomiser specialist Cooltherm achieved the changeover
with less than a 12 hour interruption to chilled water services.

The existing machine, a 630kK York air-cooled chiller, had served the hotel well for 20 years. However, being based on R22 and with compressor problems beginning to arise, the decision was taken to replace it.

Cooltherm identified that the typical base load was around 150kW, with chilled water required 24/7 throughout the year. Part load performance would therefore be critical to achieving energy savings.

The Turbomiser chiller selected provides 630kw of cooling 6/12 at 35deg C ambient, based on two TT300 Turbocor compressors working with a flooded evaporator and operating on R134a refrigerant. On the controls side, the client has access to the machine via a GSM gateway for remote troubleshooting and setting adjustments. It also
features SMS alarm notification.

Energy savings

The plant is anticipated to deliver 30 per cent energy savings compared with traditional designs based on reciprocating, screw or scroll-based compressors.

Ken Strong, managing director of Cooltherm, says: “The flooded evaporator design maximises the benefits of
Turbocor, enabling a high evaporating and low condensing temperature.

“In this application, at the typical part load point, we find the machine running with 5degC saturated suction and 25degC condensing temperature.

“This delivers a remarkable COP of between five and six. This compares with the previous machine’s part load COP of around two. It takes chiller performance into new territory.”

Customer feedback

Trevor Bennett, facilities manager at the Hilton, London Stansted Airport, was delighted with the result: “The project has been an unqualified success, and executed with great professionalism by Cooltherm.”

He added: “It combines innovative engineering, outstanding performance and serious energy savings – in one compact
package. We are delighted with the result.”

Noise was not a critical requirement in the project, however the results impressed the client. “When running at part load, the machine is so quiet you have to check the display to see if it is operating”, said Mr Bennett.