Huge energy savings with new chiller technology

New Turbomiser chiller delivers ground-breaking efficiency at The Dorchester and Hilton, London Stansted Airport.

With energy costs escalating, end users are demanding savings in plant running costs.

Enter the new Turbomiser chiller, the frugal contender that breaks new ground on efficiency - evidenced in two recent high profile installations Chillers based on the oil-less centrifugal Turbocor compressor have been around for a while.

Their compact design, variable speed capability and magnetic bearings are known to deliver a combination of excellent performance and class leading energy efficiency.

Now, however, leading Italian manufacturer Geoclima claims to have developed a unique approach to harnessing the benefits of the innovative centrifugal machines that takes the technology an important stage further - and delivers unprecedented energy savings for clients.

Two recent high profile installations in the UK highlight the outstanding performance of the Turbomiser chiller, and substantiate the claims being made.

The first project was carried out recently at the world-famous Dorchester Hotel, on London's Park Lane.

The installation has a combined chiller capacity of 3MW, and involved the installation of three Turbomiser chillers, model TMA 1050/34, each in turn housing three high efficiency Turbocor compressors.

The plant was supplied by Wimbledon-based specialist Klima-Therm/LH plc, while consulting engineer on the project was Cudd Bentley Consulting (Birmingham office), and the installer All Group Services.

LH plc de-commissioned and removed the existing water-cooled, R22-based Carrier chillers and cooling towers, which had reached the end of their working life.

This was done in stages to minimise cooling down-time during final changeover.

The new plant was sited externally, with one chiller positioned on the roof of the rear third floor, and two chillers on the roof of the tenth floor, freeing up the hotel's basement plant room.

Site constraints included limited roof space, with two chillers located in space previously occupied by the cooling towers.

There were also strict planning conditions regarding noise.

In addition, the main condenser water riser had to be converted for chilled water use.

The key benefit for the client of the Turbomiser design was anticipated savings in running costs - to be achieved through improved chiller energy performance and use of air-cooled condenser, saving on water and chemical treatment costs.

Since being installed, the system is reported to have delivered in excess of GBP10k savings in energy costs per month, compared with the previous system.

This is even better than the substantial savings of GBP8-9K per month savings anticipated.

With this level of saving, the installation is expected to deliver a payback on the additional capital cost over conventional chillers in the first year.

The other significant advantages of the solution were the compact dimensions and low weight of the Turbomiser chillers.

This enabled the new machines to be sited on rooftops, freeing up the former plant room space for alternative use.

The chiller's outstanding energy performance is due to specific design features incorporated in the chiller by Geoclima.

It uses a combination of flooded evaporators to maximise heat exchange, and therefore cooling capacity, and employs control technology fully integrated with the compressor control, plus high efficiency fans.

Ian Mundie of Klima-Therm says: "The Turbocor compressor is a superb and innovative piece of engineering, however Geoclima has taken it a stage further.

By harnessing its capabilities to the full, Turbomiser builds on an already impressive machine and delivers truly outstanding performance".

The approach ensures maximum COP is delivered at all times, optimising chiller performance in response to changing ambient temperatures and load.

Ray Pask, chief engineer at The Dorchester Hotel, said: "The installation has delivered everything promised, and more.

I am a strong believer in Turbocor technology, having specified it before on another high profile project.

It offers major efficiency benefits, and the oiless bearings make start-up from stand-by mode straightforward.

"The Turbomiser chillers installed at The Dorchester Hotel have worked superbly and the energy savings already achieved are substantial, and should result in an even better pay-back time than anticipated.

"We look forward to continuing to benefit from the excellent performance of the system and the substantial savings in running costs over its lifetime".

The second Turbomiser installation was carried out recently at the Hilton, London Stansted Airport.

Again 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, Bristol-based Cool-Therm achieved the changeover with less than a 12 hour interruption to chilled water services.

The existing machine was a 630kK York air-cooled chiller, which 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.

Cool-Therm 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.

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 Cool-Therm, 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 saturtated suction and 25degC condensing temperature.

"This delivers a remarkable COP of around five, including fans.

This compares with the previous machine's part load COP of around two.

It takes chiller performance into new territory".

Trevor Bennett, facilities manager at the Hilton, London Stansted Airport, said: "The project has been an unqualified success, and executed with great professionalism by Cool-Therm.

It combines innovative engineering, oustanding 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", says Mr Bennett.

Further similar projects for Turbomiser installations at Hilton hotels are currently under discussion.

With energy costs predicted to rise significantly in the future, end users are increasingly demanding solutions that deliver savings on the cost of operating building services plant.

Ian Mundie says: "There is no doubt that Turbomiser is a technology whose time has come.

We believe it has an important role to play in delivering what the market needs, and with a pay-back that is shortening with every rise in energy prices.

The level of interest from clients supports this view".

Ken Strong said: "With end users under pressure to reduce costs and their carbon footprints, we are convinced that the future of medium capacity water chillers will be oiless technologies, based on small compact centrifugal compressors with flooded evaporators, coupled and high efficiency fans.

Turbomiser delivers this in compact package, proven to work".

The projects described here provide a compelling argument that few clients can afford to ignore.

Back to top