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Maximise Efficiency

There are several areas which we come across on a regular basis where energy is being wasted in refrigeration systems: Dirty condensers are a common problem.

The purpose of condensers is to reject heat from a refrigeration system and in our experience less than 20% are subject to the correct cleaning regime. A fouled condenser could easily reduce refrigeration efficiency by 10% – 20%.

We recently modified a 500kw aircooled chiller. When we pointed out to the site manger that the condenser coils needed cleaning, we were told that they had been done a couple of months previously and that the contractor had cleaned all four chillers in less than a day.

We offered to clean one chiller properlyn to demonstrate how the job should be done. This took a full day but the result was that discharge pressures dropped by over 1.5 bar - just this basic maintenance improved efficiency of the unit by over 10%.

Excalibur LPA can provide detailed instructions on how a deep condenser clean should be undertaken.

Faulty Fans

Condenser fans are only effective if they work! This might seem obvious but many only get repaired when we have a heat wave and the plant is threatening to shutdown due to high discharge pressures: For the rest of the year, chances are that broken fans have remained un-repaired and efficiency has been compromised.

Leaks

Many refrigeration and air conditioning systems leak refrigerant. This can result in a very significant loss in efficiency, even in a plant which appears to be running satisfactorily. Tests conducted by Excalibur LPA reveal that a packaged chiller which is 15% short of refrigerant shows a 45% reduction in capacity. Often this does not become apparent until we have some hot weather and inadequate refrigeration causes temperatures to drift outside limits.

Regular monitoring of operating parameters using a permanently installed monitor, or periodic checking with the Climacheck Performance Analyser, provides early warning that refrigerant has leaked from the system and allows leaks to be traced and repaired quickly and efficiently.

Check Temperatures

Review the temperature that your system is running at; aircon chillers are generally designed to operate at a chilled water flow temperature of 6°C, although most will provide sufficient cooling if this temperature is increased to 8°C. For every 1°C that the temperature is raised, efficiency is increased by 2-4%.

In fact, some chillers have the facility to adjust the setpoint remotely so temperatures can be constantly optimised.
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Darren Crook | Operations Director | J O Sims Ltd

“Not only were the improvements in efficiency immediate and measurable, but previously it could take 48 hours to pull a chamber down to temperature, this can now be achieved in 12 hours, enabling us to respond to customer requirements very much quicker”.

2 Sisters Food Group

"Excalibur installed LPA and inverter control to our Bitzer screw pack, the work was completed to a very high standard with minimum effect to production. Monitoring over the first 12 month period showed a reduction in power consumption of 38%. Several evaporators which had been starved of refrigerant now achieve temperatures where previously they struggled.
There have been no reliability issues and we are benefiting from a system which is not only energy efficient but also provides  improved refrigeration performance"

Andrew Miller | General Manager | Euro Foods Ltd

Before installation Excalibur monitored all three refrigeration systems to establish their condition

The work was carefully planned and shut-down periods were kept to a minimum.

Following the modifications, the system now operates more efficiently at much lower head pressure.

Technical Manager | Avalon Leisure

"Excalibur completed energy efficiency projects at 3 of our Leisure Centres, the installation of boiler and inverter control (to pumps and fans) showed a very impressive reduction in both gas and electricity consumption on all 3 sites.

The opportunities were identified by Excalibur, who then completed the work to a very high standard, and have continued to provide support as required."

Richard Shoulders | Operations Project Manager | British Telecom

"Excalibur have been undertaking energy efficiency projects for British Telecom for over 10 years, as a company they have always been professional and diligent. Their proactive approach has also identified several areas where we have been able to improve the integrity of our equipment."

Andy Watson | Energy Manager | BAA Heathrow Airport

"Following successful trials Excalibur have undertaken the installation of Liquid Pressure Amplification, inverter control of condenser fans and adiabatic condenser cooling to all of the large packaged chillers at Heathrow Airport, this project was completed successfully despite the difficulties of working airside.

As a result of the improvements in chiller efficiency, Excalibur have successfully completed similar projects at Stansted, Edinburgh and Glasgow Airports. "

George Fletcher | Senior Project Manager | Norland Managed Services

I would like to take this opportunity to thank you and all others from within Excalibur involved with the development of this project, from my initial involvement through to today's handover meeting. All of which has run extremely well, with any issues uncovered being easily resolved with the proactive nature of you and your site team, which are a credit to Excalibur.

Hopefully, in the not to distant future I will have the opportunity to call upon Excalibur’s assistance and experience again on another LPA Project. Though in between times I would thank you again for your support and guidance.

Services Facilities Manager | Manchester Airport

"Throughout the LPA project at Manchester Airport Excalibur provided a thorough and professional service ensuring the project was delivered on time with minimal operational disruption. The project delivered savings as quoted, the refrigerant change helped re-life ageing equipment and was seen as a great success, so much so that we are about to embark upon a second phase during 2010"

Tony Bacchetta | Guoman Hotels

Excalibur have completed energy efficiency projects in many of our hotels, one of our major concerns is any disruption to the operation of the hotel and our customers.

The work was completed to a very high standard, and we were always kept informed of progress.

We are achieving the level of energy reduction projected with no adverse affect on the business and would have no hesitation in using Excalibur again.

Chris Prentice | Project Management | UK NRG LTD

"Excalibur have installed Liquid Pressure Amplification and Inverters to 2 off 1300 kw data centre, process chillers. The cooling system is critical to this business, Excaliburs’ professional approach provided the customer with the confidence to undertake the project. Their condition monitoring also raised several maintenance issues, which we were able to resolve during the contract. Initial monitoring is demonstrating a 46% reduction in electrical consumption."

Dave Jeffs | Energy Matters

I have employed Excalibur to improve the energy efficiency of 8 Dunham Bush and Hitachi process chillers on two newspaper print sites, both systems showed a reduction in power consumption in excess of 35%. The installations were undertaken 6 years ago and have operated reliably since their commissioning. I would have no hesitation in working with Excalibur again.