Home > Products > Liquid Pressure Amplification

Liquid Pressure Amplification

Liquid Pressure Amplification (LPA) Overview

Patented in the USA, LPA was developed to allow refrigeration equipment to operate at more efficient levels.

It is well known that refrigeration efficiency improves as discharge pressure is reduced, this is commonly referred to as floating head pressure and is advocated in many Carbon Trust publications (click here for downloads

For example, take the manufacturers figures for a typical reciprocating compressor

  Capacity   Input
  15 bar   75.5kw   27.1kw   2.78
  10 bar    92kw   21.7kw   4.23


It can be seen that by reducing discharge pressure by 5 bar, capacity has increased by 21.8%, absorbed power has reduced by 19.9% and COP (efficiency) has improved by 52%.

LPA allows these levels of efficiency to be achieved.  

Document Actions

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.


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. "

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.

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”.

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"

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."

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.

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.

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."

LPA / Inverter project, Blast chiller
Excalibur 05
LPA / Inverter project, Blast chiller
Excalibur 05