Reduces carbon footprint by switching to ammonia

Since switching to a new ammonia-based cooling system based around Alfa Laval heat exchangers, the Homerton University Hospital has increased cooling capacity by 50 percent, significantly reduced the refrigerant charge, and reduced its overall environmental impact.

DATE 2023-11-28

Thanks to the imaginative, modular design and the use of U-Turn separators, the refrigerant charge is 33 percent less than in a conventional ammonia system. Consequently, it not only delivers highly efficient cooling but also eliminates greenhouse gas emissions. A failsafe shutdown program ensures that any leaks are contained within the system – a vital feature given the sensitive nature of the location.

Steve Gowing, Applications Engineer, J&E Hall: “The safety features we have built into the system will ensure that if there is a leak, not a drop of ammonia will escape into the atmosphere.” With the transition, more than 300 kg of R22 has been replaced with just over 50 kg of ammonia. Yet despite the huge reduction in refrigerant, the hospital has achieved a 50 percent increase in cooling capacity”.


  • The U-Turn is a liquid separator especially designed for use with plate heat exchangers in ammonia applications, which ensures minimum pressure drop losses and maximum energy efficiency.
  • The module provides an effective and compact installation with less vertical rise and smaller overall dimensions than any other solution.
  • All ammonia connections are grouped on the same side, which allows the module to be installed in close proximity to walls or on the perimeter of a main skid.

U-Turn liquid separator


To provide compact, lightweight high performance heat transfer components for the refrigeration modules in the hospital’s new ammonia based cooling system.


  • Two J&E Hall Aquachill modules, each including the following Alfa Laval components:
  • One AlfaNova all-stainless steel heat exchanger
  • Two twin frame M10BW plate heat exchangers for evaporating and condensing
  • One U-Turn liquid separator

The end customer

  • Homerton University Hospital.
  • Located in the London borough of Hackney.
  • Provides general hospital services and specialist care to around 250,000 people.
  • Designated hospital for the 2012 Olympic Games (situated 3 km from the Olympic Village site).