Key features of the Indigochiller unit include:

  • Onboard PLC with built in performance monitoring/reporting  and option for remote access
  • Flooded shell and tube heat exchanger
  • Enhanced tubing for close temperature approach
  • Floating suction pressure control
  • No refrigerant loss
  • Easy to clean
  • Turbocor centrifugal compressors
  • Oil free design
  • Variable speed control
  • Low noise and vibration
  • Low maintenance

Refrigerant type

HFCs (Hydrofluorocarbons) are non ozone depleting and the refrigerant of choice in a wide range of new refrigeration and air conditioning equipment.

HFO is a low global warming potential (GWP) refrigerant for use in automotive air-conditioning systems.

Designed and engineered by Star Refrigeration, Indigochiller offers unrivalled long term performance in air conditioning and process cooling. The low charge, high efficiency unit is suitable for medium to large scale applications.

Other benefits consist of:

  • 3 year parts, efficiency and refrigerant warranty available
  • 10 years in field product experience
  • Good access space for maintenance
  • Unique Indigochiller ‘leak tight’ design
  • Realtime monitoring and reporting of chiller performance to ensure optimum efficiency and reliability
  • Low noise operation
  • Choice of HFC or HFO refrigerant
  • Choice of water or air cooled solutions

Indigochiller Case Studies

  • BSkyB


    Star Refrigeration has completed the installation of its revolutionary Indigochiller cooling system at BSkyB’s headquarters in London.

    BSkyB is a leading broadcaster of sports, movies, entertainment and news. The company operates the UK’s largest digital pay television platform from its headquarters at Grant Way in Isleworth. Cooling solutions specialist Star has installed a range of Indigochillers to provide chilled water for air conditioning and computer server cooling in two studio buildings on the BSkyB site. 

    Three state-of-the-art Indigochillers were installed to replace existing package chillers located in a compound between the Sky Sports and Sky News buildings. Star combined two existing independent chilled water circuits serving both buildings into a common system, boosting operating efficiency. 

    The Indigochillers provide chilled water, which is then pumped through insulated pipework to wall or ceiling mounted air handling units (AHUs). Air is circulated across the chilled water coil in each AHU to provide cooling throughout both BSkyB buildings. Broadcast facilities within the two buildings include TV studios, production suites, general offices and computer server rooms.

    A carefully phased four week installation programme ensured no disruption to broadcast operations. Temporary chillers were installed to provide supplementary cooling whilst the existing chillers were removed to make way for the new Indigochillers. 

    Star’s Indigochiller was developed in direct response to proposed F-Gas regulations. The unit’s unique design aims to eliminate refrigerant leakage and have minimal effect on the global environment. 

    All components are selected to minimise the risk of refrigerant leakage. Each unit features a welded plate and shell heat exchanger, sealed expansion valve and welded steel pipework. Leak detection requirements have been reduced to a few simple checks.

    Each Indigochiller features the revolutionary oil-free Turbocor centrifugal compressor, designed to offer reliable operation and low maintenance. The compressor operates on electromagnetic bearings and uses the synthetic refrigerant R134a. This ensures minimal vibration and noise, even when running at very high speed.

    The high efficiency, low noise Indigochiller range is ideal for medium to large-scale applications, with capacities ranging from 250kW up to 1,500kW. It features a robust PLC control system to monitor running conditions and optimise efficiency. Additional options include remote access and email alerts via a built-in modem, as well as a direct link to Star’s 24/7 call out facility. The air-cooled unit is available in two noise ranges: Standard (57 dB(A) to 61 dB(A) @ 10m) and Residential (50 dB(A) to 53 dB(A) @ 10m).

    Star’s research shows the Indigochiller uses only 60% of the energy required by a standard chiller operating on typical load and ambient profiles. This offers end users a significant saving in energy and running costs.

    Following on from the success at Isleworth, two further IA500 units have been installed at the same site and a further three have been installed at BSkyB’s offices in Dunfermline.  


  • Financial Institution Data Centre


    Star Refrigeration has installed a bespoke cooling system at a UK data centre operated by a major financial institution for retail and commercial banking.

    A world leader in cooling and heating system innovation, Star replaced an existing R22 refrigeration plant with a highly energy efficient, low maintenance solution. Star has provided the banking client with a state-of-the-art data centre cooling system designed for low carbon, cost saving operation.

    Operating as a data centre since 1990 in a confidential location, the building features two main data halls, each with independent power and cooling infrastructure. Earlier this year IT and computer server systems in one of the data halls were being replaced as part of a major refurbishment programme.

    Elevated air temperature within the refurbished hall due to the new server equipment demanded a new cooling system with a total capacity of 4,400kW.

    The existing plant had a total cooling capacity of 2,700kW and operated on R22, an ozone-depleting HCFC refrigerant currently being phased out by EU regulations.

    The new cooling system features four 1,100kW chillers operating on the synthetic refrigerant R134a. The innovative design incorporates revolutionary oil-free Turbocor compressors, with variable speed drives and high efficiency at full and part load. The chillers also feature an air-cooled refrigerant circuit configured for thermosyphon operation to provide “free cooling” when possible.

    Star Refrigeration’s Director of Sales – Process, Alan Walkinshaw, says: “Power consumption in data centres has quadrupled by some estimates over the last decade. Operators are increasingly looking to reduce energy usage by IT and associated building support systems such as cooling.”

    He adds: “In this case our banking client wanted a cooling solution with up to date technology, high efficiency and minimal environmental impact. The solution we adopted was an innovative design using revolutionary Turbocor R134a compressors and an air-cooled refrigerant circuit. The system is configured to provide free cooling by automatically switching to thermosyphon operation for much longer periods than the previous system.”

    Additional AHUs (air handling units) to deal with the increased heat load were mounted on the perimeter of the data hall to maintain room air at a supply temperature of 22°C. A new exterior deck was built alongside the existing plant room to accommodate flatbed air-cooled condensers.

    The condenser features variable speed EC fans for low noise operation and maximum efficiency, with epoxy coated fins for longevity. The chillers are fully packaged to minimise potential for refrigerant leakage, with welded steel piping and bellows seal valves.

    When it comes to designing energy efficient cooling and heating systems, Star is a natural innovator. Star works with strategic partners across the globe to deliver low carbon, cost saving solutions.


  • GSK, Brentford


    Star Refrigeration has installed a high efficiency Indigochiller cooling system for specialist air conditioning at GlaxoSmithKline’s global head office.

    GlaxoSmithKline (GSK) is one of the world’s leading research-based pharmaceutical and healthcare companies. GSK House in Brentford, Middlesex, is the company’s prestigious global headquarters.

    Star has designed and installed an environmentally conscious, low carbon footprint chiller solution for GSK House. Star’s compact, packaged Indigochiller is serving a new IT data centre at the Brentford site.

    The data centre operates around the clock with a continuously high base heat load generated by a mass of computer servers. Star’s Indigochiller was chosen following a competitive tender process, which highlighted a significant saving in energy, carbon emissions and lifecycle running costs.

    GSK’s water-cooled Indigochiller has a total capacity of 1,000kW. The system employs water from the local canal to cool the condenser and maximize efficiency. Located externally, the compact packaged chiller delivers cooling to the data centre building via chilled water pipework.

    Star’s Sales Director Rob Lamb says; “As a reliable, high efficiency system, Indigochiller met GSK’s carbon reduction requirements and exceeded expectations with its low life cycle running costs.”

    He adds: “Indigochiller offers the ultimate cooling solution to forward-thinking operators. It is designed for unrivalled performance in process cooling and air conditioning.”

    Star worked in conjunction with the facilities management company for GSK House. The contract was one of a number of cooling projects undertaken by Star for GSK in 2008, including sites at Ware, Barnard Castle and Dungarven.

    Star’s Indigochiller is a low charge, high performance chiller for medium to large scale air conditioning and process cooling operations. Available as an air-cooled or water-cooled unit, Indigochiller has capacity options ranging from 240kW to 1,500kW.

    Indigochiller is highly energy efficient. Star’s research shows that it uses only 60% of the energy required by a standard chiller operating on typical load and ambient profiles. This offers end users a significant saving in energy and running costs.

    Indigochiller is engineered to have minimal effect on the global environment. Developed in direct response to F-Gas regulations, the design aims to eliminate refrigerant leakage. It features bellows seal valves, sealed expansion valves and welded steel pipework.

    Indigochiller features the revolutionary Turbocor centrifugal compressor. It operates on low noise electromagnetic bearings and uses the synthetic refrigerant R134a. The unique oil-free system offers reliable, hassle free performance and requires minimal installation, servicing and maintenance. A robust PLC control system allows the user to monitor running conditions and optimise efficiency.

    Indigochiller is part of Star’s range of environmentally conscious cooling and heating solutions for the building services and process cooling markets. Other products include the low charge ammonia packaged Azanechiller, Freechiller – the ‘free cooling’ solution for IT data centres and Envitherm, providing cooling and heating for hotels, offices and factories.

    Star Refrigeration is the UK’s largest independent industrial refrigeration engineering company. Star focuses on the design, manufacture, installation, commissioning and maintenance of industrial refrigeration systems.


  • Indigochiller for Air Conditioning


    Forward thinking operators looking for high efficiency, low maintenance air conditioning should only consider a chiller that is built to last, says cooling expert Star Refrigeration.

    Star is renowned for designing cooling solutions that provide over 20 years service. The company is currently seeing a rising number of replacement projects in which standard AC chillers have suffered early component failure or corrosion problems in less than ten years.

    Star believes that environmentally conscious building services operators should consider the chiller’s expected lifespan as a matter of priority, or be faced with a costly problem all too soon.

    Star Refrigeration sales director Rob Lamb says: “We have recently seen a number of high profile operators who have previously invested in chillers that have soon become damaged or corroded. Even if the chiller features high efficiency components, poor build quality can cause early loss of performance or even break down.”

    With growing demand to cut refrigerant leakage to meet F-Gas regulations, Star developed its Indigochiller for medium to large scale air conditioning and process cooling. Engineered to have minimal effect on the global environment, Indigochiller’s robust design aims to eliminate refrigerant leakage and offer over 20 years service.

    Star’s confidence in Indigochiller’s construction and reliability means options are available for extended warranty on both equipment and refrigerant loss.

    Rob Lamb adds: “Indigochiller stands out from the rest of the market thanks to a range of unique design features and leak-tight components. It is manufactured to ensure both long-term reliability and low life-cycle costs. These should be key considerations when selecting a chiller.”

    The low charge, high performance Indigochiller features a revolutionary Turbocor compressor, which is low maintenance by design to ensure lifelong trouble free running. The oil-free compressor operates on electromagnetic bearings and uses the synthetic refrigerant R134a. The system offers reliable performance and requires minimal installation, servicing and maintenance.

    Indigochiller is manufactured from the highest quality components selected to minimise the risk of refrigerant leakage, reduce maintenance costs and enhance operating life. Standard features include ‘leak-free’ bellows seal valves, sealed expansion valves and welded steel pipework. The air-cooled Indigochiller has epoxy coated condenser fins as standard to reduce the risk of corrosion damage.

    Available as an air-cooled or water-cooled unit, Indigochiller has capacity options ranging from 250kW to 1,650kW. A robust PLC control system allows the user to monitor refrigerant charge, running conditions and optimise efficiency.

    Indigochiller is highly energy efficient using only 60% of the energy required by a standard chiller operating on typical load and ambient profiles. This offers end users a significant saving in energy and running costs.

    Star Refrigeration is the UK’s largest independent industrial refrigeration engineering company. Star focuses on the design, manufacture, installation, commissioning and aftercare of industrial refrigeration and HVAC systems.

    Star provides total cooling solutions for refrigeration, air conditioning and process cooling. The company offers a turnkey supply and support package to all users of cooling equipment. Star continues to invest in the development of new products to provide energy conscious cooling systems for the benefit of customers and the environment.


  • John Lewis


    Star Refrigeration has installed a high efficiency cooling system at the flagship John Lewis department store in central London.

    The state-of-the-art Indigochiller system forms part of an ongoing refurbishment by the leading UK retailer at its Oxford Street store. Project Beacon aims to futureproof the 50-year-old building and provide a platform for further development by the John Lewis Partnership. 

    Cooling solutions specialist Star has completed the installation of three Indigochillers on the sixth floor roof, each with a 1,000kW capacity. The air-cooled units circulate chilled water for air conditioning, providing comfort cooling throughout the building.

    The John Lewis Partnership was looking to improve the instore environment for shoppers and staff by installing a larger capacity high efficiency cooling system. It was vital that the comfort cooling system allowed year round temperature control, particularly during summer months. As well as an environmentally conscious design, low starting current, quiet operation and minimal maintenance were key requirements.

    John Lewis Partnership Development Engineer Stuart Watson says: "Star’s new roof-mounted Indigochillers are more efficient and will allow us to increase cooling capacity with no increase in electrical demand. They form part of a heating and cooling efficiency drive that will allow John Lewis to meet energy reduction targets and reduce its carbon footprint."

    Star’s Indigochiller was developed in direct response to proposed F-Gas regulations, which aim to limit fluorinated gas emissions. The unit’s unique design aims to eliminate refrigerant leakage and have minimal effect on the global environment. Star’s research shows the Indigochiller uses only 60% of the energy required by a standard chiller operating on typical load and ambient profiles. This offers end users a significant saving in energy and running costs.

    As well as Star’s new cooling system, additional work on infrastructure at the John Lewis Oxford Street store includes the installation of more efficient boilers, cabling and an electricity substation. Project Beacon also includes new retail departments, restaurant facilities and escalator banks to improve access and open up the building.

    Work on the overall 18-month refurbishment project is due to be completed in Autumn 2007, with trading continuing throughout. It is currently the largest retail project within an operating store in Europe.

    Star’s Indigochiller is a complete refrigeration package housed in one unit. Typical applications include new and retrofit air conditioning systems in the building services and process cooling industries. Ideal for medium to largescale applications, unit capacities range from 250kW up to 1,500kW. 

    Each Indigochiller features the revolutionary oil-free Turbocor centrifugal compressor, designed to offer reliable operation and low maintenance. The compressor operates on electromagnetic bearings and uses the synthetic refrigerant R134a. This ensures minimal vibration and noise, even when running at very high speed. The air-cooled unit is available in two noise ranges: Standard and Residential.

    All Indigochiller components are selected to minimise the risk of refrigerant leakage. Each unit features a welded plate and shell heat exchanger, sealed expansion valve and welded steel pipework. Leak detection requirements have been reduced to a few simple checks.

    The Indigochiller features a robust PLC control system to monitor running conditions and optimise efficiency. Additional options include remote access and email alerts via a built-in modem, as well as a direct link to Star’s 24/7 call out facility.


  • Refrigerant R-1234ze(E)


    Engineers at Star Refrigeration have teamed up with Danfoss Turbocor and Honeywell to develop and test a chiller using HFO 1234ze(E) refrigerant, which has a global warming potential of 7. 

    The chiller is based on Star’s very successful Indigochiller range and uses the new Turbocor TG310 prototype compressor.

    "Working with R-1234ze proved to be quite challenging," said Star’s Group Engineering Director, Dr. Andy Pearson. "We found particularly good performance at part load in lower ambient, where the efficiency was up to 20% better than the original predictions. Across the full range of load and ambient conditions performance was generally better than predicted."

    He added: "The development included some tricky puzzles. Some of the materials used in joints and seals did not perform well so we had to source special o-rings for some of the system components. We also learned that the lower gas density can cause increased pressure losses in some unexpected places, so care needs to be taken when assessing condensers, evaporators and control valves to make sure they are not going to cause excess pressure drop which would negatively affect the chiller efficiency."

    Star worked with Danfoss Turbocor to select R-1234ze(E) as the most promising fluid for this application and then in a three-way development team with Honeywell, who developed Solstice ze (R-1234ze)  for use as a refrigerant, foam-blowing agent and other applications.

    The chiller was comprehensively tested at Star’s chiller factory in Glasgow, including operating in an ambient of 40oC on Star’s 1500kW test rig. Turbocor worked closely with Star during the testing and were able to verify and adjust their control software while the compressor was in operation. This was the first time that Danfoss Turbocor had access to the prototype compressor on a live air-cooled chiller to verify their theoretical calculations and lab tests. The adjustments helped to raise the efficiency of the chiller by a few percentage points.

    Now that the tests are complete, the chiller has gone to its spiritual home – on the Honeywell site at Buffalo, NY where the HFO-1234ze(E) refrigerant was originally developed. The chiller will operate on the base load for the lab air-conditioning system, helping to keep the developers of the next generation of refrigerants comfortable at their work.

    Dr. Rob Lamb, Group Sales Director at Star, said: "This development is part of our long range plan. It allows us to give our customers confidence that we can help them transition to low GWP refrigerants moving forward. As the European F-Gas regulations develop, Star Refrigeration will be prepared to offer our customers a variety of refrigerant solutions."


  • Sky Studios, Isleworth


    BSkyB’s brand new sustainable landmark broadcast facility features a revolutionary air conditioning system from cooling and heating specialist Star Refrigeration.

    BSkyB is a leading broadcaster of sports, movies, entertainment and news. The company operates the UK’s largest digital pay TV platform from its headquarters in Isleworth, London.

    Star has supplied five of its state-of-the-art Indigochiller refrigeration plants to provide cooling within Sky’s new Sky Studios building. The ground-breaking facility will provide TV studios, technical and post production space for Sky.

    Five air-cooled Indigochiller units, each with a 1MW cooling capacity have been installed on the roof of the new building. Each Indigochiller provides chilled water, which is then pumped through insulated pipework to air handling units (AHUs). These AHUs will provide comfort cooling throughout the Sky Studios building, as well as some computer server cooling.

    Star Refrigeration Sales Manager Michael Reeve says: “A ground-breaking building such as Sky Studios required a state-of-the-art chilling system. Our Indigochillers have a strong track record at BSkyB, with the first installed at Isleworth over six years ago. They have proven efficiency benefits, are low maintenance by design and highly durable.”

    Star has worked in partnership with BSkyB on multiple building cooling projects since 2005 and has installed 36 Indigochiller units to date. Indigochillers are providing a total 18.85MW of cooling across fifteen BSkyB buildings, from Southampton to Livingston.

    Star’s energy efficient Indigochillers are just part of BSkyB’s efforts to ensure Sky Studios helps to reduce carbon footprint, minimise environmental impact and assist renewable energy generation at the Isleworth site.

    Designed for large-scale air conditioning and process cooling, Star’s Indigochiller is manufactured to ensure maximum efficiency, longterm reliability and low life-cycle costs. Each Indigochiller now comes with a three-year ‘no quibble’ guarantee covering component reliability, efficient performance and leak-tight operation.

    Engineered to have minimal effect on the global environment, Star’s Indigochiller has a robust design that aims to eliminate refrigerant leakage and offer over 20 years service.

    The low charge, high performance Indigochiller features a revolutionary Turbocor compressor, which is low maintenance by design to ensure lifelong trouble-free running. The oil-free compressor operates on electromagnetic bearings and uses the synthetic refrigerant R134a. The system offers reliable performance and requires minimal installation, servicing and maintenance.

    Indigochiller is manufactured from the highest quality components selected to minimise the risk of refrigerant leakage, reduce maintenance costs and enhance operating life. Standard features include ‘leak-free’ bellows seal valves, sealed expansion valves and welded steel pipework. The air-cooled Indigochiller has epoxy coated condenser fins as standard to reduce the risk of corrosion damage.

    Available as an air-cooled or water-cooled unit, Indigochiller has capacity options ranging from 250kW to 1,650kW. A robust PLC control system allows the user to monitor refrigerant charge, running conditions and optimise efficiency. Indigochiller is highly energy efficient using only 60% of the energy required by a standard chiller operating on typical load and ambient profiles. This offers end users a significant saving in energy and running costs.

    When it comes to designing energy efficient cooling and heating systems, Star is a natural innovator. Star works with strategic partners across the globe to deliver low carbon, cost saving solutions.


  • Strathclyde University


    Students using the library at the University of Strathclyde in Glasgow are keeping their cool thanks to an air conditioning system from Star Refrigeration.

    The University of Strathclyde was looking to replace an aging refrigeration plant in the Curran Building. The six-storey facility is home to the Andersonian Library, which houses university archives and main collections including books, journals and electronic resources.

    Star had previously supplied an Indigochiller refrigeration plant for cooling in another building on the Glasgow campus. The university was impressed with the build quality and performance of Star’s Indigochiller, which is designed for reliable and highly efficient operation.

    The university’s library had an existing air conditioning plant operating on R22, a refrigerant currently being phased out due to its ozone depletion potential. Engineered to have minimal effect on the global environment, Star’s Indigochiller has a robust design that aims to eliminate refrigerant leakage and offer over 20 years service.

    Star designed, manufactured and installed two Indigochillers on the roof of the Curran Building, each with a 750kW cooling capacity. The chillers cool water from 12°C to 6°C, which is then pumped to air handling units throughout the six-storey building for comfort cooling. The building also houses training facilities for the University of Strathclyde’s National Centre for Prosthetics and Orthotics.

    Andy McWatt from the University of Strathclyde’s Estates Management department says: “In recent years the failure of standard package chillers from other manufacturers had proved both disruptive and expensive for the university. We considered various products featuring the state-of-the-art Turbocor compressor. We found Star’s Indigochiller had the operating efficiency and build quality we were looking for.”

    Star Refrigeration’s Sales and Marketing Director Rob Lamb adds: “Indigochiller stands out from the rest of the market thanks to a range of unique design features and leak-tight components. It is manufactured to ensure maximum efficiency, longterm reliability and low life-cycle costs. These were key considerations for the University of Strathclyde when selecting a chiller.”

    The low charge, high performance Indigochiller features the revolutionary Turbocor compressor, which is low maintenance by design to ensure lifelong trouble-free running. The oil-free compressor operates on electromagnetic bearings and uses the synthetic refrigerant R134a. The system offers reliable performance and requires minimal installation, servicing and maintenance.

    Indigochiller is manufactured from the highest quality components selected to minimise the risk of refrigerant leakage, reduce maintenance costs and enhance operating life. Standard features include ‘leak-free’ bellows seal valves, sealed expansion valves and welded steel pipework. The air-cooled Indigochiller has epoxy coated condenser fins as standard to reduce the risk of corrosion damage.

    With growing demand to cut refrigerant leakage to meet F-Gas regulations, Star developed its Indigochiller for medium to large scale air conditioning and process cooling. Highly energy efficient, it uses only 60% of the energy required by a standard chiller operating on typical load and ambient profiles. This offers end users a significant saving in energy and running costs.

    Available as an air-cooled or water-cooled unit, Indigochiller has capacity options ranging from 250kW to 1,650kW. A robust PLC computerised control system allows the user to monitor refrigerant charge, running conditions and optimise efficiency.

    When it comes to designing energy efficient cooling and heating systems, Star is a natural innovator. Star works with strategic partners across the globe to deliver low carbon, cost saving solutions.