Condition Based Monitoring

There are two different types of maintenance or aftercare:

Reactive Maintenance, often called 'Traditional Maintenance'traditional maintenance regime involves a programme of planned site checks by engineering specialists, where a series of performance health checks are carried out and immediate adjustments are made to correct any issues. This means high maintenance costs due to the number of site visits and also a greater margin for error

Proactive Maintenance, also known as 'Condition Based Monitoring'. With this type of preventative maintenance, the reliability and optimal efficiency of the refrigeration plant is constantly monitored in order to advert and prevent any potential system failure, and therefore reducing your business operating costs; Typically, savings are about 20% of the total operating costs.

This type of proactive maintenance involves the use of remote monitoring, data collection 24/7, analysis of data and generation of task list, including:

  • Vibration Monitoring

Vibration analysis, when performed by a qualified technician, can predict failure of compressor components and can even often predict when the failure will occur.

The objective of vibration monitoring is to identify noise or vibration in an operating compressor. Items that must be analysed are: imbalance of rotating parts, misalignment of couplings and bearings, bentor cracked shafts, worn speed increaser gears, worn or damaged antifriction bearings, or worn or damaged sleeve bearings on the compressor and motor, hydraulic forces, rubbing forces, and electromagnetic forces.

Why Vibration Analysis?

  • It reduces maintenance costs because maintenance is scheduled only when needed.
  • It reduces overtime because you can predict when the machine may fail, requiring weekend and night work. Emergency repairs are reduced dramatically.
  • It reduces repair costs because major repairs are practically eliminated due to a thrust bearing failure or a gear failure that may ruin the compressor.
  • It reduces unplanned system, or possibly plant, downtime.
  • It extends the life of the compressor.
  • It increases plant safety.
  • It helps control insurance costs.
  • Oil Management

There are a number of substances that can contaminate the oil within the refrigeration system. Commonly, these are water, iron, insolubles (general muck), refrigerant, and general debris.

Contaminated oil can and will cause premature failure of components within the refrigeration system, which in turn could result in a total loss of refrigeration!

Frequent checking of the oil's condition allows the maintenance engineer to address any out of specification issues and, if necessary, replace the oil, filters, control valve internals, clean strainers, etc., which will help to maintain the system at its correct operating conditions.

  • Leak Testing

The F-Gas Regulations require that many refrigeration systems using F-Gases must comply with provisions that include a specified leak test programme, carried out by a suitably qualified person, and in some cases, installation of permanent leak detection equipment. We can provide these services and help you to comply with the statutory regulations.

  • Laser Alignment 

 Incorrectly aligned direct drive refrigeration compressors coupled to drive motors have caused the failure of both drive motors and compressors. Misalignment also causes the failure of the shaft seal potentially resulting in the release of refrigerant and oil. In Ammonia plants this could result in evacuation of plant rooms and loss of cooling which in turn will affect controlled temperatures and production facilities, all very good reasons why this capability is a must have for a market leader.

This can be carried out using a number of methods:

  • Straight Edge.
  • Dial Indicators (Clock Gauges)
  • Laser

 Star Refrigeration use laser alignment because it is both quicker and  more accurate than the other two methods using their own in house laser equipment and trained  service engineers.

This service is available to all customers either within the scope of a maintenance agreement or a one off visit to resolve ongoing issues.

Consequences of misalignment

Poor alignment can lead to the following:

  • Increased friction to equipment and hence
  • increase in KWHr consumption
  • Increased vibration and noise
  • Drive motor bearing failure
  • Compressor bearing failure
  • Shaft seal failure
  • Coupling failure

In a case study we  found significant cost savings can be achieved by the accurate application of this method of alignment because of the improved reliability of equipment (less down time) and the prevention of major failures to plant and machinery through planned preventative maintenance (regular alignment checks). 

  • Refrigerant Management

The objective is to ensure the containment of the refrigerant within is system without loss, by correct design and using the properly rated equipment. Also, ensure that the system itself is operating safely and to its design specifications. Thus achieving and maintaining its operation using the minimum amount of electrical energy necessary. Operating a plant that is not correctly charged with refrigerant costs a lot more money to run and possibly not even achieving its design operating conditions.

The task would involve a regular leak-testing regime using either a hand held leak detector / soapy water / etc. and in the case of ammonia, you could use phenolphthalein / litmus leak detection paper. Refrigeration plants containing larger quantities of refrigerant, and depending upon the current regulations, would require to have a fixed refrigerant leak detection system installed, regularly serviced and maintained, to ensure its correct functionality in the event of a refrigerant leak occurring.  

  • Water Treatment

The objective is to ensure the control of Legionnaires disease within the water cooling system of evaporative condensers used in larger refrigeration plants and that they comply with the current regulations set out by the Health & Safety Executive. 

The task would involve the installation of a water treatment system (installed and maintained by a qualified water treatment contractor) and could be either chemical based or using a non-chemical system. There are several different types available but Star tend use the VRTX centrifuge system if possible, which has produced excellent results on the sites that have it installed. The water treatment contractor would supply a water treatment logbook, which is filled in every month during his service visit recording all the required data. Weekly dip slides are taken either by the engineer attending site or the customer themselves with their results recorded in the logbook; this records the level of bugs within the water system and shows the level of compliance over the whole annual cycle. If however the dip slides show an increase in the contamination then other protocols can come into play (place solid biocide tablets within the condenser water pan itself).  Bi-annual clean and chlorination’s of the evaporative condensers are also included within the water treatment program to ensure there is no build-up of algae which would encourage the growth of Legionella bacteria ensuring the health of the system overall.      

  • Cooler Cleaning

The objective is to ensure that coolers/evaporators are clear and free from dirt/dust and/or snow/ice etc. allowing unhindered airflow giving maximum heat exchange through the coil block. 

The task would involve scheduled regular cleaning of the coil block, by either our own staff or through a sub-contractor, who would supply all necessary equipment to complete the task safely. The process would include safely screening the cooler to prevent over spray of the water during the cleaning process falling down onto the customer’s product below. Star get our sub-contractor to also record before and after air flows across several areas of the cooler to prove the increase of air velocity following the cleaning process. Once complete the cooler is almost back to its original condition giving maximum design refrigeration duty. 

  • Condenser Cleaning

The objective is to ensure that the evaporative condensers are being maintained within the Health & Safety guidelines, which states that, every condenser should receive a clean & chlorination service at least twice a year, (sometimes more depending upon their location), to ensure the cleanliness of the condenser is maintained at a level that will control & prevent Legionella.  

The task would involve a scheduled clean & chlorination with the removal of the condensers drift eliminators (they would receive a wash down to remove dirt, algae etc.) The condenser internal walls, fans etc. will be treated with chemicals and washed down into the water pan, which would then be drained down and cleaned. Once the cleaning process is completed, the condenser would be refilled with water and hypochlorite added to carry out the disinfectant of the tower. This recirculating process can take several hours to complete within the condenser itself. Once complete the water is again drained and refilled. Once complete the condenser is returned to service.

  • Ammonia Drier

The objective is to ensure that the ammonia refrigerant within the system is clean and free of contamination.

The task would involve the installation of an ammonia drier into the refrigeration system to absorb and control any water at a level of below 1%. If the percentage of water is greater, it has the effect of increasing the evaporating temperature within the system, resulting in achieving longer compressor running times and possibly not achieving the design duty set points. It also has the effect of introducing internal corrosion of the ammonia circuit, which could result in future refrigerant leaks. Reduces the working age of the refrigeration lubricating oil and the formation of sludge, which in turn, could block/restrict the flow of refrigerant through filters and valves thus reducing the plant efficiency even further.

  • Thermo Scans

 The objective is to ensure that all the electric controls are photographed using an infrared camera, which shows up any hot spots within the control panel itself. Highlights where there is an issue on any piece of equipment without the need of any invasive isolation of the panel or refrigeration plant rather than waiting until the component fails, possibly resulting the shutdown of the total refrigeration system itself and resulting loss of production.

The task would normally involve an annual scheduled thermographic scan carried out by a sub-contractor. The engineer would open the live control panel and a photograph taken; this would then be checked for any issues, and if possible attended to at that time. If however, due to operational reasons, the plant cannot be switched off, then following the issuing of the annual report, the repair would be arranged at a time suitable to the customer.

  • Refrigerant Quality Check (ARQ)

Refrigerant quality checks are especially important, as any water in an ammonia system, for example, can lead to severe loss of cooling capacity and rising energy costs. Water contamination of 1% or below is not something to worry about, as long as it is monitored. But for every 1% of water, your running costs go up by 1%. If left unattended, this will also lead to oils breaking down quickly and component failure, which will cause your operating costs to increase even further.

Checking the quality of the refrigerant within the refrigeration system 

This procedure requires that a sample of liquid ammonia is taken and collected within a calibrated flask. The ammonia is then allowed to evaporate off with the water being left. This is then measured against the total sample taken, and the resultant figure is converted to % of water contamination. At Star, this procedure is carried out by one of Star's commissioning engineers.


James Ward

Operations Director

Related Case Studies

  • Leader in clinical supply chain management

    A worldwide leading clinical supply chain management company focusing on the packaging and distribution requirements of clinical trials across the world and with operations in Horsham, West Sussex, came under threat recently when a cooler in their freezer room suffered from ice damage. Star Refrigeration’s local service and maintenance engineering team assessed the situation and replaced their existing cooler with an upgraded version which allowed the company to continue business as usual without process interruption.

    Star’s engineers found that the ice build up forced an evaporator coil to split, leaving the cooler unable to maintain its set temperature levels and thus it became obsolete. To ensure no damage or loss to production, the customer was advised to move all products from the cooler and into another storage facility until a replacement cooler could be installed.

    John Simpson, Regional Manager- South East at Star Refrigeration, who worked closely with the customer, said: “The ice build up was first noticed by the client and reported to us, then we attended the site, inspected the damage and investigated the cause, which was a failed drain pan heater.”

    Since the customer had held a maintenance contract with Star Refrigeration since 2011, the engineers had a good understanding of the site’s operation requirements and were able to provide a swift response by recommending an upgraded cooler from the same manufacturer in order to solve the problem without unnecessary delays.

    Star worked closely with the customer’s maintenance management facilitator, Bouygues, on the project. Jamie Gray, Bouygues Manager said, “Star was able to install a new cooler within two weeks. There was no production loss from the refurbishment, as the timeframe between sourcing and installing the new equipment meant that we were able to empty the produce from the obsolete plant into replacement chillers on our site.”

    “Since Star Refrigeration maintained the original chillers, their site and product knowledge meant they were able to work quickly when selecting and installing alternative equipment to provide the same functions as the original.”

    The works involved installation of the new cooler, pipe brazing, pressure tests, system strength and tightness tests, drain and evaporator installation, as well as refrigeration cycle and defrost cycle tests.

    Jamie Gray added, “Star is an approved supplier for our company, so we were aware of the procedures carried out by the company for projects like these. Their risk assessments were always very well organised and detailed, and their method statement was well planned.”

    With headquarters in Glasgow, Star Refrigeration are the UK’s leading industrial refrigeration company, delivering 24-hour service to customers from nine branches spread throughout the UK. In total, the business employs nearly 350 staff and their Operation Group has extensive experience of delivering practical solutions and services to global leaders in the industry. Making up for about half of the company total’s revenue with an annual total for last year of over £20 million, the Operations Group helps over 300 businesses nationwide through their branch offering which includes consultancy, training, design, installation, commissioning, maintenance and service of cooling solutions, as well as the supply of spare parts for industrial refrigeration systems.  

  • Star helps British healthcare provider become more efficient

    A leading global healthcare provider, recruited Star Refrigeration’s Operations team to resolve ongoing maintenance issues at one of their sites in Scotland.

     Star Refrigeration had developed a good relationship with the company over the past ten years, and gained a good reputation for the design and maintenance work carried out at other sites across the country. This led to the customer taking out a three-year maintenance contract with Star Refrigeration Operations Group's.

     When Star engineers arrived on site, they found that the customer’s ammonia plant was overcharged with oil due to incorrect setup. Soon after taking over the contract, the plant’s expansion valves were replaced in order to regulate gas back to normal working pressures and levels while ensuring Star's maintenance routines had no impact on the customer's normal operations.

     An important part of Star Refrigeration’s aftercare work was to bring the British pharmaceutical company’s ammonia plant up to date with current regulations as well as the implementation of SAP procedures to the air conditioning systems were routinely assessed and subject to regular and consistent maintenance.

    As part of Star's proactive maintenance plan, the plant performance was reviewed on a frequent basis. Working closely with the customer’s energy supervisor, Star monitored the plant's energy usage. After identifying when the plant was not operating at maximum efficiency, Star introduced measures to minimise energy waste such as the installation of timers in all air conditioners at the site’s central offices, which reduced the customer’s energy bill by £8000 per annum.

     Star’s good performance during the initial contract period resulted in the customer renewing their aftercare contract for another three years. In addition, Star's Aberdeen team was entrusted with a new project which involved the design and installation of a brand new refrigeration plant for an extension to their facilities.

     Star Refrigeration Operations Group offers 24-hour technical support for the customer from nine branches across the UK. This includes design, maintenance, service, contracting and spare-parts.

     Star Refrigeration Operations Group is now pioneering the use of condition based monitoring for industrial refrigeration end users and delivering improved efficiency, greater reliability and lower total cost of ownership to over 300 customers across the UK.

  • AGC Chemicals Europe

    Based in Thornton Cleveleys, AGC Chemicals Europe is a global leading producer of fluorochemicals used in industrial applications, agriculture, construction and much more.
    When the site was hit by a major failure of  one of their process heat exchangers, an onsite contractor recommended Star as the reliable experts for the job.

    The equipment failure meant that AGC Chemicals could not operate its refrigerant process line. The process fluid needed to be cooled to below -300C which required specialist Low Temperature (LT) refrigeration equipment. Downtime on this process line is extremely costly to the business if it is not operational, so it was essential that an assessment and plan of action was developed rapidly in order to deliver the right solution. The client was looking for a temporary refrigeration solution for their process line that would allow them to  be operational again as quickly as possible.

    A team of senior engineers from Star’s local branch attended site within half an hour of the call-out. The issues were established and the temporary solution requirements were identified. Thanks to a business partnership with temporary supplier of chillers, Aggreko, Star was able to deliver the specialist temporary temperature controlled solution to site within a short time frame. Aggreko provided 2 off VLTC chillers for approximately 150kW of cooling to below -300C, two off heat rejection air cooled chillers, a special LT heat exchanger which was connected into the customer’s process line, circulation pumps, a buffer tank and generators. 

    Dr. Rudolph Prince, Head of Engineering at AGC Chemicals Europe, said, “The thing that really impressed us about Star was the speed in which they reacted to our situation. We needed the equipment on site as soon as possible so we could start up production again with minimum disruption. It was all coordinated over the weekend, and the temperature solution allowed us to be fully operational again within a few days so we didn’t suffer from further downtime.”

    Furthermore, the chemical plant found that the temporary refrigeration equipment was much more efficient than their fixed site equipment. Star’s selection of the right temporary solution for the site capacity and temperature requirements delivered a more effective cooling process, allowing for a larger output of product than the plant it replaced. This allowed the site to catch up with the back log of production from the downtime very quickly once they were operational again.

    Now that AGC Chemicals are aware of Star Refrigeration’s expertise, the companies are likely to form a long term partnership. Star has already delivered a second temporary solution with Aggreko elsewhere on site, and there is scope for consultation on overall site requirements.

    In terms of future work at the plant, Star plan to ensure AGC’s  peace of mind by protecting their business operations-should the unthinkable happen-with Star’s Refrigeration Temperature Control Contingency Plan Scheme. This will help the site prepare better for future refrigeration equipment failures. AGC Chemicals will turn to Star for any future equipment installation needs, with Star’s technical consultants, STS, ready to undertake a full site survey and produce a technical specification for a new installation to replace the time served plant.

    This successful project highlights how Star Refrigeration’s UK branch network can provide expertise and a rapid response in an industrial emergency situation. While the equipment failure was unwelcomed by AGC Chemicals Europe, it provided an opportunity for the company to see how more efficient technology could benefit them in the long term, both economically and environmentally.

    For more information on Star’s preventative services and contingency planning visit /news/chiller-contingency-planning-for-critical-cooling-situations-keeps-star-refrigeration-customers-cool.aspx

  • DFDS Logistics

    DFDS Logistics offers end-to-end supply chain solutions across Europe, serving 20 different countries and a range of different industries. The company specialises in cold chain transport services, and is the largest provider of transportation solutions to the Scottish salmon and seafood industries. Its site in Larkhall has an annual intake of 300.000 tonnes of fresh seafood products for storage and distribution, with a plant consisting of cold and chilled storage, blast freezing and a distribution warehous

    Until recently, the equipment was managed by the original equipment installers and other contractors – but the level of service was not sufficiently adapted to cover DFDS Logistics strict requirements. DFDS Logistics experienced low quality work, cancelled visits and poor site attendance which had resulted in overall inadequately maintained equipment. The company decided to partner with Star Refrigeration’s maintenance team in a rolling contract to assess the contractors ability to offer an improved quality service – and have stayed with them ever since. 

    All of Star’s maintenance plans are tailored to each individual customer and the specific site requirements. Engineers conduct a thorough survey of the equipment and facilities to produce an effective bespoke maintenance programme taking into account the system’s refrigerant, condition, age, any legal or best industry practices and health and safety requirements.

    During the initial survey at DFDS Logistics, Star’s senior Service & Maintenance Manager, Gary Beckwith, identified a number of issues and presented recommendations. Firstly, there was an access problem to reach the evaporators for ongoing maintenance of the evaporators in the various chill areas for inspection and leak testing. As a consequence, routine maintenance had never been performed in the evaporators before. Star recommended the hire of a scissor lift every two months to allow access to the evaporators – which was approved by the customer.

    The quality of the previous maintenance programme had been questioned by the customer after one of the control panels had caught fire. It was quickly extinguished, but DFDS Logistics was understandably concerned and wanted Star to ensure this would not happen again. As part of the Star maintenance package, annual thermographic surveys, which can rapidly assess control panel health and highlight areas of concern, are carried out.

    Gary Beckwith, who worked with DFDS Logistics said, “A thorough site survey both from a technical and a health & safety perspective results in a well planned and executed maintenance programme and at the same time offers an accurate and realistic maintenance contract proposal to the customer. Previous contractors failed to include access equipment to reach high level parts of the system, which resulted in missed maintenance routines and additional unforeseen costs for the customer to provide access.”

     “By having a good conversation with the customer during the tender process, DFDS Logistics was quick to understand the need for inclusion of additional services within the contract. For example the site had previous issues with overheating on the controls which lead to a small fire, and a simple method of reducing this risk is for an annual thermographic survey of the control panels. This has already highlighted areas of concern which require remedial works to improve safety.”

    Additionally, the customer was wary of contractors who would regularly fail to turn up for visits or rush through maintenance checks to visit another site. Star’s Bellshill branch in Glasgow have a pool of nine qualified engineers to cover central Scotland, so can always keep on track of regular site maintenance visits.

    In addition to the premium level of engineering service provided, Star advises on refrigerant phase out requirements and replacement plant options, both of which are available within the company’s resources.

    Star offer a professional service provided by senior and qualified engineers as well as well-trained apprentices and a good support team. DFDS Logistics has been extremely happy with the competence of Star’s award-winning engineering staff, response time and the level of service provided. Peter Carswell, Maintenance Manager at DFDS Logistics said, “Star Refrigeration keep current equipment maintained to a high standard and advise us of future industry changes.”

    Star Refrigeration Operations Group provides fast response and 24-hour technical support from a UK-wide network, offering maintenance, service, contracting and spares services across a wide range of business sectors of all sizes. The Operations Group accounts for about half of the company’s total revenue, with an annual total for last year circa £20 million and helps over 300 businesses nationwide.

    Each branch offers a complete range of services, from consultancy to design through to installation, commissioning and maintenance of cooling solutions to suit a variety of different business needs at local, national and international levels.

  • Asda Rochdale PPM

    Asda’s distribution centre in Rochdale works with its local Star Refrigeration branch in Manchester to maintain its refrigeration plant in the most efficient way possible. Star Refrigeration has a national maintenance contract with ASDA, working in partnership with the customer to provide a preventative maintenance plan and ensure any faults are dealt with promptly and safely when these unexpectedly occur. At this particular site, palletised goods are broken down and delivered to individual stores, and the temperature needs to be controlled and maintained throughout the operation.

    The client requires 24/7 cover of its refrigeration plant including remote monitoring and planned preventative maintenance (PPM) visits. Star keeps the plant safe and legal, with services including Written Schemes of Examination, calibration of the ammonia detection system and other sub contract works managed by Star. Working alongside Star the retailer has strict contingency planning procedures in place to ensure a rapid response in the event of a mechanical failure, supported by a qualified team of engineers from Star’s local branch. Generally, major faults are uncommon in large, complex industrial plants which are regularly serviced and maintained. However, end users need to be well prepared in advance, should the unthinkable happen, to minimise and, where possible, avoid any losses.

    When an ammonia leak occurred overnight at the Rochdale site, ASDA and Star Refrigeration worked together to assess the situation and get the plant up and running again as soon as possible.

    Via the monitoring Hub at Star’s headquarters in Glasgow standby engineers at the Manchester branch were notified of a ‘low stage drum high level’ and attended site to address the situation. The low stage surge drum was full of refrigerant and had carried over to the compressors. One of the low temperature (LT) compressors had developed an ammonia leak, and the compressor had to be isolated from the ammonia system – however the concentration of ammonia in the plant room was too high to allow safe entry.

    Star Refrigeration’s engineers followed the company’s specified action plan to drop the ammonia  concentration in the plantroom including activation of local ventilation fans, and deployment of additional extract fans and ducting to ensure there were no ammonia levels above 25ppm.

    Once the plant room was safe to enter, a plan was put in place to transfer liquid between the surge drums and fit a replacement valve. There were three Star Refrigeration engineers on site in addition to the customer’s, working as a team to get the plant back up and running. The cold store plant was out of action for 11 hours in total.

    Colin Taylor, SHE Manager at the ASDA site said, “What really impressed us about Star was the way our emergency was handled. The plant tripped out at 9 pm, and with two senior engineers and a manager attending and working through the night, the cold store was working again on by at 8.30 am the next day.”

    “We have access to local trained and experienced engineers who have procedures in place for such an incident. It’s great that we have a branch local to our site and a second branch less than 50 miles away to assist if needed. Star offers a local team with the added benefit of a robust national infrastructure”.

    Dave Brown, senior maintenance engineer at Star Refrigeration- Manchester- said, “Working in partnership with the customer and planning for such events including devising safe systems of work for contingency situations such as this, which could occur at any plant, was dealt with promptly, safely and with minimum disruption to their business operation.


    Both companies have enjoyed a strong business partnership for the last decade and ASDA remains a key customer of Star Refrigeration. “It is the intention that we will continue to explore ways to maintain the successful relationship with Star Refrigeration in the future for the benefit of our respective customers, businesses, shareholders and other stakeholders”, said Taylor


  • Star Maintenance

    Operating and maintenance typically contributes to more than 80% of the life cycle cost of refrigeration plant. When selecting new plant, emphasis is often placed on purchasing the most efficient design but this does not guarantee low running costs. Pro-active maintenance is key to ensuring the plant continues to operate at its design parameters throughout its life.

    Star Refrigeration’s operations team is focused on ensuring our customers have plant that operates efficiently and reliably throughout the year. Our nationwide network of nine branch offices are fully staffed with experienced management teams and we have more than 80 mobile field engineers to support your business.

    Our aftercare team continuously reviews plant performance against design parameters to ensure the lowest possible running costs for our customers. We look for ways of improving performance from simple changes to operating parameters through to the retrofitting of new energy enhancing technology to existing systems.
    Examples include:

    • Application of inverter technology (compressors, condenser fans, pumps)
    • Defrost on demand
    • Automatic oil recovery
    • Electronic expansion valves

    We work closely with our customers to develop a proactive maintenance programme, tailored to their needs. When undertaking a new contract, we review the existing equipment and provide a free of charge plant review that highlights areas for action to bring the plant back to design and suggestions for improving reliability and efficiency. These are then developed into an action plan that is reviewed regularly with our customers.

    Our Telstar control system enables offsite monitoring of plant faults and alarms. More recent installations also include maintenance alerts which detect movement away from the plants design conditions. These provide early warning of reduction in efficiency and potential future problems, enabling our engineers to attend site to resolve before a problem occurs.

    Our proactive approach to maintenance is effective in reducing life cycle costs and is demonstrated in data measured by our customers. Below are examples of how the Star approach to maintenance has reducing operating costs for two customers.

    Case Study 1 - Temperature Controlled Distribution Centre

    This multi-temperature distribution store was completed in 2006 and has a two stage central ammonia refrigeration system installed by a competitor. The plant consists of three high stage screw compressors, two low stage reciprocating compressors, two evaporative condensers and 20 evaporators in three temperature controlled chambers. Following an 18 month maintenance period with the original installer Star took over. Following a full site survey, modifications were made to reinstate the plant back to its design conditions. We made a number of zero cost changes to the plant control to enhance operating efficiency and improve store temperatures. Refrigerant was also added to the plant as the survey found it was running undercharged. This improved both efficiency and reliability.

    An energy monitoring system installed on site has provided detailed energy data since the plant was installed. The graph below compares running costs from 2007 and 2008. A comparison of plant running costs over 12 months indicates an average energy saving of 100,000kWhr per month since Star took over the site maintenance contract. This corresponds to a saving of £6,000 per month based on an energy costs of 6p/kWhr. Data for 2009 is following the same trend as 2008, underlining our ability to reduce and preserve operating cost savings.

    Case Study 2 – Brewery

    Star has recently completed modifications to an existing brewery maintenance customer’s cooling system to enhance operating efficiency. The customer has three modular water cooled plants as indicated in the following diagram:

    Star modified one of the three systems, installing a new inverter controlled reciprocating compressor package (in place of the original fixed speed machine). A new compressor sequencing system was also installed to supervise the starting and stopping of all three systems. This has resulted in a £2,000 per week reduction in running costs and a payback of less than 2 years on the investment.

  • Farmfoods Solihull

    Star Refrigeration has the reputation for installing and maintaining long-lived quality refrigeration solutions able to meet the needs of some of the biggest and most respected names in the UK. Farmfoods is one of the companies we work closely with. 

    Farmfoods is dedicated to bringing superior frozen food to its customers. A Scottish-run family business, it relies on quality equipment to ensure its range remains in perfect condition. For the past three decades, the Star installation at Solihull has ensured that every product is maintained and despatched to stores at the optimum temperature.

    “Originally built for Birds Eye, the depot was purchased by Farmfoods in 2000”, said Julian Hill, Engineering Manager at Farmfoods.  “Since Farmfoods took over the system there has been just a six month period where it wasn’t in use. When Birdseye left and Farmfoods took over, it was closed down. Our engineer came in every day just to make sure everything was okay, but once we bought it, we turned it all back on and Star has ensured it runs smoothly ever since”.

    Andy O’Brien, Senior Engineer at Star Refrigeration, further highlighting the reputation forreliability Star has in the cold storage industry, said, “The plant is 33 years old. Built to Lloyd’s requirements in 1984, the two stage surge ammonia refrigeration plant includes four reciprocating compressors, a low temperature surge drum, intercooler, receiver, hot gas defrost valve stations and waste heat recovery for the glycol underfloor heater mat. Provision was made for future expansion of the store and in 2003, three further evaporators were added to the system, increasing cooling capacity by 225kW”. 

    The warehouse has 13,000 pallet spaces across three different chambers - a cold store, a chill store and an ambient area. 

    The system uses environmentally-friendly ammonia, which is a natural occurring gas with zero ozone depleting and global warming potential. It is one of the most efficient refrigerants for this type of application. According to Farmfoods Engineering Manager, “the use of future proof ammonia, the robust industrial build quality of the system, and regular pro-active maintenance are the reasons the system has survived the test of time”.

    Since it was first installed, Star Refrigeration has provided full maintenance including a major overhaul of compressors and liquid pumps or any other works required by Lloyd’s insurance as well as cover for out of hours service calls. Hill said, “Maintenance work on the plant includes review of operating performance, inspection of equipment including compressors, evaporators and condensers and oil recovery”.

     Despite the system’s age, Farmfoods has experienced uninterrupted operation. Hill said, “There have been no major problems, no forced shutdown of the plant”.

    Modifications have also been made to improve plant reliability and efficiency. The original evaporative condenser was still in use and according to the manufacturer, the condenser was their oldest in operation in Europe. To safeguard the future operation of the facility, it was decided to replace the condenser.  Andy O’Brien described the process, “it involved a carefully planned programme including a short shut down of the system to enable the addition of new connections and extended pipework. Prior to the shutdown, the store temperature was lowered, to ensure product remained at the desired temperature”. 

    Farmfoods confirmed that “the replacement works were completed to plan and with no disruption to our operation”.

    To enhance operational efficiency, the new condenser was fitted with Star’s Aether control system. Aether varies fan speed based on heat rejection load and ambient conditions, saving motor power and ensuring optimum condensing conditions throughout the year.

    Star’s focus on efficiency and extended working life, as well as reducing carbon emissions, has helped Farmfoods keep running costs down over the years.

    Farmfoods and Star Refrigeration have enjoyed a successful and longstanding relationship for decades. In addition to the condenser works at Solihull, Star has also recently installed two Azanefreezers and an Azanechiller at Farmfoods new facility in Bristol in 2014 and will continue to support the frozen specialists in the years to come.