Colruyt Group Technics, one of Belgium’s biggest refrigeration companies

Are refrigeration technicians enjoying a well-deserved summer holiday? ‘We’re working on it now within Colruyt Group and that makes me happy,’ said Peter Basteleus, HVAC department head. About 30 people perform maintenance on 500 sites or so. And they usually also take on at least one new system a week. ‘Starting in 2014, we’ve also been converting all of our F-gas plants. And we’re nicely on schedule to have this completed by 2030.’

We have been employing its own refrigeration technicians for quite some time now. Our engineering department has 35 engineers. It is responsible for all building technologies, lifts, escalators, sprinklers, water, refrigeration units, hydrogen, etc. In 2014, EU Regulation 842/2006 and later 517/2014 changed the regulations to reduce emissions of certain greenhouse gases in the refrigeration sector. This particularly affected systems using fluorinated greenhouse gases or F-gases (HFCs, PFCs and SF6). Specifically, cooling systems must be installed by certified refrigeration technicians and refrigeration companies. We immediately ensured the company was certified. This meant testing and documenting its systems and providing appropriate training to qualify its engineers and technicians.

In-house refrigeration technicians make a difference

‘I really want to keep our refrigeration technicians on hand so they can respond quickly. This ensures we aren’t dependent on third parties and our customers don’t have to wait in line when demand is high. Our quick response prevents “waste” and contributes to the sustainability of the entire operation,’ said Basteleus. This is also how we minimise leaks with our cooling systems. ‘The refrigerant leakage rate for larger retailers in Flanders is about 10% per year. It may even be higher for small independent operations that check systems less, which means they have no leakage figures available. We limit leaks to 3%’ How does the HVAC service manage this? First, we have specialists and second, we completely standardise our processes and systems. Refrigeration technicians are divided across two separate departments. The first has about 20 people and takes care of the systems in shop branches. The second has a dozen or so people and looks after the ‘big buildings’. These include computer rooms, distribution centres, and factories, such as for meat processing.

Standardisation, machine learning and artificial intelligence

‘In shops, we have a completely standardised way of working. We keep everything in-house from start to finish,’ said Basteleus. Designers and project engineers follow strict specifications to ensure that every shop has basically the same system. For example, you will usually find the same sensor in the same place on a PCB. ‘Today, it’s very usual to have the system as a separate unit next to the shop.’ Automation, i.e. the software programming, is done by our own programmers. The department also handles purchases. This standardisation means our technicians receive focused training that makes them experts in their field. ‘Any employee who wants to take evening classes can get their refrigeration certificate at their own pace in two, three or four years.’ Standardising also reduces the number of different spare parts, making a huge warehouse unnecessary. ‘It also meant we could develop our own leak detection system,’ said Basteleus. The machine learning software collects data from temperature and pressure sensors, power meters, etc. It automatically sets off a leakage alarm when it detects a deviation among certain parameters. ‘If we lose just 1% of refrigerant gas, we know about it,’ he said.

‘It’s very sensitive. Previously, a system only failed when leakage losses exceeded 20%. Only at that point did our technicians take action to find and repair the leak.’ That is no longer the case. Our department has systematically increased the sensitivity of leak detection. Today, it is almost 10 times more sensitive than just under a decade ago. A system has buffer tanks, so it will not shut down with very small leaks. Nevertheless, our technicians are alerted very early on and will then diagnose and repair the leak. ‘Our automatic leak detection – actually, the AI software – works across our numerous shop systems. And it’s only possible because of all the standardisation in place. These types of systems only gain the confidence of technicians when they really work, do what they’re supposed to do and don’t set off occasional false alarms. And… it works.’

Circular learning

‘We are seeing the climate change,’ said Basteleus. The design of our cooling systems has been adapted to the higher outdoor temperatures. In summer, our technicians monitor systems closely during heat waves. A control room shows all the systems on a screen. ‘We remotely monitor and adjust our systems. We only need to send out a technician when there are problems.’ We also have a post-summer evaluation. Which systems experienced difficulties? Why? If a system runs too hot, there is the risk it will fail under pressure. If it is too humid, it risks creating condensation in the shop. According to Basteleus, Colruyt Group gets through the hot summer without a hitch entirely because of its pared-down organisation. ‘Our designers know the customer – Colruyt Group – really well. If it has an idea, it tests it with us and we figure it out together. Ease of use and easy maintenance are also a core concern of our designers. Once a system is operational, the engineers give their feedback to the project technicians.’ So, the learning circle closes very quickly. We also take the information gleaned from all of the data and provides feedback to its suppliers about their machine systems and components. ‘We have an open relationship where we discuss things and they learn along with us.’

Large buildings

For our shops, we opt for cooling systems using natural refrigerants, such as propane or propylene. By 2030, all old systems using synthetic refrigerants will be replaced. In the meantime, the largest systems run on ammonia. These include distribution centres, central buildings, computer rooms and factories (meat processing). The first system using ammonia was commissioned back in 1999. An ammonia-powered heat pump was installed as far back as 2017. ‘Ammonia is a very stable refrigerant,’ said Basteleus. It only requires a sufficiently large system design and timely maintenance. Otherwise, any leaks mean the system must be shut down for safety reasons. In other words, preventive and predictive maintenance. ‘The strength underlying a reliable system is the technician’s knowledge.’ One technician is responsible for one system. ‘He hears and senses his equipment. He knows it inside and out. Of course, we also provide him with the tools he needs to carry out proper maintenance.’ Measurements on the compressor, electrical boards, etc. ‘We run the system at full power and then point an IR camera at the PCB to locate any heat spots.’ Sometimes, redundancy provides the required certainty. The two large computer rooms run side by side, but can take over each other’s operation when required. They receive power from two different sources. There are two emergency groups and two cooling systems. ‘The chillers currently still run on F-gases, but will also be replaced by a natural refrigerant by 2030.’

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