|John Ellis, owner, Ellis Training, emphasized the importance of having a proper skills base to reduce refrigerant leakage. (Photo courtesy of MasterCool)|
In the last five years, the Institute of Refrigeration (IOR) has made strenuous efforts to emphasize the fundamental importance of containing refrigerant to the performance of systems, while at the same time highlighting the industry’s responsibility to improve its reputation in how it handles leakage.
Its strategy has evolved steadily over the years — starting with its award-winning Real Zero campaign, designed to take all levels of the supply chain through its responsibilities and to provide ‘back-to-basics’ advice for everyone involved, through to the wider education and training campaign of Real Skills Europe, improving containment by bin partnership with a range of European bodies.
So perhaps it is not surprising that the IOR chose the subject of refrigerant containment for the re-launch of its annual conference, enabling it to assess progress and examine technology. And, of course, to roll out its latest initiative, the Real Alternatives campaign, previewed recently in RAC, which sets out to ensure that the containment principles are also applied to alternative refrigerants.
IOR president Graeme Maidment, in officially launching Real Alternatives, pointed out that losing 20 kg of refrigerant from a hydrocarbon (HC) system was still a costly problem for the end user, even if it is not so high in carbon emissions as the same leak from a hydrofluorocarbon (HFC) system. Part of the Real Alternatives research will be to attempt to assess the skills at the industry’s disposal, he said. “There is a potential skills shortage at the technician level in terms of ensuring the safety, efficiency, reliability, and containment of any refrigerated system.”
To set the tone for the conference, David Bostock, managing director, GEA Refrigeration Technologies, offered a global perspective on leakage. His provocative message was for everyone to take on board the fact that all systems, even sealed systems, will leak, it’s just a question of to what degree and how the suppliers apply that in their approach to the global industry. The key thing, he noted, is that the population growth will occur largely in the ‘developing world,’ which is almost entirely in hotter countries than Europe and therefore strategies need to be created that tackle the inevitable rise in refrigeration and air conditioning there.
“The bulk of population growth is going to come from Africa. Europe is just a sideshow by comparison, that’s not where the problem is going to be,” said Bostock. “And Africa is not regulated in the same way.”
He added that most of the predicted large urban areas — so-called mega cities — will be in hot countries, too, leading to huge rises in demand for commercial and domestic air conditioning. “We can talk about the importance of maintenance, but what maintenance will be done on a domestic air conditioning unit in a big city in Africa? Very little, probably, so it is going to leak. It is what is in that unit that will count.”
For that reason, he contended, suppliers needed to think about an approach for the developing world that centers on natural refrigerants and sealed units.
To dispel any complacency that it is just developing countries that have a serious leakage challenge on their hands, Bostock also noted that the commonly accepted leakage trigger rate for the repair of commercial refrigeration in the U.S. Clean Air Act was 35 percent, although California had its own much tougher state laws.
But, he noted, in Europe, where there was already a tougher inspection and recording regime to deal with, there were new challenges, depending on the outcome of the f-gas regulation.
Although everyone in Brussels is focused on environmental matters, he said, the fact that a change away from HFCs could have negative effects on energy use should also be taken into account.
Fortunately, Bostock had a positive spin on this for the industry — don’t try to sell better leak reduction on the environmental angle, but appeal to their pockets. “It is possible to ‘do the right thing’ for the wrong reason,” he said.
By emphasizing the potential running cost disadvantage from leaks, from repair costs, to energy losses to the cost of refrigerant, the case can be made for better leak management, he said. “Refrigerant has become a capital cost now,” he said, noting that those who have delayed R-22 replacement since the phaseout was first announced have seen a 2,000 percent rise in gas costs.
This, of course, is becoming even more important with the advent of hydrofluoroolefins (HFOs) that are running at five to 20 times the cost of R134a, he said.
“With all this in mind,” he concluded, “isn’t it time we dropped the fight between what is ‘synthetic’ and what is ‘natural’ and just referred to ‘sustainable refrigerants’ that achieve the best result for our overall target of carbon emissions reduction?”
The practical challenges of leak reduction were addressed in different ways by both John Ellis of Ellis Training and Jane Gartshore of Cool Concerns. Ellis looked at the importance of keeping things tight, emphasizing only fitting gauges when they are needed, and ensuring that the engineers understand the gas laws so the relation between temperature and pressure loss is properly analyzed. “If you don’t, you can spend a hell of a lot of time looking for a leak that isn’t there, and that’s what causes people to lose faith in the whole leak-checking process. And indirect leak testing requires more than just a set of gauges.”
Ellis concluded by emphasizing how important it is to have a proper skills base for the battle to reduce leakage. “Every maintenance engineer should have sufficient skills, equipment, and knowledge to understand refrigerant behavior.”
Gartshore highlighted some of the key areas where the original Real Zero project had identified leak issues. One of these is that Schrader cores are not always sized correctly for the application and that the correct torque is an essential element in the component’s leak tightness, so torque tools and torque tables are vital elements in the engineer’s armory. “Virtually no one in the U.K. knows how to use a torque tool,” she contended.
She also underlined the contribution of factory-made flares or flare solder adaptors to leak-tightness, as opposed to manual flaring. Correct use of these, she said, could probably make as good a connection as a brazed joint.
Gartshore also provided some provocation to the audience over CO?. “More complex systems with more joints risk more leaks. Together with higher standstill pressures leading to venting out of the pressure relief valves— use of CO? will result in very high leak rates if we just continue with ‘business as usual’”, she said. “Even where R744 design and installation changes have been made, such as in Scandinavia, leak rates are still reported to be up to 15 percent, indicating that this combination of central plant and R744 is not a leak-tight solution.”
She contrasted this with hydrocarbons, where the emphasis on standards could lead to much lower leak rates ‘because it can’t be business as usual’. “The requirement for factory-tested components and low charge sizes with hydrocarbons would result in ‘almost zero leakage,’” she said.
In conclusion, Gartshore said that although leak reduction is higher on the agenda, the industry still needed a cultural change in order to embrace the culture of zero leakage. This would entail following the guidance in the standards available, specifying low-leak systems, allowing sufficient time at installation, and granting sufficient time for planned maintenance.
This rigid enforcement of standards was backed up by City FM’s John Bonner, who showed the rapid decline in leakage since City and Asda adopted their ‘zero tolerance to leaks’ approach — from a rate of 54 percent in 2000 to a 7 percent average this year, with an increased estate. He added that the intention was to go beneath the magic 7 percent, helped by a move towards proactive maintenance.
John Skelton of Sainsbury’s called for a change in behaviors if the industry is to cut emissions either directly or indirectly. One of his key moves, to increase buy-in from the company, has been to refer to refrigerant as the ‘fourth utility,’ after electricity, gas, and water. “It enables the processes to be easily understood by the board, and it enables refrigerant use to be measured and targets set. It is talked about at the board level because of the carbon impact.”
He also challenged the engineering base to do more to cut leaks, since Sainsbury’s CO? ambitions would mean an expansion of higher pressure systems, bringing the risk of faster loss of charge. The retailer has removed all Schrader valves; brought in a single skid pack construction to reduce the number of joints; and replaced the service valves on display cases, “‘but refrigerant usage is still far higher than it should be,’” he said. “It needs a behavior change. Somebody said to me, ‘Everybody knows how to leak-check,’ but it is simply not true for all engineers.”
Skelton also reiterated that he was committed to CO? for the long term. “It is difficult to go back to the business and tell them there have been more bans on refrigerant. I am hoping that CO2 will be a refrigerant to stand the test of time. We are being driven by the carbon impact, not the energy efficiency, but the CO? systems are delivering against the 2005 stores. Improving the energy efficiency is the next challenge.”
SIDEBAR: The German Experience
Wolfgang Zaremski, president of German refrigeration body VDKF, described the success of its certification scheme in reducing leakage. The Leakage and Energy Certificate takes in random audits and regular inspections as well as a label for systems that qualify as ‘zero leakage.’ The result, Zaremski described, was an average leak rate across 74,000 refrigeration and a/c systems of only 3.2 percent. Sorted by refrigerant, R-134a systems totaled just 2.1 percent, while R-410A was just 0.82 percent, largely due to eliminating conventional flare nuts and soldering, he said. The success of the inspection regime could be clearly seen, he added, by the fact that the average leak rate for systems under 3 kg, which didn’t qualify for regular inspections, was significantly higher at 5.38 percent.
Content for the European Spotlight is provided courtesy of Refrigeration and Air Conditioning Magazine, London. For more information, visit www.racplus.com.
Publication date: 4/21/2014