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- EXTRA EDITION
The ‘R’ in Refrigeration Service Engineers Society (RSES) got its due at the 76th RSES Annual Conference and HVACR Technology Expo in Pittsburgh, Pa. Topics ranged from the latest trends in refrigerants to the servicing of equipment, from basic components to complex systems using such refrigerants. Training was available for beginners and professionals.
In his keynote speech, Robert Wilkins, vice president of public affairs, Danfoss, said, “Change is coming. Refrigerants are the largest single issue with a global perspective.” He called on contractors and technicians to become involved in developments because it would be better to solve a problem before it reaches the critical phase. He specifically referenced efforts globally to move from primary use of hydrofluorocarbons (HFCs) to use of carbon dioxide and hydrocarbons (HCs). He said current proposals to phase down production of HFCs within the context of the Montreal Protocol are not imminent but may come in two to three more years with a few more years to negotiate adaptations in various countries.
He encouraged contractors and service technicians to develop refrigerant management programs, and to stress inventorying of refrigerants. This would especially be beneficial in large supermarket chains, for example, with stores that had been using primarily hydrochlorofluorocarbon (HCFC)-22 and are facing closing or equipment retrofitting with non-HCFC refrigerants. The recovered R-22 could be inventoried by the chain for use in other stores still running well on R-22.
He also urged reducing leaks, noting supermarkets, on average, have 25 percent leak rates while even the best of the best in terms of leakage are at or near 15 percent.
He noted, “Refrigerants have value and the value of the inventory will increase. That’s the carrot. The regulatory and fining powers of the U.S. Environmental Protection Agency (EPA) are the stick.” The reference was to the possibility of the EPA imposing refrigerant regulations regardless of what might be happening from a global perspective.
He also said manufacturers are looking at new products to use CO2, HCs, and hydrofluoroolefins (HFOs), so “the role of RSES in training (regarding such refrigerants) will be more important than ever.”
Taking a look at the current trend of retrofitting systems designed for R-22 with an HFC refrigerant was Stephen Spletzer of Arkema Inc. He said such retrofits are important because the phase out in R-22 production will be completed in six years, leaving a large amount of R-22 equipment still in need of servicing.
He said the best option is to continue to use existing stockpiles of R-22, including gas submitted for reclamation. But there will come time to consider HFC retrofits. In fact, he noted the process is underway. “Last year, there was a lot of retrofit action in air conditioning, so we are getting feedback.” That is in addition to work that has started in the supermarket sector with refrigeration retrofits, he said.
A key point for Spletzer is that there are no HFCs that are drop-ins, so technicians have to be mindful of oil changes, elastomers, and O-rings among other aspects of retrofits. HFC retrofit characteristics and issues, including fractionization and glide, also need to be considered, he said.
The heart of a system, the compressor, also came in for updated review during the conference. James Bowman, national technical manager for HVACR, RectorSeal Corp., took a look at hard starts and the use of hard-start kits.
He said hard starts are needed when dealing with low supply voltage, poor quality of the power supply, undersized wiring, pressure differential at the start, multiple units running at once, and peak energy usage times. True hard-start kits, he said, consist of “a mechanical potential relay connected to a start capacitor that is wired into the compressor to aid in compressor starting.” He added, “It is important to know not only the differences between hard-start technologies, but what the effects of using the wrong hard-start components are in relationship to compressor life, warranty, and energy efficiency.” He further said that heat kills compressors, and discussed the proper method of testing a run capacitor.
The “Understanding Essential Refrigeration Service Components” presentation by Capitola Lau, channel sales manager for Ranco, an Invensys brand, got into the nitty-gritty of pressure-temperature enthalpy diagrams, selection and installation of solenoid valves, as well as thermostatic expansion valves (TXVs).
Regarding solenoid valves, Lau started with the basics. “Install solenoid valves when you need to control the refrigerant flow. Normally closed is when the coil is de-energized and the plunger stops the refrigerant flow. Normally open is when the coil is energized and the plunger stops the refrigerant.
“TXVs regulate the refrigerant flow into the evaporator by the superheat control.” Lau provided a comprehensive list of considerations to review when selecting a TXV including type of refrigerant, evaporator capacity, evaporating temperature, condensing temperature, liquid refrigerant temperature, pressure drop at the liquid line and evaporator, and connection flares.
She also covered dehydrators and filters. “Filters have been developed for specific installations on refrigerating systems using HFC or HCFC refrigerant fluids mixed with polyolester lubricants or mineral lubricants.” Hands-on lab work was included to reinforce the presentation.
The Professional Technician
Amidst all the highly technical presentations came one, “Peak Performance for the Technical Professional,” by Jim Johnson of Technical Training Associates. He began by saying, “There are enough resources for the technical side, but it is more of a challenge to deal with customers.” He said that may be referred to by such phrases as “soft skills, customer service, communication skills, morals, and ethics.”
In suggesting technicians take part in workshops related to such topics, he said, “The point here is that technicians need to be told up front that the focus of the workshop is the development of their ability to provide top-notch service to customers, and that the theory behind this philosophy has two fundamental components, which are a technical professional’s ability to recognize a customer’s needs and developing the skills to provide solutions for those needs.”
He added, “What it all boils down to for the technician is that, as a technical professional, you never expect to get something for nothing. You realize before you get something, you’ve got to put something in.”
Publication date: 1/6/2014