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Instructors heard from Jim Mowery, national sales manager for Bacharach Inc., on recovery methods, equipment, and safety. Mowery spoke from experience, having taught service techs on the subject and having a hand in the development of several refrigerant recovery machines on the market today.
He noted that a lot of people who use Bacharach instruments have no training in the HVACR industry, while others are often faced with misconceptions about refrigerant recovery.
"Unfortunately, we have to train some people who have been trained improperly," Mowery said.
He said that a whole new industry revolving around refrigerant recovery was created from the Montreal Protocol, which pointed out the harmful effects of chlorine on the Earth's ozone layer and the need for chlorine recovery. Mowery added that 75 percent to 85 percent of ozone depletion is caused by human activity.
Human activity also includes illegal discharge of refrigerants. According to Title VI of the Environmental Protection Agency's Clean Air Act, criminal fines can be levied for discharge.
Refrigerant Methods And EquipmentMowery said that early recovery methods were "vapor only" and now the most prevalent method is liquid vapor recovery. He added that there are "pull liquid charging" and "push liquid recovery" methods which are not always easily understood or applied correctly.
"There are residential and commercial recovery machines that are not adequate to do the job," he said.
"Some are used to pump refrigerant instead of the intended use of recovery.
"The push method evacuates 15 pounds per minute as opposed to the pull method which evacuates five pounds per minute."
Mowery added that the new refrigerant R-410A takes extra work and tools for recovery, such as higher-pressure hoses and different sets of gauges. He noted that there are many misconceptions about R-410A and "people need to be educated about the differences."
He also said that cylinder capacity will vary depending on temperatures and atmospheric conditions. To compensate for the differences, some cylinders are fitted with an 80 percent shutoff feature, which takes the place of a scale or gauge.
Recovery TipsMowery offered five important tips on refrigerant recovery, noting that speed is the most important.
1. Use the shortest possible hose for the job.
2. Identify the refrigerant being recovered.
3. Always pump liquid out of the system first and then recover remaining vapors.
4. Use liquid push or pull method with large amounts of refrigerant.
5. When possible, recover from the high and low service ports on the system.
Mowery added that it is important to understand the markings on the cylinders and tanks. "Understand that the knobs on top can be color-coded differently based on the manufacturer," he said. "Read the knobs first."
Publication date: 08/15/2005