Refrigeration Tech Talks Refrigerants
A day in the life of a refrigeration service tech provides a lot of different tasks — tasks that include working with a variety of refrigerants. And Troy Singer has seen his fair share of refrigerants in his brief career as a supermarket refrigeration/HVACR service technician apprentice for Fazio Mechanical Services of Pittsburgh.
The third-year technician said his workload is around 70 percent supermarket refrigeration and 30 percent HVAC. “We also have some light commercial accounts that include gas stations with walk-ins, ice machines, and reach-ins,” Singer said.
His daily duties include complete monthly preventive maintenance checks at stores under contract with Fazio. “This includes a thorough refrigerant leak check (perhaps the most critical part of a PM [preventive maintenance]), cleaning all self-contained unit condensers, and changing air filters on the associated units,” Singer said. “I also check case airflow and all fans in walk-ins and condensing units. Basically a preventive maintenance check helps to prevent little problems from becoming disasters.
“Finding a ‘little leak’ keeps a tech from going on a call in the middle of the night because a ‘little leak’ turned into a blower that sets the store leak detector off. Maintenance helps to keep emergency calls down and the stores are in better shape.”
Working With Refrigerants
Singer gets his taste of everything by being on 24/7 call and that includes working with a number of different refrigerants.
He listed some of the refrigerants he works with. “R-22 is used primarily in medium-temp applications (coolers and some low-temp racks that have demand cooling due to the high discharge temps associated with R-22),” Singer said. “Most of our HVAC RTUs use 22 as well.
“R-404A is our primary low-temp refrigerant. It is also being used in some of our newer stores for medium-temp applications. This is, of course, because of getting away from HCFC's to HFC refrigerants. R-402A (HP-80) is also used in some of our older stores that had R-502 at one time. R-401A (MP-39) is rare on racks in our stores, but I know of one store for sure that uses it as an R-12 replacement gas.
“I know of one store that has a glycol system, but I have only been there once, so I do not know much about it.”
Singer noted that the major changes he has seen over the past few years involves the phasing out of HCFCs. “R-22 in supermarkets is moving into R-404A,” he said. “I have seen two of our stores go from two of their R-22 racks to R-407A.”
Singer said he enjoys working with top-of-the-line equipment that uses a variety of different refrigerants, and much more. “The positives are learning how a rack system works mechanically and how the rack controller monitors all of the case temps, defrost schedules, alarms, and countless other variables that take years to gain a full knowledge and confidence in.
“One of the more interesting changes I’ve seen was in a small market that had perhaps 16 refrigeration split systems was changed over to one split-suction rack with R-404A,” Singer said. “It’s nice because it’s all on one system with a Danfoss rack controller, which means saying goodbye to all those remote condensing units.”
Singer explained that one of his least favorite parts of being a refrigeration tech is having to be on call, especially when he is called while preparing to go to sleep for the night. “Few people understand the physical and mental stress that can be part of this job,” he said. “I walked into a motor room the other day on a holiday weekend and all three racks were silent. It was an easy fix, but silence is never a good thing in refrigeration.
“Some of the middle-of-the-night service calls you have may beat you down, but at the same time they are the greatest blessing, because I never forget what it takes to fix that equipment while everyone else is home in bed sleeping.
“The middle-of-the-night calls are tough but in the end, you help prevent a store from having product loss and that is worth the effort.”
Publication date: 09/26/2011