As the need for alternates looms, contractors would be wise to develop a comprehensive strategy (Part I).
October 1, 2013 by Dave Demma
Do you remember when you were in grade school? The days in class seemed to pass excruciatingly slow, especially approaching the Christmas break. I recall getting out of school the Friday before Christmas, and it always seemed like an eternity before the big day finally arrived. Nowadays, it seems like months pass at the rate that days used to pass.
So, what has this to do with the R-22 situation? Well, for nations that have subscribed to the terms of the Montreal Protocol, January 1, 2020 is the beginning of life without the manufacturer or importation of new R-22. That day will be here before you know it.
While prices have increased over the past few years, there is currently a good supply of R-22. There will be some R-22 available on January 1, 2020; however it is likely to be in limited supply. More importantly, it is likely to be expensive.
Equipment owners are acutely aware of the current R-22 situation, as the invoices they pay for service and repair bills reflect the above mentioned pricing increases. As prices continue to rise, contractors can expect to field questions from their customers about alternatives to the high refrigerant prices. As such, it would be prudent for every contractor to develop a comprehensive R-22 strategy, and discuss it in detail with the sales and technical personnel. As important as it is to have a good strategy, it is equally important that the contractor’s staff deliver a unified message to the customer base.
So…what is that strategy?
As a start, do not panic. There is a good supply of R-22 available and there will be for some years to come. It would be best to take the time to study the various options, formulate a comprehensive conversion plan and then implement it as needed.
There are really two major decisions to make when formulating a refrigerant conversion strategy: when and what.
The when is self explanatory. At what point does it become in your customer’s best interest to convert the system from R-22 to an R-22 alternative. There is no need to arbitrarily start converting R-22 systems to the alternative flavour of the month. Systems that are operating properly, and more importantly, not experiencing catastrophic refrigerant leaks, do not need to be converted immediately. They can be properly maintained and possibly be kept in service until their useful life has passed. When that time comes, replacing the older equipment with something current will remove R-22 from the discussion.
Now, it is not conceivable that every R-22 system in use will operate trouble free for the remainder of its time in service. That fact is the beginning of determining the “when” part of the strategy. (Note that these factors all assume there is a plan in place.)
• For larger systems that undergo annual maintenance, plan to change the mineral oil to POE. This will eliminate one of the major obstacles in an easy conversion to a refrigerant that requires POE, and make a conversion simpler.
• One of the expenses involved in a refrigerant conversion is the labour and materials (reclaim machine and recovery cylinders) necessary to remove the R-22 charge from the system. In the case of a catastrophic refrigerant leak, this step has been eliminated. It becomes a simpler and less expensive conversion.
• When the system experiences a compressor failure, a replacement compressor with POE can be acquired. This eliminates the extra step in replacing the oil. In addition, for those small- to medium-sized systems requiring refrigerant recovery as part of the compressor replacement process, this necessary step in performing a refrigerant conversion now takes place without any additional expense when replacing the compressor.
In addition to converting refrigerants as part of repairing a system failure, there are a few other drivers, which would prompt consideration of a conversion.
• Some systems seem to experience perennially large refrigerant leaks. While the prudent course would be to repair the leaks, sometimes the age of the system guarantees that there will be a constant supply of leaks for years to come. In these cases, the total system charge combined with the annual leak rate will determine whether a refrigerant conversion is justified. See Table 1 for some examples:
• For equipment owners such as supermarket chains or building owners who have multiple locations utilizing R-22, converting some percentage of their systems each year will “kill two birds with one stone” as it were. It will reduce the number of systems that are subject to the higher priced R-22 when refrigerant is required for recharge after experiencing leaks. In addition, the recovered R-22 can now be used to supply replacement refrigerant for the remaining R-22 systems.
Now for the “what” part of the strategy: which refrigerant will be the refrigerant of choice for R-22 conversions? There are many options available and each has its plusses and minuses. But, just as there were no perfect replacements for R-12 or R-502, there is no perfect replacement for R-22. And the term “drop in” is a misnomer. There is no single replacement refrigerant with properties that are identical to R-22.
When choosing the replacement that best suits the system being considered for conversion, the following properties and issues must be considered and compared to the properties and issues peculiar to R-22:
• COP (Coefficient of Performance)
• Thermodynamic properties of the conversion refrigerant
• Pressures of the conversion refrigerant
• Cooling capacity of the conversion refrigerant
• Discharge temperature of the conversion refrigerant
• Has the compressor manufacturer evaluated compressor performance and wear with conversion refrigerant
• Oil requirements of the conversion refrigerant
• Environmental concerns (conversion refrigerant GWP)
• Price and availability of the conversion refrigerant
• Complexity of the conversion (TEV and/or refrigerant distributor replacement required)
• Seal/gasket replacement required
I am certain that the anticipation of learning which refrigerant is the best all around choice is almost getting to be too much. Unfortunately, the answer to that question will have to wait until the next issue, as the discussion of all of the pertinent factors in making that decision is a lengthy one. Be sure to check out the December issue for Part II. <>
Dave Demma holds a degree in refrigeration engineering and worked as a journeyman refrigeration technician before moving into the manufacturing sector where he regularly trains contractor and engineering groups. He can be reached at email@example.com.