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AC Refrigerant: A Really Hot Topic

AC Refrigerant maintenance
September 2017

As maintenance teams look back at the number of air-conditioning service calls they performed this summer, some might want to check out their supplier partner’s catalog or website and review the myriad repair options. Add to these choices the challenge of finding appropriate training resources to guide the average maintenance staff person and the community is left with a troubling—and potentially expensive—decision to make.

All refrigerants are to be treated as controlled substances. (Beginning January 2018, this includes hydrofluorocarbons (HFCs), organic compounds that contain fluorine and hydrogen atoms. For information, the Environmental Protection Agency has produced a fact sheet that can be found at epa.gov.

The price of R-22 refrigerant continues to rise because of its increasing scarcity. This cost is driving owners and management companies to seek options. Two options communities can consider are to keep their R-22 equipment operating as long as possible, putting off the cost of replacement for a couple more summers; or replace the system with one that uses R-410A.

R-22 Option: Keep the Existing Equipment

In August, the price of R-22 was more than $800 for a 30-pound jug. With a price that high, it is cheaper to replace a condensing unit ($600 to $700) than it is to buy the refrigerant that the system was designed to use. To keep the existing equipment — and to spend less than the current price of R-22 — there are several ways of doing so:

  • Recycle existing R-22. This option is the least expensive. It can require extra service time because of the time and administration of tanks and to ensure that the cleanest of refrigerants is used. A technician can recycle refrigerant by testing it for acid before removing it (recovery) from the system. If acid is discovered, the refrigerant must be recovered to a “dead” tank; meaning that it will never be reused and turned in for reclamation. For best results, the technician will need to recover the good, used refrigerant through an inline filter dryer to help remove moisture. This refrigerant then may be used in the repaired system or any other system elsewhere at the same community.
  • Retrofit the system to an HFC replacement. (Note: This option is not recommended by HVAC equipment manufacturers and will void any accompanying applicable warranties.) There are several refrigerants sold as being a “drop-in” replacement for an R-22 system at a much lower price. (Do not mix any refrigerant.) Any of these retrofit refrigerant manufacturers state that their product will operate in existing systems with correct installation. There are a couple of warnings for this option.

1. Every retrofit refrigerant is less efficient than R-22. In some situations, a retrofit may not maintain the temperature that the thermostat demands during high-demand days.

2. Every retrofit is different than R-22. Each option will have its own pressure temperature chart that must be referenced for correct charging.

3. If your community decides to change to a retrofit refrigerant, a good recommendation is to choose ONE option. Each different refrigerant added to a community increases the potential to mix refrigerants. When that happens a technician is introducing further problems to a community.

R-410 A Option: Replace the System

This option can be summed up in a simple statement: “Out with the old, in with the new.” Currently, the only residential split-system air conditioners use R-410A refrigerant. This system is the most common one used in apartments. While it may be possible to use these

with part of the existing infrastructure, each instance should be separately evaluated. There are many variables that may determine if any of the current equipment can be effectively repurposed. These potential challenges to the new equipment can include:

  • Lineset age, diameter and length
  • Indoor equipment age and manufacture
  • Metering device size and type
  • Air-flow demand
  • Recent upgrades (insulation, windows, etc…)

HVAC Service Tips

Performing proper service is critical. If the refrigerant system is ever opened to the air, a proper vacuum (down to at least 500 microns) must be performed. And, a filter dryer must be installed if none is on the system or, if one exists, it must be replaced.

  • Before adjusting or checking the amount of refrigerant in a system, the air-flow should be verified. This means that all registers need to be open, the coils clean (both indoor and outside) and the filter replaced.
  • The correct amount of refrigerant must be placed in the system. To calculate, a technician has only three options: weight, superheat or sub-cool. The proper method is determined by the system’s design and the manufacturer’s specifications.