Saturday, September 19, 2009

R22 Conversion

Most HVAC/R programs have a large number of R22 air conditioning systems in their shop. The ban on the use of R22 in new equipment begins January 1, 2010 – only a few months away. Although R22 will be available for servicing existing equipment, the amount of new R22 available is scheduled to be reduced by 75% in 2010. The EPA and many people in the industry believe that this will create a shortage of R22 in 2010. What this all means is that R22 will become more expensive and harder to get. I began exploring for an R22 replacement refrigerant to keep our shop equipment operating when R22 is either not available or not affordable. I would like to share a few things to consider when examining potential R22 replacement refrigerants.

Whenever possible check with the equipment manufacturer. Chances are they have some insight into what works, and more importantly, what does not work. Copeland has a six page service bulletin that discusses conversion from R22 to R422A and R422D in commercial refrigeration systems.

Copeland 422 Conversion

Tecumseh offers five service bulletins that discuss R22 refrigerant conversion. They are available at

Tecumseh Service Bulletins

There are a number of replacement refrigerants offered to replace R22 in existing systems. However, even if the system operates and cools, there are some potential negative outcomes that you should be aware of before proceeding.

Make sure that any refrigerant you propose to use has been approved for use by the EPA. You can check the SNAP list to see if the refrigerant is listed.

EPA SNAP List

There are many hydrocarbon based replacement refrigerants for sale on the internet which are NOT approved by the EPA for use in the US. Some are even manufactured in the US, but they may not be used in the US.

For the most part, most manufacturers do not endorse refrigerant conversions. Just because the EPA approves a particular refrigerant does not mean that the manufacturers must approve its use. Using a replacement refrigerant that is not approved by the manufacturer usually means any warranty is voided.

Systems may lose their UL approval since the UL testing was done with the original refrigerant. Many alternate refrigerants have been tested and classified by UL, but many have not. Consult UL or the refrigerant manufacturer to find out if the refrigerant is UL classified.

Zeotropic refrigerants (400 series blends) should never be used for flooded chillers. The refrigerant will separate in the evaporator. Since nearly all replacement refrigerants are 400 series blends there are very few acceptable non-ozone depleting replacement refrigerants for flooded chillers.

Finally, the refrigerant manufacturers will help. Even if you decide to proceed without the equipment manufacturer’s help you are not entirely on your own. The refrigerant manufacturer also bears responsibility for the application of their product. All refrigerant manufacturers offer application bulletins and guidelines for the use of their products. A few are:

Dupont

Forane

Honeywell

Smaller companies that primarily manufacture replacement refrigerants obviously have an incentive to help. ICOR has one of the most interesting support ideas – a toll free telephone number which you can call to talk to an experienced service technician.

ICOR Help

For more detailed information on refrigerants check out Unit 23 Refrigerants and Their Properties in Fundamentals of HVAC/R. For specific details on complying with EPA refrigerant regulations check out Unit 26 Refrigerant Management and the EPA in Fundamentals of HVAC/R.

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