We’ve assembled a panel of plant operations experts to answer any question you have on plant-floor issues. To pose a question, go to www.FoodProcessing.com/ClarionKC. This month’s question was answered by Douglas Stricker, senior project leader at Hixson (www.hixson-inc.com), an architecture and engineering firm (513-241-1230).
Tip of the month
When is it likely that R-22 and hydrochlorofluorocarbon refrigerants will be phased out? Then what will we do?
The Montreal Protocol on Substances That Deplete the Ozone Layer is a 1987 international treaty designed to reduce greenhouse gas emissions. To comply with the timetable set forth in the act, U.S. production of Class I chlorofluorocarbon (CFC) refrigerants was halted in 1996. CFCs are considered to be most damaging of ozone depleting substances (ODS), chemicals that may impact the climate.
One alternative was Class II hydrochlorofluorocarbon (HCFC) refrigerants such as R-22. Because these refrigerants allowed companies, in most cases, to retrofit existing CFC equipment, this option was initially less expensive than replacement of equipment.
Yet it was not a perfect solution. Just like CFCs, R-22 and HCFCs are ODS and may impact the climate. Because of this, no new HCFC equipment is being produced. Plus, a 65 percent reduction in production of these refrigerants is mandated by Jan. 1, 2010.
While the complete phase-out of all HCFC refrigerants is currently scheduled to occur in 2030, a date that may seem far off, it is still something that needs to be reckoned with. In addition, current discussion at the federal level may speed up the phase-out to 2020.
Plant owners and managers need to consider:
- Alternatives available and how these will work within the operation.
- Age and service history of existing equipment and the difficulty of retrofitting, servicing and maintaining that equipment over time.
Those considerations should help determine whether you need to replace merely the refrigerant or the piece of equipment. The available non-ODS alternatives:
- Hydrofluorocarbons (HFCs) are an approved replacement for both CFCs and HCFCs for a retrofit and are not scheduled to be phased out at this time. However, while considered to be non-ODS, these refrigerants may impact the climate and therefore may also be placed on the phase-out list sometime in the future.
Should this happen, the same issues affecting HCFC refrigerants will occur for HFCs, such as decreased capacity and efficiency, along with an inability to obtain spare parts for aging equipment. For retrofits, some HFC options include: R-407c, R-417, R-422a, R-422d and R-507. Some of the HFC options for new equipment include: R-134a, R404a, and R410a.
- Non-ODS alternatives. Ammonia R-717 is the main non-ODS, non-climate-impacting refrigerant. As such, there is little danger that it will be phased out anytime soon. At the same time, ammonia is toxic and flammable, and facilities that use it may need to adhere to OSHA’s Process Safety Management of Highly Hazardous Chemicals standard (29 CFR 1910.119).
When considering conversion options, a goal should be to limit the number of different refrigerants used on site while maintaining the same equipment performance and capacity levels. Each replacement refrigerant poses different operating issues, such as capacity reduction, higher operating pressures and temperature glide.
If consideration is given to convert existing equipment, it is important to consider the current operating conditions of the equipment. If the existing systems were well maintained, they can be operated to the end of their expected service lives using the appropriate replacement refrigerants.
In reviewing existing equipment and considering the move away from Class II refrigerants, two big issues to consider are the probability of future leaks and age of the equipment. Because non-ODS refrigerants operate at higher pressures, a system that has been susceptible to leaks in the past and/or has reached the end of its useful lifecycle will have a higher leak rate than new equipment.
In general, it is better to replace these units with new equipment than convert them to a non-ODS refrigerant.
As a rule, most HCFC equipment has an average life expectancy of 10-20 years;
however, some can operate well past that date.
Equipment 20 years or older is generally a good candidate for replacement. This equipment will have reached the end of its useful life and newer equipment will typically have higher operating efficiencies.
Equipment in the 10-20 years range is difficult to bracket. Equipment condition, maintenance history, equipment capacity vs. load, and equipment operating efficiencies all must be taken into account. Companies may want to contact a qualified engineer to assess the usefulness of equipment at this age.
Equipment under 10 years is likely a good candidate for conversion. This age group usually reflects improved design efficiencies, and they are in the middle of their industry-standard lifecycles. However, equipment condition and leak history must be taken into account for each unit.
As with the conversion from CFC to HCFC, costs and speed of the return on investment certainly will be factors in whether to move completely to a non-ODS refrigerant or to use an HFC refrigerant to replace existing HCFC supplies. It is a decision that every company will face and should be based on the individual circumstances of the operation.
The most important thing, however, is to do something today. Consider all the options available and begin planning for the future by developing a long-term, comprehensive plan for addressing refrigeration conversion issues.