In eight years, the most common air-conditioning refrigerant in the world, HCFC R-22, will be phased out of production. It is likely that your school uses this refrigerant in its air-conditioning system. While this is hardly a doomsday proclamation — in fact, it should be celebrated for environmental reasons — it does require administrators to think ahead when making decisions about their capital investments. Knowing a few phaseout dates and refrigerant alternatives will help school officials decide whether to replace, repair or retrofit their cooling systems.
From invention to extinction
Along with space flight and computers, refrigeration made the “top 10” list of greatest inventions of the 20th century. The refrigerants used in these systems changed very little since the 1920s when CFC R-12 was used in the first centrifugal chiller. The fledgling air-conditioning industry grew into a multibillion dollar industry, and refrigerants fueled their growth.
But by the end of the century, the two refrigerant families most commonly used in air-conditioning systems — CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons) — made another list — the extinction list. The chlorine in these substances damages the ozone layer, and the refrigerants are being phased out in accordance with the Montreal Protocol of 1987. Signed by 180 nations, this worldwide agreement targets CFCs and HCFCs as ozone-depleting substances, and requires that they be phased out over the 40-year period that began in 1990.
To replace CFCs and HCFCs, a new family of refrigerants was developed. HFCs (hydrofluorocarbons) are ozone-friendly and safe for daily use in schools. A common HFC, R-134a, is widely available as a refrigerant in large cooling systems. It is a direct replacement for CFC R-12 and is already the workhorse refrigerant of the foreseeable future.
Whether to repair existing equipment or replace it — and when — are key decisions administrators will face as a result of the Montreal Protocol. For example, what is the expected life of your existing equipment, and how long will the refrigerant in it be available? If you're thinking about a new purchase, what type of refrigerant does it use and how much longer will it be manufactured? Phaseout dates and replacements will influence those decisions.
The Montreal Protocol and the EPA Clean Air Act
Two laws — one international, the other national — regulate the phaseout of ozone-depleting refrigerants. On December 31, 1995, production of CFCs stopped under the terms of the Montreal Protocol. Until then, CFC R-11 and CFC R-12 were the most common refrigerants for air conditioning. Now, these refrigerants are available only from reclamation (reclaimed refrigerant from systems no longer in operation), and only for servicing systems already in use.
Also on the phaseout list are HCFCs. This group includes R-22 and R-123, which still have some chlorine that damages the ozone layer. To replace them, manufacturers are developing refrigerants safe for operation and the environment. This third generation is the HFC family.
With the CFC phaseout behind us, the current emphasis is the phaseout of HCFC refrigerants. The Montreal Protocol accomplishes this gradually. For example, all HCFC production is already capped at the 1989 production level, and by 2004, HCFC production must be at 65 percent of the cap. The Montreal Protocol treats all HCFCs equally, and does not specify that production of one stop before another.
The United States has modified the Montreal Protocol so that substances more dangerous to the ozone layer are phased out sooner, thus allowing more common refrigerants to be in production longer. This is accomplished under the EPA Clean Air Act of 1992 (Section 604). For example, in 2003 the EPA will stop production of HCFC R-141b, a foam-blowing agent not used in refrigeration, so that HCFCs R-22 and R-123 can remain in production for a longer period.
Your school probably uses HCFCs (such as R-22 and R-123), HFCs (such as R-134a or R-410a) or both in its air conditioning systems. Here are some recommendations for making sense of these refrigerants:
Safe, efficient, and available for the foreseeable future. HFC R-134a soon will replace R-22 as the most popular refrigerant in the world. HFCs do not contain chlorine, have no ozone-depletion potential, and are classified by ASHRAE Standard 34 as being just as safe as their predecessors (low toxicity and low flammability). All positive-pressure centrifugal chillers and screw chillers now are being designed for R-134a. If you buy equipment that uses R-134a, you are prepared for the future.
Widely available, but support will decrease. While it's currently the most popular and versatile refrigerant in the world, HCFC R-22 cannot be used in new equipment after 2010. A small amount will be manufactured to service equipment until 2020, when its production will stop completely.
If your equipment runs on R-22, you can continue to operate it for its useful life, even after the phaseout date. Like all “extinct” refrigerants, R-22 is grandfathered in the United States. Once the systems are in the field, they can stay in the field. Because R-22 is so popular, there should be enough reclaimed refrigerant for service and repair without a significant increase in the price.
The industry is still developing replacements for R-22. There is no exact replacement for R-22 in the same way that 134a is a direct replacement for R-12; different refrigerants will replace various applications of R-22.
In general, screw chillers and other large machines over 150 tons will use R-134a as a replacement for R-22. In small systems, R-410a will be the main replacement for R-22 within the next 24 to 36 months. Currently, R-410a is available for residential refrigeration and for commercial water-source heat pumps. It will be widely available for commercial refrigeration as soon as manufacturers finalize development of cost-effective systems.
Available for 18 more years, but it has no current replacement as of yet. Used almost exclusively in negative-pressure centrifugal chillers, R-123 replaces CFC-11. It will not be available for new equipment after 2020. From 2020 to 2030 it will be available only for service, and after 2030 only from reclamation.
There is no clear replacement for R-123. The two closest HFC refrigerants are R-245fa and R-245ca. R-245ca was found to be flammable, so it is not a good candidate. R-245fa may work as a replacement for R-123, but it operates at a slightly higher pressure and cannot be used as a replacement in existing equipment. Although you will be able to operate R-123 equipment for its useful life, keep an eye out for replacement technologies as they are developed.
What about retrofit?
The market's experience with the CFC phaseout that began in 1995 may help you decide whether to retrofit your HCFC equipment. Then, the viewpoint was that the price of phased-out refrigerants would skyrocket with dwindling supplies, and owners would either buy new equipment or retrofit their existing systems.
It turned out there was plenty of reclaimed refrigerant for service, enough to keep the price stable and chillers in good repair. Owners tended to run their R-12 or R-11 equipment for its useful life, buying refrigerant as they needed it, and replacing the system when it wore out. To date, about half of the existing CFC chillers have been replaced. In comparison, a retrofit chiller can cost as much as $50,000 to $75,000, and it often made more sense to buy a new one. Nobody can predict for sure, but based on this experience, and remembering that there are ample inventories of R-22 refrigerant, it is possible the HCFC phaseout will follow a similar pattern.
Although there will be plenty of R-22 refrigerant available for service, one alternative is to retrofit an R-22 system with R-407c. Depending on the equipment, there may be a performance loss, so check first with the manufacturer to make sure R-407c is a viable retrofit refrigerant.
Plan now for the future
The age of your school's air-conditioning system, the cost to maintain it, and the cost to replace it are all factors to weigh as HCFC refrigerants are phased out. Your best preparation for the future would be to take an inventory of the types of refrigerants in your school, determine which, if any, are being phased out, and recommend some replacement alternatives. You will have taken a big step toward efficient, cost-effective operation, and a bigger step toward making the world a greener place.
Amount of U.S. energy consumption attributed to the operation of buildings.
Number of nations that signed the Montreal Protocol in 1987, which required the phaseout of CFCs and HCFCs.
Year that the CFC phaseout began.
Portion of existing CFC chillers that have been replaced.
Sidebar: A molecule of chemistry
For years, CFCs and HCFCs provided the safety, stability and efficiency required for air-conditioning systems. However, they contain chlorine, and chlorine damages the earth's ozone layer.
CFCs and HCFCs are stable molecules and do not react easily with other substances, which gives them a long atmospheric life. This long life allows CFCs and HCFCs to rise high up into the stratosphere where ultraviolet light decomposes the CFC and HCFC molecules and frees the chlorine. Ozone, being reactive, quickly breaks down in a catalytic process when exposed to the free chlorine. A single chlorine atom can destroy thousands of ozone molecules, thus thinning the earth's protective ozone layer.
The concentrations of CFCs, HCFCs and other ozone-depleting substances in the lower atmosphere peaked in 1994 and now are slowly declining. Recent evidence suggests that concentrations in the stratosphere also may have peaked. The ozone layer is expected to return to pre-industrial levels by the middle of this century.
SIDEBAR: Efficiency and the Kyoto Protocol
The Montreal Protocol attempts to protect the ozone layer by preventing the direct release of refrigerants into the atmosphere. A corresponding agreement, the Kyoto Protocol, regulates greenhouse gases and the resulting effect of global warming on the earth's atmosphere.
HFCs are included in a “basket” of six greenhouse gases whose collective emissions must be reduced. Although R-134a is an HFC, only its emissions are regulated. There is no phaseout date for HFCs.
About one-third of the energy in the United States is consumed in the operation of buildings. The energy used to operate a refrigeration system comes primarily from burning fossil fuels. The carbon dioxide released in this process contributes to global warming. The more efficient a refrigeration system, the less carbon dioxide released. Approved in 1997, the Kyoto Protocol is intended to reduce carbon-dioxide emissions. The United States has not ratified the Kyoto Protocol.
Crowther, PE, is application director for McQuay International, Minneapolis, which delivers engineered, flexible solutions for commercial, industrial and institutional HVAC requirements.