Refrigerant round up

Engineered Systems, Oct, 2002 by Caroline Fritz

It has been a relatively quiet year for refrigeration.Chlorofluorocarbons' (CFC) phaseouts continue to-move at a glacial pace, thesearch for alternative refrigerants continues, and new releases have been charting a course in the post-CFC world.

Sure, you know that the modern commercial air conditioner celebrated its 100th anniversary this past July. But did you know that CFCs celebrate their 74th anniversary as well? GM employees Thomas Midgley Jr. and Charless Kettering received a patent on December 31, 1928for invention of the first CFC, which was given the trade name Freon. Not only has Freon been used for air conditioning and refrigeration, but also as a propellant in spray cans. Everyone knows what happened next: Freon was accused of depleting the ozone layer and was banned in the 1990s.

According to the United States Environmental Protection Agency (EPA), the ozone layer is currently depleted at 5%. Without the CFC ban, this depletion rate could have reached 20% or more, the agency said. The ozone layer is expected to recover around 2050.

The "Montreal Protocol on Substances that Deplete the Ozone Layer" effectively restricted the use of GFC- and hydrochlorofluorocarbon- (HCFC) based refrigerants by the countries that signed the agreement. The manufacture of CFCs was banned at end of 1995, and HCFC production will be banned in the United States beginning on January 1, 2004. This HCFC phaseout will be accomplished by a combination of consumption and production caps, with a worldwide ban scheduled by 2030. As a replacement refrigerant, hydrofluorocarbons (HFCs) are being used.

Chiller replacements and conversions have been slow since the CFC ban was announced. One reason, especially this year, said Edward Dooley, Air Conditioning and Refrigeration Institute (ARI) spokesperson, is the national economic downturn. In 2001, 7, 171 non-CFC chillers were shipped for new buildings and replacements, a 7% decrease compared to 2000.

There are more than likely additional reasons for the continuing slow changeover. An informal survey taken by Engineered Systems in 2000 found that chillers weren't being replaced because of money issues, existing CFC-based chillers were still in good condition, and refrigerant reclaimed from converted machines was sustaining other nonconverted machines.

According to ARI's annual survey of large-tonnage liquid chiller manufacturers, more than CFC chillers will still be in use after which translates into 48% of the original CFC chillers that will still use the banned refrigerants. During 2001, 2,391 CFC chillers were converted to non CFC refrigerants or replaced by new non-CFC equipment, with 3,124 more expected to follow suit in 2002.

At the current pace, it will take manufacturers until the end of the decade to phase out the thousands of CFC chillers still in use, said.

The EPA is urging facility owners to replace their equipment earlier than that, stating "A new energy-efficient chiller can easily pay back the investment cost of replacing an old CFC chiller in five years or less in virtually all locations that cool for more than three months a year. In fact, replacement chillers can pay for themselves in as little as two or three years, with a typical return on investment of 20% to 35%."

The EPA has reported that using alternative refrigerant chillers adds up to billions of kilowatt hours of electricity saved annually.

THE EUROPEAN INVESTIGATION INTO HFC'S

Although HFCs are considered a viable, long-term refrigerant substitute, attendees at the Purdue University Compressor and Refrigeration Conference (West Lafayette, IN), held in July, heard papers debating this position, at least in Europe.

Francois Billiard, director of the International Institute of Refrigeration, in remarks at a joint session of the 16th International Compressor Engineering Conference and the 9th International Refrigeration and Air Conditioning Conference, said that governments in Denmark, Austria, and Switzerland have begun efforts "that could phase out HFCs in their countries within five years." The HFC global warming potential is a cause for alarm for some researchers.

The conference also focused on the role that other substances, such as ammonia and [CO.sub.2], will play as refrigerants in the future. Two researchers from India stated that, "Natural refrigerants like [NH.sub.3], [CO.sub.2], hydrocarbons, and water, which have no ozone depletion potential and negligible global warming potential, are the best long-term alternatives that can replace CFCs."

Several projects have gone on-line in Europe using [CO.sub.2] in conjunction with ammonia, although, according to researchers, more investigation is needed to improve [CO.sub.2] system performance.

REFRIGERATION LITERATURE

ASHRAE has demonstrated its commitment to the research of ammonia technology.

At ASHRAE's Winter Meeting, held Jan. 12-16 in Atlantic City, the organization approved the "Ammonia as a Refrigerant Position Document" which commits the society to several initiatives, including continuing research on ammonia topics such as handling, application, operation, control of emissions, and new technology; maintaining and developing standards and guidelines for practical and safe application of ammonia in refrigeration systems; and providing programs and publications on innovative designs and application of ammonia refrigeration.