Are you ready for the CFC phase-out?

CFCs or chlorofluorocarbons were first developed in the 1930s. Although CFCs possess excellent heat transfer characteristics, they do not break down in the lower atmosphere when released. Instead, they are able to reach the stratosphere, where ultraviolet rays break them up, causing a release of chlorine atoms which destroy ozone. The most recent evidence from NASA indicates an annual loss of 3 to 5 percent of stratospheric ozone during the past decade. Therefore, the U.S. and more than 80 other countries reached a landmark pact to halt the production of ozone-eating chlorofluorocarbons or CFCs.

The CFCs named in the Clean Air Act include CFCs 11, 12, 113, 114 and 115 and the HCFCs. Those most commonly associated with large system air-conditioning are CFCs 11, 12 and HCFC-22. As of July 1, 1994 only 78 weeks or 546 days of CFC production remains. Dupont announced that it would stop CFC production at the end of 1994, one year ahead of schedule. In 1994 and 95, CFC production cannot exceed 25 percent of the 1986 level. DuPont, a major CFC producer, predicts that demand for CFC-11 will exceed the supply, making a shortfall of 2.7 million pounds. It means roughly 10,000 low pressure centrifugal chillers will have to do without a supply of CFC-11 in 1996.

Shortages will put price pressure on CFCs. In addition, hefty excise taxes are accelerating the price pressure. The excise tax on CFC refrigerant this year is $3.35 per lb. In 1994, it will be $4.35 per lb; in 1995, $5.35 per lb. After the CFC phaseout, the excise tax will increase from $5.80 per lb. in 1996 to $7.15 per lb. in 1999.

It is necessary for the equipment owners to establish a thorough program to conserve all refrigerants now in use. The program should include periodic leak testing and repair to eliminate refrigerant emission; the addition of high efficiency purge systems where necessary; proper handling, recovery, recycling, reclamation and disposal of refrigerants; and required training for operating and maintenance personnel. ASHRAE Guideline 3-1990 gives specific recommendations on how to reduce the emission of refrigerant.

Owners of chillers using CFC refrigerants face decisions resulting from regulations on use and future availability of refrigerants. They can proceed with one of these options: Continue using the CFC refrigerant, but modify the unit so emissions are minimized and refrigerant can be recovered and reused. This is a containment strategy. This option has low first cost but could face CFC shortage problems after CFC phaseout.

The other option is to remove the chiller and replace it with either a new chiller using an HFC or HCFC refrigerant, or an absorption chiller. This replacement strategy is likely to be more expensive from a first cost standpoint. The leading candidates emerging as alternate refrigerants are HCFC-134 (R-123) to replace R-11 and HFC-134a (R-134a) to replace R-12 and R-500.

Analyze the age and condition of your existing chillers. If your chiller is nearing the end of its life (20 years or more), replace it as soon as possible and recycle the refrigerant to service other machines. If the chiller is relatively new, conversion strategy is probably the way to go. With the conversion, ventilation and refrigerant monitoring should also be addressed. Decision about chillers in mid-life are difficult. You may need the help of independent consultants in making decisions. Management may not like the costs of replacement and/or conversion of chillers, but the cost of procrastination will be higher and more uncomfortable.