Managing the operation and maintenance of a facility's air conditioning equipment has always been a major responsibility, as chillers often represent the single largest electrical load in a facility. Since the annual cost of operating chillers is a major component in both the electrical and maintenance budgets, engineering and maintenance managers should take the necessary steps to ensure systems operate efficiently, effectively, and safely.
The phaseout of ozone-depleting refrigerants has made management of chillers and refrigerants even more important. The use of non-CFC refrigerants has changed the way chillers are manufactured and operated. To reflect these changes, new standards and EPA regulations have been introduced, and old ones have been modified or updated. Managers must stay on top of these changes if they are to keep their facilities in compliance and their chillers operating at peak efficiency.
Title VI Section 608 Refrigerant Leak Repair Regulations
Title VI Section 608 Refrigerant Leak Repair ReguChiller leaks have long been recognized as a major source of refrigerant emissions into the atmosphere. The current leak repair requirements, promulgated by the Environmental Protection Agency under Section 608 of the Clean Air Act Amendments of 1990, require that when an owner or operator of an appliance that normally contains a refrigerant charge of more than 50 lbs discovers that refrigerant is leaking at a rate that would exceed the applicable trigger rate during a 12-month period, the owner or operator must take corrective action.
For all appliances that have a refrigerant charge of more than 50 lbs, the following leak rates for a 12-month period are applicable:
- Commercial refrigeration — 35%
- Industrial process refrigeration — 35%
- Comfort cooling — 15%
- All other appliances — 15%
In general, owners or operators must either repair leaks within thirty days from the date the leak was discovered, or develop a dated retrofit/retirement plan within thirty days and complete actions under that plan within one year from the plan's date. However, for industrial process refrigeration equipment and some federally-owned chillers, additional time may be available.
Industrial Process Refrigeration
Industrial process refrigeration is defined as complex customized appliances used in the chemical, pharmaceutical, petrochemical, and manufacturing industries. These appliances are directly linked to the industrial process. This sector also includes industrial ice machines, appliances used directly in the generation of electricity, and ice rinks.
If at least 50% of an appliance's capacity is used in an industrial process refrigeration application, the appliance is considered industrial process refrigeration equipment and the trigger rate is 35%. Industrial process refrigeration equipment and federally-owned chillers must conduct initial and follow-up verification tests at the conclusion of any repair efforts. These tests are essential to ensure that the repairs have been successful. In cases where an industrial process shutdown is required, a repair period of 120 days is substituted for the normal 30-day repair period. Any appliance that requires additional time may be subject to recordkeeping and reporting requirements.
When Additional Time Is Necessary
Additional time is permitted for conducting leak repairs where the necessary repair parts are unavailable or if other applicable federal, state, or local regulations make a repair within 30 to 120 days impossible. If owners or operators choose to retrofit or retire appliances, a retrofit or retirement plan must be developed within 30 days of detecting a leak rate that exceeds the trigger rates.
A copy of the plan must be kept on site. The original plan must be made available to EPA upon request. Activities under the plan must be completed within 12 months (from the date of the plan). If a request is made within 6 months from the expiration of the initial 30-day period, additional time beyond the 12-month period is available for owners or operators of industrial process refrigeration equipment and federally-owned chillers in the following cases. EPA will permit additional time to the extent reasonably necessary where a delay is caused by the requirements of other applicable federal, state, or local regulations; or where a suitable replacement refrigerant, in accordance with the regulations promulgated under Section 612, is not available; and EPA will permit one additional 12-month period where an appliance is custom-built and the supplier of the appliance or a critical component has quoted a delivery time of more than 30 weeks from when the order was placed, (assuming the order was placed in a timely manner).
In some cases, EPA may provide additional time beyond this extra year where a request is made by the end of the ninth month of the extra year.
Relief From Retrofit/Retirement
The owners or operators of industrial process refrigeration equipment or federally-owned chillers may be relieved from the retrofit or repair requirements if: second efforts to repair the same leaks that were subject to the first repair efforts are successful; or within 180 days of the failed follow-up verification test, the owners or operators determine the leak rate is below 35%. In this case, the owners or operators must notify EPA as to how this determination was made, and must submit the information within 30 days of the failed verification test.
For all appliances subject to the leak repair requirements, the timelines may be suspended if the appliance has undergone system mothballing. System mothballing means the intentional shutting down of a refrigeration appliance undertaken for an extended period of time where the refrigerant has been evacuated from the appliance or the affected isolated section of the appliance to at least atmospheric pressure. However, the timelines pick up again as soon as the system is brought back on-line.
Minimizing Leaks Requires a Leak Management Plan
Restrictions on refrigerant releases and regulations on mandatory leak repairs have made chiller leak management and refrigerant conservation more important than ever. Maintenance engineers must be properly trained, and they must know what the specific regulations and requirements are in order to effectively manage refrigerant leaks and comply with EPA requirements.
While any maintenance engineer who services or oversees chillers should be knowledgeable about traditional preventive maintenance procedures for chillers, as well as steps to minimize refrigerant discharge, some of the maintenance steps that involve refrigerant handling and transfer must be performed by technicians who are specially trained and EPA-certified to do such work. Penalties for letting uncertified personnel service refrigeration equipment are substantial. Implementing a defined leak management program that incorporates regulatory requirements and good maintenance practices is one of the key components of successful refrigerant compliance management.
Today, the new regulations, rising prices of refrigerants, and reduction of energy efficiency of improperly charged refrigerant chillers demand a more comprehensive and sophisticated approach to refrigerant conservation and leak management. A leak management program should include the following:
- Develop a leak management plan;
- Implement a refrigerant recordkeeping system;
- Maintain existing equipment and refrigerant supplies; and
- Replace old or inefficient equipment.
Detailed records of equipment stocks and refrigerant are essential for making informed decisions about refrigerant usage and leak management. Priority should be given to equipment with the largest charge. Inventory sheets should individually list chillers and pieces of commercial refrigeration equipment. Information is needed on the manufacturer, model, serial number, year installed, capacity in tons, charge size, leak rates (based on records of recharging or “topping off”), refrigerant, and location. Small appliances — such as household refrigerators and window air conditioners, package units, vending machines, water coolers, and ice machines — should also be inventoried and can be recorded as groups. The quantity of refrigerant purchased, consumed, disposed, or reclaimed should be monitored and analyzed. Refrigerant inventories should be kept by type and should include the volume contained in each piece of existing equipment, as well as amounts that are currently stored. These inventories should be updated regularly. Local codes for storage limits should be consulted.
Develop a Plan, Then Keep Records
A good plan is based on accurate equipment and refrigerant inventories and usage. The plan should address compliance with applicable laws and regulations, continued supplies and service, reduced emissions, and recovery/recycling. The plan should emphasize responsible refrigerant handling practices.
Company polices and procedures regarding each of the following issues should be included:
- Refrigerant purchase, sales, and disposal;
- Safe transport of refrigerants;
- Refrigerant tracking and recordkeeping;
- Contaminated refrigerant guidelines;
- Leak testing, leak prevention, and leak repairs;
- Equipment and refrigerant inventory;
- Refrigerant storage;
- Certification for technicians;
- Penalties for noncompliance;
- Compliance audits and surveys;
- Refrigerant recovery, recycling, and reclaiming;
- Servicing practices;
- Refrigerant cylinder handling; and
- Venting and losses.
Tracking refrigerant leak repairs, refrigerant used, preventive maintenance performed, and refrigerant conservation practices are critical to successful leak management.
Log your chiller operation, maintenance procedures, and repairs. Create a log for each appliance containing refrigerant. Each log sheet should contain chiller model and serial numbers, manufacturer, asset number or identification number, location, age, type of refrigerant used, and the designed refrigerant charge in lbs. (You should have this information from your initial inventory performed above.)
Include a space to record each refrigerant leak: where the leak occurred, if it was repaired, and type of detector used and refrigerant added. Also include recovery/recycling equipment used, amount recovered, whether it was reused, other disposal methods used, and the amount of refrigerant added. Record any other refrigerant losses including a description of the situation that caused the loss, the amount of refrigerant released, and the amount added as makeup.
The EPA expects facilities professionals to know how their chillers are doing, even if an outside contractor is servicing the equipment. Refrigerant records are important for another reason: EPA will use those records to determine when the 30-day repair period begins. EPA enforces the leak repair requirement by inspecting buildings. Some inspections are triggered by complaints, but the agency also inspects buildings in targeted areas.
Maintaining Existing Equipment and Refrigerants
Conserving refrigerants through leak detection, equipment repairs, refrigerant recovery, and installation of high-efficiency purges is equally important. Air-Conditioning and Refrigeration Institute (ARI) Standard 740-1995, addresses the issue of leaks during refrigerant recovery and recycling. The standard establishes acceptable and realistic levels of refrigerant loss during recovery activities, and it sets testing procedures for certifying recovery and recycling equipment. Using equipment that conforms to ARI standards is essential to comply with the EPA requirements.
Management of existing refrigeration supplies is an important element of a leak management program. It involves the proper handling of refrigerants, including the recovery and recycling of refrigerants in equipment undergoing maintenance or replacement. Employees need to be trained in the correct use of recovery/recycling equipment usage and refrigerant emission minimization techniques during service. Replacing aging equipment is an opportunity to improve energy efficiency and performance while lessening the impact on the ozone layer. This option requires the greatest initial outlay of capital, but in the long run it may yield savings in energy, maintenance, and refrigerant costs.
Chiller manufacturers also are working to reduce refrigerant losses through basic design changes. Some new models offer annual leak rates as low as 0.5%; their lower leak rates will help organizations comply with regulations, conserve refrigerants, and keep chillers operating at peak efficiency.
Heed the Bottom Line
In addition to contributing to the wellbeing of the environment, there are significant financial incentives for establishing and maintaining good refrigerant management procedures.
- The impact of regulatory noncompliance. Noncompliance with EPA refrigerant regulations can result in severe penalties upon enforcement, including civil penalties up to $27,500 per day and criminal penalties of up to 5 years imprisonment.
- The financial impact of refrigerant losses. In the past, leaking chillers were tolerated due to the readily available refrigerant supply and inexpensive cost. Today, if a refrigerant charge is lost, the cost can be substantial. For example, a typical 500-ton CFC chiller that loses its refrigerant charge due to leaks or system malfunction could incur over $30,000 in refrigerant replacement costs.
- The financial impact of chiller efficiency losses. Refrigerant leaking from your chillers costs more than just the expensive replacement refrigerant. The loss of refrigerant also results in a loss of chiller efficiency. Chiller leaks result in a shortage of optimum refrigerant required for the design heat transfer in both the cooler and condenser. The result is a loss of efficiency, up to 12% in some cases, resulting in increased electrical demand to produce the same cooling effect. Prevention of these leaks will lower your power bills.
There are refrigerant management software programs on the market that can automate most of these requirements, including leak rate calculation, as well as help you with leak management and regulations compliance. A good refrigerant management software program should keep you on top of your refrigerant management and leaks, and pay for itself in less than a year. ES
Sidebar: Owners cool to chiller conversions
Despite a 1995 ban on the production of chlorofluorocarbons (CFC), organizations with chillers that use the ozone-depleting chemicals are replacing the equipment at a slower-than-expected rate.
Owners of CFC chillers converted only 4,231 units in 1998, according to a new survey of chiller manufacturers by the Air-Conditioning & Refrigeration Institute (ARI).
About 52,060 chillers — 65% of the estimated 80,000 CFC chillers in service in the early 1990s — required CFCs to remain in service at the start of 1999. At the current rate, ARI says, it would take until 2010 to eliminate use of CFC chillers in the United States.
In earlier surveys, manufacturers had expected that by Jan. 1, 1999, there would be many thousands fewer chillers competing for CFCs. With so many CFC units still in service, manufacturers will have steady demand for replacement chillers for many years longer than expected, according to ARI.
Despite the slower than expected phaseout, production in 1998 of 7,558 non-CFC chillers for use in the United States and abroad is almost double the rate of CFC chillers manufactured annually a decade earlier. The chart below shows replacements for the years 2000 and 2001 using centrifugal, screw, reciprocating, and absorption chillers.