HVAC Trends: Refrigerant Update
By Thomas E. Watson, P.E.
Published in the January/February 2013 issue of Today’s Facility Manager
Conversations about sustainable facilities typically focus on water conservation, energy efficiency, and building materials. Also important in this discussion is the need to reduce the impact of refrigerants on the environment. Emitted chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) refrigerants have been directly linked to the destruction of stratospheric ozone, which in the upper atmosphere shields the earth from harmful ultraviolet B radiation. These and hydrofluorocarbon (HFC) refrigerants also act as greenhouse gases with potential consequences for global warming and other climate change effects.
As industries transition away from ozone depleting and high global warming potential (GWP) substances, members of the facilities industry must turn to a more holistic analysis in their selection and regulation of refrigerants and the systems that use these chemicals.
Certainly, much progress has been made concerning the use of refrigerants to heat and cool indoor environments. At a recent conference on this topic hosted by ASHRAE and the National Institute of Standards and Technology (NIST), keynote speaker James M. Calm, P.E. shared his thoughts on refrigerant transitions and categorized the transition of refrigerants into four generations.
The first generation spanned from the 1830s to 1930s and could be characterized by “using whatever worked.” The second generation (1931 to 1990s) focused on safety and durability, which included introduction of CFCs and HCFCs as well as continued use of ammonia and, to a lesser extent, hydrocarbons. More recently was the third generation (1990 to 2010s) when industry concern turned to ozone protection and began the phaseout of CFCs and later HCFCs.
Now, the industry has entered the fourth generation of refrigerants with a focus on low GWP options. In his presentation, Calm emphasized the need to address the several application requirements and looming environmental concerns together. Piecemeal approaches will not meet the eventual targets. The industry must be forward-looking and make selections beyond minimum mandates. Otherwise, stakeholders will be forced to face still another generation of refrigerant transitions.
While traveling during 2012 for both my ASHRAE service and my work, I heard much conversation about the need for holistic analysis and an increasing focus on using low GWP refrigerants in high efficiency HVAC/R systems. Improving efficiency in air conditioners, heat pumps, and refrigeration will remain critical as the energy used and resulting combustion emissions has more significant impact on climate change than the refrigerants themselves. So it is critical that facility managers (fms) carefully address not only refrigerant selection and leak minimization, but system efficiency.
Programs And Initiatives
Currently, there are several programs and initiatives underway that focus on the technologies, methods, and means needed to accommodate the imminent phase-down of high GWP refrigerants.
One such measure is the cooperative Low GWP Alternative Refrigerants Evaluation Program (AREP) by the Air-Conditioning, Heating, and Refrigeration Institute (AHRI). Launched in March 2011, the program aims to identify and evaluate alternatives to high GWP refrigerants for major product categories, and to provide common sets of quality data. The products covered include air conditioners, heat pumps, chillers, water heaters, ice makers, and refrigeration equipment.
The AREP program seeks to help the industry select the most promising refrigerants, avoid duplicative work, understand technical challenges, and identify the research needed to use these new refrigerants. The program will not prioritize these alternatives; rather, it will identify potential replacements for high GWP refrigerants and present the performance of these replacements in a consistent, standard manner. There are currently 38 alternatives being evaluated.
Results of the AREP program so far were summarized at the ASHRAE/NIST conference, with the program expected to be complete by the end of the first quarter 2013. (Five completed reports can be downloaded on the AHRI website.)
Many of the new low GWP refrigerants are classified as mildly flammable under ANSI/ASHRAE Standard 34-2010, Designation and Safety Classification of Refrigerants, new 2L safety classification. In addition, ASHRAE Standard 15-2010, Safety Standard for Refrigeration System, is undergoing revisions to address the 2L classification.
Another project in development is the Guide for Sustainable Refrigerated Facilities and Systems by ASHRAE and the United Nations Environment Programme. This resource, slated for release in early 2014, addresses the entire range of facility and equipment design and efficiency alternatives for refrigerated processing, storage, and distribution (the cold chain) in both developed and developing countries.
The guide is also important as parties to the Montreal Protocol face upcoming compliance deadlines. For developing countries, that meant a freeze in HCFC consumption and production by January 1, 2013, followed by a 10% reduction in 2015 and a 97.5% reduction by 2030.
Currently, HCFC-22 is the preferred refrigerant for many facilities and systems, particularly for small and medium sized conditioners; this ozone depleting gas is being phased out under the Montreal Protocol. In the U.S., a ban on the sale and distribution of pre-charged new equipment containing HCFC-22 has been effective since January 1, 2010.
Meanwhile, ASHRAE is creating a voluntary refrigerant management plan, with initial publication planned in the U.S. In addition to proper cradle to grave management, the document will provide guidance on suitable refrigerants to be used to meet growing demand. The goals for this project include tracking and reporting refrigerant use and life cycle, minimizing environmental impact of refrigerant use, and raising public awareness of the environmental issues and the economic impact of refrigerant use.
So what can we as an industry do to reduce refrigerant impact on the environment? We need to focus on our efforts where they will have greatest impact.
We need to match the technology to the need. The contributions of fms, and all stakeholders, are needed to identify not just new options but those that will provide maximum benefit.
Watson, P.E., Fellow ASHRAE, Life Member is the 2012-13 ASHRAE president. He is chief engineer at Daikin McQuay located in Staunton, VA, where he oversees new product development for centrifugal compressor technology and is primarily involved in technical areas related to refrigerant applications, aerodynamics, bearing design, and motor applications. He holds five patents related to refrigerant, gas, and chiller compressors.