HVAC Refrigerants: A Balanced Approach

In the early years, the primary focus of the HVAC industry was simply on finding a refrigerant that would provide effective cooling. Many of the early refrigerants such as sulfur dioxide, methyl chloride and ammonia met that objective but posed safety hazards due to their toxicity or high flammability potential. In the 1930s, chlorofluorocarbon (CFC) refrigerants were introduced as safe alternatives to the chemicals used before them. CFCs came to dominate first refrigeration and later HVAC because of their safety and efficiency. Hydrochlorofluorocarbons (HCFCs) were added to the portfolio of refrigerant alternatives in the 1950s. In the 1970s, environmental concerns came into play. Scientists discovered that CFCs—and to a lesser extent HCFCs—were contributing to the depletion of the ozone layer. Montreal Protocol. Global concern about depletion of the ozone layer resulted in the Montreal Protocol, an international treaty that established phase-out dates for the use and production of ozone-depleting substances. It went into effect in 1987, first targeting CFCs, then HCFCs. CFCs were replaced with HCFCs, which have lower ozone-depletion potential (ODP), or with hydrofluorocarbons (HFCs), which have zero ODP. The CFC phaseout was completed in 1996. Due to their low ODP, the phase-out dates for HCFCs were set out later— from 2004 to 2030 (2040 in developing countries). Kyoto Protocol. In the 1990s, concerns grew that the refrigerants being phased in because of their favorable ODP were contributing to global warming. The global-warming potential (GWP) of refrigerants now became a factor. These concerns with global climate change led to the Kyoto Protocol, created in 1997. Kyoto set reduction targets for greenhouse gases, including HFCs, in developed countries. Because CFCs and HCFCs were already covered under the Montreal Protocol, they were not included in the Kyoto Protocol. Where we are today. Both protocols allow each participating country to control its own reductions of the refrigerants to meet their compliance obligations. In the United States, the U.S. Environmental Protection Agency (EPA) issued regulations under the Clean Air Act to phase out the One of the constant themes throughout the history of the HVAC industry is the search for a better refrigerant. When considering alternative refrigerants, manufacturers need to balance efficiency with environmental impact to determine the optimal replacement. This EN will provide a brief history of refrigerants used in the HVAC industry and the developing regulations. From there, we'll discuss considerations for new and existing equipment, along with refrigerant replacement options …