プロジェクト概要

Modern society is dependent on refrigeration to process, store, and transport food, as well as on air conditioning in the built environment and motor vehicles. Reliable and cost-effective cooling is also critical for other commercial and industrial processes, such as in pharmaceutical and chemical production, oil refining, aerospace and defense technologies, data servers, and ice rinks. These diverse applications typically rely on refrigerants, the chemical coolants that can reach low temperatures and transfer heat by undergoing a phase change between liquid and gas (through condensation). Up until the mid-1990s, chlorofluorocarbons (CFCs) were in widespread use as refrigerants. CFCs destroy the Earth’s protective ozone layer and are also powerful greenhouse gases (GHGs). Under the Montreal Protocol and United States Clean Air Act, nearly all CFC production ended in the United States in 1996. As a result, many applications transitioned to using hydrochlorofluorocarbon (HCFC) refrigerants, which also contribute to ozone depletion and climate change, although to a lesser extent than CFCs. With the phase out of HCFCs currently underway, the most commonly used refrigerants today are hydrofluorocarbons (HFCs). HFCs, while safe for the ozone layer, are also powerful GHGs when released to the atmosphere. Across the various refrigeration and air conditioning applications, there are a number of approaches that can be used to reduce GHG emissions from both new and installed equipment. This methodology focuses on reductions from new equipment, as described below. For limited applications, some businesses are using alternatives to HFC refrigerants with little or no global warming potential (GWP) as they manufacture and install new refrigeration systems. These alternatives include hydrocarbons, ammonia, carbon dioxide, and hydrofluoroolefins (HFOs). In some advanced commercial refrigeration systems, these alternatives completely replace the use of HFC refrigerants, while in other advanced systems these alternatives are used in combination with HFCs. For example, secondary loop and cascade refrigeration systems used in supermarkets often use HFC refrigerants in combination with refrigerants that have lower GWPs (such as carbon dioxide) or heat transfer medium (such as glycol). This methodology provides the quantification framework for the creation of carbon offset credits from the reductions in GHG emissions resulting from the transition to advanced refrigeration systems in the eligible sectors. It's intended to be used as an incentive within the relevant industries to increase these activities, and is based on a robust data set. The latter includes the United Nations Environment Programme Technical Options Committee for Refrigeration, Air Conditioning and Heat Pumps, the United States EPA Vintaging Model, the 2016 ICF Accounting Tool to Support Federal Reporting of Hydrofluorocarbon Emissions, the United States EPA GreenChill Partnership, and the 2006 International Panel on Climate Change Guidelines for Greenhouse Gas Inventories.