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Life Cycle Climate Performance (LCCP) is a widely accepted metric to evaluate the carbon footprint of air conditioning (AC) systems “from cradle to grave.” This paper: (1) reviews the invention and evolution of LCCP, including a comprehensive timeline and bibliography; (2) documents the successful application of LCCP in the replacement of HFC-410A with HFC-32 in room air conditioners; (3) compares the conceptual frameworks and the operational approaches; and 4) reflects on the drawbacks of current LCCP research and points out possible future work.

The major policy-relevant findings are: 1. The indirect emissions caused by energy consumption is 70 to 80 percent of the LCCP of AC systems in most countries but will decline in importance as electric power supply shifts rapidly from fossil fuel to renewable energy sources, which have near-zero carbon intensity; 2. The embodied greenhouse gas (GHG) emissions in refrigerant manufacture are, in most cases, negligible but the physical and chemical properties are crucial for system optimization for low carbon footprint; 3. The LCCP metric can be used for multiple purposes such as refrigerant selection and AC system architecture optimization; and 4. Data limitations in material manufacturing and the carbon intensity of electric power are the most significant challenges. Finally, this paper describes a variety of methods to fill in data gaps, including the correction factor method, the data-driven method, and the database searching method. The next-generation LCCP will be an enhanced evaluation process considering local climate, heat islands, and local power supply characteristics.

This paper presents a pioneering benefit assessment framework and indicative quantification of the community and national benefits of operating cost savings from super-efficient room air conditioning (RAC) that are spent locally and not for imported fuel, electricity, and power plants. It also estimates the benefits of expanded employment to replace and service the new RACs and to recover and destroy obsolete and contaminated ozone-depleting and greenhouse gas (GHG) refrigerants. Shifting spending from foreign to local purchase improves balance of trade, strengthens domestic currency, and creates jobs and prosperity as funds circulate in the local economy. Added to that are the community benefits of mass replacement of RACs and their service to maintain energy efficiency over the life of the appliance. This community impact grows over time as savings accumulate on avoided fuel and energy infrastructure and as the income from the new jobs circulates in the local economy.

The comprehensive carbon metric accounts for the fact that AC electricity use and the integrated carbon intensity of that electricity can be up to 48% higher than estimated using national “average” assumptions. Taking real-world operating conditions and the actual carbon intensity of electricity generation, transmission, and distribution at the end-use into consideration provides for a more accurate assessment of the significant climate and economic benefits from energy efficiency and power grid investment.

This article was published in ASHRAE Journal, November 2018. Copyright 2018 ASHRAE. Posted at

The Kigali Amendment to the Montreal Protocol phases down the production and consumption of hydrofluorocarbon greenhouse gases that were once necessary to rapidly phase out ozone-depleting substances but are no longer needed. The Kigali Amendment complements the emission controls of the UNFCCC Kyoto Protocol and contributes to satisfying the “nationally determined contributions” to reduce greenhouse gas emissions pledged under the 2016 Paris Climate Agreement. In 2016, the International Institute of Refrigeration proposed using Life-Cycle Climate Performance metric for air-conditioning systems while summing up carbon-equivalent direct refrigerant emissions, indirect power plant greenhouse gas emissions, and carbon equivalent embodied emissions. This paper describes an Enhanced and Localized Life Cycle Climate Performance metric developed by a team of international experts to reflect real-life air conditioning system operations.