Assessment of commercially available energy-efficient room air conditioners including models with low global warming potential (GWP) refrigerants

Abstract

Improving the energy efficiency of room air conditioners (RACs) 1 will be a critical step toward reducing the energy, peak load, and total lifecycle emissions impacts of RACs while transitioning to low global-warming-potential (GWP) 2 refrigerants under the 2016 Kigali Amendment to the Montreal Protocol. Previous research quantified the energy and climate benefits of leapfrogging to high efficiency in tandem with the transition to low-GWP refrigerants for RACs (Shah et al., 2015) and identified opportunities for initial action to coordinate energy efficiency with refrigerant transition, focusing initially on economies constituting about 65% of the global RAC market . Previous research by Oak Ridge National Laboratory (ORNL) determined that flammable HC-290 (R-290) and HFC-32 (R-32) are inherently more energy efficient than nonflammable HFC-410A (R-410A).This report describes further research performed to identify the best-performing (i.e., most efficient and low-GWP-refrigerant using) RACs on the market to maximize the lifecycle energy, cost, direct and indirect emissions savings discussed in previous work. By defining and describing current best available technology (BAT), this report can help support market-transformation programs for high-efficiency and low-GWP equipment such as minimum energy performance standards (MEPS), labeling, procurement, performance assurance requirements for imports, and incentive programs. Furthermore, the new strategy of bulk government procurement is proving that high efficiency can be achieved at affordable cost by capturing economies of scale in production, sales, distribution, and installation Mathur et al., 2017).The report focuses more on RACs that maximize efficiency as long as the GWP of refrigerant is marginally lower than the baseline, for the following reasons: Energy related indirect emissions typically dominate carbon footprint over the lifecycle of the RACs jurisdictions where the carbon intensity is high from fossil fuel and biomass electricity generation but are insignificant in jurisdictions where the carbon intensity is low from nuclear, wind, solar, and geothermal electricity generation. (Goetzler et al., 2016).  With the adoption of the Kigali Amendment there is a global agreement to phasedown high GWP HFCs, with two associated decisions addressing energy efficiency (XXVIII 2 and 3)  The technology used in the highest efficiency RACs with high GWP non-flammable refrigerants is similar to technology used in RACs with flammable low-GWP refrigerants.We studied RACs available in six economies-China, Europe, India, Japan, South Korea, and the United States-that together account for about 70% of global RAC demand, as well as other emerging economies. The following are our key findings:1 This study focuses on ductless split ACs, because the global RAC market is dominated by this type of unit, known in the United States as mini-splits. 2 We use the term "low-GWP" to mean "lower than the baseline refrigerant being replaced." 4  Fixed-speed RACs using hig...

Performance metrics for room air-conditioners: energy, comfort and environmental impacts

“…COP is widely used Jain et al Buildings and Cities DOI: 10.5334/bc.127 to compare RACs since it can be measured instantaneously. The energy performance of RACs is quantified using the energy efficiency ratio (EER), seasonal energy efficiency ratio (SEER) and heating seasonal performance factor (HSPF), as defined in various studies (Abhyankar et al 2017;Power Knot 2011;Shah et al 2017;Waide et al 2011).…”

Water-energy-food-environment nexus in action: Global review of precepts and practice

“…But with burgeoning populations, urbanization, changing lifestyles and agricultural intensification, this approach proved unable to deal with absolute water scarcity in many parts of the world (Seckler et al, 1999;Jaeger et al, 2013). Climate change is all set to make matters worse (Hoff, 2011), signifying the limits of insular, infrastructure-based water governance (GWP, 2000;World Economic Forum, 2011;Shah, 2016). This realization has led to growing clamor for a more holistic approach that accounts for intersectoral externalities and combines infrastructure creation with demand-side management.…”

“…However, throughout the 1990s and beyond, IWRM was aggressively promoted as a package of practices, often as conditionalities of loans/grants by donor countries and global financial institutions. In implementation, many practices on the IWRM template such as registration and licensing of water users, issue of water permits, pricing of water and water servicesfaced vigorous resistance and pushback from people, civil society and governments (Muller, 2010;Shah, 2016). As a result, enthusiasm for IWRM began to ebb in the new Millennium (Biswas, 2008).…”