1. The document evaluates future refrigerant options for air conditioners based on their global warming impact, energy efficiency, flammability, toxicity, and cost.
2. It finds that R32 has a much lower direct global warming effect than R22 or R410A, and its impact could be further lowered through design modifications. It also has equivalent or better energy efficiency than alternatives.
3. While R290 (propane) poses flammability risks, the document argues for early adoption of technologies available now to significantly reduce future greenhouse gas emissions from refrigerants.
Future Refrigerant Options with Low Climate Impact for Stationary Air Conditioners
1. Future Refrigerant Options with Low Climate Impact for Stationary Air Conditioners >Global Warming Impact > Energy efficiency & Peak Load >Flammability & Toxicity >Affordability - “Quick Gain”
2. How to Evaluate Refrigerants? – Global Warming Impact - LCCP comparison (3.5 kW Room A/C) based on cooling and heating (3) Emissions during refrigerant production (2) Direct emissions (1) Indirect emissions Total Emissions = ( Precondition for Calculation ) - Recovery rate = 30%, Leakage rate= 5%/yr, Source of Emissions during refrigerant production is JRAIA 2004 Kobe Symposium GWP=IPCC 4th (the EU F gas regulation, the GWP of the IPCC1 apply where R410A is 1975) *1 Taking low pressure loss into consideration, narrower heat exchanger was used to reduce charge volume. *2 To improve efficiency, HX size was increased : Indoor HX x 1,1 + Path x 2, Outdoor HX x 1.2, and connecting pipe increased from 3/8=> 5/8 *3 To meet IEC requirements, charge volume was reduced: Indoor HX x 0.8, Outdoor HX x 0.5, narrower piping was used. *4 To Improve efficiency: Outdoor unit HX was increased x 1.1 3.5kW Room A/C in Europe – EuP Average Condition (EU Average = 0.43Kg/kWh) (Kg = Charge volume) R410A (1.2kg) R744 (0.84Kg) (*4) R290 (0.37kg) (*3) R32 (0.84kg) (*1) HFO1234yf (1.32 kg) (*2) R22 (1.14kg) (Kg ・ CO2) (1) 14000 (2) 1 (3) 0.5 (1) 15000 (2) 1 (3) 0 (1) 12000 (3) 390 (2) 1800 (1) 12000 (2) 2100 (3) 23 (1) 13000 (2) 4 (3) 23 (1) 12000 (3) 12 (2) 480 Disregarding IEC, the charge volume is 0.58Kg, and Indirect impact could be reduced by 16% 0 7000 9000 11000 13000 15000 May 9 th , 2011 Daikin Industries, Ltd.
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5. How to Evaluate Refrigerants – Safety: Flammability - Consideration on the use of 2L refrigerants classified by ASHRAE 34 and ISO 817 1. Flammability of Class 2L is similar to ammonia. Consideration is ongoing to clarify the safety requirements to use 2L refrigerants 2. Commercial refrigeration and MAC (wrong use) which employed R290 caused fire accidents in the field 3. ASHRAE 34 recently reclassified R32 & HFO 1234yf down to new Class 2L (Lower flammability, low burning velocity) Beer cooler incident in Australia 10/19/95, CA: charging while engine was still hot 8/18/96, MS: low pressure hose from evaporator blew off 9/27/96, AR: torch used on truck AC unit after venting refrigerant Source: US-EPA in Bogotá 2008 <Fire accident examples> Fire accident s in case of HC use for cooking & heaters : avg.68/yr, death: avg.1.3/yr (01-06) ,:Source METI Japan Propane explosion in a New Zealand supermarket. Source: EFCTC newsletter ASHRAE 34: Class 1 = Non flammable, Class 2L Mildly flammable Class 2= Flammable, Class 3 = Highly Flammable May 9 th , 2011 Daikin Industries, Ltd. Class 1 (No flame propagation) Class 2L (Lower flammable with low burning velocity) Class 2 (Lower flammable with high burning velocity) Class 3 (Higher flammability) CO2(R744 ) R410A R22 HFO 1234yf R32 Ammonia (Toxic) R152a Propane (R290)
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7. How to Evaluate Refrigerants – Cost up Factors - The Example of Room A/C Component which increases cost Consideration: CO2 requires significant cost for performance improvement. Consideration: Propane requires additional cost when taking safety measures in application and handling. Required in Japan May 9 th , 2011 Daikin Industries, Ltd. Important (ex.230g) Special joint Sealing etc. Necessary Necessary Necessary Unnecessary Unnecessary Unnecessary Unnecessary Necessary Special joint Unnecessary Unnecessary Unnecessary Necessary Special joint Unnecessary. Unnecessary Unnecessary Cost for safety Charge reduction Joint Electronic parts Leak detector Ventilation Modified facility Qualification Qualified person Qualified person Two-stage comp. High-pressure etc. Cheap CO2(R744) Larger comp. Larger pipe etc. Near as R410A Same as R410A Modification required Same as R22 Cost for performance Compressor, EX, etc. Modified facility Modification Modification Modification Modification Expensive HFO1234yf Cheap Cheap Refrigerant price Modified facility Modification Modification Modification Modification Special facility Qualification Qualified person Qualified person Qualification Cost for handling Manufacture Supply chain Installation Service Disposal R32 Propane (R290)
10. Conclusion May 9 th , 2011 Daikin Industries, Ltd. 2. A2L Class refrigerants for all capacity ranges can be used with only minor modifications To address climate change issues, quick actions are required. We are confident that R32 technology is one of the solutions that can quickly reduce greenhouse gas emissions from refrigerants, in both developed and developing countries. 1. Evaluate not only GWP but also the total GHG emissions (LCCP) 4. Earn “Quick Gain” for lowering future global warming impact. 3. Peak load should be considered when choosing candidates. In case of R32, higher efficiency and less refrigerant charge will lead to lower greenhouse gas emissions. Additional leakage prevention measures will contribute to emission reduction further, as is the case of all refrigerants. Not only seasonal energy efficiency but also efficiency in extreme temperature conditions (peak load) should be taken into consideration. It is important for the power supply infrastructure.