Grantee Research Project Results

Final Report: High-Performance, Low-Global-Warming Refrigerants for Domestic Refrigerators

EPA Contract Number: 68D99082
Title: High-Performance, Low-Global-Warming Refrigerants for Domestic Refrigerators
Investigators: Nimitz, Jonathan S.
Small Business: Environmental Technology and Education Center Inc.
EPA Contact: Richards, April
Phase: II
Project Period: September 1, 1999 through September 1, 2001
Project Amount: $224,966
RFA: Small Business Innovation Research (SBIR) - Phase II (1999) Recipients Lists
Research Category: SBIR - Pollution Prevention , Pollution Prevention/Sustainable Development , Small Business Innovation Research (SBIR)

Summary/Accomplishments (Outputs/Outcomes):

This Phase 1 effort has demonstrated the technical feasibility of two new high-performance low-global-warming refrigerants for domestic refrigerators. The results showed that both Ikon A and Ikon B refrigerants can give performance gains of 10-15% compared to R-134a in a new domestic refrigerator.

Testing was based on modified ASHRAE and ANSI/AHAM procedures. An 18 cubic foot Whirlpool refrigerator with top-mounted freezer was instrumented, loaded, and placed into a chamber maintained at 75oF and 50% relative humidity. Test segments included pulldown from room temperature followed by temperature maintenance with and without door opening. Temperatures, pressures, and energy consumption were recorded. Baseline performance was measured with R-134a and R-12. Ikon A, Ikon B, and one additional blend were tested. The data collected allowed analysis of both energy efficiency and capacity.

Ikon A and Ikon B had very similar performance. Compared to R-134a, during pulldown the new refrigerants showed average 10-11% capacity increases and 5-6% lower energy use per unit time, resulting in overall pulldown energy savings of 8-10%. It is believed that this high capacity is related to the higher vapor densities of Ikon refrigerants compared to R-134a, which leads to more weight of refrigerant vapor pumped per compressor cycle.

The energy savings of higher-capacity refrigerants are not reflected in steady-state (temperature maintenance) operation. Consequently during maintenance the Ikon refrigerants showed essentially identical performance to R-134a. During maintenance the evaporator is fully flooded and significantly more refrigerant is being pumped than is required by the thermal load on the system. Installing a higher capacity refrigerant does not lower energy use of this oversized compressor, since the added capacity is not used. Higher capacity can be converted into higher energy efficiency by appropriate hardware changes. For example, the additional capacity should allow use of a smaller compressor (in this case 1/6 HP instead of 1/5 HP), which would give lower initial hardware cost and substantial energy savings.

Overall, the results show that energy savings of 10-15% could be achieved in domestic refrigerators by using one of the Ikon refrigerants and a smaller compressor. The payback time for the refrigerant is about 1.5 years. The initial net refrigerant cost of less than $6.00 per refrigerator would save approximately $4.15/yr in electric costs. Assuming an average U.S. market share of 25% and average total sales of about 10 million units/yr through 2010 this would correspond to average annual savings of 1.25 billion KWh of electricity, $100 million, and 800,000 metric tons of CO2 emissions. Acceptance in one U.S. market, such as domestic refrigeration, would most likely lead to acceptance in other countries and in sectors such as commercial refrigeration and cooling, generating significantly more savings.

Total equivalent warming impacts (TEWIs) account for both the global warming potential (GWP) of the refrigerant when released and the warming impact of the CO2 generated to produce the electricity to run the refrigerator. TEWIs calculated for Ikon A and B were estimated to be 13% less than the TEWI for R-134a in domestic refrigeration.

An independent commercialization study by Foresight Science & Technology (attached as Appendix A) concludes that these products have a very good possibility of making a significant contribution to the reduction of global warming and that their higher efficiency more than makes up for the slightly higher initial cost.

In Phase 2, a high-performance, low-global-warming refrigerant will be readied for commercialization. A refrigerator will be optimized by adjusting capillary tube length and decreasing compressor size. The DOE refrigerator test procedure will be conducted to provide standardized performance data for comparison. Independent third-party measurements of performance will be obtained. Ikon A, Ikon B, and one new blend will be tested. Discussions with compressor, refrigerator, and chemical manufacturers will be held. The long-term compatibility of the refrigerants with equipment will be determined. For the top-ranking refrigerant, an application and supporting data for assignment of an ASHRAE refrigerant number will be submitted.

Supplemental Keywords:

Sustainable Industry/Business, RFA, Air, Scientific Discipline, Toxics, HCFCs, Chemical Engineering, Civil/Environmental Engineering, Chemistry, Environmental Chemistry, Engineering, Chemistry, & Physics, Chemistry and Materials Science, tropospheric ozone, CFCs, Atmospheric Sciences, cleaner production/pollution prevention, air toxics, climate change, Environmental Engineering, air quality, alternative refrigerants, chemical use efficiency, clean technology, Global Climate Change, pollution prevention, stratospheric ozone, emissions control, zero ozone depleting potential, CO2 concentrations, emission controls, environmental monitoring, global warming, refrigerant, global change, green design, air emissions, climate variations, environmentally safe refrigeration, reduced CO2 production, alternatives to CFCs, climate variability, Ikon refrigerants, refrigerators, adaptive technologies, emission control technologies, refrigeration, alternative materials, ambient air, cleaner production, energy efficiency, ozone, ambient air pollution, emissions contol engineering, ambient air quality, greenhouse gases, ozone depletion, Refrigerants

SBIR Phase I:

High-Performance, Low-Global-Warming Refrigerant for Domestic Refrigerators  | 1999 Progress Report  | Final Report