Experimental Study on the Compatibility and Miscibility of a Compressor Nano-Lubricant with Sustainable Refrigerant Mixtures for Efficient Cooling Systems
Nayra ELHELW, Naser ALI, Ammar M. BAHMAN
Abstract. According to the International Energy Agency, by 2027 global building energy consumption is expected to increase by nearly 8% compared to 2025. Since air conditioners (ACs) are among the primary contributors to energy use, research has increasingly focused on improving energy efficiency, particularly through enhancing compressor lubrication, thereby supporting environmental sustainability. In real-world refrigeration systems, refrigerants and compressor lubrication oil often mix, which can compromise compressor reliability; therefore, AC systems should be designed to account for such scenarios. This study examines a nano-enhanced lubricant (0.025 vol.% short SWCNTs in POE32 lubricating oil) in combination with environmentally sustainable refrigerants: propane (R-290), and R-410A to assess compatibility and miscibility. Compatibility tests revealed that the addition of nanoparticles had a positive impact on the tested materials by repairing some surface microcracks and generally polishing the surfaces. In miscibility testing, vapor pressure measurements confirmed that the refrigerants were miscible within the typical operating ranges of refrigeration systems when nanoparticles were present. Their presence even had beneficial effects on the vapor pressure, as evidenced by the local immiscibility that R-290 experienced with the pure lubricant, but not with the nanolubricant. This, in turn, reduces the likelihood of oil buildup in heat exchangers, leading to improved heat transfer efficiency, while also aligning with environmental regulations that promote the adoption of environmentally friendly refrigerants. Accordingly, the promising results from using nano-enhanced lubricants combined with sustainable refrigerant mixtures suggest that building energy demand could be reduced, thereby contributing to a greener future. As a next step, a mathematical model will be developed to predict miscibility through vapor pressure measurements rather than relying solely on experimental testing. In addition, deeper investigation of compatibility will be conducted using high-resolution material characterization techniques such as X-ray diffraction (XRD), X-ray fluorescence (XRF), and scanning electron microscopy (SEM).
Keywords
AC, Compressor, Refrigerants, Nano-lubricant, Compatibility, Miscibility
Published online 5/10/2026, 7 pages
Copyright © 2026 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA
Citation: Nayra ELHELW, Naser ALI, Ammar M. BAHMAN, Experimental Study on the Compatibility and Miscibility of a Compressor Nano-Lubricant with Sustainable Refrigerant Mixtures for Efficient Cooling Systems, Materials Research Proceedings, Vol. 66, pp 34-40, 2026
DOI: https://doi.org/10.21741/9781644904152-5
The article was published as article 5 of the book Advanced Materials and Sustainable Energy Technologies
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
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