{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,13]],"date-time":"2026-04-13T04:18:30Z","timestamp":1776053910027,"version":"3.50.1"},"reference-count":38,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2022,6,17]],"date-time":"2022-06-17T00:00:00Z","timestamp":1655424000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Competitiveness Operational Program-Innovative Energy Efficient Sales Systems for Urban Use","award":["MySMIS code 121420"],"award-info":[{"award-number":["MySMIS code 121420"]}]},{"name":"The European Regional Development Fund through the Competitiveness Operational Program","award":["MySMIS code 121420"],"award-info":[{"award-number":["MySMIS code 121420"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Energies"],"abstract":"<jats:p>The purpose of this research is to design an energy-efficient off-grid vending machine that has a refrigeration system powered by an environmentally friendly refrigerant. The paper presents details from the equipment\u2019s design phase in terms of the resistance structure, photovoltaic panels area dimensioning, but also in terms of the necessary cooling load to be provided by the refrigeration system. The refrigerant chosen was R290 following a comparative analysis, which showed that it has an efficiency 6.6% higher than R134a. During the monitoring periods, the outdoors temperature varied between \u22124\u201328 \u00b0C, the relative humidity between 22\u2013100% and yet only a slight indoor temperature variation of \u00b11.5 \u00b0C compared to the set value was recorded. The battery module managed to store enough energy from the photovoltaic panels to keep the vending machine functional through three consecutive days with adverse environmental conditions, as evidenced by the low variation of indoor temperature<\/jats:p>","DOI":"10.3390\/en15124433","type":"journal-article","created":{"date-parts":[[2022,6,17]],"date-time":"2022-06-17T11:45:44Z","timestamp":1655466344000},"page":"4433","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Study on Energy Efficiency of an Off-Grid Vending Machine with Compact Heat Exchangers and Low GWP Refrigerant Powered by Solar Energy"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7056-574X","authenticated-orcid":false,"given":"R\u0103zvan","family":"Calot\u0103","sequence":"first","affiliation":[{"name":"Department of Thermodynamic Sciences, Faculty of Building Services, Technical University of Civil Engineering Bucharest, 66 Pache Protopopescu Blvd., 020396 Bucharest, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mihai","family":"Savaniu","sequence":"additional","affiliation":[{"name":"Department of Thermodynamic Sciences, Faculty of Building Services, Technical University of Civil Engineering Bucharest, 66 Pache Protopopescu Blvd., 020396 Bucharest, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alina","family":"Girip","sequence":"additional","affiliation":[{"name":"Department of Thermodynamic Sciences, Faculty of Building Services, Technical University of Civil Engineering Bucharest, 66 Pache Protopopescu Blvd., 020396 Bucharest, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4267-5236","authenticated-orcid":false,"given":"Ilinca","family":"N\u0103stase","sequence":"additional","affiliation":[{"name":"Department of Thermodynamic Sciences, Faculty of Building Services, Technical University of Civil Engineering Bucharest, 66 Pache Protopopescu Blvd., 020396 Bucharest, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Matei R\u0103zvan","family":"Georgescu","sequence":"additional","affiliation":[{"name":"Department of Thermodynamic Sciences, Faculty of Building Services, Technical University of Civil Engineering Bucharest, 66 Pache Protopopescu Blvd., 020396 Bucharest, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4064-150X","authenticated-orcid":false,"given":"Oana","family":"Tonciu","sequence":"additional","affiliation":[{"name":"Department of Thermodynamic Sciences, Faculty of Building Services, Technical University of Civil Engineering Bucharest, 66 Pache Protopopescu Blvd., 020396 Bucharest, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,6,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1016\/j.appet.2015.03.007","article-title":"Vending machine assessment methodology. 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