{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,2]],"date-time":"2026-04-02T03:05:27Z","timestamp":1775099127521,"version":"3.50.1"},"reference-count":36,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2021,7,8]],"date-time":"2021-07-08T00:00:00Z","timestamp":1625702400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100008530","name":"European Regional Development Fund","doi-asserted-by":"publisher","award":["032061"],"award-info":[{"award-number":["032061"]}],"id":[{"id":"10.13039\/501100008530","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["01-0145"],"award-info":[{"award-number":["01-0145"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Buildings"],"abstract":"<jats:p>One strategy to increase energy efficiency of buildings could be the reduction of undesirable heat losses by mitigating the heat transfer mechanisms across the building envelope. The use of thermal insulation is the simplest and most straightforward way to promote thermal resistance of building elements by reducing the heat transfer by conduction. However, whenever there is an air cavity, radiation heat transfer could be also very relevant. The use of thermal reflective insulation materials inside the air gaps of building elements is likewise an effective way to increase thermal resistance without increasing weight and wall thickness. Some additional advantages are its low-cost and easy installation. In this work, the performance of a thermal reflective insulation system, constituted by an aluminium foil placed inside an air cavity between a double pane lightweight steel framed (LSF) partition, is experimentally evaluated for different air gap thicknesses, ranging from 0 mm up to 50 mm, with a step increment of 10 mm. We found a maximum thermal resistance improvement of the double pane LSF walls due to the reflective foil of around +0.529 m2\u2219\u00b0C\/W (+21%). The measurements of the R-values were compared with predictions provided by simplified models (CEN and NFRC 100). Both models were able to predict with reasonable accuracy (around \u00b15%) the thermal behaviour of the air cavities within the evaluated double pane LSF walls.<\/jats:p>","DOI":"10.3390\/buildings11070301","type":"journal-article","created":{"date-parts":[[2021,7,8]],"date-time":"2021-07-08T10:42:17Z","timestamp":1625740937000},"page":"301","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Thermal Performance of Double-Pane Lightweight Steel Framed Walls with and without a Reflective Foil"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0134-6762","authenticated-orcid":false,"given":"Paulo","family":"Santos","sequence":"first","affiliation":[{"name":"ISISE, Department of Civil Engineering, University of Coimbra, 3030-788 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9565-6648","authenticated-orcid":false,"given":"Telmo","family":"Ribeiro","sequence":"additional","affiliation":[{"name":"ISISE, Department of Civil Engineering, University of Coimbra, 3030-788 Coimbra, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,7,8]]},"reference":[{"key":"#cr-split#-ref_1.1","unstructured":"European Union (2018). Directive"},{"key":"#cr-split#-ref_1.2","unstructured":"(EU) 2018\/844 of the European Parliament and of the Council of 30 May 2018 amending Directive 2010\/31\/EU on the energy performance of buildings and Directive 2012\/27\/EU on energy efficiency. Off. J. Eur. Union, 156, 75-91."},{"key":"#cr-split#-ref_2.1","unstructured":"European Union (2018). Directive"},{"key":"#cr-split#-ref_2.2","unstructured":"(EU) 2018\/2001 of the European Parliament and of the Council on the promotion of the use of energy from renewable sources. Off. J. Eur. Union, 328, 82-209."},{"key":"ref_3","unstructured":"Santos, P., Sim\u00f5es da Silva, L., and Ungureanu, V. (2012). Energy Efficiency of Light-weight Steel-framed Buildings, European Convention for Constructional Steelwork (ECCS), Technical Committee 14\u2014Sustainability & Eco-Efficiency of Steel Construction. [1st ed.]."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Roque, E., and Santos, P. (2017). 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