In recent years, external wall fires (or façade fires) are occurring due to mixed contribution of exterior cladding and continuous insulation in the chimney like construction of rainscreen façades. In the present work, a new experimental setup is developed and demonstrated for initial screening of façade assembly at lab-scale. It incorporates the real physics for investigating the fire hazards of flammable polymeric materials and chimney effect together. Different combinations of exterior cladding (Al-45, Al-45 Class O, Al-45 Class B) and continuous insulation (Expanded polystyrene, Polyisocyanurate and Mineral wool) with and without chimney are selected for studying their fire behaviour. The pressure differential combining with re-radiation inside the cavity led to 3–6 times higher mass burning rate, flame height and temperature in tests with chimney effect to that of without for the same combination of products. With chimney, secondary fire sources are generated due to dripping of products which further enhanced the burning and spread rate. A critical width of the chimney (13–50 mm) is established at which maximum vertical fire spread was recorded. Furthermore, the visual observations indicated that the products having thin outer Al sheets are prone to 30% early structural failure. Comparison of results with large-scale tests validated the usefulness of the present setup as intermediate test between small and large scale for studying fire behaviour of façade materials.

近年来，外墙火灾（或立面火灾）的发生是由于外墙覆层和烟囱中连续保温的混合作用，如雨幕幕墙的施工。在目前的工作中，开发并演示了一种新的实验装置，用于实验室规模的立面组装的初步筛选。它结合了真实的物理学，用于研究易燃聚合物材料的火灾危害和烟囱效应。选择不同的外墙覆层（Al-45、Al-45 O 级、Al-45 B 级）和连续绝缘（发泡聚苯乙烯、聚异氰脲酸酯和矿棉）的不同组合，有和没有烟囱，以研究它们的防火行为。压差与腔内再辐射相结合，使质量燃烧率提高了 3-6 倍，烟囱效应试验中的火焰高度和温度与相同产品组合的无烟囱效应试验中的火焰高度和温度。对于烟囱，由于产品的滴落而产生二次火源，进一步提高了燃烧和蔓延的速度。确定烟囱的临界宽度（13-50 毫米），在该宽度处记录到最大垂直火势蔓延。此外，目视观察表明，具有薄外铝板的产品容易出现 30% 的早期结构失效。结果与大规模测试的比较验证了本设置作为小规模和大规模之间的中间测试的有用性，用于研究外墙材料的防火行为。产品的滴落产生二次火源，进一步提高了燃烧和蔓延的速度。确定烟囱的临界宽度（13-50 毫米），在该宽度处记录到最大垂直火势蔓延。此外，目视观察表明，具有薄外铝板的产品容易出现 30% 的早期结构失效。结果与大规模测试的比较验证了本设置作为小规模和大规模之间的中间测试的有用性，用于研究外墙材料的防火行为。产品的滴落产生二次火源，进一步提高了燃烧和蔓延的速度。确定烟囱的临界宽度（13-50 毫米），在该宽度处记录到最大垂直火势蔓延。此外，目视观察表明，具有薄外铝板的产品容易出现 30% 的早期结构失效。结果与大规模测试的比较验证了本设置作为小规模和大规模之间的中间测试的有用性，用于研究外墙材料的防火行为。