Are the local sky temperature models and the global thermal standard model EN ISO 6946(2017) numerically compatible?

Abstract

Local sky temperature models are often used by researchers to improve the estimation of building heat losses. Besides the local sky temperature models, there is a global temperature model implemented in EN ISO 6946(2017) that may also produce reasonable results if it is conveniently applied. To assess the competitiveness of global and local models, it is desirable to perform a direct numerical comparison of their results. Such a comparison has not been published so far. This study aims to analyze the computational differences between three models of sky temperature, namely, the Swinbank model, the universal model and the standard model implemented in EN ISO 6946(2017). The study verifies the robustness of the global thermal standard model to account for the acting of the cold sky on building envelopes compared to local sky models specially designed for this purpose. The quasi-nocturnal conditions are supposed to reveal the main features of the long-wave infrared interactions between the building facade and the sky. The study has proved the capability of the global standard model to successively compete with the local sky temperature models at least within the conditions of the quasi-nocturnal environment.