Modeling of under-floor heating systems: A compromise between accuracy and complexity

Abstract

When compared to conventional convective heating systems, under-floor radiant heating systems are becoming very competitive in terms of energy savings. The major reason for this competitiveness is the ability of these radiant systems to directly heat the human body, thus achieving thermal comfort with lower inside air temperatures. However, the design of such systems is usually very complex and is strongly influenced by the prevailing weather conditions of the region under investigation. In this article, a new integrated model for under-floor heating systems is developed and validated with published data. The model provides a compromise between the accuracy and complexity of other models found in the literature; it is found to be reliable for energy simulations over extended periods of time (accuracy in the range of 4.8–7.1% for indoor air temperatures measurements), and the simulation rum time is considerably reduced when compared to computational fluid dynamics simulation software. The model is used to assess the feasibility of under-floor systems for typical living spaces under the weather conditions of Lebanon, where a comparison between under-floor systems and convective systems is performed under equal comfort levels and indoor air quality. The results indicate that the use of under-floor heating provides a 26% saving in the peak demand and a 30% reduction in energy consumption.