A comparative study on the applicability of six radiant floor, wall, and ceiling heating systems based on thermal performance analysis

Holistic comparisons of radiant heating systems that would help make an informed decision on the selection of the most convenient system for the specific application are lacking. The applicability of six representative radiant floor, wall, and ceiling heating systems was therefore compared in terms of thermal output and surface area required, controllability, short-term and long-term heat storage, suitability for building retrofit, and investments. Temperature and heat flux distribution in the structure, time constant tau(63), response time tau(90), and the number of operating cycles were computed by a custom-made and verified software tool using the finite volume method. Thermal energy stored was used to determine the ability of energy storage, whereas investment costs indicated affordability. Wall heating with pipes attached to a thermally insulating core had the highest thermal output, was easy to control, suitable for building retrofit, and most affordable while providing limited thermal storage. The performance of the wall system was retained when locating the pipes in plasterboard separated from the core by an air gap. Floor heating performed consistently in all the aspects evaluated. It was demonstrated that inserting a metal fin between pipes and the concrete spread layer improved thermal output, controllability, and storage capacity of the floor system with minor effect on investments. Ceiling with pipes insulated from the core performed well when thermal storage was not required. Ceiling with pipes embedded in the core was only feasible when long-term heat storage was needed.

Automated summary

This study compared six representative radiant heating systems in terms of thermal output, controllability, short-term and long-term heat storage, suitability for building retrofit, and investments. It was found that wall heating with pipes attached to a thermally insulating core had the highest thermal output and was most affordable.