Field evaluation of performance of radiant heating/cooling ceiling panel system: Fid-Bau Portal

Field evaluation of performance of radiant heating/cooling ceiling panel system

Li, Rongling / Yoshidomi, Togo / Ooka, Ryozo / Olesen, Bjarne W.

Highlights • Good agreement was found between the theoretical heat flux and the measured data. • Overall heat transfer coefficient was ∼3.7 for heating and 4.8W/(m² K) for cooling. • The downward heat flux ratio was 61–65% for heating and 65–72% for cooling mode. • An optimal water temperature is assumed to exist with high heat use efficiency. • A category B thermal environment was obtained.

Abstract As in many other countries in the world, Japan has witnessed an increased focus on low-energy buildings. For testing different engineering solutions for energy-efficient buildings, a low-energy building was built at the University of Tokyo as an experimental pilot project. In this building, a radiant heating/cooling ceiling panel system is used. However, no standard exists for the in situ performance evaluation of radiant heating/cooling ceiling systems; furthermore, no published database is available for comparison. Thus, this study aims to not only clarify the system performance but also to share our experience and our results for them to serve as a reference for other similar projects. Here, the system performance in relation to its heating/cooling capacity and thermal comfort has been evaluated. The heat transfer coefficient from water to room was 3.7W/(m² K) and 4.8W/(m² K) for heating and cooling cases, respectively. The upward heat flux from the panels was found to be as large as 30–40% of the water heating/cooling capacity; this would translate into heat loss in certain operating modes. Several proposals for reducing the upward heat flux were discussed. The measurements also showed that a category B thermal environment was obtained using the radiant ceiling heating/cooling system.