ENERGY AND BUILDINGS, vol.268, 2022 (SCI-Expanded)
The application of radiant heating and cooling systems in building retrofit could facilitate the use of renewable energy sources in existing buildings. This research focused on adapting the design of a ceiling and wall system with pipes underneath the surface and a wall system with the pipe embedded in a bricklayer. These systems are suitable for installation in retrofitted rooms, but the findings are also applicable to new buildings. Heat transfer was computed using a validated numerical model. With a conductive core, insulation thickness of up to 3 cm was appropriate for an internal wall. With an insulating core, insulation was not necessary even if the core was only 15 cm thin. The increase in output per 1 cm of pipe spacing was maximal at 6 cm. Spacing below 3 cm was inefficient. A dense spacing maximized the system output per energy input by creating a uniform surface temperature, while also shortening the response time. Attaching a metal fin to a pipe in plaster increased the output by as much as reducing the pipe spacing from 10 to 6 cm (14 M-2, i.e. 20%). Attaching a metal fin to a pipe embedded in insulation for a compact design led to the highest output of all cases studied. Placing the pipe in a brick layer added to a conductive wall did not increase the heat storage capacity of the wall. (C) 2022 Elsevier B.V. All rights reserved.