Adapting the construction of radiant heating and cooling systems for building retrofit

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.