Adjusting the design of a radiant heating system for office retrofit

Abstract

Installation of low-exergy water-based radiant systems can help alleviate the negative effects of increased energy consumption due to their suitability for combination with low-grade renewable energy sources. Radiant heating and cooling installations in buildings are common, but their application in existing buildings as part of retrofit is relatively rare. The present study investigated some of the aspects of the installation of radiant heating systems in existing buildings. Wall and ceiling systems with pipe underneath the surface were considered because of various potential benefits. These include the possibility of operating as cooling in summer and heating in winter, easy installation in existing buildings, minor space requirements, and no or little need to reduce the height of the storey, especially in the case of walls. It was found that with a thermally conductive core, only a thin insulation layer of 1 cm may suffice if the temperature difference between rooms is relatively small. For an insulating core, no insulation may be needed even at higher temperature differences between rooms. Reducing the pipe spacing to about 5 cm was found to be efficient in terms of increased thermal output per 1 cm of spacing. The location of the insulation had a small effect on the thermal losses, but the output was higher for insulation placed on the outer side of the wall due to a more uniform temperature distribution in the structure. This configuration also allows for considerably higher heat storage capacity.