Non-uniform operative temperature distribution characteristics and heat-source-controlled core-area range of local heating radiators

Heating the whole space, which is currently used in northern China, leads to high energy consumption and substantial pollution. A transition to local heating has the potential to help address this problem. In this paper, the effects of radiator-related parameters (position, power, and size) and room-related parameters (aspect ratio and height) on local heating were studied. Two evaluation indices, the effective coefficient of operative temperature (OTEC) and the effective coefficient of local heating (LHEC), were proposed. In addition, the heat source-control core-area (HSCCA) was proposed, and the effect range of heat sources in the space was evaluated by the attenuation of operative temperature. The findings demonstrated that the radiator position has a greater influence on local heating than size. When the position of the radiator was changed from "close to the inner wall" to "close to the outer wall", the LHEC (the interior one-quarter of room is a local heating zone) was found to decrease by 73%. The size of the radiator, which is close to the inner wall, doubled or quadrupled, and the LHEC increased by 9% and 18%. Moreover, rooms with a larger aspect ratio or small room height were found to be the most optimal for local heating applications. The area of the HSCCA decreased as the position of the radiator approached the outer wall. The findings of this study can be used as a design reference for the radiator when the heating mode changes from "full-space heating" to "local heating".