Low-temperature Radiant Heating System Research Articles

A Study on Radiant Heat Exchange between the Human Body and Indoor Surfaces for the Clothed Body in Low Temperature Radiant Heating System

A Study on Radiant Heat Exchange between the Human Body and Indoor Surfaces for the Clothed Body in Low Temperature Radiant Heating System

Exergy analysis of a low temperature radiant heating system

The purpose of this study is to gain insight into the process of heating a room with a low-temperature radiant heating system and solar energy, considering energy conversion and heat transfer steps in the building (where heat is required), in the incident solar radiation (which supplies part of the heat required) and in the heating system (which provides for the additional heating needs, by using electricity from a gas-fired power plant to drive a heat pump). We applied a theoretical framework developed by Shukuya et al., to a dynamic simulation model and did numerical calculations for a room with an exterior wall, with and without a south-facing window, during a heating season in the Netherlands. The exergy analysis allows direct comparison between different energy types (e.g., heat, electricity, fuel) on a common basis, and the concept of exergy consumption is useful for expressing how and where energy is dispersed in the course of energy conversion and heat transfer steps. The results show that exergy consumption in the room (demand side) is relatively small compared to the supply side (fuel burned at the power plant and the sun reaching the ground and facade). The calculations also show that the total amount of exergy consumed during the heating season can be larger than the total amount of exergy supplied during the same period, as a result of heat storage in the building mass, and of changes in the outdoor temperature between the moment of heat storage and heat release.

基礎断熱した床下空間を利用したパッシブ換気・暖房方式の実住宅への適用 : 寒冷地のパッシブ換気に関する研究 その2

This paper presents the application of passive ventilation system with crawl space heating to the practical house. Ventilation rates, in door thermal conditions and heat loss with ventilation were measured and discussed. The results are as follows; 1) Proper ventilation rate realized during whole year except mid summer, just by operating the number of exhaust stacks, such as one for the heating period and two for the other season. 2) Estimated heat loss with ventilation was 10 % larger in the measured ventilation rate than that in the constant 0.5 ach. The difference was corresponds to the difference of ventilation rate. As a result, airflow fluctuation did not increase the heat loss. 3) Floor surface temperature in the living space was 1-2℃ higher than in door air temperature by crawl space heating. Therefor, in door thermal comfort of this system was similar to low-temperature radiant heating system like a floor heating.