Hydronic floor heating: Analysis of energy consumption, temperature, and velocity fields

Abstract

Hydronic floor heating has been recognized as one of the important systems utilized for warming residential buildings, therefore, the flow field and temperature distribution studies of the floor and locally heated residential spaces are essential. In this work, such a study is performed on a room with different horizontal aspect ratios through three dimensional numerical simulations using FLUENT software. The governing equations accounting for the continuity, momentum, and energy together with the radiation have been solved using the Boussinesq approximation, the radiation DO model, and themodified k2e turbulence model, while the SIMPLE method was utilized. Results show that at least 65% of the total heat transfer from the heated floor is due to radiation, while in the locally heated room, the radiation from the radiator was at most 55% of the total. When floor heating was utilized, the uniform temperature is obtained for all of the room aspect ratios, whereas in the case of local heating, thermal stratification occurs along the room height, as the temperature was considerably higher at upper heights. In the floor heating, the air velocity throughout the room was less than 0.2m/s, whereas, for the local heating, the air velocity was higher than 0.2m/s close to the radiator. In comparison with the local heating, the floor heating caused at least 20% energy saving and optimum thermal and velocity comfort conditions.