Abstract

The objective of this paper is to analyze the difference in energy input by comparing the control characteristics of radiant floor heating systems during the low load heating period through experimentation. The experiment simulated district heating using heat source devices and divided it into three cases: Case 1: OR+BB vs. BB, Case 2: VF vs. BB, Case 3: OR+BB vs. OR+FB, in order to assess the effectiveness of OR, VF, and OR+FB controls. From the experimental results, it was found that: 1) OR+BB control reduced the heat output compared to BB control, thus reducing the overshooting of indoor temperature, but it required longer pump operation time. 2) VF control, when using PID control based on the error with the indoor set point temperature, had a higher possibility of overshooting due to the delayed response caused by the thermal inertia. 3) OR+FB control showed the best performance in terms of reducing overshooting and indoor comfort.