Comparison of the energy flexibility potential of different heating ends in residential buildings

Abstract Demand response is now recognized as an effective approach to tackle the issue of grid instability, with heating systems in buildings serving as a vital flexible resource on the demand side. Split air conditioning and floor heating systems are the two most common forms of heating in southern China. This study quantitatively compares the energy flexibility of residential buildings using different heating systems by employing a variety of control strategies. The results reveal that the floor heating system can significantly reduce the subsequent load within 3 hours after preheating is halted, whereas the air conditioning system achieves similar reductions only within 1 hour, while maintaining comparable indoor thermal comfort. Extending the preheating duration, increasing the preheating temperature, and improving building insulation performance can boost system flexibility. Especially for the underfloor heating system, high-insulation buildings show an improvement in the average load reduction rate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mover> <mml:mi>γ</mml:mi> <mml:mo stretchy="false">_</mml:mo> </mml:mover> <mml:mi mathvariant="normal">L</mml:mi> </mml:msub> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> </mml:math> by 0.44%-67.12% compared to low-insulation buildings. Furthermore, incorporating outdoor environmental factors into demand response control enhances building energy flexibility.