To address the capacity mismatch between heat injection and thermal diffusion in thermally activated walls, this study proposes an enhanced thermally activated wall (ETAW) design to improve energy-storage efficiency and energy-saving potential. A dynamic heat transfer model is developed to compare the thermal performance of ETAW with that of conventional thermally activated walls (CTAW) and conventional energy-saving walls (CW). Local sensitivity analysis is conducted to investigate the economic impacts of fin parameters, climate conditions, and insulation thickness. Results demonstrate that ETAW exhibits significantly superior dynamic thermal performance relative to CTAW and CW, although the degree of improvement depends on the heat injection mode. Increases in trunk fin size and branch fin size both effectively reduce total operating energy consumption and costs, with the branch fin size exhibiting a more pronounced influence. Adopting a smaller branch-fin inclination angle (e. g. 60°) and a left-oriented installation can reduce operating costs and energy consumption by approximately 10.9% and 10.7% respectively. Insulation thickness shows strong correlations with energy efficiency and economic performance; recommended reduction rates should not exceed 40% in severe cold zones and may be extended to up to 60% in hot-summer zones.

A modular thermo-activated wall (MTAW) with specialized internal cavities for thermal diffusivity fillers was proposed to solve the problem of low-grade heat accumulation, which restricts the heat injection efficiency of thermo-activated walls. A dynamic heat transfer model of the MTAW was established., and its performance was compared with two reference walls under typical winter conditions in a cold climate zone. The study examined the effects of the filler cavity inclination angle(θ), cavity geometry ratio(a:b), and thermal conductivity of the filling material(λ_f) on energy-saving potential and economic performance. Results show that incorporating filler cavities and thermal diffusing materials significantly reduces total operational energy consumption and costs. Compared with the reference walls, when the the MTAW filler cavity’s long axis is oriented transversely with an a:b ratio of 1:2, the total operational energy consumption decreases by 2.60% and 14.13%, respectively. Compared with the reference walls, operational costs are reduced by 12.41% and 50.04%, respectively. When the long axis of the filler cavity is inclined toward the room side, heating energy consumption initially decreases and then increases as θ rises, with optimal performance observed at θ_L=60°. Additionally, a:b and λ_f are inversely proportional to both total operational energy consumption and costs. For example, when λ_f is 12λ_c, heating energy consumption and gas operating costs are reduced by up to 3.03% and 34.53%, respectively.