Open Access

ARTICLE

Research on Flexible Cooling Load Strategy of Air Conditioning in University Classroom Based on Wall Heat Storage and Load Shaving

Wenzhi Yang^1,2, Guojian Li^1,2,*
1 Zhejiang Sci-Tech University, Hangzhou, China
2 Zhejiang Key Laboratory of Green, Digital and Intelligent (GDI) Renovation for Urban Infrastructures, Hangzhou, China
* Corresponding Author: Guojian Li. Email:
(This article belongs to the Special Issue: Clean Energy and Low-Grade Energy Utilization: Material, Component, and System Innovation)

Energy Engineering https://doi.org/10.32604/ee.2026.088140

Received 29 June 2026; Accepted 14 September 2026; Published online 20 September 2026

Abstract

University teaching buildings constitute a major class of public buildings with high cooling demand and intermittent occupancy patterns. However, the cooling load regulation potential of building envelope thermal mass under inter-zone thermal coupling remains insufficiently quantified in summer cooling contexts. This study aims to quantify the cooling load shaving potential of envelope thermal mass and its underlying mechanisms under inter-classroom thermal coupling, with a focus on intermittent air-conditioning operation in university teaching buildings. A detailed thermophysical model of a representative middle classroom was developed and simulated using EnergyPlus to compare cooling load profiles across five HVAC operation schemes. Wall-surface heat flux integration was employed to elucidate the heat storage and release dynamics governing cooling load regulation. Simulation results indicate that poorly scheduled staggered occupancy triggers a thermal storage backlash effect, increasing afternoon cooling loads by 11.5%–11.6%. In contrast, the pre-cooling strategy achieves substantial cooling load reductions of over 20% for afternoon and evening load spikes, at the cost of a 6.2%–7.1% increase in total daily cooling energy. Night-time natural ventilation yields negligible daytime cooling load-shaving benefits (<1%). The hybrid scheme combining pre-cooling and night ventilation marginally outperforms pre-cooling alone, though the additional gain is minimal. Quantitative heat flux diagnostics confirm that pre-cooling redistributes the thermal energy stored within the envelope to align with high-demand cooling load hours, constituting the core mechanism of its load-shaving performance. This study elucidates the time-dependent heat storage and release cycles of partition walls under inter-zonal thermal interactions, providing theoretical support for energy-flexible HVAC scheduling in university classrooms.

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Keywords

Envelope heat storage and release; cooling load shaving; EnergyPlus; university classroom; building energy flexibility; HVAC operational strategy

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