Hierarchical Control Framework Integrating LLMs with RL for Decarbonized HVAC Operation

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Zhong, Dianyu, Xing, Tian, Sun, Kailai, Yang, Xu, Huang, Heye, Qaisar, Irfan, Jia, Tinggang, Wang, Shaobo, Zhao, Qianchuan
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911547934113792
author Zhong, Dianyu
Xing, Tian
Sun, Kailai
Yang, Xu
Huang, Heye
Qaisar, Irfan
Jia, Tinggang
Wang, Shaobo
Zhao, Qianchuan
author_facet Zhong, Dianyu
Xing, Tian
Sun, Kailai
Yang, Xu
Huang, Heye
Qaisar, Irfan
Jia, Tinggang
Wang, Shaobo
Zhao, Qianchuan
contents Heating, ventilation, and air conditioning (HVAC) systems account for a substantial share of building energy consumption. Environmental uncertainty and dynamic occupancy behavior bring challenges in decarbonized HVAC control. Reinforcement learning (RL) can optimize long-horizon comfort-energy trade-offs but suffers from exponential action-space growth and inefficient exploration in multi-zone buildings. Large language models (LLMs) can encode semantic context and operational knowledge, yet when used alone they lack reliable closed-loop numerical optimization and may result in less reliable comfort-energy trade-offs. To address these limitations, we propose a hierarchical control framework in which a fine-tuned LLM, trained on historical building operation data, generates state-dependent feasible action masks that prune the combinatorial joint action space into operationally plausible subsets. A masked value-based RL agent then performs constrained optimization within this reduced space, improving exploration efficiency and training stability. Evaluated in a high-fidelity simulator calibrated with real-world sensor and occupancy data from a 7-zone office building, the proposed method achieves a mean PPD of 7.30%, corresponding to reductions of 39.1% relative to DQN, the best vanilla RL baseline in comfort, and 53.1% relative to the best vanilla LLM baseline, while reducing daily HVAC energy use to 140.90~kWh, lower than all vanilla RL baselines. The results suggest that LLM-guided action masking is a promising pathway toward efficient multi-zone HVAC control.
format Preprint
id arxiv_https___arxiv_org_abs_2603_26050
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Hierarchical Control Framework Integrating LLMs with RL for Decarbonized HVAC Operation
Zhong, Dianyu
Xing, Tian
Sun, Kailai
Yang, Xu
Huang, Heye
Qaisar, Irfan
Jia, Tinggang
Wang, Shaobo
Zhao, Qianchuan
Systems and Control
Heating, ventilation, and air conditioning (HVAC) systems account for a substantial share of building energy consumption. Environmental uncertainty and dynamic occupancy behavior bring challenges in decarbonized HVAC control. Reinforcement learning (RL) can optimize long-horizon comfort-energy trade-offs but suffers from exponential action-space growth and inefficient exploration in multi-zone buildings. Large language models (LLMs) can encode semantic context and operational knowledge, yet when used alone they lack reliable closed-loop numerical optimization and may result in less reliable comfort-energy trade-offs. To address these limitations, we propose a hierarchical control framework in which a fine-tuned LLM, trained on historical building operation data, generates state-dependent feasible action masks that prune the combinatorial joint action space into operationally plausible subsets. A masked value-based RL agent then performs constrained optimization within this reduced space, improving exploration efficiency and training stability. Evaluated in a high-fidelity simulator calibrated with real-world sensor and occupancy data from a 7-zone office building, the proposed method achieves a mean PPD of 7.30%, corresponding to reductions of 39.1% relative to DQN, the best vanilla RL baseline in comfort, and 53.1% relative to the best vanilla LLM baseline, while reducing daily HVAC energy use to 140.90~kWh, lower than all vanilla RL baselines. The results suggest that LLM-guided action masking is a promising pathway toward efficient multi-zone HVAC control.
title Hierarchical Control Framework Integrating LLMs with RL for Decarbonized HVAC Operation
topic Systems and Control
url https://arxiv.org/abs/2603.26050