Abstract
As energy-efficient ventilation systems become increasingly essential in the design of low-carbon buildings, rotary heat exchangers play a pivotal role in meeting the competing demands of energy conversion and sufficient indoor air quality. However, achieving both high heat recovery efficiency and low pressure loss involves a fundamental design trade-off. Despite the widespread application of the heat recovery in design of energyefficient buildings, systematic multi-objective optimization of rotary heat recovery systems remains limited. This study develops and experimentally validates a comprehensive multi-objective optimization framework for rotary heat exchangers used in ventilation systems. Theoretical models for sensible effectiveness and pressure drop were established using the ε–NTU method and empirical correlations. They were validated through laboratory measurements under EN 308-compliant testing conditions. Both conventional aluminium exchangers with sinusoidal channels and high-performance plastic exchangers with circular channels were evaluated. The model predictions showed strong agreement with the experimental results, with deviations largely remaining within the quantified measurement uncertainty.
The optimization was conducted using the non-dominated sorting genetic algorithm (NSGA-II), generating Pareto fronts that visualize the trade-offs between thermal effectiveness and pressure drop. For the aluminium exchanger, increasing effectiveness from 72% to 77% caused a pressure drop rise from 10 Pa to 100 Pa. The optimization results indicate that plastic rotary heat exchangers can theoretically achieve a maximum sensible effectiveness of 95% at a corresponding pressure drop of 19 Pa, while the minimum pressure drop of 5 Pa corresponds to a sensible effectiveness of 86%. These results highlight the significance of integrated design strategies that jointly consider material selection and channel geometry. The proposed framework may enable informed decision-making in the design and application of rotary heat recovery units and support the development of energy efficient ventilation systems.