Evaluation of System Improvement Through Frequency Optimization of Fan Coil Systems Using ANOVA and the TOPSIS Method

This study focuses on frequency optimization of aging fan coil systems. Through on-site experiments and one-way Analysis of Variance (ANOVA), significant differences were observed in indoor/outdoor temperature and humidity as well as compressor operation under different frequencies, while chilled water and supply air temperature and humidity remained stable. The Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) analysis identified 20 Hz as the optimal operating frequency, balancing energy efficiency and system performance. Future work is recommended to explore a wider range of frequency combinations and seasonal conditions, providing practical guidance for energy-saving upgrades of aging Heating, Ventilation, and Air Conditioning (HVAC) systems and promoting the development of energy-efficient and intelligent control strategies.