Abstract: The long-term performance of air-conditioners will decrease after long-term operation due to the coverage of particulate fouling in heat exchangers. The purpose of the present study is to summarize the recent research on long-term performance of air-conditioners and heat exchangers. The introduction to the influence of dust particles on the performance degradation of heat exchanger covers the effect of dry dust particles and the effect of wet dust particles on the air-side heat transfer and pressure drop. The research on the long-term performance evaluation covers the evaluation standard and the testing method of long-term performance degradation. The research of prediction method on the particle deposition on heat exchanger includes the dry particle deposition model and the wet particle deposition model. The dust removal techniques of heat exchangers and their application fields are also introduced.

Key words: Long-term performance, Evaluation standard, Accelerated dust testing, Particle deposition, Dust removal technology