Wavy finned-tube heat exchangers are widely used in outdoor units of air conditioners

and their performance will be decreased when covered by dust particles. The purpose of this paper is to investigate the characteristics of particle deposition on wavy-finned tube heat exchangers. The particle distribution has been observed and the mass of depositing particle has been measured. The range of fin pitch is from 1.6mm to 3.2 mm

the particle concentration is from 80 kg/m3 to 280 kg/m3

the air velocity is from 1 m/s to 3 m/s

and the particle injection time is from 15 s to 90 s. The results show that particles mostly deposit on the leading edge of fins and windward side of tubes. The mass of depositing particle per unit of area increases up to 52% as fin pitch decreases from 3.2 mm to 1.6 mm

meaning that small fin pitch is beneficial to particle deposition. The mass of depositing particle per unit of area increases up to 88.2% with increasing particle injection concentration from 80 kg/m3 to 280 kg/m3

indicating that high particle injection concentration is helpful to particle deposition. The mass of depositing particle per unit of area decreases up to 6.3% as air velocity increases from 1m/s to 3 m/s

revealing that high air speed can restrain particle deposition.