Metal foam has very large specific surface area

and it has great potential in dehumidification. The key for designing metal foam heat exchanger for dehumidification is to promote the drainage performance of metal foam. The influence of structure factors on drainage performance of metal foam with three different surface wettability was investigated by dynamic dip test in this study. The results showed that

the drainage performance was deteriorated with the increase of pore density or height and promoted with the increase of porosity. For hydrophobic samples

the drainage performance of 5—40PPI metal foams was promoted

while water retention was reduced by 26%—60%. For hydrophilic samples

the drainage performance of 5—10PPI metal foam was promoted with the maximum reduction of water retention of 23%

while the drainage performance of 15—40PPI metal foam was deteriorated with the maximum increment of water retention of 13%.