A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Wetting Coatings for Dehumidifying Heat Exchangers
In dehumidifying heat exchangers, hydrophilic coatings applied on the fins reduce the airside pressure drop under the wet condition. Although coatings have been used for at least a decade, the coating characteristics are not well known. Further, the wetting mechanism of hydrophilic coatings in the literature, and the durability of the coatings is not known.
In this paper the types of coating (or surface treatment) are categorized, and the wetting mechanism is described. Dry/wet cycling tests on coupon samples were conducted to test the ability of the coatings to maintain a small contact angle. Cycling sample tests were also conducted to determine the effect of fin press oil on contact angle. Prior to initiating the cycling test, contact angles as small as 10° to 15° were measured. The contact angle of most commercial coatings increased with increasing number of dry/wet cycles, with a maximum in the 55° to 65° range after 1000 cycles. The uncoated aluminum surface showed improved wettability with increased number of dry/wet cycles. This is believed to occur because of surface oxidation and contamination. Based on the current understanding of the wettability mechanism, a unidirectional grooved surface is suggested as an alternative to a wetting coating.
Wetting Coatings for Dehumidifying Heat Exchangers
In dehumidifying heat exchangers, hydrophilic coatings applied on the fins reduce the airside pressure drop under the wet condition. Although coatings have been used for at least a decade, the coating characteristics are not well known. Further, the wetting mechanism of hydrophilic coatings in the literature, and the durability of the coatings is not known.
In this paper the types of coating (or surface treatment) are categorized, and the wetting mechanism is described. Dry/wet cycling tests on coupon samples were conducted to test the ability of the coatings to maintain a small contact angle. Cycling sample tests were also conducted to determine the effect of fin press oil on contact angle. Prior to initiating the cycling test, contact angles as small as 10° to 15° were measured. The contact angle of most commercial coatings increased with increasing number of dry/wet cycles, with a maximum in the 55° to 65° range after 1000 cycles. The uncoated aluminum surface showed improved wettability with increased number of dry/wet cycles. This is believed to occur because of surface oxidation and contamination. Based on the current understanding of the wettability mechanism, a unidirectional grooved surface is suggested as an alternative to a wetting coating.
Wetting Coatings for Dehumidifying Heat Exchangers
Hong, Kwangtaek (author) / Webb, Ralph L. (author)
HVAC&R Research ; 6 ; 229-242
2000-07-01
14 pages
Article (Journal)
Electronic Resource
Unknown
Wetting Coatings for Dehumidifying Heat Exchangers
| British Library Online Contents | 2001
Wetting Coatings for Dehumidifying Heat Exchangers
| British Library Conference Proceedings | 2001
| Taylor & Francis Verlag | 2000
| British Library Conference Proceedings | 2001
| British Library Online Contents | 2001