Are plastic heat exchangers feasible for solar water heaters? Part 2: Material choices

Conference · Thu Jul 01 04:00:00 EDT 1999

OSTI ID:20030571

Raman, R; Mantell, S; Davidson, J

Development of low cost plastic heat exchangers for solar water heating depends, at least in part, on the suitability of polymers for this demanding environment. Since the heat exchanger is in contact with pressurized potable water, some technical issues must be addressed that are not necessarily relevant to the development of polymer-based collectors. These include long-term pressure and temperature capabilities; compatibility with municipal drinking water and propylene glycol, and compliance with applicable plumbing codes. In this paper, polymers that are most appropriate for this application are identified. Because polymer strength, stiffness, and thermal conductivity requirements depend on the heat exchanger design, no single polymer emerged as ideal for every heat exchanger component. Fiber reinforced PolyPhthalAmide (PPA) and PolyPhenylene Sulphide (PPS) are recommended for fittings and manifolds. Unreinforced high temperature nylon (HTN) is recommended for thin walled tubes (either straight or coiled). Cross-linked polyethylene (PEX) is also recommended for coiled tubes. The selection process was based on three criteria levels: (1) polymer compatibility with potable water, (2) polymer behavior in hot water or propylene glycol, and (3) polymer attributes such as strength, stiffness, thermal conductivity and cost.

• Research Organization: Univ. of Minnesota, Minneapolis, MN (US)
• OSTI ID: 20030571
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
COMPATIBILITY
COST
HEAT EXCHANGERS
MECHANICAL PROPERTIES
PLASTICS
POLYETHYLENE GLYCOLS
POLYMERS
SOLAR WATER HEATERS
THERMAL CONDUCTIVITY