The all-day, average-day performance of evacuated tube solar collectors using off-normal incidence angle test data

Conference · Fri Jan 01 04:00:00 EST 1982 · ASHRAE Trans.; (United States)

OSTI ID:6412749

Platt, D M

The development of solar collector testing and evaluation methods has been heavily influenced by the historical predominance in the commercial market of collectors of the flat plate type. To attempt better correlation of all-day collector performance with standard test methods, an additional test parameter, the ''incident angle modifier,'' was defined, and procedures were introduced into the ASHRAE 93-77 test standard to estimate it. Initially it was hoped this could be expressed as a single function of the incidence angle, and, in fact, it can be so expressed for the majority of flat plate collectors. However, for tubular collectors, the incident angle modifier becomes highly complex and highly individual in each variation of collector design. One result is that specifications are being written that often fail to achieve the writer's objective of getting the most useful energy for the money and sometimes actually contradict the writer's intent. A second result is that owners, more often than not, get substantially less energy than they expect from their systems. This problem is exacerbated by poor predictive models and the incompleteness of the collector test procedure, which does not consider the diffuse light, night losses, or varying wind effects.

• Research Organization: Sunmaster Corporation, Corning, NY
• OSTI ID: 6412749
• Report Number(s): CONF-820112-
• Conference Information: Journal Name: ASHRAE Trans.; (United States) Journal Volume: 88
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
141000* -- Solar Collectors & Concentrators
CALCULATION METHODS
CORRELATIONS
DAILY VARIATIONS
EFFICIENCY
ENERGY TRANSFER
EQUIPMENT
EVACUATED COLLECTORS
EVACUATED TUBE COLLECTORS
EXPERIMENT PLANNING
HEAT TRANSFER
INCIDENCE ANGLE
INSOLATION
PERFORMANCE TESTING
PLANNING
SOLAR COLLECTORS
SOLAR EQUIPMENT
TESTING
THERMODYNAMICS
VARIATIONS