Development Of Solar Domestic Hot Water Systems Performance Prediction Methodology Based On System Test Results. Final Report. 01-84. 1V. (Various Pagings). (Copies 1,2).

Secondary Author(s)

Block, David

Report Number



Solar Thermal


Solar manufacturers have a means to evaluate and certify solar domestic hot water (SDHW) systems through a system test procedure. This procedure is based on an ASHRAE 95-81 system test with test conditions specified by a certification organization (SRCC, ARI, TVA). One result of the SDHW system test is the ability to compare different systems and system types. However, this comparison is only valid for the specific conditions used in the test. The experimental test produces a single-day performance result. FCHART produces monthly and annual performance results. The methodology described here has used TRNSYS to the FCHART annual performance prediction. The methodology is to bridge the gap between prescribed single-day test results and the FCHART annual performance preduction. The methodology is applicable to active, integral collector storage (ICS), and thermosyphon solar systems and involves the development of a detailed description of the system for input to TRNSYS. The input parameters are then adjusted to obtain agreement between the TRNSYS simulation results and the SDHW system test results. Next, the TRNSYS input parameters are translated into a set of FCHART input parameters. FCHART can then be used to predict the annual system performance for the given system at a particular location (i.e. a city in the FCHART data base). The primary output of this methodology is the set of FCHART input parameters for each solar system which can be used by anyone with access to FCHART. It is also possible to evaluate system performance at other locations and the effect of system design changes on annual performance.Comparisons of experiment test results and TRNSYS simulation results have achieved good agreement in all cases. Agreement between experimental test results and simulated results also indicates that changes in environmental parameters can be simulated without additional testing.

Date Published


Local Subjects

Solar Thermal


FSEC Energy Research Center® Collection

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