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I am working with Type 15 and Type 45 in TRNSYS and have a question regarding the surface slope definition.
In Type 15:
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Parameter 8 defines the surface slope
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Output 29 provides the incidence angle
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Output 30 provides the surface slope
In Type 45:
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Parameter 6 defines the surface slope
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Input 4 is the incidence angle
My question is:
Is it necessary to ensure consistency between the slope defined in Type 15 and the slope defined in Type 45?
More specifically, since Type 45 already includes the surface slope as a parameter, is there any need (or recommended practice) to link or otherwise enforce the same slope value used in Type 15?
@ken,
The short answer is that I would recommend making sure that the two surfaces have the same slope and azimuth.
The longer answer is that in the early TRNSYS days some of the solar collector models contained their own algorithms for computing diffuse radiation so that they could get a ground reflected component as well as the diffuse sky component. Others took the diffuse radiation from the weather data reader and radiation processor. In more recent years we have moved to solar collector models that take all of their needed radiation components from the weather data processor. Type45 is a bit of a legacy component and I would guess that it internally assumes an isotropic sky when it comes to diffuse radiation calculations.
~david
Thank you @davidbradley.
