Hi everyone!

Does anyone have a working sunspace model?

I am trying to model an enclosed balcony space and verify the model output with a few back-of-the-envelope calculations.

To eliminate the effects of solar radiation and thermally massive elements in an attempt to simplify things, the calculations described below were done using overnight values and all the walls in the space were converted to "quick" constructions. Also calculations were done in winter conditions (28F exterior, 77F interior, sunspace unconditioned)

Using the model output for temperatures of the unconditioned sunspace, interior and exterior, I calculated the conduction heat losses through the window and walls. E.g. heat lost from the conditioned zone to the sunspace, and the sunspace to the exterior. When I could not resolve these numbers, I tried reducing the temperature of the sunspace by increasing the infiltration to the space of outdoor air. By reducing the sunspace temperature, conduction losses from the conditioned zone to the sunspace should increase and losses from the sunspace to the exterior should decrease. The model results showed that the converse was true in both cases, which does not make sense.

The variables I am using to compare with my calculations are:
Zone variable 58: Heat gain by conduction (unweighted) through int windows (Btu/hr)
Zone variable 60: Heat gain by conduction (unweighted) through opaque parts of the int walls (Btu/hr)
Exterior Wall variable 5: Unweighted heat transfer from wall to space (Btu/hr)
Window variable 17: Conduction heat gain through window (Btu/hr)

Oddly, the Window variable 17 only works for my exterior window and not my interior window. Any advice on where I have gone wrong would be much appreciated! I've tried many different variables and these seem the most reasonable. I have also reviewed the Topics, Dictionary, and Libraries documents for details about sunspace model development with no luck.

I'm not sure what the best files to attach here are, so if someone is able to help, please let me know what you need to see and I will send them.

Thank you very much in advance!

Marianne

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Marianne Touchie, B.A.Sc., B.Bus., LEED AP