Suncast dodgy results please help

[chwang]

Hey guys,

First post. Got some dodgy results from Suncast was hoping someone can point me in the right direction? I'm modelling which basically a single gable warehouse with full curtain glazing.

Please see screenshot below:



After running Suncast, the results show that there is zero sun exposure throughout the year for the East-facing wall (which is impossible due to sunrise).

I've checked the model, and it contains no errors (ModelIT -> Settings -> Adjacency separation distance 0.001m). Obvious things such as orientation and location of the model is also correct.

Anyone have any clues?

[Terence]

That is strange. What location/weather file are you using?

Go to ModelIT and in the key-in field type "fix" and hit Enter and then run Suncast again. Is the result still the same?

[chwang]

Hi Terence,

Thanks for your reply.

I'm using APLocate's 'Location & Wather Data Wizard - ASHRAE database'. I'm running Suncast again (takes about an hour). Can you please elaborate on what 'fix' does when entered in key-in field?

Cheers,
Jason

[chwang]

Results are still the same. Suncast shows no sun exposure to the East-facing external wall . Are there any other suggestions?

[mcowan]

Hi Jason,

Did you end up resolving this issue? I realize it's been a while since you posted, but I'm having a similar problem with my east-facing exposures (there is, for some reason, no solar gain in any of my east-facing rooms).

Thanks,
Monica

[mcowan]

I solved my problem: some of my walls in these spaces are underground, so I had changed the adjacency of those walls to something other than "outside air." When I reverted the adjacency of these walls back to "outside air," and made a wall construction for these spaces which included a few feet of dirt as the outside layer, I began to see non-zero solar gain results. Lesson learned: watch out for adjacency settings.

[PCully]

Hi Monica,

Good catch there. yes we denote a ground contact or below ground surface by assigning a constant temperature adjacent condition (profile) which then triggers Apache/SunCast not to calculate solar gain on the surface.

A good troubleshooting tip for SunCast if you doubt the exposure results is to generate a series of images and then review solar incident angles, effects of shading etc. This should always reflect the results you had previously calculated, just be aware of the design day the calcs are run for.

Phil

[JohnLloyd]

Another thing to keep an eye out for is intersections, including intersections with shading surfaces. I've noticed that having this will cause Suncast to assume 100% shade for those surfaces / rooms.