defining open ceiling in energy plus [closed]

asked 2019-02-11 01:00:06 -0600

zahro
373 ●1 ●9

updated 2019-02-11 01:03:00 -0600

Hello, I am having a building with an open ceiling, and ceiling surface as the boundary for air volume. For now, I model the roof surface of the open ceiling as the Shading:Building surface with its transmittance schedule.

However, I did not see any differences in the fenestration solar contribution for the cooling load when I changed the transmittance schedule from 0.04 (the calculated number according to products specification) to 0.9 (just try to see the sensitivity.

This is my model from energy plus:

image description

Here, I have 2 different types of cooling capacity result, as explained in the image below. image description

However, bed 8 and 10 have two different orientations (one is vertical and another is horizontal). I believe that it should not be the case when you have different orientation. The site has 45 deg orientation relative to North.

I did not really sure which part of the model I input wrongly. I need help in which parameter do I need to check carefully, to find the mistake, since the big difference comes from solar transmittance of my skylight surface in the ceiling.

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Closed for the following reason the question is answered, right answer was accepted by zahro
close date 2019-02-19 00:27:11.055828

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answered 2019-02-19 00:23:42 -0600

zahro
373 ●1 ●9

I realized my mistake after digging the rate of transmitted solar radiation for each zone and each surface. In my model, I have four similar buildings with different orientations, and I did a copy paste of my model then rotate it according to each orientation.

However, when I check the orientation of each building, they have different local north axis orientation, not in line with the global north axis orientation of the facilities. It seems that the local north axis is also getting rotated when I copy paste and rotate the building. It leads to the complexity of each building north axis orientation, that's why the result did not make sense.

When I tried to make the model from scratch again (without copy paste and rotation), the result makes sense and consistent with the building orientation.