Zone Window Heat gain is higher after shading

asked 2016-10-10 06:28:35 -0500

Gurneet gravatar image

updated 2016-10-10 06:29:03 -0500

Hi,

I have modeled two identical buildings, one with shading and other without shading. The screenshots of the same are attached for your reference. I am getting lower zone window heat gain peak load in building without shading. The time of peak is on 21st may at 15:00 hours. 1)Max Zone window heat gain without shading: 4497 W 2)Max Zone window heat gain with shading: 4963 W

The shading has been designed to block the sun for maximum time of the year and I hoping to see a considerable reduction in window heat gain due to extensive shading. However, the heat gain has increased after shading. I would appreciate if someone can explain this behaviour.

C:\fakepath\Buildingwoshading.JPG image description

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Comments

Try running the zone_report measure with your model. It will give you the heat gain components. Also, your zones seem very large. Usually, buildings are broken into core + perimeter zones to account for the different solar loads on the facade at different times of day. You should still be seeing a reduction with shading, but this is something you might want to fix.

mdahlhausen gravatar imagemdahlhausen ( 2016-10-10 11:36:56 -0500 )edit

Hi, Thanks for your input, I tried running the zone_report measure with the model and it is also showing similar results i.e. model without shading has lower window gain. IS this something to do with reflection form shading devices? I will also try to break the zone to smaller zone.

Gurneet gravatar imageGurneet ( 2016-10-12 03:08:40 -0500 )edit

As a reality check, looking at the zone_report summary, is the solar gain component larger or smaller in the shading case? We would expect it to be smaller. You can also check to make sure your internal gains (lighting, plugs, people) are the same.

mdahlhausen gravatar imagemdahlhausen ( 2016-10-12 11:21:16 -0500 )edit