[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[EnergyPlus_Support] RE: Shading of many overhangs and calculation time

Hi Patrick,

it depends a bit on your building design. If the balconies are rectangular and easily related to the windows below, then Shading:Overhang will be the fastest to model and calculate. They are linked to a specific window and input is therefore simple.

"Detailed" always describes a shading object that may have a shape other than rectangular and a vertices count other than four. Shading:Zone:Detailed is therefore an option if more than one window are covered and/or the shape is non-rectangular.

Shading:Building is an object related to the building but not linked to any specific surface. Mostly used to describe an external object shading the building.


---In energyplus_support@xxxxxxxxxxxxxxx, <jcrossett@...> wrote:

It would defiantly make a difference in model creation time, and also in optimizing your design scenarios. 
------->With shading overhang you have the benefit of a symmetrical model where you could add all your shading in a ratio based method so it would be a global setting- might want to do so on a orientation basis.. Also shading detailed may involve many surfaces, the primary issue with long runtime.  I am not so familar with shading building. Also you might consider use of controlled blinds. 

Jeremiah D. Crossett  | Senior Analyst  |  Phase Change Energy Solutions
120 E. Pritchard St.  | Asheboro, NC 27203  | Mobile 503-688-8951

On Thu, Nov 14, 2013 at 11:02 PM, Patrick Bivona <patrick.bivona@...> wrote:

I'm working on a high-rise tower block. I'd like to model balcony overhangs that provide shading to the glazing below.

There are 3 objects I can think of using:
1. Shading:Building
2. Shading:Zone:Detailed
3. Shading:Overhang

Knowing that I have about 500 balcony overhangs, I'm wondering if there are significant differences in terms of calculation time between these 3 options.

My thinking is that a Shading:Overhang object is only shading the glazing it's attached to. Whereas, for the 2 other options, E+ has to calculate the effect of each shading surface on all the other building surfaces in view.

Does it make that much difference?

Many thanks,


Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx

The primary EnergyPlus web site is found at:

The group web site is:

Attachments are currently allowed but be mindful that not everyone has a high speed connection.  Limit attachments to small files.

EnergyPlus Documentation is searchable.  Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.

Your email settings: Individual Email|Traditional
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe