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New Member
mhur
Posts: 2
Registered: ‎10-06-2010
Message 1 of 5 (1,150 Views)

Direct Solar Gain is the same when I add sunshades!

1150 Views, 4 Replies
10-28-2010 07:04 PM

I add sunshades and made direct solar gain analysis but the data that I get is exactly same as the data without sunshades.

What's the problem?

 

I will appreciate your help.

Employee
barrytsai
Posts: 10
Registered: ‎11-23-2004
Message 2 of 5 (1,100 Views)

Re: Direct Solar Gain is the same when I add sunshades!

11-12-2010 09:35 AM in reply to: mhur

Need more information here. I saw different sunshdes created different solar gain result from Ecotect 2011. If you can attach the model or send it to me, we can have a look at it.

Member
KjuWeeDee
Posts: 4
Registered: ‎06-14-2010
Message 3 of 5 (1,046 Views)

Re: Direct Solar Gain is the same when I add sunshades!

12-02-2010 05:55 AM in reply to: barrytsai

I am having the  same problem. I am using an experimental cube with only one window faced to the south to test different facade elements placed in front of the window. I want to optimize to maximum direct solar gains in winter and to maximum average daylightning all year round.

Calculation of the Daylight Factor and Daylightning gives me workable results, but I cannot get any differences in Solar Gains between the sunshades.  I do get different results (as expected) by changing the size of the window, changing the material of the walls of the cube, etc... but different facade elements do not seem to have any influence on direct solar gain calculations (as I would expect to happen).

I have experimented placing the facade elements directly in front of the window, at a small distance (100mm) from the window... but no differences.

I do get small differences in the calculation of MRT, but this is not what I am analysing nor do the results correlate directly to the differences I am imposing on my sunshades. 

 

Any suggestions about how to proceed?

 

Thx,

 

Dirk

Contributor
jon.gardzelewski
Posts: 25
Registered: ‎08-31-2010
Message 4 of 5 (936 Views)

Re: Direct Solar Gain is the same when I add sunshades!

12-27-2010 02:45 PM in reply to: KjuWeeDee

Are you evaluating zonal solar gains, or insolation (incident solar radiation) on the window objects.  If you are evalution insolation, a couple of important things you should be aware of:

  • Floor objects don't provide shading, make sure your shading elements aren't floor objects.
  • Analysis must be done with the "surface sampling" set to 5x5 or 10x10
Member
KjuWeeDee
Posts: 4
Registered: ‎06-14-2010
Message 5 of 5 (894 Views)

Re: Direct Solar Gain is the same when I add sunshades!

01-02-2011 02:37 PM in reply to: mhur

Thx Jon for your reply.

 

My shading devices are set to Panel - Plastic (no floor object) and I am calculating Direct Solar Gains and Passive Gains Breakdown. I do Inter-zonal Calculations before the analysis, with Surface Sampling set to 2500 (I need very quick calculations) and with Shading Masks set to 5x5 grid.

Meanwhile I could get some very small differences after setting all the values in Zone Settings to zero and tampering a little with the material properties of the window (Solar Heat Gain Coef and Visible Transmittance set to 0.99). So I suppose diferences before did exist but were to small to show. Anyhow I am still not convinced that my results are valid, I do expect greater differences. 

 

Dirk

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