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Ecotect - Thermal values

11 REPLIES 11
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Message 1 of 12
nielsthuesen
3382 Views, 11 Replies

Ecotect - Thermal values

Hi

I am studying civil engineer and are use one semester to evaluate Ecotect and it results.
I am having problems with the thermal calculations in Ecotect, because the calculated temperature inside the zones becomes too small. If I make a small room with almost 100% window it the sought facade the temperature does not raise to most more than 26 degrees (compared to other calculations the temperature should be around 35-40 degrees)
I have tried to change the Solar Heat Gain Coeff. and other parameters for the window and the wall but still the result is not correct

Anybody that has had the same kind of problem or knows that the problems are? Hope that I can get some help.

Niels
11 REPLIES 11
Message 2 of 12
fakeson
in reply to: nielsthuesen

hi

i encountered the very same problem. i had a simulation model set up
with thermal problematic zones (small room, around 12m², facing south,
almost 100% glazing, location kabul afghanistan, no ac) and was stunned because
the temps never exceeded 29°C. seems there's no need for any optimization.

so, to evaluate i created kind of a bungalow, around 16m² total, low mass,
no insulation, huge windows. a worst case scenario for thermal performance.
simulated in several different summerhot locations. got the same results,
operating temps hovering around 1-2 over outside temp, hardly ever exceeding
the comfort zone.

i really wonder how reliable ecotect output is.

when simulating the same scenario in energyplus, the results look much
more believable. temps easily climb up to 35-40°C, just as i expected they
would.

hope we get any answers from the autodesk staff...

cheers,
sebastia
Message 3 of 12
peterlou
in reply to: fakeson

Hi there,

 

Did you get a confirmation on the validity of the thermal analysis?

 

I am having the same problem and begining to doubt the result coming from the thermal analysis within Ecotect. I have modeled a 35m2 6m high building with no ventilation and infiltration from wind. I have applied double glazed windows to roof and the walls so it's pretty much like a green house. I would have expected the temperature inside be higher than the outside on the brightest or hottest day which is not the case shown in Ecotect. The result showed that the temperature inside follows the outside temperature and was below it most of the time.

 

Can someone comment on the validity of the thermal analysis in Ecotect? Thanks!

Message 4 of 12
maxschimke
in reply to: nielsthuesen

Hi,
seam that like everyone before I'm getting the same problem.
some one of you found out what the solution is?

Max

Message 5 of 12
peterlou
in reply to: maxschimke

Yea, is there anyone out there who can answer our problem? Thanks!

Message 6 of 12

The Ecotect Thermal simulation is not applicable for all situations, and I have found it particulalry untrustworthy in solar heating scenarios.  It might be worth your while you work through the Ecotect export to energy plus, taking advantage of the model you already have.

 

Message 7 of 12
iremsozen
in reply to: nielsthuesen

I am having similar problems... Temperature inside a sun space is lower than exterior temperature during most of tha day.... It is higher onlyduring noon times. After 16:00 it drops very fast, sometimes 10 degrees lower than exterior. . Could anyone help about this, urgent please....
Message 8 of 12
flamelily
in reply to: nielsthuesen

Hi,

 

have had similar issues can someone please advice?

Message 9 of 12
mgimond
in reply to: nielsthuesen

Have you made sure that the surface normals (for walls, windows, etc...) are facing the right direction (i.e. away from the zone)? This will make a big difference in thermal analysis results.

 

To view the surface normals, select  Display >> Surface normals. Arrows should appear on the surfaces. If they are pointing towards the inside of the zone, select the surface then click Ctrl+R to toggle the arrow direction. 

 

Message 10 of 12
arqyt
in reply to: nielsthuesen

The thermal calculation is Ecotect theoretical premise of the admittance. Is a simplification of analysis, widely used but that "simple". With the data comentais seems that perhaps the data "zone property/Thermal properties" are incorrect.

 

Are there active systems?

Hope this helps
Best regards

Jose M Carralero.
ArqyT
Message 11 of 12
mattb10
in reply to: nielsthuesen

 

I am having same problem as below....Did anyone ever receive a helpful answer to this thread?

 

For example, I made a 10ftx 10 ft x10 ft  cube with the same  very low U value on each of the six surfaces. I did a thermal analysis for various window areas on the south wall. My understanding of basic passive solar design is that expect that should get passive gains during day and losses at night from night, at some optimum window area (e.g. 10% of window area) would get a decrease in heating load from passive gain.

 

  However Ecotect showed that the heating load constantly increased as window area increased in small increments from 1ft x 1ft to 9ft x 9ft. Tried various window types, usually low e double pane and various parameters for window and walls to optimize absorptionand transmission surface normals are outward but got same results

 

If it cannot model this simple situation how reliable  the thermal model is for passive design?

 

 

Thanks for any help

Message 12 of 12
lukyn.fric
in reply to: mattb10

I have same problem and I'm disappointed, because i think, that it is internal problem of Ecotect.

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