May be somebody can help. To compare different materials and to get used to thermal analysis with ecotect I designed a very simpel model; 16 x 16 x 4 m, plaster floor, no HVAC and stuff.One time I choose single glazing for all external surfaces, one time double glazing (better insulation). Please see screenshots and model attached.
My problems:
I doubt the absolute temperatures calculated for a bright summer day - in both cases.
The model with single glazing heats up more than the better insulated model with double glazing.
Both room temperatures drop below outside temperatures before outside temperatures start rising again and while the sun is still shining.
To avoid mistakes I always set primary material = secondary material.
Any advice? explanations?
cheers
| Attachment | Size |
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| screenshots_thermal_analysis.doc | 289.5 KB |
| 16m_mal_16m.eco | 115.15 KB |
Are you happy that the
Are you happy that the material definitions for your glass are appropriate for the circumstance you are trying to simulate ?
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Hey craines! Sorry, I'm not
Hey craines!
Sorry, I'm not really sure what you mean by your answer.
I'm just getting used to ecotect and its thermal analysis so I wanted to play around a bit and maybe check how big the difference is compared to another program like TRNSYS. That is how I set this model up. But then I asked my self: If a big green house heats up during the day and does not get cooled or ventilated, why does it's temperature drop below the outside temperature while the sun is still providing some aditional energy (that enters the greenhouse and is not leaving it again)? And why the peak temperature of the better insulated green house below the single glazing one? It's not sun protection glass.
So, who knows how accurately thermal calculations with ecotect are if there is a lot of solar gains and glass included?
Thank you
What I meant was, have you
What I meant was, have you gone through the material properties for your glass in detail to make sure they are appropriate for what you are trying to model ? Hard for us to know if they are/aren't just based on what you describe and not seeing the model.
It sounds to me like you may not have your "Alt Solar Gain Heavy/Light" defined appropriately. I would suggest that you do a bit of background reading on the CIBSE admittance method and these values as this will give a better idea of what will be "right" for your situation.
Hopefully this time I make more sense for you
maybe...
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