no heat gain from sun in Ecotect!!

[Anonymous]

The Ecotect model i am analyzing is not showing the correct result when I am calculating the thermal heat gain from sun – because there is not any heat gain!

I am coming to the conclusion that passive heat gain for the sun tough windows is something that Ecotect cannot calculate. This is also my conclusion, because there in this forum not are anyone there can give any concrete answers, even though there are many question on this subject.

I think that Ecotect after using several weeks evaluating the program regarding heat gain from windows are misleading which also means that the whole thermal analysis in Ecotect have to be reevaluated!

Sorry for this little bit angry massage but are just frustrated of the difficulties of getting answers…

/Lars

[Anonymous]

Hi Lars,

I may say that in general admittence calculation method, that is the one used by ecotect, is not the most accurate to evaluate passive gains. Despite of this it can give you a very general picture of how your geometry is behaving, especially in the early stages of design. If you want to get a more detailed simulation of a specific physical phenomenon such as passive heat gain through a window then maybe you should consider a different package with a more suitable calculation method according to your needs, such as the response factor method.

However it could be useful to give you a more precise feedback to know what are you expecting from the simulation you run in ecotect and what are the results you are not happy with.

Cheers

Giulio

[Anonymous]

Hi Giulio

Thanks for the replay

I can try to give you an example of what i am having trouble with. I have attached a model from Ecotect that where the room is 150m2 big and the window facing sought is 28 m2. The maximum temperature in this room peaks at 24 degrees.

I can compare the temperature graph of the room for the hottest day, and see - if i switch Solar radiation on and off - that the temperature only change around 1-2 degrees. I think it is so little that it is hard to give a general picture of how the geometry is behaving.

Cheers
Lars

[Anonymous]

Hi Lars,

I have a look later but I guess the problem is the same as in your previous post about thermal analysis, that is changing the window solar heat gain coefficient together with the alt gain coefficient!

[Anonymous]

Thanks, that would be great!

I have tried to change the solar heat gain coefficient together with the alt gain coefficient, to the worst case scenario, where there is as much solar gain as possible going inside the room.

I guessed that the worst case is with a solar heat gain coefficient = 1 and alt gain coefficient =1 and visible and visible transmittance = 1 (I did not expected that the visible transmittance should have any effect on the temperature inside the room but it does!)

In the worst case scenario the temperature inside the room still get far too little...

/Lars

[Anonymous]

Hi

I was just wandering about if you have had a look at my model and the problems I am having with calculating the temperature rise inside the room concerning the heat gain from windows. It would be big help if you could help me because i am going to use the results in my paper.

Cheers

[Anonymous]

Hi

i would just like to hear if you have had a look at the model as you said. I would be really helpful for me. There are nobody else that can answers my question, so i do not know want to do.

Are actually still thinking that Ecotect not are able to calculate heat gain from the sun that will make the temperature rise inside the room!

Really need a answar....

Lars

[Anonymous]

Hi there,

Did you get the answer from anywhere?

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!

[Anonymous]

any progress anyone?