During my IES training I was told never to use Inner Volume when entering building geometry in ModelIT as wall thicknesses will not have a significant impact on the results and the software is less likely to generate errors using single line model geometry.
I have now changed employer and find myself at odds with my new colleagues who always use inner volume.
While we are all aware of what the use of inner volume does to the model geometry we have been given different advice during IES training on when/if to use it.
Is there are definitive guideline on the use of inner volume when creating model geometry in ModelIT?
Inner Volume - When to use it.
Re: Inner Volume - When to use it.
Hi,
I don't think I'd advise never to use it, it's simply a preference and different people will opt to use it or not sometimes even depending on a specific project and the desired study.
What we will put across is for typical apache simulation thermal and energy analysis then it isn't often necessary to have the inner volumes, this will reduce floor area and room air volumes base don the assigned constructions and so should make your simulation more accurate in terms of the loads calculations etc but in the grnad scheme of modelling assumptions you will make with regards to your thermal template and system inputs then it won't make a big difference usually and aspects such as thermal mass of the fabric etc are still all calculated and represented by the assigned construction regardless of the presence of the inner volumes or not.
We often find for example daylighting analyses using Flucs or Radiance (and associated imagery) then it is more desirable to include the inner volumes though.
It can impact on how you choose to model so is good to have made the decision early on if you will model with or without the inner volumes and it also adds further complexity to your model, how it is shown in the workspace so that is worth bearing in mind as well but there is no right or wrong. If it was never to be used we would have removed it form the software interface a long time ago however.
Phil
I don't think I'd advise never to use it, it's simply a preference and different people will opt to use it or not sometimes even depending on a specific project and the desired study.
What we will put across is for typical apache simulation thermal and energy analysis then it isn't often necessary to have the inner volumes, this will reduce floor area and room air volumes base don the assigned constructions and so should make your simulation more accurate in terms of the loads calculations etc but in the grnad scheme of modelling assumptions you will make with regards to your thermal template and system inputs then it won't make a big difference usually and aspects such as thermal mass of the fabric etc are still all calculated and represented by the assigned construction regardless of the presence of the inner volumes or not.
We often find for example daylighting analyses using Flucs or Radiance (and associated imagery) then it is more desirable to include the inner volumes though.
It can impact on how you choose to model so is good to have made the decision early on if you will model with or without the inner volumes and it also adds further complexity to your model, how it is shown in the workspace so that is worth bearing in mind as well but there is no right or wrong. If it was never to be used we would have removed it form the software interface a long time ago however.
Phil
IES Worldwide Technical Support