v.2.5.4: influence of checking "explicit radiation balance"

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hs
WUFI User
WUFI User
Posts: 28
Joined: Mon Mar 01, 2010 2:41 am -1100

v.2.5.4: influence of checking "explicit radiation balance"

Post by hs »

Dear Sirs;

In order to take into account the cooling effect of long wave radiation, checking "explicit radiation balance" gave a apparently overheated interior environment through years.
It was seemed to be caused by the heat gain through window in the componet of "heat flow : exchange with windows".
In the example project, we just assumed a poor single pane window so that It could not keep gaining heat flow to the interior zone through day and night.
Similar numerical results were obtained not only for the climate file of Tokyo, but also for Willmington NC.
In Holtzkirchen we confirmed the similar tendency.

We are wondering if there are any bug report on this issue.

However the mwp file is not allowed to upload with articles in the forum, If you would check the example cases, we could provide them.
Generally speaking, the long wave radiation is seems to provide certain cooling effects, but the result for "explicit radiation balance" case showed the apparently overheated temperature profiles.


Best regards,
mpazold
WUFI SupportTeam IBP
WUFI SupportTeam IBP
Posts: 196
Joined: Wed Jul 11, 2012 11:21 pm -1100

Re: v.2.5.4: influence of checking "explicit radiation balance"

Post by mpazold »

Thank you very much for investigating this. I’ve used the same model you send for the other topic (regarding the inner temperature depending on the solar radiation) to check the explicit radiation balance. I've also tracked a pretty higher inner temperature instead of expactable cooling effects.

The window model used in WUFI Plus is still simplified based on the static method from EN-ISO 13790. We already have improved it for the upcoming version due to some issues with the explicit radiation balance for transparent components.
Meanwhile, I recommend to leave the explicit radiation balance for transparent components unchecked.

Best regards,
Matthias
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