Hi,
I am assesing a exposed floor above a car par. On the external side is the car park and on the internal side is an office.
The construction of the floor is as follows:
internal
70 mm screed,
250 mm concrete,
isulation board
External
I have followed previous advice on the forum about how to model this so i think my set up is correct. I have turned off radiation and adhering fraction of rain.
The main issue i am having is the isopleths on the exteranal side of the construction (insulation) . In most constructions this does not need to be assesed, but in this construction i think it might need to be as eventhough the conditions are external, it is still a room where humans will have access to. The isopleths suggest there will be mould growth. As i have not assesed this before, please can you advise if this is normal and does it need to be assesed in this case?
thanks,
Jacob
Floor above car park
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Jacob Grubb
- WUFI User
- Posts: 2
- Joined: Tue Feb 20, 2024 10:51 pm -1100
Floor above car park
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Daniel
- WUFI SupportTeam IBP
- Posts: 132
- Joined: Tue Jul 19, 2005 2:50 am -1100
- Location: Fraunhofer IBP, Holzkirchen
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Re: Floor above car park
Dear Jacob,
do I understand right: exposed means: without roof? Exposed to rain and radiation?
However, the available mould growth models (Bio and VTT) are both only validated for interior surfaces and "contain" species, which only can survive inside (no frost, no UV radiation, no rain etc.). Thus, you will find in nearly all climates (where also plants can grow) a result similar to yours, as the normal outdoor air humidity levels are normally sufficient to allow for mould growth at least in late summer, autumn and early winter.
On the other hand, the risk is limited even if you have many points above the curve, as the conditions vary a lot throughout the day - in difference to the indoor climate. So even if you have good conditions for a few hours during night time, the conditions may become unfavourable during day.
In summary: the validation only by isopleth is not possible, by a transient simulation with WUFI VTT or Bio it is more realistic but still far on the save side, as these models are validated for positions indoors or at least protected inside the warmer area of the assembly.
best regards
Daniel
do I understand right: exposed means: without roof? Exposed to rain and radiation?
However, the available mould growth models (Bio and VTT) are both only validated for interior surfaces and "contain" species, which only can survive inside (no frost, no UV radiation, no rain etc.). Thus, you will find in nearly all climates (where also plants can grow) a result similar to yours, as the normal outdoor air humidity levels are normally sufficient to allow for mould growth at least in late summer, autumn and early winter.
On the other hand, the risk is limited even if you have many points above the curve, as the conditions vary a lot throughout the day - in difference to the indoor climate. So even if you have good conditions for a few hours during night time, the conditions may become unfavourable during day.
In summary: the validation only by isopleth is not possible, by a transient simulation with WUFI VTT or Bio it is more realistic but still far on the save side, as these models are validated for positions indoors or at least protected inside the warmer area of the assembly.
best regards
Daniel
Dr.-Ing. Daniel Zirkelbach, Deputy Head of Department Hygrothermics, IBP Holzkirchen