Adnormal high surface temperature?

[tkc]

This is the model I am using. Basically I edited based on the tutorial model. The bottom is the office and I draw an additional 100mm ROOF layer above the office. Following which, I drew additional rooms of 0.5m, 1m, 1.5m and 5m height from the top of the ROOF layer. These additional rooms (0.5-5m) I added in 100% opening windows at the external wall and holes in between each layers to make them as an air space. Construction for my model are shown below. Pls advice if they are accurate. What i am trying to obtain is the actual ceiling temperature, roof temperature, air temperature at 0.5m,1m,1.5m and 5m from the roof surface.

Roof light:
Windows:
Ceiling
Roof:

The result for my air temperatures are reasonably correct. However for my surface temperature of the roof and ceiling they are very high. I took the floor of the 0.5m layer as the roof temperature and the ceiling of the office as the ceiling temperature. Please advice of getting the surface temperature is correct? Or should i be getting the ceiling and roof temperature in another way?

My intention is to have a total roof slab of 150mm, consisting of 10mm plaster followed by 140mm concrete above it. I defined the office internal ceiling/floor as 10mm plaster + 70mm concrete and the additional room which i named as roof component as 70mm concrete only. So they add up to be 10mm plaster + 140mm concrete. Reason in doing this is to obtain the roof temperature. I was told that my surface temperature should be in the range of 40 degree max but i obtained a peak of 70+ degree in vista simulation.

Any help or advice is highly appreciated. Thanks!

Free feel to request for more information if my explanation isn't clear.

[tkc]

I believe the key is due to the sky light. when I remove the skylight in place of a 5cm concrete, the temperature gives a more practical answer.

Putting a sky light gives me abnormal temperature of up to 60+ degree which is 30 degree more than ambient air

Can anyone gives me a advice on how to construct the skylight or other alternative?

[Complex Potential]

The surface temperature of a skylight could be 60C under the right conditions I think. I once burned my hand on a metal roof in florida.

[tkc]

Hi CP,

If my intention is actually to make it like an air gap instead of an actual sky light, how should I go about doing it?

I got the sky light setting from setting the outer most layer with 100% window setting. Intention is to make it "invisible" where solar radiation could pass through and light could pass through.

You mentioned setting hole as glass but I couldn't change the roof material to glass unless I add a 100% window on the surface. Please kindly advice

[Complex Potential]

Yep, add the 100% window in and this should start making more sense.