Adnormal high surface temperature?
Posted: Tue Jan 07, 2014 1:28 pm

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.