February 17, 2023 at 9:50 pm
Ricardo Lionar
Subscriber

 

Hi Bill and Dave, 

 

Thank you for your reply. The whole system is not attached to another wall, so it is a lightweight steel cladding. 

So, what I wanted to do is as follows:

1. Outdoor temperature is known (got from the bureau of meteorology for a certain time)

2. Outdoor facade surface heated up

3. Inner surface will be heated up

4. For transient thermal transfer, the indoor space will be heated up due to radiation from the inner surface of the wall. But for now, I wanted to try a simple steady state first (since most tutorials do steady state)

 

Therefore, my questions are:

 

  1. Do we have to assume the indoor ambient temperature at first? I saw a tutorial (not specifically for building, but more for a mechanical device) that just assumes an ambient temperature of 22 degrees celsius on the other side of the heat source boundary condition. What happens if in my case, I only know the outdoor temperature? If I do not put the interior boundary condition (in this case convection with ambient temperature), the simulation is not working.
  2. I wanted to know the performance of the facade system to transfer the heat, for example, if the outdoor temperature is 35 degree, this set of facade systems (with a certain thermal transmittance value) will be able to provide certain degree celsius of reduction on the inner surface. But if I already assume the indoor temperature, doesn’t it mean I am ‘forcing’ the simulation to produce an inner surface temperature close to the indoor temperature that I am assuming?

 

Thanks!