How to set the boundary condition for mixing of two air stream.
 

Hi

I need some help to set the boundary condition for my problem. I am working on CFD study of HVAC.

In mixing ventilation inlet air comes at 289 K and temperature of air inside the room is 300k and 1 atm for the entire fluid domain of the room is used as initial values. And the solution is runs at transisent condition. there are heat source inside the domain.

How to set temperature of the fluid domain at 300 K as initial values?
and solution stop once constant temperature has reached.

Thanks in advance.