Dear All,
I try to simulate cooling system by matlab and
simulink but I don't know how to find a transfer
function of room temperature.
If anyone know, tell me please.
Thank you

 

dear friend
in order to obtain a transfer function for a typical system you can use system identification toolbox of MATLAB .the procedure is as
follows:
by entering some inputs to the system and measuring correspondent outputs you can estimate a transfer function by one of the
modelsarx,armax,...)
note that you must have some backgrounds in digital control.
some methodes exist for this purpose such as recursive least squares method.refer to the book:
computer controlled systems by carl j. astrom 1997
system identification chapter.
a computer program for this purpose has been depicted.
though you can contact me for more information.
good luck

 

Didn't you try the model of the house in the maltalb's demos? It is simplified (no air velocity ...) but I think it will be good for your
need.

In the m-file you can find all the thermodynamical parametres of the house.

Bye

Raffaele Malutta