Hello,
It is the first thime I send a request to the trnsys users community, but I often look at the archives, which I find very useful.
I have a question regarding the c-value of the frame to be entered in the window type description :
It is said that the cframe-value has to be entered without the heat transfer coefficients
αo
and αi
.
I usually calculate the Uframe to be entered using the following equation :
As Uw, Uglass and fframe are generally known from the beginning as a performance level requirement for the building.
My question is : how can we relate the Uframe of the above equation and the c-value to be entered?
Is it ok to write that Uframe = 1/[RSo + RSi + (1/cframe-value)]?
With RSo = 1/
αo
= 0.04 m².K/W ?
With RSi = 1/
αi
= 0.13 m².K/W ?
If not ok could somenone tell the right method to enter the c-value in order to obtain the desired Uwindow?
Great thanks !
Tanguy (Lyon)