heat input

Faizan,

I would strongly recommend going through the Design Database section of the Mechanical Designer course - see here. This covers many of the topics you have raised from setting up your model to running load calculations.

I have seen the video but sir I am still confused. just guide me in adding the heat recovery into heat gain report. 

Hello Faizan, there is no facility to directly add heat recovery into steady state heat gain calculations such as CIBSE Gain. However if you know how much air and at what temperature this system will produce then you could account for it by including fixed temperate air as a workaround, as below.