How do I assess the "heat load" of a particular room

Hey CR4, I'm an audio visual technician specialising in radio studios. I have been asked to perform a "heat load assessment" on a studio i am working on presently. This will enable the building supervisors to add the room to the air conditioning supply. I can measure the volume of the room obviously however there is a fair amount of heat producing hardware in the room. Computers and rack equipment and so on. Can anyone help me with a method to calculate this answer? Thanks! Rory