AV equipment produces heat, and it can sometimes to be a callenge, there is a way to calculate how much heat the equipment produces so you can communicate this to the HVAC company, so they make sure that your AV system is not producing more heat in a room that the air condition can work with, the heat load is called BTU and stands for British Thermal Unit, and is calculated on the basis of Watt.

The formular is:

BTU= Watt * 3,4

you can't use this formular to calculate heat load (BTU) for an amplifier, if you need the BTU for an amplifier you need to look this up in the specifications, normally it is listed based on the loudspeaker impedance, for example 2, 4 or 8 Ohms

When you have the total BTU of your AV system you can use this to find a rack, and see if it can provide enough cooling, for your system.