I have to size up the air conditioning in my server room. I have calculated a total load of all the power consuming equipment in my server room, i.e. servers, networking devices, SAN, lighting, UPS, and PDUs. Since the air conditioner also consumes electrical power to run, should the wattage consumption of the AC contribute to the heat generation in the server room?
Yes and no. Air conditioners obviously do generate heat from their own power usage, but the formulae to calculate how much equipment-generated heat they can deal with already take that into account — they tell you how much externally generated heat they can mitigate. So you can ignore it for your own calculations.