Is there any difference between POE switches and normal switches when budgeting for cooling capacity for a network closet?
Normally, when I'm thinking about cooling; I can look at the power draw of a device and assume that for every watt I dump into the room; I'll need to figure out some way to get that watt out of the room in cooling.
But, with POE switches, they can draw an enormous amount of power, but that power isn't being consumed all in that room. Some of it is going to power the phones or APs (making cooling those "someone else's problem") and some of it is going to heat up the wires.
The question is, do I treat POE switches as though they draw a little bit more than their non-POE brethren? A lot more? Anyone have hard numbers or hard-learned experience?
Best Answer
Nothing from hard experience, but I would take it as a given that PoE switches draw more current than their regular cousins.
Cisco has some numbers for Catalyst 65xx series equipment. To summarize a 48-port 10/100/1000 board dissipates 443 BTU/Hr and the PoE version of that board puts out 518 BTU/Hr (+17%). To be safe I'd inflate the heat load by 20-25%...