While I didn't take Thermodynamics in school decades ago, I am 99% sure that every single watt that comes out of the wall ultimately ends up as heat in one way or another. Even the spinning fans produce heat of their own, as well as moving air.
A very small part of the wattage input into a miner get turned into usefull work communicating with the outside world, and does not end up as heat in the room the miner is in.
On the other hand, that's probably something on the order of a very small FRACTION of one watt, so for PRACTICAL purposes the entire energy usage of a miner (and it's power supply, use an INefficient PS if you want more heat) gets turned into heat eventually.
If noise is an issue, SP20E is the best option - set the fan to a "quiet enough" setting then let IT set the clocks.
I believe at least some of the Avalons could be set up that way as well, but never owned one to try it.
Avalon 4.1 are the best on sound no doubt about it. Nothing compares to them on how quiet they are. If you run underclocked especially it's amazing on how quiet it is.
Below is one in action: