Since my cards are undervolted I forced a constant fan speed at 50%. At that speed the rig is not too noisy. Of course it is not completely silent but I can live with that. As I said outside is very cold and snowy, so the moist from outside compensates the dry air from the fans. When the temps get normal - about and above 0 C, I will move my rigs in one room. They are on specially designed tables with wheels (which have breaks to be stable) so I can move them easily around
My only concern is the summer... Even in one room with AC they generate heat above 35 C so that a second AC in the next room is not capable of stopping the hot air. 
I have a similar problem with my place and the heat. Right now, my miners are heating the whole house just off the heat they are producing. I have a 6" inline fan that sucks the air out of the makeshift room and blows it into the ducked works of the house. FYI is -20+C outside. I also have a 5" intake fan that sucks cold air from outside and puts it in the small room. The house is a comfy 22C.
In the summer I was running a DC furnace fan and blowing all the air out my furnace stack and dryer vent. Even doing that the house had most of the windows open and it was +24C.
Basically what I'm trying to get at it that is this; most GPU's run at 60+C so as long as the air entering the room is less than that their will be fine. BUT the key point here is you need to get the hotter air out. You might be best to put the miners in a separate room and exhaust all the air out of the window in the room with high volume fans. Make some sort of screen for the door of the room so you have intake air. I've tried to add an AC unit but even 1300btu unit didn't even help that much and it was using 1350Watts.
. Excellent solution for heating the appartment 
. But for the summer it is a hell. Two AC 1200 are not enough. I will need a third AC or have to figure out some way of channelling the heat outside. 
