It is the same as running an older batch S9 with two boards (8THs), except silent. And they pull 2/3s the power of the older S9s as well.
Its design is probably unnecessary in a warehouse, but perfect for the living room.
The T9 is close, but it still uses dual fans. I wonder if the Avalons are quiet enough, but somehow doubt it. Someone told me 65db, which is 10db above the R4.
The fan on the R4 should be run at 100% by disconnecting the control wire, they are very quiet even at the max 3200rpm (i saw another (slower?) batch running max at 3000rpm).
Compare it with the useless A3 and tell me they were worth more spending resources than this. An Scrypt model using this same design would have probably been great as well.
I guess in the end you have to get a T9/S9 and put it inside a cooler box with holes and thermal insulated ducts...
I ran an Avalon 741 in my studio apartment for about 3 months and it heated my space pretty well for the winter months. The 841s are definitely louder.
Underclocking my 741 to -2 voltage and setting a low minimum fanspeed dropped the sound quite a bit (think ~50db @ 1 ft away, I will see if I can find a video). The fans are obviously very sensitive to temps and so I kept my unit near a cold brick wall with a window I could open at any time if it was getting too warm. Electricity cost was about the same as what I would have paid for heat.