@ firetreeactual - I'm like you and run 2 741's at home now and looking to try running 3rd soon and shipping few to Labrador soon.
I wanted to know how you handle several 741's running at home (ie. sound / heat). I had friends with free electricity that wanted to host some of them but in this summer heat miners are too much for apartments and they bailed out.
Well...I don't know where you're at...but I'm on Kaua'i Island in the western Hawaiian Islands at about 21N. Temps are relatively temperate (pun intended) here, and seldom do I see anything over 85F in my flat. I have 20in window fans running on the south and north windows to keep a cross flow. However...I have my miners on a wire shelving rack in my bath, which is fairly spacious as it's a wheelchair access flat (no, I don't use one...I just got lucky on what was open when I rented it). Their butt ends (exhaust) are up against the open louvered window, with another 20 in box fan hanging on the front edge of the rack, and blowing air (not at full blast, though) over/through the 741s, the power supply bricks, and the two 2400W line conditioners (one for each set of PSUs). I don't notice any increase in ambient heat in the bath, actually, but there's a fair amount of air moving through there, even though I keep the sliding pocket door all but 4 in closed to limit the noise as well.
Basically, if you don't have your miner (741 or otherwise) next to a window in a non-A/C room, you're basically running a room heater that's going to burn itself out rather soon.
The nice part, however, is that the 741s I'm running appear to do self-clocking...IOW, they sense the temps/fan speed/etc. and will reclock/reboot to optimize. The temp needs to get over 100, but then it will reboot to a slower clock, and continue that cycle until it reaches a relatively happy medium. Took me a while to realize this, and I kept hard booting one of them thinking something was wrong...until the one I wasn't messing with settled in, and made me look like a maroon. I've seen one of them take maybe five minutes to settle in, but one time it was 15 minutes when the ambient was higher. They've been running each at >8TH with temps around 96 for several weeks now.
Ah...the noise...well, they're better than an S7 for sure, but still rather mouthy...