Just thought I'd post here that this past week I upgraded the 3 S3+'s I had running in my office for about a year straight. They were run on a single EVGA 1300 G2 power supply that run without problems on 120v (about 1,195 watts for the setup that included 9 additional case fans and a fan controller). The 3 brought in about 8 bitcoins total (running at about 440 GH/s avg.), which I purchased additional miners with about 5 of the coins leaving about 3 bitcoins.
So, did you pay for electricity? If not, that's a huge win. I only mined 1 btc with my 5 s3+s, and 1 of them is running on hybrid solar. You really don't need that many fans imho, because s3+s can run hot and still stay perfectly fine, like s1s. S5s not so much, the reliability has gone down all the way into the s7 series. I run mine in the basement and even at an ambient of 70 they don't get very hot.
I had the 3 in a computer case to keep it a bit quieter for the office. The electricity is included in the office rent, so no electricity expense. I've upgraded to 2 S5's in a case now that's been running for about a week (it's running a bit overclocked and consumes about 1,280 watts for the setup). I would do 1 S7 but it's just too loud. The electricity for the office can't handle more than 3 S3+'s or 2 S5's or 1 S7. I flipped the circuit breaker a couple times a year ago when I tried to run 4 S3+'s, so I settled on the 3 and they ran no problem except the Air Conditioning shuts off in the building after 6pm and on weekends so the office get 80-90 degrees F.
