I've been mining for years. Thought is was about time I posted a little something.
Here's my current rig.
6 - S7's overclocked total avg. 30.40 Ths
Total system pulls 62.3 amps
Rig dumps exhaust into my forced air return duct.
Currently in my area I have my power flat rate power for the next 1 1/2 years.
Total electric for the entire house is $450 a month.
Because of the flat rate, I can run the miners and the A/C at the same time and during the winter they keep my house around 70 deg.
i like the server rack idea. with them blowing right into the return do you hear any noise leaking into the rest of the house?
No. Noise isn't an issues at all. The rack is stored in the basement with the HVAC equipment. The noise level in the basement could be better, but not really that bad. I could sound proof the room there in, if need be. In the rest of the house, the only sound we here is from the HVAC fan that has to run non-stop.
The biggest problem I've had so far, is the miners really dry out the air. So I had to disconnect the HVAC humidifier because it won't stop running.