Bitcoin mining will come with noise hazard and heat!!! for commercial mining operations you'll need the ear muff, no matter you use S5 or SP20.
I think this is where I take both you and SP-T to task for implying the S5 and SP20 are 'home' miners. I unconditionally agree regarding commercial operations in data centers, server rooms, garages, etc. But 'home' miners are in the home. At stock settings, I believe neither of these would fit that category very well.
as part of my thanks for a demo unit i advised bitmain several things to make this a "home miner" (as it is the S5 is excellent for large deployment i think). I suggested a S5-silent model that costs $20 more and includes:
1) top and bottom shrouds made with the same light durable plastic as the sides. nothing fancy or bolted down zealously.
2) a second fan, OR adjusting the temperature monitoring and PWM control to keep the fan speeds down (running at 3000RPM for 40C is silly, 2000RPM and 50C would be more like an S3)
3) default speed of 325MHz. a few percent cooler/slower/quieter and easily ovewrclocked at the expense of noise
