Quote from: sveetsnelda on September 04, 2011, 11:45:01 PM

I'm cooling:
4 x 5990s
38 x 6970s
8 x 6870s
4 x 5870s
all in one room. Roughly 12,000 watts (just a little under). Everything is being cooled buy a single window mounted evap cooler (in an adjacent room) that draws 285 watts at full fan/pump speed (and I shut it off at night). Because an evaporative cooler is being used, I'm able to keep temperature *and* humidity in check. If you want to run a large Bitcoin farm, a desert climate is definitely the way to go.

12.000w of heat cooled with 285w ? Air cooled?
285w? do you have a killawatt meter?
i doubt is 285w.

don`t forget to add video card fans:
HD6970 are 2A = 24watt fans.
12v x 2A = 24watt. each. * 54 cards = 1296watts.

the noisier the hungrier.

assuming your calculations: not including video card fan power draw "free"
not including the price of adding more cooling "also free".

285w/h *12h "half day" = 3.5kw/day.
*7 days *4 weeks =98kw/month.
*12months = 1176kw/year.
if you pay 0.25usd. x kw = $294usd./year.

Cappacitors last 10 Years working under <80°C.
lets see how long yours last.

assuming they last 10years = ~$3000usd. without adding inflation-.
add 5% inflation each year. = ~$5656usd. You Pay, with added cooling alone.

with $3000usd. can buy 30x 6970 waterblocks.
Car/Truck radiators are "free" in junk yards.
only need tubes, pumps & distiled H2O every month.

I think, i stick with WaterCooling.
as they say: "Watercooling system minimizes failure".

The guy on this video:
http://www.youtube.com/watch?v=eLt8Se3vVNg
http://www.youtube.com/watch?v=G5f_e4P6gMA

has 3x4=12x 160watt fans. = 1920watts hour = ~2kw/h running 24h = 48kw/day = x7x4 = 1344kw/month x12 = 16.128kw/year. or *365=17.520KW/ year.
*10 years = 175.200 KWatt.
without adding video card fans @ 0.192usd. = $33.638,4usd. without inflation.
5% inflation over 10 Years = ~$54.793,4usd.

24 pcs x2 5970 = 48 gpu fans at 24 watt each = 1152watts/h x24 hours = 27,648kw/day x7x4x12x10 = ~92.897,28kw (or 100.915,2KW if x365x10)*.192 = $17.836,27usd. (or $19.375,7184) * inflation = $29.053,4usd. (or $31.561usd.)
= $83.846,8usd. or ($86.354,4usd.) without adding cooling investment, failure rate, etc...

Bitcoins today are $4usd. & difficulty 144k
http://www.bitcoinmonitor.com/
http://bitcoincharts.com/markets/
if makes 50 Bitcoins a month @ $4usd. = $200usd.
cooling eats $2118,144KW a month, fans only not including PSU effficiency, capacitor aging, motherboard, cpu, usb drive or hdd.
*0.192usd. kw/h = $406,69usd.

= needs to make 100 Bitcoins a month to pay cooling. 0 profit.

how much BTC you make a month?
if goes under $4usd. or difficulty over 200k will loose money.

4x 5970 run 3009 MH/s = 752,25 each.
the guy in the video has 48 = 36.108 MH/s or 36.1GH/s

If the fastest computer in the word is watercooled its because its cheaper.
the electric bill of the K computer = 10.000 homes.