Robert G. Brown wrote:
On Tue, 28 Feb 2006, Don R. Baker wrote:
for 8 years, but consider myself to still be a beginner. I have a room
with 4, 15 amp circuits and a 20 000 btu air conditioning unit installed
that I can use for the next 2 years, but after that I may need to find
another home for the system.
Let's see. 20KBTU is a bit more than 1.5 tons of AC, call it the
ability to remove 5800 Watts total. 4 x 15 x 120 is is 7200 Watts peak,
or about 5000 Watts RMS. In my opinion this is going to leave you a bit
light on AC if you run the circuits fully loaded, and don't forget warm
bodies (60 W) and built in light bulbs etc. on other circuits (maybe
several hundred W more). You have to not only remove the heat as fast
as it comes in but get ahead some, correct for heat that infiltrates
through the walls, and get the room temperature down below 20C (68 F) if
at all possible. 15-16C is more like it -- cold enough to just be
uncomfortable.
Sensible conclusion, but: A 15 amp circuit should deliver up to 15 amps
RMS (otherwise, a 15A heater would immediately trip a 15A breaker).
Peak currents during the cycle can be higher. This fine point is
academic, though, since in this example the air conditioning capacity
limits maximum power dissipation.
BTW, when it comes to heat dissipation, humans count about as much as a
bright light bulb (100W+ depending on activity level -- 100W corresponds
to 2064 kcal/day).
I personally would reject #3 out of hand, unless you buy three year
onsite service contracts on the Dells (spending nodes as required).
Dell doesn't do Opterons, I don't think, as well. HPs ditto.
Dell is Intel only, but HP sells AMD CPUs, including dual core Opterons
(e.g. HP xw9300 workstation -- but compare costs carefully).
Sincerely,
Josip
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