response 26 of 96:

Aug 2 11:53 UTC 1995

Also
3.) The pipe getting in the way of future construction on those stairs.
(They city approved keeping the stairs, but only if the landlords put in a
bunch of additional work on them.)

response 28 of 96:

Aug 2 22:23 UTC 1995

I was thinking of using the other window, at the south end of the
dungeon. It is in a storage room, and a pipe installed there would
not get in anyone's way. One could install a "plenum" connection
to the window by the stairway, by using the space between the dungeon
and the east wall of the basement as the "duct" (this was described
in #0), if one wanted the intake and exhaust at separate windows.

Since ca. 90% of the dungeon heat production was going to the basement
anyway, what ajax suggests would have brought the dungeon down to about
80 F too. My concern about this was making the basement uncomfortably
hot (and maybe too hot for the machines too), but that does not seem
to happen now, so maybe it should be tried first. When I moved the
floor fan from just circulating air in the dungeon to blowing it out,
the dungeon temperature quickly dropped 10 F. At the time I thought
that that was going to heat the basement more, but since I did the
calculation that 90% of the heat is going into the basement *anyway*,
it is definitely worth trying ajax's suggestion.

response 30 of 96:

Aug 5 00:35 UTC 1995

  As Mayor Daley said to the relatives of those poor oldfolks who were/are
dying from heat-related illness in chicago...."Air Conditioners Save 
Lives...Fans Dont"  Its going to be a hot month.  September might be hot.
Even when blowing hot air out, hot air is coming in.  Buy an A/C...even
a cheap used one.  Maybe it wuld add $50-60 to the electric bill but
if it spares the equipment it would be worth it right?

response 32 of 96:

Aug 5 01:35 UTC 1995

It might be rated for 40 C, but does age degrade that rating any?  Also, an
ambient temperature is not the same as the chip temperature, which could also
be worsened by dust.

response 34 of 96:

Aug 5 04:03 UTC 1995

  Re #13, I read a Consumer's Reports review of "portable a/c's" a year
or two ago, and it corroborated what the salesfolk said: expensive and
very inefficient.  But they said in rare instances, they might fit a need.
Grex's is probably one of those, except that we need something that's
neither expensive, nor inefficient!
 
  Kerouac, buying a cheap used a/c would be worth a try, but the Dungeon
doesn't seem to have any obvious windows in it, so landlord permission
and ductwork would probably be needed.  Not as simple as adding one to
a bedroom.
 
  Even putting a hole in a wall to blow air out to the basement looks
challenging...the wall with the door on it is adjacent to a closed storage
area outside the dungeon...there's less than a foot of free wall next to
the door, or the door itself, in which fans could be installed, at least on
the door side of the dungeon.  Though embedding a few 3" muffin fans in the
door could look kinda cool, in a techno-anarchist sort of way.  (Maybe
after the electrical inspection though!!!!)

response 36 of 96:

Aug 5 05:45 UTC 1995

Another problem is that the wall that is best suited for having a fan placed 
in it, is also the wall that we mounted all the shelves on for the modems.
Logistically, there's no good place to do this.

response 38 of 96:

Aug 5 12:17 UTC 1995

The studs are directly against the stone on the east wall.
Dunno how those spaces connect to ceiling spaces behind the walls,
but my recollection is that there's a wooden beam that goes across
the top of the vertical spaces, before you reach any horizontal spaces.

response 40 of 96:

Aug 6 00:07 UTC 1995

That should be OK, to diffuse the air flow somewhat. I thought that
another prospect is in the *south* wall, near the opening into that
padlocked (?) storage room. The air would circulate into the basement
from there. It looked like a hole could be placed to pass air but
be impossible to squirm into. 

I (re)estimate the required air flow to be 400 cfm, for the dungeon to not
get more than 5 F hotter than the basement. This is equivalent to a flow
of 8 feet per sec through a 1 foot diameter hole. I would think a box fan
could attain this. There should be an adequate opening for air to enter
too, of course - perhaps with a filter on it. 

response 42 of 96:

Aug 6 06:22 UTC 1995

Unfortunately, the liquid those Crays used was a fluorocarbon compound that
costs around $10,000/gal.  Coolant leaks tended to be very expensive in Cray
shops...

response 44 of 96:

Aug 7 12:09 UTC 1995

Having just gutted a Sun 3 compatable, I gained some insight on how the
cooling system works.  The "hot" air is expeled on both sides of the machine.
I bet that one side could be blocked of without much change in the cooling
preformance.  (Keeping the filters in the side covers clean would have a 
much larger impact.)  One could then fabricate a piece of sheet metal to
vent the air discharge from the remaining, unblocked, side into 6" duct-work.
This would requite hacking one of the side covers and would vent only the
air drawn down through the Sun.  The machine I gutted had a 1,000 W supply
in it.  Line input was rated at a maximum 15A @ 115v or 1,725 Watts.

response 46 of 96:

Aug 7 18:49 UTC 1995

Something like this is an option - capture and vent only the Sun 3
"exhaust". The air flow rate is not very great. I do not recall that, on
our machine, it vents the exhaust air at the bottom on *both* sides - does
it? The Sun 3 raises the cooling air temperature by ca. 14 F, but of
course if that circulates into the room, the room gets hotter, so the
cooling air gets hotter, but still *increases* by 14 F. Exhausting just
the Sun 3 exhaust air will interrupt this "cycle, eliminating more than
half of the heat produced in the room. If exhausted to the basement, the
basement will be heated to the same extent as before, but instead of the
dungeon being 15 F hotter than the basement, it would be only 7 F hotter.
Venting more air than just the Sun 3 exhaust would cool the room even
more. A simple construction would be to have a box around the Sun 3, open
on the front, and exhausted to the basement at the rear. This would
require less air flow for the same cooling of the room: ca. 170 cfm rather
than 400 for a 5 F room temperature rise (but the exhaust air, being
heated more directly by the Sun 3, would be 12 F hotter than the the
basement air). 

response 48 of 96:

Aug 8 01:10 UTC 1995

Ok, how about a flexible dryer hose (4 or 5 inches in diameter), with a muffin
fan on the out end, and a simple hood with some kind of clip system or bungee
cords to attach to the case.  In the winter, the whole system sits in a drawer
or on a shelf.  A plate can be attached to the wall with a through hole to
wherever, with a piece of sheet metal or whatever for winter.  The fan will
suck air from the Sun, so a tight seal would not be important.  I was thinking
about suggesting a fan anyway, to keep duct pressure from reducing airflow
through the chassis..