Re: Computer Based Garage Heat (was 09 BBQ)

From: jon@dakota-truck.net
Date: Sat Jan 24 2009 - 23:28:50 EST


Terrible Tom <silvereightynine@aol.com> wrote:

>> Terrible Tom <silvereightynine@aol.com> wrote:
> I have heard many opinions on this next question... what's a safe operating temp?

  I don't know how accurate it is, but this may help, as far as the
CPU goes:

http://www.pantherproducts.co.uk/Articles/CPU/CPU%20Temperatures.shtml

  What I have been more concerned with lately are the hard drives.
I've had a few go on me, and I think it was heat related. (That's the
main reason I started trying to keep the air moving through my
workstation.) I've got a couple of fans blowing directly on the
drives now. A while ago, I built a rackmount enclosure which holds 8
drives, and the entire front is wall to wall fans, so its basically
like a wind tunnel. Overkill probably, but they run nice and cool.
:-) (http://www.jonsteiger.com/temp/drive_enclosure) In the photos,
there are only 6 drives installed, but there is room for 2 more. I
could probably condense the drives a bit and fit more in there, but at
the time I built it, I just had another drive die due to heat and I
was set on full overkill mode. :-)

[...]
> Question.. do you see any danger to the electronics, if the computers were left to operate in
> an unheated garage? I know they have a range of normal operating temps... currently its 5F
> outside.

   Based on my limited research in this area, they should be fine,
certainly down to 0F, and I have heard that some components such as
the CPU can be run even cooler, like -20 or so. The only thing that
would concern me is the possibility for condensation. When the cold
air hits the warm computers, the water vapor might condense into
liquid inside the computer, which obviously isn't a good thing. I'm
not sure if that would actually be an issue or not - I mean, usually
you get condensation when you put a cold object in a warm environment,
and you'd be doing the opposite. Plus, the humidity level during the
winter is going to be very low, so I don't know if there's much of any
water vapor to condense in the first place. And, the constant air
flow through the computer might be enough to prevent condensation.
I've never tried it though, so those are just random thoughts. :-)

[...]
> Thoughts? Comments?

   I like the idea. :-) You'd still need to figure out what to do
during the summer of course, but putting them out in the garage during
the winter sounds good to me, as long as they will be protected from
dust/debris, etc.

> (undetermined amount of time passes)

> ok I just researched BTU's and it seems the method of calculation is watts x 3.412 = BTU/H

> My UPS unit reports an average load of 625 watts... which translates into approx 2132 BTUs per
> hour. And that's a conservative figure, because it does not take into account the Wifi A/P,
> the switches, and one computer in another room on its own UPS.

> So its theoretically possible that all those computers could keep a smallish sized, unheated
> but insulated room, some degree of "warm".

   I'm not sure if you can use that kind of calculation. I think when
you convert watts to BTUs, the calculation assumes something like an
electric space heater, which is extremely efficient in converting
watts directly into heat. However, your computers are using the watts
for other purposes, and the heat is just a by-product. A computer
will not be anywhere near as efficient as an electric heater at
converting watts into heat. (That's probably a good thing!) ;-)

   The direction I would take if I were you would be to use the
calculators which determine how many BTUs it takes to heat a certain
space. For example:

http://www.herman-nelson.com/BTU_calculator.cfm?type=F

 
   What I might do in your place is to leave your bedroom window shut
and let the heat reach its max (unless you already know what temp it
would reach). Compare the current temp in the rest of the house to
the temp in your room, and use the calculator to figure out how many
BTUs your equipment is generating. Then, you can plug in the
dimensions of the garage and the outside temp to figure out what temp
would result, using the BTU figure you came up with earlier. Of
course, the amount of insulation in your room vs the garage will play
a huge role, so I don't know how accurate it will end up being, but
I'd lean towards that route as opposed to a watts/BTU conversion when
the heat source is a computer.

-- 
                                          -Jon-

.- Jon Steiger -- jon@dakota-truck.net or jon@jonsteiger.com -. | '96 Kolb Firefly, '96 Suzuki Intruder, Miscellaneous Mopars | `-------------------------------- http://www.jonsteiger.com --'



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