computer building? was[rescue] Noise levels

[James Lockwood]

On Wed, 19 Jun 2002, James Sharp wrote:

> Build the building, but split the space with a fairly solid wall.  use one
> part for the "Server Room" and the other part for the "Workstation Room".

Agreed.

> Use the ground as a heat sink?  There are several companies that make
> systems that are pretty much nothing but heat exchangers that pump heat
> into the ground via a deep hole.

Electricity is cheap enough out here and it cools off enough at night
to allow that to work in the summer.  It would be quite inefficient in the
winter, you would need another heat source or a lot of machines.

> LEDs. Cheap & cool to run.

Not really.  White LEDs are operating in the 5-8 lumens/watt range.  Even
conventional incandescents beat that, halogens beat it handily, and
fluorescents can be close to an order of magnitude more efficient. The
only current advantages of LED based lighting are exceptionally long life,
the ability to easily run off of low voltage DC, the ability to be highly
directional without losing much efficiency, and the ability to radiate
over a narrow frequency range.  Only the first seems relevant here and
probably not worth the costs.

Candela figures are meaningless to compare on their own when you are
trying to light a room.  Monochromatic LED arrays can reach over 15 lumens
per watt.  _This_ is why they are used in places like traffic lights, your
15lpw incandescent with a red filter in front of it only radiates about
2-3lpw of "red".

Incandescents will radiate less heat for the same amount of "white" light
radiated.  Sorry, but it's true.  I don't know what exact objections the
original poster has to fluorescents, but in my experience mixing equal
wattages of cool fluoro and incandescent light yields a highly efficient
very neutral looking light.  This is what most drafting/artists lamps do.

The other real alternative is HID lighting.  I don't think you have the
ceiling height or room size to make metal halide practical, though.  They
have an exceptionally high efficiency but some tradeoffs (long startup
time).

I have a 400W MH in a small box on wheels with a glass lid (and
ventilation).  It makes a _fantastic_ undercar shoplight, once you teach
yourself not to look at it.  :)

-James