RE: PG&E on data centre cooling..

["Alex Rubenstein" <alex () corp nac net>]

(beware, weekend engineering and number pulling here)

If you have 250 fixtures, which are each (2) 4' T8 fluorescent bulbs,
which would make for (500) 32 watt bulbs, that would be 16 kw, or at
$0.13 cpkwhr, would be $1,497/month. But, don't forget, you'd have to
cool the heat load generated by the bulbs.

250 fixtures would probably be around a 16 kft datacenter (perhaps
smaller). 16 kft in todays datacenters would be about 1.5 mw of usage,
between power consumption and HVAC. That'd be $140,400/month. Lighting
would account for 1.0% or so.

We use a combination of LED and CF (compact fluorescent) for lighting,
which with reduced bulb changes (and the associated labor) because of
longer live, and the significantly less energy usage, the savings do add
up over time. I mean, it adds up in absolute dollars, but perhaps not
relative.

In our town, the fire folks do not require the emergency lighting to be
battery-backed, so long as it is on generator and will not be off for
more than 15 seconds.

We use an Edison-base style LED fixture, something like

        http://www.superbrightleds.com/specs/E27-x24_narrow.htm

It provides about 15 to 20 watts of equivalent incandescent light, using
only 3 watts.

Has a neat look too.

        http://www.nac.net/nac_mmu.jpg





> > John(damn I've been in a DC with clear floor tiles...why didn't I
> think
> > of this then?)
>
> How about the concept used in movie theatres?  Line the walkways with
> white LEDs so that people can walk safely.
>
> Far less power, easy to run from small UPS, and use LED exit lights to
> keep the fire marshalls happy.  Even mark the location of fire
> extinguishers in LEDs.
>
> Customers would be encourages to bring their own florescent panel
> lamps;
> rentals would be available for the forgetful.