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Re: Lights & Tom

Square Foot Gardening List - http://www.flinet.com/~gallus/sqft.html

Bill writes:
> *They [fluorescents] are 90% efficient where an incandescent is 25%
> about.  You are at about 65%.  Replace them.  hard on ballast and
> waste electricity.  Plants get less benefit.  Estimate the date,
> write on bulb.  Use for temp use in a laundry room if you must keep
> them.

According to http://www.state.sc.us/energy/efflight.htm, incandescents
are no more than 10% efficient, while fluorescents are "up to 5 times
more efficient", which presumably means 50% or less.  A little further
down, it explains that low-pressure sodium lights are "the most
efficient light source presently available", with an efficiency of
35%.  Another web page (http://www.holophane.com/School/HL-862.htm)
explains that LPS lights deliver 100-180 lumens per watt; 180 lumens
per watt is ten times the efficacy of a standard 100-watt bulb.

It's hard to find good info on absolute efficiency of light bulbs;
these figures obviously all contradict one another.  Still, it seems
doubtful that fluorescents are 90% efficient.

One of the points the various lighting-efficiency pages made is that
you might be better off with a high-intensity discharge lamp (such as a
mercury light) in a situation like this.  HID lamps have some
disadvantages for normal use --- they take a few minutes to turn on,
they're not available in small wattages, and they have relatively poor
color rendition --- but those don't seem to figure here.

> *Yeah... engineers are such jerks , huh.  Always with blindres on.
> Can only see straight ahead, and only with that right hat on and
> matching coffee cup and pencil protector.

Uh, yeah.  Thanks.  Now, where did I put my "pencil protector"?

-- 
<kragen@pobox.com>       Kragen Sitaker     <http://www.pobox.com/~kragen/>
The Internet stock bubble didn't burst on 1999-11-08.  Hurrah!
<URL:http://www.pobox.com/~kragen/bubble.html>
The power didn't go out on 2000-01-01 either.  :)


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