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Re: PCFs Again

NorbSpitzer at gateway_net wrote:

>In a message dated 09/06/2001 1:00:16 AM Pacific Daylight Time, 
>Aquatic-Plants-Owner at ActWin_com writes:
><< PCs are more efficient than normal 
> florescent bulbs. >>
>If PCs are more efficient, from  whence does the dissipated heat that is 
>causing all the problems come????  

They are _somewhat_ more efficient, but still dissipate about 70% of the
input energy as heat. Take a look at the main table at


at the "Effic." column. That's the ratio of total luminous energy output, by  
total electrical energy input. No bulb that I could get data on has an 
efficiency larger than about 30%.

PCs are T5 bulbs. _Linear_ T5 bulbs, because they are thiner, can be optically
coupled to reflectors better than thicker T8 or T12 bulbs. But PCs defeat
this factor by having their tube bent in a U shape. Thus the effective cross
section for restrike is much larger than that of a linear T5. The geometry is
such though that it is possible to get somewhat larger reflector efficiencies
for PCs than for T12s, maybe the same reflector efficiency of a high-end T8
luminaire. PCs are better for our purposes mostly because they pack a lot of 
punch (Watts) into a small footprint. The efficiency factor is secondary.

- Ivo Busko
  Baltimore, MD

  "Buy a fish, Save a tree !"
  Project Piaba: http://www.angelfire.com/pq/piaba/