"Harry Bloomfield" wrote in message
...

Discharge lamps only achieve economy once they have been turned on for a
while. I once saw the calculations for the short period use of a
fluorescent light versus an equivalent output filament lamp - taking in
all of the factors such as wear and tear, consumption, cost of labour
replacing etc.. The filament lamp proved to be more economic upto 1 hours
use.

How long ago were you looking at these calculations? CFLs are now really
very cheap, and I suspect rather more reliable than several years ago.

cheers,
clive