In article ,
"Toby" writes:
Just after some opinions on Metal Halide vs Halogen and fluorescent lighting
for outdoor use...

I am after the most energy efficient lamp that is practical to illuminate a
patio area, a 500w halogen does the job well, but is 500w, obviously.

I am not bothered if there is a few minute warm up time, as I won't be using
it for PIR activation, just general use when having a BBQ etc.

My options seem to be, stay with a standard 500w halogen, go for a
fluorescent like this
http://www.qvsdirect.com/Low-Energy-...-pr-22878.html

Or a metal halide unit
like this 70w one
http://www.qvsdirect.com/Floodlight-...-pr-22951.html

or this 150w one
http://www.qvsdirect.com/Floodlight-...-pr-22952.html

This would be the nearest in light output to a 500W halogen.
However, as Nige says, a 500W halogen is normally quite unsuitable
for the use to which you are putting it, unless you have a very large
patio and the lamp is mounted 18'-25' high so it points downwards.

Multiple smaller wall lights would be much better, fitted with CFL's.

What is the average lamp life of these units, and the approximate halogen
equivalent light output?

Somewhere in the 8,000-12,000 hours range when switched rarely
(can get higher with electronic control gear, but not worth it
for what you want it for).

You want to get a warm white lamp for it if you can, or it will
look rather cold outdoors at night.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]