GU10 Dichroic Reflector confusion

[JA]

I notice that on the Screwfix website some of the mains voltage GU10 halogen lamps are described as having a "dichroic reflector". Does anyone know what "dichroic reflector" means in this context? I had assumed the term dichroic just applies to lamps with the GZ10 style cap which direct any heat towards the back of the lamp, as opposed to lamps with the GU10 style caps which direct any heat towards the front of the lamp. Now seeing GU10 halogen lamps described as having a dichroic reflector has confused me somewhat.

[John Rumm]

I presume the same as it normally does...

Yup, the reflector is translucent toward the infra-red end of the spectrum - so some of the heat gets radiated through it rather than all being reflected forward.

Although its uncommon (and quite possibly an error on the SF site), there is no reason in theory why you could not use the same reflector on the mains bulbs. There may however be a problem with some of the fittings not being designed to cope with that amount of heat from the back of the bulb.

[Rick Hughes]

Dichroic lamps allow some of heat to pass backwards .. often used in lamps which would put too much heat on object or person it was illuminating (eg PAR 38 spots)

I had opposite requirement I wanted non-dichroic lamps for my Low-Voltage down lights as I do no want the heat pushed back into housing .... they over heat & trip transformer.

[Adam Aglionby]

It must be a misprint , GZ lamps with the chamfered corners are dichroic, GU lamps are aluminsed, fittings are designed one way or other , best not to mix.

Cheers Adam

[Adam Aglionby]

Aluminised LV MR16 are very rare, no idea why, mebbe remote the transformer?

Cheers Adam

[Rick Hughes]

Aluminised LV MR16 are very rare, no idea why, mebbe remote the transformer?

No problem getting them - I simply order mine from 'Lightbulbs-direct.com'

My issue is that house is very well insulated, so no heat escapes upwards .... and even with t/f 200mm away they still overheated if on for an hour or more.

Changed to Phillips Aluminum reflectors (Phillips Pro Alu) and no problem since .. heat goes out through front of lamp rather than through rear.

[Adam Aglionby]

Remote wound trafos, but copper cost can get excessive.

Hadn`t encountered them before thanks: