Dimmer switch or not?

[Adam Aglionby]

Reflector lamp CFLs are really poor. LV halogen and some patching of the holes works better.

Cheers Adam

[NT]

Halogen downlighters fare badly too. They may have higher lamp efficacy than GLS, but their method of installation means that the overall install is much less efficient, and way more energy is used.

NT

[Kostas Kavoussanakis]

Any answers to these still gratefully received.

Thanks, but I would rather not do all that. :-) I am also a bit concerned about high currents and transformers in the heavily loft, but I may be wrong.

Interesting, can you expand? I have been following the ng and don't recall seeing this before.

Thanks,

[D.M.Chapman]

No, I don't think they do. I tried them when they were on offer at toolstation. Might save the planet a bit in using less leccy, but I' suspect they are less efficient to make.

Don't bank on them saving you cash :)

Darren

[Adam Aglionby]

R50 is probably generating fair amount of heat ;-)

Trafo per lamp and dont warp them up , high current is only on the output .

Think what NT is meaning is covering ceiling is spots is not good way from scratch for general lighting, they are after all, spot lights not flood lights.

CFLs aren`t spots and dont adapt well to spot style housings, heat is the premature end of them.

In your circumstatnces, change the bulbs, =A32.29 a lamp, save 12W per point and get a nicer light , dimmer switch will extend lamp life

[Kostas Kavoussanakis]

Well, I did the math. As per Adam's post[1], one can get a 28W Halolux for 2.29 (I remember I could get them from the same place for 1.45 or sth and baulked at the P&P charges :-( ) and a standard 40W R50 for

0.92. Let's assume that the Halogens run for 2,000 hours and the standards for 1,000.

After 2,000h (two) standards will have consumed 80kWh and the (one) halogen will have consumed 56. I pay about 9.5p/kWh and the bottom line is that 2,000h later the standards will have cost 9.44 and the halogen 7.61.

Does my math hold up?

[1] One can get the Philips counterparts for the same price from Saino's, skipping the P&P charges.

Cheers,

-- Kostas

[Kostas Kavoussanakis]

[Adam Aglionby]

Sorry my bad typing, meant wrap

Electronic trafos are thermally protected , if they overheat they shut down, classic symptom of `flashing ` lv downlights, overheating trafos.

They dont get incredibly hot but need some free air around them, tafo per lamp is usually easier.

LV fittings also need an air gap behind them because the heat goes backwards, the dichroic bit. GU10 are aluminised and heta goes forward, get GZ10 mains voltage dichros but almuinised LV are beside the hens teeth :-(

Darn, side effect of smaller filament in lamp,its something that may vary a bit by brand, some ludicrous prices being quoted for halogen R series, some of the `eco ` vendors sticking it right in at 5 odd quid a lamp.

Well brought back round :-)

Cheers Adam

[Kostas Kavoussanakis]

I guess sitting on the insulation will not be great for them, nor for the thick wires between them and the lamp.

Ok, so I will be lighting the loft. Nice :-)

I think I will take the hint from this and skip them for now. Sure, I would reduce my consumption compared to the GU10, but I am not sold. Plus, I usually only use 4 GU10s at 20W each so no great deal.

Well, I found 28 W Osram Halolux at 1.95 at Somerfield and thought I would try two. The light is whiter (bluer?) than the regular ones and probably more narrow, but the effect is not as pronounced as with the

40W GE that I have tried (these have a flat head which I really like, but they are too focussed). Given the economic argument I will gradually replace the other 7 in the kitchen with these as I run out of standard ones.

Many thanks for your input!