Outdoor Lighting, Metal Halide?

[Aragorn84]

So now the clocks have changed and its dark by 4pm i've realised that having a light mounted above my garage, shining out over the driveway would be quite useful when carrying out maintenance on my cars (the landrover doesnt fit inside the garage, so i need to work on it on the drive for example)

I've looked around and saw these metal halide lamps available in 70, 150 and higher wattages, and wondered how they compared to the usual halogens?

I guess they will use a lot less power, but whats the equivalent? Will a 70W halide give similar output to a say 300W or 500W halogen? I realise they wont fire up instantly, and have issues with restrike time, but i dont think thats a problem for me as its not going to be on a PIR, just a switch inside the garage to power it up.

Anyone used them and care to comment on how they found them?

Cheers.

 

[Steve]

Metal halide is what they use in big warehouse style shops, those bright white lights. They give excellent colour rendition. They are similar to streetlights, which are high pressure (yellow) or low pressure (orange) sodium lights. They work the same, and are very efficient. Low pressure sodium is the most efficient money can buy, but its also the worst, monochromatic light!

You cannot use them with a PIR - they are useless as a security light, unless burning for several hours on a timer.

You will also see metal halides on car showroom forecourts. Cant comment on wattage though! Never used them myself!

 

[Lectrician]

A 150watt metal halide will be perfect for you IMO. A 70watt would do, a 150watt would be pukka.

I wouldn't go bigger.

 

[ban-all-sheds]

IME a bright source of light is hopeless for that sort of work, as you'll get places in deep shadow.

A larger number of lower powered lights arrayed to fill in all of the shadows would be much better.

 

[Steve]

On his drive? Neighbours will love that

 

[RF Lighting]

The sun seems to manage ok

 

[Steve]

Just been thinking, what about a twin strip IP fluorescent mounted on the front of the garage, they give off a lot of light. Combined with a portable 500w halogen work lamp. Could replace the halogen with a Metal halide, though not sure how good they are at vibration resistance.

 

[Aragorn84]

Given that metal halides need a ballast (ie they'll be bulky) and the lamps can explode in certain circumstances, i'd rather not have one as a work light anywhere near me!

A Fluro based inspection lamp for messing around in/under the vehicle would be my preferred choice for that i think.

I'm just considering ideas for lighting for the driveway in general. I hear what you mean by multiple lesser powerful lights, however mounting them further down the drive would mean they'd end up bolted to the house itself, which makes it all a bit problematic.

At some point in the near future the landlord is supposed to be employing someone to rewire the garage, and getting the spark to wire up a single floodlight to the new garage supply while he's here shouldnt be too much of an issue.

Drilling holes in the house itself and connecting many floodlights up however is a bit different!

I think a bright area near the garage with some shadows is better than pitch blackness!

I guess i could use a pair of 70w's one mounted either corner of the garage to provide the light from two angles to reduce shadowing?

 

[ColJack]

if it's on the garage and you're under the bonnet, then you're already in your own light..
you'll need a hand lamp for getting light in the right places..

also be aware of the stoboscopic effect when working with rotating machinery..

 

[ericmark]

I have a 70W Metal halide and it is better than 500W tungsten but this is also because it is bigger so has better reflector and of course is all within plastic casing so if it did burst all contained. Mind you same is required for 500W tungsten it within 15 foot of personnel. They do not only give off visible light.

Now 9 years old never changed to bulb. Spare bulb had to be dumped when my wife fitted it to a standard up lighter she wondered why the fuse went!

My fault I left garage unlocked.

 

[Aragorn84]

They do not only give off visible light.

What do you mean by that? Do they output lots of UV as well or something?

 

[aptsys]

Lots of infra red.

 

[Aragorn84]

The halide gives off lots of IR? or the Halogen?

http://en.wikipedia.org/wiki/Metal_halide#Eyes

That seems to suggest its UV, but i guess its less of a problem with a lamp mounted up on a garage roof than one mounted in a fish tank your sitting inches away from?

 

[Stoday]

I have two in my house: 70W to light my drive, in a street lamp sort of lantern and 150W for my fibre-optic chandelier. Both are fully enclosed to contain the fragments should a lamp explode at the end of life. (The bulb goes black, absorbs more heat and explodes).

I have replaced the drive light that dimmed out after 10,000 hours.

The advantage of halide is the very small arc and thus the improved optical control. Plus, of course, the very good colour. The 70W and 150W are both the same size, about the size of a man's thumb. The arc itself is about the size of a large pea. You would not want to look at the arc directly and the lantern should be designed so that you cannot see the arc directly. Those lamps take no more than a couple of minutes to heat up and need the same time to cool down if you want to switch them off then on.

You can't compare tham to a filiament lamp because the lantern has to be very different. The lamp itself costs around £25.

 

[Lectrician]

Metal halides MUST have a GLASS lense designed to catch any debris should the lamp implode. They do from time to time, granted.

I don't think it was suggested that he use a metal halide has a moveable handlamp - he wants to fis it to his wall. I would prefer to see the MH on the wall as opposed to a twin floury.