Metal Halide

[Ramper]

I see TONS or 400 watt metal halide light for sale on CL. Why are people getting rid of these? They seem to be an option for my pole barn (open ceiling) and/or my shop 10 foot ceiling. What am I missing? I have searched GJ, but now I am just more confused.

 

[nehog]

Most are being replaced with more energy efficient systems. There is no reason why you can't use them in your shop/barn, I did just this and love them. In my case they were (basically) free, which meant that I'd have to use them a lot to make up for the slightly less efficient electrical usage over other newer designs.

I sold about 50 of these on CL myself (that's why my lights were free...) for between 20 and 40 each.

 

[Gooch]

as far as efficacy(lumens per watt) Metal Halide is on par with T8's. the draw backs are from the long start cycle and restarts so they generally are not switch other than the begining of the day and end of the day. where as T8's and T5's are instant. so you can set zones on motion sensor or turn them off and on as needed.


for a personal shop I'd go with a different option unless you will spend long periods of time in there(i.e. 4-5+ hrs.)

 

[Stuart in MN]

The ones you see on Craigslist are most likely high bay fixtures, designed for rooms with ceilings 20 feet high or more. In a room with a 10 foot ceiling the light distribution wouldn't be very good - you'd end up with 'hot spots' under each fixture. Also, remember they're usually pretty large, around 18" tall, so they'll hang pretty low.

 

[r_olson_06]

also alot of power companies around are area are giving out a rebate to switch to these "Energy Efficient Lights". We have done a couple thousand fixture switch outs from the old Metal Halide 400W & 1000W to the T8 & T5. Most people are practically giving these things away.

 

[Charles (in GA)]

My thread on the installation of 400W MH fixtures in my shop in 2008.

http://www.garagejournal.com/forum/showthread.php?t=21048

Many of these fixtures are not capable of 120V. Unless they are dedicated 120V ballast, or have a multi-tap ballast 120/240/277/460 You may not be able to use them. Pay close attention to the voltage rating on them.

If they have a metal/aluminum reflector, they are almost certainly high bay and need to be mounted with the bottom of the fixture at least 20 ft above the floor. I have ones with polycarbonate translucent reflectors, they are technically high bay due only to the mounting bracket on the reflector, the same reflector with a different bracket can be classified as Low bay.

The reflectors are about 24 inches in diameter and the entire fixture stands about 24 inch high so you need a rather high ceiling.

The bulbs have a long life rating of about 30,000 hrs when they are started once a day, but multiple starts will reduce that life by half or less. Remember, the fixtures you are buying are used and the bulbs may have much of the life already burned out of them.

I bought 13 fixtures (I needed 12 but wanted a spare) and the seller gave me 19 bulbs to make sure i had good ones.

Charles

 

[nehog]

as far as efficacy(lumens per watt) Metal Halide is on par with T8's. the draw backs are from the long start cycle and restarts so they generally are not switch other than the begining of the day and end of the day. where as T8's and T5's are instant. so you can set zones on motion sensor or turn them off and on as needed...

I have both the HID and also T8s in the shop. The T8s are on whenever the HIDs are used, so if there is a power glitch, I'm not in the dark. As well, each bay has a halogen backup lamp built in to one of the fixtures. This bulb lights whenever there is power to the fixture but the main HID bulb is not yet up to full brightness (it is automatic, turns off when the HID bulb is fully on... Nice safety feature.)

I've wondered if I could then go and get a rebate to replace those fixtures with new ones now? Sorta recycling the recycling... (Naw, I'd not bother.)

As to the comment on voltages, if the shop is unoccupied, you can wire 240 volt lamps, however most of the ones I've seen are multi-tap ballasts which work on 120/208/240/277.