Larger LED Lights?

[mltdwn12]

I know everyone recommends switching to LEDS, but my question is does anyone used any larger model fixtures? The shop at the house I just bought has these big lights that take about 2 minutes to power up. I want to get lights and fans in before I start looking at insulation options.

 

[Capt Chrysler]

We replaced those with 2, 4' three bulb fixtures (8' LED's were not available when we did this.).

I can't wait till the others die so we can replace them. Also the power company shows up to check the meter. Seems our new lights power consumption is lower. When I told them what we did, they laughed and left.

Capt. Chrysler

 

[zmotorsports]

To answer your question, yes. I chose to go with the larger 27k lumen fixtures that are specified for hi-bay lighting. I purchased mine from econolight.com. They are the replacement for the T5HO fixtures and with my 16' ceilings work perfectly. Equating to just over 100 foot candles to the floor and no shadows.

I can't remember the exact fixture off the top of my head but I provide a link to them in my shop build thread which there is a link to in my signature.

 

[Zexx]

You could go with some direct wire LED bulbs, bypass the ballast, keep your current fixtures.

 

[Bert_]

You could go with some direct wire LED bulbs, bypass the ballast, keep your current fixtures.

I have never done any this way but I have seen them elsewhere. I was always less than impressed, always seemed dimmer than with the metal halide lamps... Not to mention you still have the same crappy fixture efficiency.

A new fixture would be a huge step up from a retrofit lamp.

 

[walta]

If you are changing to save on your electric bill you will need to select your LED carefully. Your current fixtures look like metal halide lamps that should be around 75–100 lumens per watt.

When I shop for LED 25% are less than 75 lumens per watt, 85% less than 90 lumens per watt. Only 10% make over 100 lumens per watt and generally they are not the low priced LEDs.

Walta

 

[American Locomotive]

MH is 75-100 lumens per watt, but most MH fixtures unless they're very high end have atrocious efficiency. The fixture can eat as much as half the light the bulb emits.

 

[Stuart in MN]

This guy retrofitted that style light fixture with LED lamps:

 

[cybrdyke]

I know everyone recommends switching to LEDS, but my question is does anyone used any larger model fixtures? The shop at the house I just bought has these big lights that take about 2 minutes to power up. I want to get lights and fans in before I start looking at insulation options.

I wonder what the wattage of those fixture is. They could be 400w Metal Halide. If so, the mean lumens (average light output after 8000 hours of burn) is 20,000 lumens. You're using 458 watts to light them, so you're at 43 lumens per watt, which is very poor. It's actually less than that because the fixtures themselves prohibit a fair amount of the lumens from getting out of them.

Today's LED highbays are extremely efficient. A common one would be around 18,000 lumens, which is pretty much what you're getting with your existing fixtures. It would run around 120 watts (150 lumens per watt) and will cost under $200 each. Depending on how long you burn the lights will determine if this makes sense for you or not. Your existing lights cost you about a nickel per hour to run. The LEDs are just over a penny. (*based on 10c per KwHr). Not to mention the extremely long life of the LED vs the short life of the Metal Halide lamps.

What you need is someone to do a lighting layout for you so that you know how many you neeed based on the size and the intended use of your space.
Good luck,
CD

 

[Lelandwelds]

Metal halides aren't very efficient. I think I remember the outer envelope can leak UV and damage your vision.

Buy some nicer quality LEDs. There is lots of info here on making a great choice. You won't regret it. I haven't built my garage but I toured local businesses and talked to people who put them up. Some were excited and eager to overshare the LED gospel. It was a bit like asking to see vacation or grandkids pictures.

 

[walta]

Maybe my friend Google is only telling me ½ of the story and not counting the ballast. But this is what it tells me when I ask “metal halide lamps lumens per watt”

Walt

 

[cybrdyke]

Maybe my friend Google is only telling me ½ of the story and not counting the ballast. But this is what it tells me when I ask “metal halide lamps lumens per watt”

Walt

The Wiki-fu is weak with that one....it only accounts for a brand new lamp with no regard for light distribution or photometry, so it's not a relevant number. Here's what it should say:
For 400w Metal Halide:
The ballast uses 58 watts, so total is 458w.
A brand new lamp will be near 35,000 to 40,000 lumens.
But it rapidly drops off and so it only operates at that level for a short period of time. The "mean lumen" figure is more representative of how much light the lamp delivers over a long period of time...and that number is around 20,000 lumens. 20,000/458=43.6 LPW.
A typical MH highbay is only about 60% efficient, or less, meaning that only 60% of the light can get out of the fixture. 20,000 x .6 = 12,000. Divided by 458 is 26 LPW. MH highbays are very inefficient.

 

[FTG-05]

The Wiki-fu is weak with that one....it only accounts for a brand new lamp with no regard for light distribution or photometry, so it's not a relevant number. Here's what it should say:
For 400w Metal Halide:
The ballast uses 58 watts, so total is 458w.
A brand new lamp will be near 35,000 to 40,000 lumens.
But it rapidly drops off and so it only operates at that level for a short period of time. The "mean lumen" figure is more representative of how much light the lamp delivers over a long period of time...and that number is around 20,000 lumens. 20,000/458=43.6 LPW.
A typical MH highbay is only about 60% efficient, or less, meaning that only 60% of the light can get out of the fixture. 20,000 x .6 = 12,000. Divided by 458 is 26 LPW. MH highbays are very inefficient.

Good to know. I have four of those things in my 76'x36' shop.

Individually, they put out a lot of light, especially if you look right at them. However, light at the working surface has a lot of shadows and dim light areas. Hence, I've been adding those Sams Club/Honeywell 4500 lumens and 5000 lumen shop lights. Fifteen in all and the light is now far better!

What would you recommend to replace these 400 watt MDs?

Thanks,

 

[sierradmax]

Check with rebates from your energy supplier. We are replacing our flourescent T5HO high bay fixtures with LED high bay at only LABOR COST in our shop warehouse.

 

[cybrdyke]

What would you recommend to replace these 400 watt MDs?

Thanks,

Depending on your ceiling height, an LED highbay with about 13,000 to 15,000 lumens. Over 15', about 15,000 to 18,000 lumens.
CD

 

[FTG-05]

Depending on your ceiling height, an LED highbay with about 13,000 to 15,000 lumens. Over 15', about 15,000 to 18,000 lumens.
CD

Thanks CD!

 

[LesCharles73]

I have never done any this way but I have seen them elsewhere. I was always less than impressed, always seemed dimmer than with the metal halide lamps... Not to mention you still have the same crappy fixture efficiency.

Can you expand on this? If you're bypassing the ballast, the only efficiency issues would be related to the lens (if applicable) and reflector. Not that I endorse retrofitting MH high bays. Just curious what you meant by crappy fixture efficiency.

 

[Bert_]

Can you expand on this? If you're bypassing the ballast, the only efficiency issues would be related to the lens (if applicable) and reflector. Not that I endorse retrofitting MH high bays. Just curious what you meant by crappy fixture efficiency.

These lowbays have pretty bad fixture efficiency. CD claims something like 60% of the light from the bulb makes it out of the fixture. It doesn't help that nobody ever keeps them clean inside.