Question for lighting guru (MEP).

[I.B. Washincars]

I have a wash with three 60' tandem bays, one pictured below.

They each have eight 175W metal halide wall packs. I would like to replace the wall packs with three 400W Scottsdales mounted on the ceiling. Will this be as bright or brighter than what I have now? Will it be cheaper to run the three 400s as compared to the eight 175s?

 

[MEP001]

To directly answer your question:

175W x 8 = 1400W, 320W x 3 = 960W, so yes, cheaper.

(Avg.) 13000 lumens x 8 = 104000 lumens, (Avg.) 27000 lumens x 3 = 90000 lumens, so no, less light.

Actually I'm switching to this type:

http://www.goodmart.com/products/1425074.htm

In the listed configuration they're as bright per watt as the pulse-start metal halides (87.5 inititial lumens per watt), much more light per watt than the wall-packs. With the 28W T8 bulbs/ballasts they're 100 lumens per watt. A six-bulb T8 fixture is as bright as a Scottsdale and costs about the same (Plus $60 for bulbs) and is enough cheaper to operate to more than cover the cost of the bulbs over their life. The biggest upside is they maintain 95% of their light output throughout their life; with the Scottsdales they are down to about half light output (My own guesstimate) in 18 months, so I'm constantly replacing bulbs/ballasts to keep them bright.

 

[I.B. Washincars]

Actually, I was thinking of using the 400W Scottsdales and not the 320. I know that the total wattage is less, but was wondering about the actual light output (lumens?) and positioning them on the ceiling rather than on the wall. Will it be brighter or not as bright if I go with the 3-400W on the ceiling?

 

[MEP001]

Sorry, I didn't know they had a 400W option. I checked a bunch of different brands of bulbs and the average seems to be 42000 lumens, so 3 would be 126000, so more light and less overall wattage. Ours are catacorner in the bays (which you can sort of see in my avatar), which I like because each light lights up two sides of the car. A friend has the same two in each bay and about the same distance apart, but in the middle, and it still lights very well. I like mine better though. With your bright white walls I should think three would do the job very well.

One of the reasons I want to switch is because (if I read the tech sheet correctly) the fluorescents are wired in and can be controlled in pairs. I plan to turn off half the bulbs in each fixture at midnight. I've figured it will save about $50 per year per fixture. The other reason is output lost over time; you can see in my avatar that there's a shadow in the bay from light cast by the 250W wall pack outside on the column shining into the bay where there's a 320W shining straight down on the floor. When the bulbs/capacitors in the Scottsdales are new, there's no shadow there. I'll find and post the full-size photo or take another if you want.

 

[mjc3333]

T-8 4 bulb fluorescent

I switched to a similar fixture 3 years ago and cannot believe the savings in electric and the output in comparison to the 175W MH lights. My fixtures are 4 bulb T-8 enclosed / waterproof, but are two bulbs end to end. The result is an 8 ft light. I chose to only have one ballast per fixture (all 4 lights) instead of the more common one ballast per two light systems. The light was cheaper with one ballast. I shut off one complete fixture per bay after midnight. The only two bays that are lit all night are directly next to the equipment room. For my situation it gets the job done. I have not had to change one bulb in the 50 fixtures for the past 3 years. One ballast went bad. Definitely go with the T-8 lights, they seem to me to be the most economical pulse start light.

 

[Earl Weiss]

Be interesting to know the light output for the T8 vs the F48T12 HO.

My bays had 4 four foot single tube fixtures and as the Ballasts Die I am replacing with Grainger 4 foot double tube fixtures. They are each mounted about 9 feet up on the sidewalls with about 8 feet between them so they are about 2 feet in from the ends. Do a great job. Each bulb is spec'd at 60 watts so it's 480 watts per bay.

Still cann't help but wonmder if we are in the Dark ages. Went to a petroleum marketer symposium and a lighting gut said the LED substitute for the 320 Watt Scottsdales had a 2.5 year payback at a 24 hour operation. My gas store is not open 24 hours so the # of hours the fixtures burn is probably 1/3 of a 24 hour store so the payback time would be 7.5 years. (contd)

 

[Earl Weiss]

Another supposed advantage is supposedly no maintanence - no bulb or Ballast replacement for 10 years. I would think most tunnels and Self Serves would burn the lights as many hours as a 24 hour Gasolinne retailer so payback would be the same.

finaly, if we turn some bay lights off during some hours, why can't we put the others on motion sensors like we now see in many commercial enterprises?

 

[soapy]

T5 bulbs are even better than t8 for efficiency and longevity. Farm tech has some great prices on waterproof fixtures in the T5 format. The advamtage to T8 is that you can easily convert a T12 fixture to accept T8s. If you are buying new fixtures go with T5s.

 

[mjc3333]

T-5 bulbs are 2-3 times more expensive than the T-8 counterpart. For now, this was my determining factor on choosing the T-8 fixture over the T-5 fixtures. I have 50 4 bulb fixtures, at 2-3 times the price, it gets more expensive. The T-8 bulbs actually last longer than the T-5 bulbs by about 4000 - 5000 hours depending on the usage. Also the light output is optimal at about 75 F for the T-8 compared to the 100 F of the T-5. We don't get too many 100 F days in the bays.

The T-5 is definitely the future of fluorescent lighting for many reasons. I made my decision based on the pricing of the components today. For me the T-8 was cheaper to purchase and costs the same to run as would a T-5 setup.

 

[MEP001]

Earl, I've looked long and hard at LEDs. They're still in the "dark ages" of development because the best ones only produce 50 lumens per watt. Pulse-start metal halides and T8 fluorescent are 85 lumens per watt, T5 are 100. If you look at it that way, T5 fluorescents are the most efficient in delivering a full-spectrum light. You mention "LED substitute for the 320 Watt Scottsdales" - there is no such thing if you need an equivalent amount of light. To get as much light as two 320W Scottsdales in one SS bay you'd need fifteen 70W LED fixtures. How well do you think four of those LEDs will light a bay? I would think very poorly.

 

[lighthousecarwash]

I'm alittle confused on which is the most energy efficient lighting options. Are the metal halide fixtures any good, or should I be leaning towards CFL, or flourescent fixtures. What's everyone's opinion on my setup?

I have 4- 400W metal halide fixtures in the corners of each bay. I recently just turned off half of them and the 2 fixtures seem to light the bay well enough. I would like to change them to something more energy efficient, but not sure what to go to. I have thought about turning all 4 of them back on and wiring around the ballast and installing the mogul base CFL's. After reading this post, I'm thinking maybe 2 of the 8' florescent fixtures would be better. I would have to mount these on the ceiling as opposed to the side walls, so not sure how much that would affect the lighting. Seems like too many options. Just want to find the one that will keep the meter from spinning so much and keep the bays lit.

Thanks,
Lighthouse

 

[MEP001]

I'm alittle confused on which is the most energy efficient lighting options.

One way to look at efficiency is the efficacy (Lumens per watt). CFL's are around 50 lumens per watt. Pulse-start metal halide and T8 fluorescent are around 85. T5 HO fluorescent are 100 lumens per watt. Of course if you just cut down on the wattage you're saving money.

 

[mjc3333]

I had the exact same setup for 20 tears. 4 MH 175w each two on each wall in the corners. I have since switched to 2 8ft T-8 FL on the ceiling centered from entrance to exit about 1 foot off the wall for a total of 2 lights per bay. To me the light gives better coverage and the savings on electricity is great. I chose a fixture with 4 four foot T-8 32 watt bulbs. There are 2 bulbs end to end side by side. The result is an 8 ft enclosed fixture. I am running 128 watts per fixture. When you do the math comparing wattage, there is a huge difference in costs. The actual output in efficiency is also greater, giving me the best of both worlds.... less wattage and more light.

 

[Earl Weiss]

You are going to get lots of opinions and IMNSHO the answer is "It depends".

If the walls are not very reflective I think 2 8 foot fixtures centered in the bay may not give the lighting down along the sides that a SS customer needs to see. If the walls are very reflective it may be great. So, aside from simple lumens per watt calculations you need to determine if the fixture will put the light where you want it.

To use your existing wiring locations you could use the 4 foot double bulb HO enclosed fixtures from grainger I referred to earlier.

You could start with 2 in diagonaly opposed corners running lengthwise and see how that works. They are 120 watts per fixture. even if you use 4 in the existing locations your wattage is less than 1/3 of what you have now.

 

[Earl Weiss]

Still...... can't help but wonder if an SS burning lights average of 12 hours a day would not benefit from an LED option.

 

[lighthousecarwash]

I.B., I love the look of those wall panels in your bays. I agree they would brighten up the bays quite a bit. Any idea how much a sq/ft that stuff runs? Might be a nice addition to the new lights.

Thanks,
Lighthouse.

 

[I.B. Washincars]

Actually, I don't. We installed those at the same time we did a major addition to the wash. My partner at the time is a GC and they were just part of the total job which was about 400K. I don't have the foggiest idea what that part cost.

 

[soapy]

I checked with my utility company today and they will pay 50% of the cost to upgrade the lights at my washes. This includes labor cost to replace or retrofit the lights. LEDs are one of the options that I will have. If I did not want the 50% option they will fianance the whole thing at 0% and just add it to the utility bill over a course of time.

 

[lighthousecarwash]

Well, I finally bit the bullet and installed new lights in all the bays. I replaced 4 - 400W metal halide fixtures in each bay with 2 - 160W 8ft flourescent sealed fixtures mounted on the ceiling. The bays look so much cleaner and less cluttered with those big junking looking lights out of each corner now. I went to the wash last night and I really love the light that they put out. The metal halide fixtures were blinding when you looked up at them and seemed to place a lot of shadows in the bay. The new lights concentrate the light down the white walls and the top and sides of the car. I know that 320W compared to 1600W should equal a ton less light, but I really don't know that it made that much of a difference. The FL lights are just a cleaner looking light and really makes the whole bay glow. I'm sure the white walls and ceiling help with this also. This may be the first time I have actually ever anticipated the next electric bill to see what the savings are going to look like.

Thanks to everyone on the forum for your comments and opinions on this subject.

P.S.....anyone looking for 28 used 400W metal halide fixtures???????

Lighthouse

 

[soapy]

I finally got the energy audit back on all my washes. They want to refit all of my existing 8 foot T12 lights with T8 ballast and bulbs at a fixture cost of $64 each. For my 175, 250 and 400 watt metal halide fixtures they are proposing replacing them with a simple 42 watt wall pak CFL. The CFL wall paks produce 2720 lumens per fixture at a fixture cost of $32 each with the lamp.
Most of my SS bays use 2 250 watt MH and 1 400 watt MH now. That gives me about 48000 lumens of light per bay. I was very skeptical that 8160 lumens of light from 3 small 42 waTT cfls would be anywhere nearly close enough to providing enough light. In one bay they installed them so I could look at them and compare them to the other bays. I was very surprised last night. The new lights provided plenty of light and was not much dimmer than my regular bays. I think that 1 or 2 more of these wall paks would give the impression of the same amount of light while using about 70% less energy.
The electric company will let me add more lights to the bid if I want until I get the light needed. If I follow the bid as given it shows about a $2600 per year per location savings in electricity.