High Bay Lights for 30x60x14 Shop

[mkimler]

Hi everyone. I recently constructed a 30x60x14 steel building with a truss style roof (~17.5' peak)and it is fully insulated so the ceiling provides good reflective properties. I do a little bit of everything in there but would like to have good general lighting.

After researching this forum for the last few weeks, my initial thought was to use the cheap and proven T8 fixtures but last i read, it will eventually see the same fate as the T12 bulbs so I would like to somewhat future proof myself. LED may possibly be the future, but that is too much money right now.

I finally landed on T5HO but I have some reservations. Below are my questions that I would appreciate some help answering.

1.)Does anybody here have experience with the T5HO at roughly 14.5-15 ft? I have seen these at HD and they are extremely bright. Will I walk in the shop and be blinded by lights at the far end due to the angular line of sight?

2.)Would it be better at that height to have white reflectors or polished alum? Is uplighting necessary?

3.) If T5HO or T5's in general are supposed to be the common future fluorescent bulb, why is it that 95% of what you find at HD or Lowes is T8? The info I read was dated a while back about T12 and T8s, so maybe things have changed and I just cant find that information.

4.) Is going with T5HO a bonehead move?? haha. I'm not completely stuck on it, just seems like it gets you more light with fewer bulbs.

 

[Charles (in GA)]

At the heights you want to install them at, they will work fine. If the interior is white or has the ability to reflect light, I personally prefer some uplighting to help prevent what is called "cave effect" where it is very dark above the lights. Also helps prevent hot spots under the lights.

Is this a steel STRUCTURED building, or a wood building (Pole or stick) that is metal skinned?

Thread on T5HO lighting

Charles

 

[bob_the_builder]

Check out my garage build (link in my sig). Not the same application but I have been very happy with my T5 HO lights. They are mounted 10' from the ground. The colour temp is 6500k.

Bob

 

[skyking]

Love my t5's.

 

[mkimler]

Charles,
Yep, it is a steel structure. Picture attached (best I had on hand). What are your thoughts about the alum reflectors vs white? My thoughts were that the white broad reflector would be best for the most even coverage. I like the uplighting idea, they just dont seem to exist in the box stores. Maybe something like this?
https://www.platt.com/platt-electric-supply/Fluorescent-T5Ho-High-Bays/Lithonia-Lighting/IBZ-654/product.aspx?zpid=867522

I would put 8 total in two strips down the length of the shop. The visual lighting tool I believe gave me a total foot-candle of ~82 if mounted somewhere around 15 ft.

Bob,
Thanks for the link. I will check that out this evening!

Thanks,
Michael

 

[Linkon]

I just hung some 8' T5 fixtures (4 54 watt bulbs in each fixture) on my 14' ceiling and they are great until the temperature gets down to about 25 degrees or less, then they arent quite as bright as when its warmer out.

These are the ones I have (but I got them on sale):
http://www.menards.com/main/p-2360586-c-7495.htm

 

[Petey156]

T5's are nice. Remember using 240v instead of 120v will cut your bill in half

 

[Charles (in GA)]

Just use the open strips. You will get a lot of light spread from them.

Charles

 

[Platonic Solid]

1. Considering the massive level of R&D put into the super T8 bulbs and ballasts your concern that T8 bulbs will be obsoleted before T5s is unfounded. It's not going to happen.
2. To repeat what I've posted before:
Unless otherwise stated in the manufacturer's literature:
High Bay = 20 ft minimum from floor to fixture face.
Low Bay = 25 ft maximum from floor to fixture face.
Standard fixtures = 16 ft maximum from floor to fixture face.

Best practice for your 14.5' height puts you in the Standard fixture category = F32T8. That doesn't mean that you can't use T5HO, but you will have some minor glare.

As far as light distribution goes you'd be better off with 12 of the $90 HBL632 arranged 3 rows of 4 than 8 of the IBZ654 in 2 rows of 4. Both will yield the same overall light output.

FWIW: Specular (mirror) reflectors are almost always more efficient than painted white reflectors.

 

[Norcal]

T5's are nice. Remember using 240v instead of 120v will cut your bill in half

It will do no such thing, watts are watts, and 1 amp at 240 volts and 2 amps at 120 volts both equal 240 watts.

 

[Linkon]

I dont know what people are talking about when they say there will be "glare" if you hang T5's at 14ft. If there is some kind of glare, I sure havent noticed it.

 

[barnjunkie]

These are my Metalux T5ho in a 40x 60x14. There are 12 lights total. I would not use less per sq Ft unless the floor was going to be white.

 

[Platonic Solid]

I dont know what people are talking about when they say there will be "glare" if you hang T5's at 14ft. If there is some kind of glare, I sure havent noticed it.

Your eye naturally adjusts to the light within your field of view. The greater the luminance difference between the light source in your field of view in comparison to the luminance of the task objects, the more difficult it is for your eye to define contrast (aka: Glare). The more difficult it is for your eye to define contrast, the more light is required on the task. As your eyes age, you will need more light to define contrast of task objects and your eyes become more sensitive to excess light emitting from sources within your field of view. Optimal visual acuity is achieved via balanced surface luminance which is best accomplished via multiple lower output light fixtures as opposed to fewer high output concentrated light sources.

It’s not rocket science, it’s common sense. I’m not going to argue to defend facts. Just because you and many others may have F54T5HO fixtures at 15’ or less doesn’t make it the optimum solution. With equal overall lumen output, 3 rows of 4 F32T8 light fixtures will always provide better visual acuity than 2 rows of 4 F54T5HO fixtures.

 

[RicochetFord]

This weekend I installed two T5 6 bulb fixtures in my 30x30x14 metal building. The quality of lighting is much better then the four 8' T12 fixtures I had previously.

Really haven't had a chance to work under them yet but so far a like them. I will probably get two other fixtures at some point to put on one end of each bay so that the open hood of a vehicle doesn't block the light so much and to light the work bench up better since the fixtures are behind you. I would even consider two of these six bulbs again except for the cost factor.

I have read everything I could find on lighting and finally decided to take the advice of my brother in law on these fixtures, so far so good.

 

[mkimler]

Thanks for all of the responses. I am glad to see some people are having good results with t5ho.

I certainly don't disagree that using the 32t8 in 3 rows of 4 would provide the best overall lighting. I just hesitated going that route because I thought T8 bulbs were going to be phased out. After a little more digging it looks like the 700 series are but the more efficient 800 and 900 meet the energy efficiency standards. Seemed weird to me you can't hardly find any t5 at the box stores if this were true.

The other reason I started looking at t5ho was my ceiling. I have an ibeam that goes down the top of the trusses from one end to the other for a chain hoist. T5 let me get away with two rows of 4 but obviously it will not be as evenly distributed. For the T8s, I would have to have 4 rows to keep it somewhat even. Maybe 4 rows of 3 length wise?

I don't know. When you start doing the math on 12 fixtures vs 8 and all the bulbs, it seems like the t5 may come out a little ahead.