High Bay lighting for my 100'x40' Barn?

[VolksWomble]

I need to add some lighting to my barn (see link in my sig for pictures...) which is 100x40 using s steel frame structure which provides trusses at roughly 12.5' intervals - thereby effectively creating 8 bays. The eaves are 16' tall and the ridge is roughly 24'. At the moment the barn is completely un divided inside and therefore it seems that High Bay lighting seems to be the way to go - specifically LED High Bays...

I want decent working light at floor level, and accept that I may need some additional task lighting, but would really like to minimise it if I can. I would expect the arrangement below to need to be replicated 4 times though the barn for even lighting - which may not be required, as I will wont necessarily have working areas throughout.



A and B on the diagram are natural fixing points in the existing truss. Using these will save modifying the truss.

By way of an experiment, I have acquired 4x 200W LED UFO fixtures (these ones)...

My current assertion is that even at 200W, hanging a single fixture at point B (the ridge) will not give a great spread at floor level despite the 120 degree pattern the fixture claims, and I would be better off using 2 of the units at position A in the diagram.

Knowing a lot of people here have used these sort of fixtures, I wonder if anyone could comment on whether this is overkill or far from satisfactory?

Thanks in advance....

 

[Rubicon914]

I’d use 250 watt UFO lights in the higher middle row and 200 watt units on the eves. Maybe get them all with 0-10V dimmers too so you can control the brightness.

 

[manwithtools]

I would think three rows would work well, one at the ridge and two equal distance between ridge and eaves. With a steel frame building, you can use clamps to hand the fixtures, no modification to the structure. I will say you choice of lights a 6500k may be very harsh, I personally would prefer 5000k.

Many lighting companies have modeling tools you can use to simulate coverage. Definitely get 0-10v dimmable as you already have.