2many, how many 8', 4x4' 32w T8 fixtures would you recommend? I had originally planned fewer lights, but was advised by numerous posters on GF to add fixtures.
The usual "Rule of Thumb" for serious workspaces is about 100 lumens/ft.^2 at working height. Your somewhat higher-than usual ceiling (hence presumed mounting height) will impose somewhat greater losses at said "working height" than with lower-mounted lights; but that's OK, since it ALSO inherently makes for better (i.e., more even) light DISTRIBUTION.
So... 30'x45' = 1,350 ft.^2 to cover. To ensure 100 lumens/ft.^2 at working height (and with somewhat aged tubes), I'd arbitrarily aim for about 125-130
source lumens/ft.^2 (you can nail this down more precisely using a lighting calculator; but this should be close enough for a first cut). So that's a total of 168,750-175,500 initial source lumens. Assuming standard F32T8 tubes @ 2,800 initial lumens, that works out to 60-62 tubes.
Obviously, this is indeed just a "first cut", and much depends on the actual layout. That in turn depends on how you're planning to use that space, and exactly what activities will be performed where within it.
One other important note: I'm not sure; but based on some of your other posts I got the impresion that you might have an open-truss ceiling. If so, you'll want to use fixtures which provide SOME sort of reflector, in order to keep from wasting upwards of half the total "lighting power" illuminating the waste space above the fixtures. That said, you don't necessarily need "High Bay" fixtures; and I probably would not recommend them given the fact that not ALL of your ceiling is up at the 16-foot level.
I was planning on wiring 3 banks of light (2 sides and the center), what is your recommendation?
What you're describing is commonly called "zoning"; and it can make a lot of sense in larger workspaces which are often sparsely occupied. But in your case, the space isn't REALLY all that big; so I would consider it somewhat less useful than being able to vary the lighting intensity throughout the space, as needed on a day-by-day basis. Typically, I recommend three switch banks per workspace (or "per zone"): Some minimal amount of "walk-through" lighting on one switch (which can cover all zones, even if also doing zoning); about 30-40% of the "main" lighting on a second switch; and the remaining 60-70% of the main lighting on a third switch. The fixtures assigned to each of these switch banks should be distributed more-or-less as evenly as possible throughout the controlled area. Typically, that means something approximating an "every other fixture" approach; but it is often useful to "fudge" that somewhat depending on, again, the exact way the space will really be utilized (and also, such influences as open garage doors, skylights & windows, etc. -- in other words, put the light where it will be most needed). Ideally, you want to do both zoning and intensity control; but that can lead to a LOT of switches to flip, unless using something like Insteon to control things. So if you're not comfortable with either of those prospects, I'd go with (at least mostly) the intensity-control approach.
