I work for an engineering firm and I have 20 years of experience in lighting and electrical design. I always design per code requirements and IESNA recommended lighting levels for the space. The current ASHRE 90.1 energy code for your “workshop” will allow 54 32W T8 lamps. (1104 sq-ft x 1.59W/sq-ft allowed = 1755W allowed. 1755/32 = 54.8 lamps allowed.)
Fortunately, "thetruck454" is not subject to such constraints in his private residential garage.
That is more than I’d install considering the garage doors and their tracks/structure. The layout attached below has 46 lamps. This is 1472 watts, which is a single 20A, 120V circuit for lights.
Maybe. Maybe not. It would depend in part on the particular fixtures (specifically, the ballasts) chosen. But even
IF it could all be squeezed onto a single circuit, it is not necessarily a good idea to do so. Regardless of the load magnitude, a good argument can be made that the lighting should be split between at least two circuits, so that if/when one breaker trips (or needs to be thrown in order to work on something), he won't be left in the dark.
This layout gives you an average of 67 FC and uniformity of 2.6:1, which is pretty good.
Actually, I think that layout leaves a LOT to be desired.
First, a goodly portion of the light in the "parking" area is being wasted, by being directly over the vehicles. How often do you need to brightly illuminate the roof of your car?
Second, given that "wastage", there is precious little light being put where it's actually needed, which is mostly around the perimeter of the vehicles. That second row of five "crossways" fixtures is in about the right place; but the first row (i.e., the one closer to the doors) should be dropped in favor of extending the "vertical" rows located between the vehicles. And given the three-car parking arrangement, I'd probably put a fourth row between the two right-side vehicles.
There is near-certainly too much "general purpose" light in the "workshop" area, vis-a-vis whatever task lighting will presumably be added.
The two-zone switching arrangement is a step in the right direction; but it doesn't go far enough. First, it lacks provision for "walk-through" lighting, as discussed previously. Second, once he gets fixtures in all the places he'll want them for working on the vehicles, the total amount of light they can produce will be high enough that he probably WON'T want to run all of them for just "casual" work. So splitting each "zone" (or at least the "vehicle zone") into at least two separate banks is in order.
I would recommend putting a fixture separately switched over your workbench.
This falls generally in the category of "task lighting"; and the specific arrangement required for that part of it will depend in large part on exactly how he sets up that workbench (particularly the presence or lack of upper wall cabinets). The rest of the task lighting will depend on what tools/machines he locates where; so it's rather impossible to predict that at this point.
Consider chain hanging the fixtures down to about 9’-0” above floor.
I view this as mostly counterproductive. As a general rule, you want the main lighting as high as possible (at least within reason), in order to give it the maximum chance of being evenly distributed by the time it gets down to "working level". Lowering the light sources concentrates the output of each fixture into a more tightly confined area, and thus leads to more of a "spotty"/"shadowy" result. Now granted, he only has 10-foot ceilings to start with, so the difference will not be huge; but still...
If you’ve a little extra money, think about installing ceiling mounting receptacles and plugging your fixtures into them.
This would require that the lights be on GFCI-protected circuits, which can lead to problems with some fluorescent fixtures. Plus, it creates an ugly rat's nest of power cords all over the ceiling. Surface-mounted "wrap" fixtures would give a much cleaner appearance.
That way, if you decide to rearrange your shop, you can rearrange your lighting without much effort.
True. But at least in terms of the general lighting (as opposed to the task lighting), if he gets it right to start with, there should be no need to rearrange it later.
I did a quick redraw with more lights. It seams a bit excessive to me but I thought I'd see what the reactions were.
Well, you're using more light than in "Version 1.0"; but that's about the only improvement I see. This plan suffers from many of the same problems I just described regarding "DwightS"'s layout. Put simply, too much of the light is in the wrong places.
I also put rough locations of the vehicles/ bikes.
Which I find confusing -- or at least curious -- for a couple of reasons. First, I suspect your vehicle images are NOT to scale (for example, the pickup truck seems to be about 22 feet long!). Secondly why are you only showing one vehicle in the "two-car" portion of the garage (i.e., the part serviced by the 15-foot door)?
All the other objects shown are some sort of machine or cabinets.
It might help if you were to put a little more thought into exactly what cabinets, machines, etc. you're going to have, and where they will be located. Particularly for the "workshop" part of the space, the general lighting required will be greatly influenced by the task lighting you wind up with. So the more you can nail the latter down, the easier it will be to determine the former.
BTW I appreciate everyone's input, I don't mind being told I'm out to lunch in my ideas
Good. Bear in mind too, part of the criticism you're getting is in the context of "playing Devil's Advocate"; it's not intended to be personal. Now is the time to thoroughly hash out ALL possible ideas.
I would suggest looking at the T5HO.
While they can be effective in true "High Bay" applications, I really dislike T5HO fixtures in situations with low-to-moderate ceiling heights. It inevitably leads to too much light concentrated into too small an area, which is generally the opposite of what is really needed.
The amount of light you posted above would give me a headache if using your car parking area and my fixtures dear god.
My point, precisely. The reason he needs more fixtures is not so much to get more light (well, in the context of his original sketch, only partially to get more light); but rather, to get that light evenly distributed throughout the "important" work areas. Even presuming F32T8s, by the time he has that requirement covered as well as possible, he'll have so much total light that he will likely want to implement "staged" multi-bank switching so as t not be faced with an "all or nothing" decision every time he walks into the garage.
