I have 2 questions about MH/MV troffers:
1) Were they ever made in 2x4 form? possibly with 2 lamps?
2) When were they invented? Did they come before or after fluorescent troffers?
Anyone have answers?

Dont know....

Out of all the related technology, the t bar 2x2 tile ceilings came later than either Fluorescent or HID, so when ceilings came, lights of either technology were already available

Recessed cans allready existed from earlier drop ceiling generations. i guess including Mercury. with ballast in the ceiling cavity

Deep channels i _think_ existed at first as architectural feature (ie. made for any building by its architects, not as a standard lighting related component), and became standard (factory made channel boxes etc) later



2x4 HID troffer makes little sense to me - a 400W lamp can still fit in a 2x2, anything brighter than that you'd probably want to split into 2 lanterns placed apart anyway, to have more uniform light distribution and less glare in the area....

I have 1 troffer that was 400W MH - converted it to 150W HPS. and a few Fluorescent ones

Dont know....

Out of all the related technology, the t bar 2x2 tile ceilings came later than either Fluorescent or HID, so when ceilings came, lights of either technology were already available

Recessed cans allready existed from earlier drop ceiling generations. i guess including Mercury. with ballast in the ceiling cavity

Deep channels i _think_ existed at first as architectural feature (ie. made for any building by its architects, not as a standard lighting related component), and became standard (factory made channel boxes etc) later



2x4 HID troffer makes little sense to me - a 400W lamp can still fit in a 2x2, anything brighter than that you'd probably want to split into 2 lanterns placed apart anyway, to have more uniform light distribution and less glare in the area....

I have 1 troffer that was 400W MH - converted it to 150W HPS. and a few Fluorescent ones

Thanks. The reason I asked about the 2x4 troffers is because I have had quite a few dreams involving them, and decided to ask if they ever existed.
Do you have a picture of the 150w HPS troffer?

Not yet. i'll take pictures once i get around to it

The swimming pool at my university has custom made 2x400W MH boxes (they might be 2x1000 but I don't think so). The lens appears to be a standard 2x4 that you would find in a standard troffer, although they aren't the standard prismatic 12. They are divided into eight squares with some type of prismatic pattern (the same for all squares). I think DaveMan has an example of such a diffuser in his gallery. I have no idea if they are ballasted together or separately, but I think they are together. I imagine they run on 208V but I'm not sure of that either. Anyways, half of them have been replaced with standard 1000W MH highbays (removed from the recently renovated arena).

Unfortunately, I don't have any pictures, and cameras are not permitted in the pool area.

The chapel at this same university has recessed lighting (seen in my gallery) that date from the 1940's. They were incandescent back then but are MH now. They are accessible from the attic for relamping so the conversion was relatively easy.

The swimming pool at my university has custom made 2x400W MH boxes (they might be 2x1000 but I don't think so). The lens appears to be a standard 2x4 that you would find in a standard troffer, although they aren't the standard prismatic 12. They are divided into eight squares with some type of prismatic pattern (the same for all squares). I think DaveMan has an example of such a diffuser in his gallery. I have no idea if they are ballasted together or separately, but I think they are together. I imagine they run on 208V but I'm not sure of that either. Anyways, half of them have been replaced with standard 1000W MH highbays (removed from the recently renovated arena).

Unfortunately, I don't have any pictures, and cameras are not permitted in the pool area.

Dang! I hate it when places don't permit pictures and they have cool lights...
Maybe if you could get one and post it on here? I would really like to see a pic of one.

This is related and also qualifies on the "Lighting Fails" topic:
A local car dealer has 250W MH reflector cans in the service waiting/parts counter room.  These are what you would see in a mall with high ceilings.  The 2x2 grid ceiling can't be more than 7 feet high (very low for a commercial building).  As you can imagine, this is a terrible choice for this space.  The area under the lights is glaringly bright and between them is dark.  Some are also greened out, so I took a look at the bulbs in them.  The greened out fixtures had 175W clear MVs!  The abused arc tubes were black in one end and these made the room look even worse.  Anyway, bad design, bad maintenance.  If they just replaced each can with a garden-variety 2x4 4 lamp F32T8 troffer, the power usage would be cut in more than half and the quality of light in the room would be vastly improved.  The surprise with this is the car dealer is owned by a big corporate chain now that, you would think, has good maintenance staff and policies.   

Matt

This is related and also qualifies on the "Lighting Fails" topic:
A local car dealer has 250W MH reflector cans in the service waiting/parts counter room.  These are what you would see in a mall with high ceilings.  The 2x2 grid ceiling can't be more than 7 feet high (very low for a commercial building).  As you can imagine, this is a terrible choice for this space.  The area under the lights is glaringly bright and between them is dark.  Some are also greened out, so I took a look at the bulbs in them.  The greened out fixtures had 175W clear MVs!  The abused arc tubes were black in one end and these made the room look even worse.  Anyway, bad design, bad maintenance.  If they just replaced each can with a garden-variety 2x4 4 lamp F32T8 troffer, the power usage would be cut in more than half and the quality of light in the room would be vastly improved.  The surprise with this is the car dealer is owned by a big corporate chain now that, you would think, has good maintenance staff and policies.   

Matt

I am suprised that they don't maintain the lights better, especially for a chain store.

I'm pretty sure HID troffers came out after fluorescent troffers. The earliest fluorescent troffers were probably made around the late '40s, which was before color-improved MV lamps became available. Fluorescent lighting definitely had a CRI advantage at that time, and coupled with the near-instant starting and re-striking of fluorescents, it was a clear winner.

What were 40s troffers like ?

For what i know back then it was not really troffers, just boxes made on site with ordinary fluorescent strip mounted in it

Here are a couple of examples of early troffers:

http://www.galleryoflights.org/mb/gallery/displayimage.php?album=233&pos=20
http://www.lighting-gallery.net/gallery/displayimage.php?album=2849&pos=109&pid=106411

That's a tight squeeze on the first one, prolly uses lead lag ballasts. The second one with the glass lens is truly unique, must be extremely rare.

I've seen troffers like mine in a few places, but they're always missing the covers. That cover is the only intact one I've ever seen. I traded it to John in April along with one of the troffers. I got another cover with the fixtures but it was broken beyond repair so I threw it out.

Something else that just occurred to me: The local post office was built in the 70's, probably when HPS was being pushed like LED is today. It is lit with HPS troffers, on a ceiling that is low enough that fluorescent would be just as good. Maybe they first came in HPS to replace fluorescent? Just an assumption.

As far as I know, the only 2 lamp HID ballasts made were 2x400 watt MV, so if they do/did exist, they were only made in that form. I'd love to have (or even see) one...