Easy CFL reflector

[Nerdly1]

High All,
I just watched a couple of videos on you tube of 1 guy building a grow light fixture/reflector out of a piece of Alum. ducting(4"x24"). He used a replacement double light socket with a stud on top for the wires and mounting. It fit 2 - 42 watt CFL bulbs perfectly and looked efficient. I did notice "hot spots" in his reflector when he turned it on. They probably aren't really hot, but they were really bright at the bulb. (naturally) and it got me to thinking about painting it white. Might be better. Then ...

The second video was almost exactly how I built the light setups in my veg. cabinet. He used $10 Wally World 4 footers, and screwed them side by side on to a piece of plywood. Both good ideas.

Plan 1 has better lights(energy use, spectrum), with less heat. Plan 2 has better reflectors.
Then it came to me, I already own 9 - 48" Flour. fixtures and as my 4' bulbs start dying, or the ballasts just quit, I'll rip the guts out of them and install dbl. replacement sockets to install CFL's in their place. You could put 4 bulbs per light, and have the best of both worlds. Lots of cheap cool light and a great reflector too.
Any thoughts, or is this just dumb?

It's late, and maybe I shouldn't be thinking this hard.
Later - Gadgetman

 

[Setting Sun]

I think it's a great idea!

Even without you posting any pics, your description of your DIY plan is clear and I can visualize your project.

The only thing I would do additionally is to drill a few small holes through the reflector right above the 42 watt bulbs so the heat isn't trapped. Probably not necessary, but couldn't hurt.

Very creative thinking bro! If you have the 48", four of those 42 watters in one of those reflectors would make a nice and compact light. Two of those reflectors with eight bulbs would be really nice and still not cost much at all, especially if you already got the reflectors.

I also have some old 4' shop lights stashed up in my attic that I had forgotten about until now, hehehe.

You know, those old reflectors would also be *excellent* for T-5 retrofit kits.

They could also be cut in half to make two 24" reflectors.

Thanks bro!

regards,

SS

 

[Nerdly1]

Thanks Setting Sun - I was sort of brain dead when I wrote that last night, i too thought of cooling holes, but forgot about them until i read your post. Great idea for T5 retro. I'm going to try and work up some figures on Lumens later. I'm sure the output of four CFL's should be much more than the standard 40w T12's.

Do the larger CFL's generate as much heat as a 40 watt ballast and T12 bulbs?

 

[Setting Sun]

Thanks Setting Sun - I was sort of brain dead when I wrote that last night, i too thought of cooling holes, but forgot about them until i read your post. Great idea for T5 retro. I'm going to try and work up some figures on Lumens later. I'm sure the output of four CFL's should be much more than the standard 40w T12's.

Do the larger CFL's generate as much heat as a 40 watt ballast and T12 bulbs?

Having four 42w CFL's would roughly double the light output of the usual two 40w T12's.

If you used four 42w CFL's, the heat output would also double, as I think they generate about the same heat as T12 tubes and ballasts.

regards,

SS

 

[Nerdly1]

Thanks again SS -
I did some temp readings with a ir temp gun. I checked the T12's in the veg room, they are about 80-90 f. in the middle and a bit hotter at the ends, the ballast area is an easy 100 f. The same fixtures and bulbs in the flower room for side lights seem to measure a bit higher, they are mounted on the wall, and are an older set - temps upper 130's f. Temps drop rapidly as distance increases.

I put 2- 23 watt GE spiral CFL's over some seedlings, and was surprised at how hot they run, around 140 - 155 f. They are only hot very close up.

Then we get to the 400w HPS in the flower room. Get too close to the bulb and the meter goes off the chart, higher than 300 f. When you get down to plant level it's about 80 f.
I've painted a room white and am flowering in it currently, I've gathered enough materials to go ahead and partition it off into 2 areas. I think I'm going to fab a couple of the light setups described earlier, for the veg area. I might also fab up a couple for side lights for the flower area. I'll post some pics when I get it built.

 

[Setting Sun]

Thanks again SS -
I did some temp readings with a ir temp gun. I checked the T12's in the veg room, they are about 80-90 f. in the middle and a bit hotter at the ends, the ballast area is an easy 100 f. The same fixtures and bulbs in the flower room for side lights seem to measure a bit higher, they are mounted on the wall, and are an older set - temps upper 130's f. Temps drop rapidly as distance increases.

I put 2- 23 watt GE spiral CFL's over some seedlings, and was surprised at how hot they run, around 140 - 155 f. They are only hot very close up.

Then we get to the 400w HPS in the flower room. Get too close to the bulb and the meter goes off the chart, higher than 300 f. When you get down to plant level it's about 80 f.
I've painted a room white and am flowering in it currently, I've gathered enough materials to go ahead and partition it off into 2 areas. I think I'm going to fab a couple of the light setups described earlier, for the veg area. I might also fab up a couple for side lights for the flower area. I'll post some pics when I get it built.

Yeah, that's why I thought adding a couple of holes for the heat to escape would be a good idea. The spiral CFL's produce about the same amount of heat as a long tube, but it's more localized, and HPS even more so.

Overall, however, watts is watts, and the *total* amount of radiated heat you have to deal with is pretty similar, you just have to be a lot more careful about not burning your plants with HPS by getting it too close.

Can't wait to see your lights!

regards,

SS