CFL reflector idea

[Marctrees]

Going to be putting the large 85-105 watt CFL's in a typical wood pole barn shop- 12' to bottom chords of open trusses.

Planning on tucking them up a foot or so within the trusses.

Here's my proposed reflector- Cheap, lightweight .

They do have an even bigger one available, but a $10 price jump.

I think for the price, super bang for the buck.

Punch a hole with an electrical knock out punch and silicone lamp into it.

Add some vent holes if you want.

Your thoughts? Marc

http://www.lionsdeal.com/wi-mxb-2000q.html

 

[toplessHO]

buy a couple of different sizes and test
just make sure that the lamp if broken can never come in contact with the bowl.

 

[Marctrees]

The large knockout hole will be sized so the bowl sits on and is siliconed to the rather large ballast enclosure top, a safe distance even from the screwshell of the lamp.

And, I'll probably put in about 4 - 3/4" vent holes around that. Marc

 

[toplessHO]

reflector is best if its based at or near the beginning of lamp

 

[Alan Douglas]

I've used aluminum pie plates for years.

 

[Showkey]

Edit....Did not see the link in the OP when I wrote the below.......

BUT


I used large cheap polished stainless mixing bowls purchased on the Internet from several different supply houses.

There is an ideal diameter and depth of the bowl compared to the bulb. 14" diameter and 5" depth with the 150 watt equivalent ( 42 watt actual ) bulb produces 1600 LUX with a 9 foot ceiling at the work bench.

I found the 125-150 watt equivalent CFL bulb produced the highest LUX at the floor or work area measured with a smart phone light meter. The light meter is the only way to judge the reflector function. There is balance between the light focus and spread.


I have tried the super size CFL 300 watt equivalent with less success. I think this is due to the length of the bulb as they are almost a foot long. So the shade has to be huge and very deep to reflect the light to max benefit with the larger bulbs.




Cut the hole in the bowl with a hand held jig saw. Thin stainless and a hole saw do not get along. The jig saw makes a lot of noise but the result is perfect.
I found the shade works best right at the bulb part. My bulbs have a heat vent and the shade is below the vents.


Bottom line .........The bowls work great........at low cost ..........

 

[Marctrees]

Pie plates would be great for much smaller lamps.

That's where my thinking started.

Note the size of these bowls.

18 3/4" x 5 1/2".

That's the attraction for me.

And they're so cheap, I'm sure they're very lightweight. Marc

 

[Marctrees]

A Greenlee knockout punch makes NO mess or noise.

Except for the initial 7/16" hole to drill for the first step 1/2" KO.

That's a very controllable small mess compared to the jigsaw.

No little chips of SS flying all over.

Use watcha got. Marc

 

[Marctrees]

As an option to resting them on tops of lamps, a guy could make a larger hole (around 3") then drill 2 - 1/4" holes to pass the 10/32's of a porcelain.

Sandwich the bowl between the porcelain and the box, obviously staying clear of the wire term's.

More rigid, more permanent. Marc

 

[Marctrees]

To cut the large hole, put bowl on wood scrap and screw down tight to wood through your 2- 1/4 holes.

Then hole saw.

Minimizes chattering, and most chips stay contained.

I guess the above is a DUHHH, but some not think of it. Marc

 

[toplessHO]

To cut the large hole, put bowl on wood scrap and screw down tight to wood through your 2- 1/4 holes.

Then hole saw.

Minimizes chattering, and most chips stay contained.

I guess the above is a DUHHH, but some not think of it. Marc

yea is a neat trick if you need to enlarge a hole in anything too

 

[Showkey]

The bowls are really really thin..........

My holes are between 2 and 3 inches depending on the bulbs. I have done this over 25 times.

Shade needs to be low on the bulb.

The 5 1/2" depth bowl is ideal for the small bulbs not good for the larger bulbs.

 

[Marctrees]

Ya - I really think THESE PARTICULAR bowls are the ticket.

They are so cheap $, so "thin" and chintzy, would be **** for a commercial kitchen, but that's what makes them perfect for this app.

The biggest one for $16.99 may be best because wider AND deeper.

But even the $6.99 ones in the direct link would be WAY better than nothing on an open framed ceiling.

I'm convinced, Lars

 

[Charles (in GA)]

Read through this thread.

http://www.garagejournal.com/forum/showthread.php?t=38658

 

[Marctrees]

Charles - Please explain what you are trying to point out in this long thread.

I have read it before, and skimmed through some just now at your suggestion. Marc

 

[LS6 Tommy]

I would think that type of reflector in a low bay application would have a very narrow beam pattern. I could be wrong, too.

Tommy

 

[Showkey]

I would think that type of reflector in a low bay application would have a very narrow beam pattern. I could be wrong, too.

Tommy

It's all relative.......

The whole idea of this reflector is pointing more light down on the work surface. The reflector quality and properties is all about the diameter, depth and bulb placement.

If compared to a spot light, the spot is far more narrow. If compared to no reflector the light is at less scattered. There is a compromise as with anything. Yes....there have been many heated debates about the cave effect vs the glare and harsh bare bob with a white ceiling.

I also prefer T8 fixtures witha reflector system built in to put more light down. Above my work benches I use T8 fixtures to put down 1000 LUX on the bench top work surface. Same with my table saw.

My CFL reflector project all started with two new to me shops with over 30 porcelain bulb holders with 150, 200 and 300 watt incandescent bulbs.

 

[fabjunkie]

Marc, I just saw your pm but thought these pics may help you in your decision. The bulb directly above my head is not working either.

 

[Marctrees]

Fab - Ya, look's good.

I'm going to do similar spacing. Marc

 

[Trey T]

When I look at designing lights, I consider these three:

1. light the subjects or work space
2. light the walls
3. light the ceiling

If your priority is #1 only, then use a bowl (narrow degrees) to focus the lights onto the subject or work space. Lighting walls and ceiling are considered aesthetic features. Sometime lighting walls can minimize the shadows onto a subject or work space.

fabjunkie current setup is lighting all three.

 

[Showkey]

Would be interesting to know the LUX value at floor and bench level ????????


(Can be measured with a smart phone app.)