How hot does a florescent tube get?

[Sulla]

OK, I am trying to figure out a way to do some interesting lighting features in my man-cave do-over. I was playing with an idea where I make a U shaped chanel from pink insulation foam and mount a florescent tube inside and have the light shine out the bottom. (Please excuse the crudeness of the drawing, I only have paint here at work.) The light is a standard off-the-shelf-in-the-USA model that plugs right into the wall.

My question is, with the pink foam enclosing the light tube on the front, back and sides, and on the bottom with light diffusing plastic sheeting, would some simple venting in the back of the U channel be good enough to prevent the florescent tube from catching fire or melting the foam or something?

Not pictured: Pink foam end caps, light diffusing plastic sheeting for the open 'bottom' of the channel, electrical connectors for the light tube.

 

[Delmustator]

They can get rather hot to the touch (spiral versions anyway). The single long tube version stay relatively cool. You should be ok as long as the material is not in direct contact with the tube glass.

P.S. Any reason why you would not use the sheathing that has reflective metal surface?

 

[Sidewinder]

You'd definitely need some vent holes - preferably in the top - as the foam is a (heat) insulator. I think the tube operating temp is 40-50°C

Is the ambient temperature controlled ie. aircon?

SAS

 

[Sulla]

Thanks all. The reason I am going with the pink foam rather than a traditional florescent light fixture are due to the following criteria:

• I am trek-i-fying my man cave. This means large fake structural elements being introduced into the room. Like bulkhead support pylons.
• Resale value - we are moving in 5 or so years and I do not want to alter my office in anyway that causes major re-construction to sell the place.
• light weight and easy to install without major structural changes to the room. Think plant-on's only as much as possible.
• Avoid changes that are more than a drywall anchor in the wall here and there.

So I decided to make some interesting pylons along one of the walls (maybe two) out of pink foam insulation. The room has no overhead light so rather than putting in some anachronistic desk lamps or buying some future-looking lamps, I thought I'd make some hidden lighting in a stretch of bulkhead made from more pink foam supported mostly from the sides at the walls where the upright pylons would meet it.

I'll do a better picture to show how it all fits together in theory. I am even constructing a 3/4 scale mock up of the room to try out different design ideas before I settle on anything. It'll all be on the blog linked above.

For now, a more accurate drawing of the light box is all I have the time to do with paint.

 

[Sulla]

Oh, and yes the room is controlled along with the rest of the house with central air conditioning.

The gaps between the florescent tube and the walls of the pink foam light box are nebulous. I can make them 1/4" or 5" does not really matter to me. I might even get away with just leaving the back ope or mostly open really.... no one will see it unless they walk back there.

I could even make some lightweight styrene or aluminum vents to cover the back of the box over the lights.

 

[Delmustator]

I did a test on a twin 4 foot I have on my 3rd floor storage room. Ran the light for 20 minutes. The bulbs were warm to the touch. But it's in a well ventilated area. So keep that in mind.

 

[Wicked]

This wouldn't be as cheap or as bright but why not use flexible LED strips or EL sheets? Hell I bet some cheapo touch lights could even work (after a bit 'o' wiring), though I think depending on how much of this lighting you're planning on doing that might be more expensive than the LED strips.

I used to work on arcade games and behind the name that runs across the top of the cabinet is one of those $4 tube based fixtures and it never caused any problems. If you were to build a small wooden channel to fit inside the foam I bet that would insulate the foam enough to keep it from overheating provided you can make some vent holes.

I really think you'd be better off with either LED strips, EL sheets, or at the very least one of those long strings of LED christmas lights (Amazon.com: Good Earth Lighting, Inc. G9524CLR-I 24-Foot Rope Lighting, Clear: Furniture & Decor). Safety first.

 

[_TiKi_]

Depends on the color temp of the bulb. Lower temp usually means hotter bulb. 2700k bulb will burn you while a 6500k bulb you could hold on to it for a long time without a problem. LEDs are great to work with and need no ballast to work just straight up DC.

 

[Delmustator]

I think you will be fine as long as you allow space between the bulb and the foam. Use a single 4' or 8' fixture.

 

[Sulla]

I was thinking of using a couple of something like these on either end rather than a whole off-the-shelf fixture.