Question on choosing fluorescent lights

[kreutz]

Hello,


This is a question about types of fluorescent tubes.

I presently have 3 x 4 = 12 fluorescent tubes in my office. The light level is good, however, I am unhappy with the heat that they emit. A friend of mine has two 4 ft (!) fluorescent lights in one of the rooms of his house and they seem to be able to provide more light and way less heat. I want to know whether I should be looking for 12 new small tubes that provide substantially less heat (do such tubes exist?), or whether I should just replace the lights with two long fluorescent tubes. Any other suggestions would also be welcome.

Thanks!

Kreutz

 

[Stoday]

I am sitting in my 10' X 12' office that has twelve 2' tubes. I don't notice any heat being given off from them, so I don't understand why yours do.

Can you feel the heat as if you were in front of a fire? Or is it just that the room heats up?

 

[Lectrician]

Photo of the ones you currenty have?

 

[kreutz]

I will try to take a photo of the lights next Monday. The brand is Osram, they're between 1 and 2 ft. Probably closer to 1 ft.

Can you feel the heat as if you were in front of a fire? Or is it just that the room heats up?

The room heats up but you can clearly see where the heat is coming from by placing your hand near the lights. The room takes about an hour to heat up though. The ends of the tubes are where most of the heat is coming from. The middle bits are less hot.

 

[kreutz]

They are Osram L 18W/535 (2 ft). There are plenty of photos of them on Google.

 

[ricicle]

It is perfectly normal for fluorescent fittings to give off heat especially those with iron wound chokes. I can honestly say I have never heard anyone say it bothers them.
What type of fitting are they - modular type ? It is possible that the heat is not escaping via the top of the fitting (if they are fully enclosed) so is all being reflected down but even then it would be barely noticable unless you have a very low ceiling ?

 

[kreutz]

OK fair enough. No, the ceiling is standard height and I don't really know what you mean by modular but Google seems to come up with what I have in image search, so I guess they are modular.

I have another set of such lights in the other office room and they are newer. They seem to emit slightly less heat even though the amount of light they produce seems to be similar. Is there a way of knowing how much heat a tube produces before buying? Also, would replacing the 12 T8s with two really long ones make the office room less hot?

Thanks,
Kreutz

 

[kreutz]

Oh and both ends of all tubes heat up to the point that you can't touch them for longer than one or two seconds. When you have 24 such heat sources in a small room, isn't it usual for it to heat up?

 

[JohnW2]

Oh and both ends of all tubes heat up to the point that you can't touch them for longer than one or two seconds. When you have 24 such heat sources in a small room, isn't it usual for it to heat up?

I'm somewhat amazed by this discussion. Although fluorescent fittings invariably produce some heat (mainly from the control gear within, rather than the tube), I would be very surprised if one would notice, or be able to measure, any significant increase in room temperature. Lets face it, even if one assumed that all the power was being converted to heat, 12 x 18W fiitings is only a total of 216W, pehaps equivalent to having a TV or small computer operating in the room.

Kind Regards, John.

 

[ricicle]

I have another set of such lights in the other office room and they are newer. They seem to emit slightly less heat even though the amount of light they produce seems to be similar.

The newer ones possibly have electronic ballasts which produce significantly less heat than electromagnetic ones (and are better for lamp life and performance as well)

You could try electronic starters in the older fittings (if they take starters) as these tend to make the chokes run less hot. You will more than likely need series starters for 18w lamps.