Power Compact Lighting lesson learned.....

[David]

Ok, so I've learned my lesson. Stupid David, Stupid. Finally
finished my new light hood for the 75 Gallon planted freshwater tank
I'm setting up. 2x96w compact flourescents in a nice custom poplar
box. Pretty easy job really. Put the thing on top of the Versa-tops
on the tank and turned it on. Wow, that's nice, very bright, great
color, I like. I keep it on while doing some final plumbing, etc.
CRACK!!! Both sides of the glass top now have a nice set of cracks
from the amazing amount of heat these things put out. I know I should
have anticipated this, but as I said in opening, Stupid David.

So here's my question. Is there any way to cool these guys without
installing a fan in the hood. Everything is a really nice fit already
and I don't think there is a lot of room for a fan. Will adding some
spacers in the corners to allow air to flow underneath the box work
well enough or am I pretty much stuck making a new box? Please help
as I'm hoping to get this up and running ASAP and the single
flourescent that came with the tank just won't do.

Thanks in advance

David

[Evergreen]

I am curious to hear the responses here. I bought a 110 watt compact
flourescent light fixture and a few days later it cracked my glass top in
half from the heat. It makes sense and I guess I shouldn't be surprised,
but it is interesting that it is a manufactured light fixture and there was
no warning at all about the heat produced. I am surprised that there
wouldn't be many purchasers encountering the same situation of having the
glass top cracked. From a discussion with a guy at the LFS, it seems my
best bet as a permanent solution is to get a new, stronger (tempered?) piece
of glass made for the top. Right now I just ignore the crack and let the
plastic piece in the back hold it together.



"David" > wrote in message
...
> Ok, so I've learned my lesson. Stupid David, Stupid. Finally
> finished my new light hood for the 75 Gallon planted freshwater tank
> I'm setting up. 2x96w compact flourescents in a nice custom poplar
> box. Pretty easy job really. Put the thing on top of the Versa-tops
> on the tank and turned it on. Wow, that's nice, very bright, great
> color, I like. I keep it on while doing some final plumbing, etc.
> CRACK!!! Both sides of the glass top now have a nice set of cracks
> from the amazing amount of heat these things put out. I know I should
> have anticipated this, but as I said in opening, Stupid David.
>
> So here's my question. Is there any way to cool these guys without
> installing a fan in the hood. Everything is a really nice fit already
> and I don't think there is a lot of room for a fan. Will adding some
> spacers in the corners to allow air to flow underneath the box work
> well enough or am I pretty much stuck making a new box? Please help
> as I'm hoping to get this up and running ASAP and the single
> flourescent that came with the tank just won't do.
>
> Thanks in advance
>
> David

[Eric Schreiber]

David > wrote:

>So here's my question. Is there any way to cool these guys without
>installing a fan in the hood. Everything is a really nice fit already
>and I don't think there is a lot of room for a fan.

I am not speaking from experience here, so take with appropriate salt.

Since heat rises, a series of holes drilled at the top of the back
side of the hood should help a lot. Being in the back they'd be out of
sight, since I'm sure you want your newly built hood to look nice.

A fan may be your only option, however, if you have to move a lot of
heat (my 2x13 watt puts out a good amount of heat - I can only imagine
what a 2x96 generates!). You can get silent fans, and should be able
to mount one pretty flush with the wood on the side or back so that it
would have minimal impact on the inner arrangement. A similarly sized
vent on the other end to allow air in would probably be a good idea.



--
www.ericschreiber.com

[Glenn]

I am using a 1x96 fixture over a glass top on a 46 gallon bowfront. It is
36" long, and has no fan. It does, however, have vents on both ends, and
lengthwise along the backside. It sits on the tank sides, and is about 1/4"
off of the glass. The convection seems to do the trick--for one bulb at
least.

--


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"David" > wrote in message
...
> Ok, so I've learned my lesson. Stupid David, Stupid. Finally
> finished my new light hood for the 75 Gallon planted freshwater tank
> I'm setting up. 2x96w compact flourescents in a nice custom poplar
> box. Pretty easy job really. Put the thing on top of the Versa-tops
> on the tank and turned it on. Wow, that's nice, very bright, great
> color, I like. I keep it on while doing some final plumbing, etc.
> CRACK!!! Both sides of the glass top now have a nice set of cracks
> from the amazing amount of heat these things put out. I know I should
> have anticipated this, but as I said in opening, Stupid David.
>
> So here's my question. Is there any way to cool these guys without
> installing a fan in the hood. Everything is a really nice fit already
> and I don't think there is a lot of room for a fan. Will adding some
> spacers in the corners to allow air to flow underneath the box work
> well enough or am I pretty much stuck making a new box? Please help
> as I'm hoping to get this up and running ASAP and the single
> flourescent that came with the tank just won't do.
>
> Thanks in advance
>
> David

[David]

Eric

Thanks for the response. Unfortunately the fixture is already quite
open at the top, being only slats of wood supporting the ballast and
reflector. The problem seems to be heat building up underneath the
reflector. I'm thinking propping it up a bit and adding a fan would
be the only way to sufficiently cool these lights. I shall report
back on how things go.


David


On Sun, 21 Dec 2003 01:15:36 -0600, Eric Schreiber
> wrote:

>David > wrote:
>
>>So here's my question. Is there any way to cool these guys without
>>installing a fan in the hood. Everything is a really nice fit already
>>and I don't think there is a lot of room for a fan.
>
>I am not speaking from experience here, so take with appropriate salt.
>
>Since heat rises, a series of holes drilled at the top of the back
>side of the hood should help a lot. Being in the back they'd be out of
>sight, since I'm sure you want your newly built hood to look nice.
>
>A fan may be your only option, however, if you have to move a lot of
>heat (my 2x13 watt puts out a good amount of heat - I can only imagine
>what a 2x96 generates!). You can get silent fans, and should be able
>to mount one pretty flush with the wood on the side or back so that it
>would have minimal impact on the inner arrangement. A similarly sized
>vent on the other end to allow air in would probably be a good idea.

[Christina James]

David and Evergreen: I'm sorry for your unfortunate experience with tank
lights, but I'm so thankful you mentioned it here. I had been wanting
"better light" in my aquarium. Had I not read your posts, I doubt I would
have given much thought to the heat generated by the "better light" - and
now I sure will. (in my mind, anything non-incandescent was probably ok)
Thanks for waking me up about lights.

"David" > wrote in message
...
> Ok, so I've learned my lesson.

[Eric Schreiber]

David <David underscore J underscore Griffiths at yahoo dot com>
wrote:

>Thanks for the response. Unfortunately the fixture is already quite
>open at the top, being only slats of wood supporting the ballast and
>reflector. The problem seems to be heat building up underneath the
>reflector. I'm thinking propping it up a bit and adding a fan would
>be the only way to sufficiently cool these lights. I shall report
>back on how things go.

Ah, right. Yeah, you're probably stuck with a fan then. I'm kind of
surprised at the build up with a vented top. I wonder if maybe vents
drilled into the reflector might help.

--
www.ericschreiber.com

[Markyt]

I just experienced this with my 46 gal bow-front from All-Glass with a Versa
Top. Last week I purchased an All-Glass CF 110w (2x55W) strip light and a
few hours later I noticed a crack in the middle of the top. I thought I may
have dropped the front pane onto the back myself cracking it. I went a
purchased a new top and what do you know, two hours after I put it in it was
cracked in the same place. I called All-Glass that same day and told them
what happened. They said that they have heard of this before and will pay
for both the second Versa Top that I had purchased and for a new tempered
glass pane which I then ordered from my local glass supplier. All totaled
it is going to cost All-Glass about $75.

All-Glass was very nice about this but they should really fix their Versa
Top or include a disclaimer about using high-output lights.

Mark

"Evergreen" <no > wrote in message
...
> I am curious to hear the responses here. I bought a 110 watt compact
> flourescent light fixture and a few days later it cracked my glass top in
> half from the heat. It makes sense and I guess I shouldn't be surprised,
> but it is interesting that it is a manufactured light fixture and there
was
> no warning at all about the heat produced. I am surprised that there
> wouldn't be many purchasers encountering the same situation of having the
> glass top cracked. From a discussion with a guy at the LFS, it seems my
> best bet as a permanent solution is to get a new, stronger (tempered?)
piece
> of glass made for the top. Right now I just ignore the crack and let the
> plastic piece in the back hold it together.
>
>

[Jeff Pratt]

David <David underscore J underscore Griffiths at yahoo dot com> wrote:

>
>
> Eric
>
> Thanks for the response. Unfortunately the fixture is already quite
> open at the top, being only slats of wood supporting the ballast and
> reflector. The problem seems to be heat building up underneath the
> reflector. I'm thinking propping it up a bit and adding a fan would
> be the only way to sufficiently cool these lights. I shall report
> back on how things go.
>
>
> David

Is it possible to separate the ballasts from the lights? If you can move
the ballasts out from under the reflector (I don't KNOW that they're there,
but the description seems to point to it) that should help significantly.
Your reflector will reflect (radiant) heat as well as light, and the
ballasts are usually where the most heat is generated.

HTH, Jeff

> On Sun, 21 Dec 2003 01:15:36 -0600, Eric Schreiber
> > wrote:
>
>>David > wrote:
>>
>>>So here's my question. Is there any way to cool these guys without
>>>installing a fan in the hood. Everything is a really nice fit already
>>>and I don't think there is a lot of room for a fan.
>>
>>I am not speaking from experience here, so take with appropriate salt.
>>
>>Since heat rises, a series of holes drilled at the top of the back
>>side of the hood should help a lot. Being in the back they'd be out of
>>sight, since I'm sure you want your newly built hood to look nice.
>>
>>A fan may be your only option, however, if you have to move a lot of
>>heat (my 2x13 watt puts out a good amount of heat - I can only imagine
>>what a 2x96 generates!). You can get silent fans, and should be able
>>to mount one pretty flush with the wood on the side or back so that it
>>would have minimal impact on the inner arrangement. A similarly sized
>>vent on the other end to allow air in would probably be a good idea.

[David]

Jeff,

The ballasts is mounted above the relfector in a relatively open area.
The problem seems to be heat build-up between the reflector and the
glass top due to very little or no circulation of air in that space.
Should have thought of it before I suppose but of course I was too
excited by the pretty BRIGHT lights. Should be fine once I get a fan
going. Although that will be a few days at least, what with Christmas
coming up and all that jazz.


David


On Mon, 22 Dec 2003 16:06:39 GMT, Jeff Pratt > wrote:

>David <David underscore J underscore Griffiths at yahoo dot com> wrote:
>
>>
>>
>> Eric
>>
>> Thanks for the response. Unfortunately the fixture is already quite
>> open at the top, being only slats of wood supporting the ballast and
>> reflector. The problem seems to be heat building up underneath the
>> reflector. I'm thinking propping it up a bit and adding a fan would
>> be the only way to sufficiently cool these lights. I shall report
>> back on how things go.
>>
>>
>> David
>
>Is it possible to separate the ballasts from the lights? If you can move
>the ballasts out from under the reflector (I don't KNOW that they're there,
>but the description seems to point to it) that should help significantly.
>Your reflector will reflect (radiant) heat as well as light, and the
>ballasts are usually where the most heat is generated.
>
>HTH, Jeff
>
>> On Sun, 21 Dec 2003 01:15:36 -0600, Eric Schreiber
>> > wrote:
>>
>>>David > wrote:
>>>
>>>>So here's my question. Is there any way to cool these guys without
>>>>installing a fan in the hood. Everything is a really nice fit already
>>>>and I don't think there is a lot of room for a fan.
>>>
>>>I am not speaking from experience here, so take with appropriate salt.
>>>
>>>Since heat rises, a series of holes drilled at the top of the back
>>>side of the hood should help a lot. Being in the back they'd be out of
>>>sight, since I'm sure you want your newly built hood to look nice.
>>>
>>>A fan may be your only option, however, if you have to move a lot of
>>>heat (my 2x13 watt puts out a good amount of heat - I can only imagine
>>>what a 2x96 generates!). You can get silent fans, and should be able
>>>to mount one pretty flush with the wood on the side or back so that it
>>>would have minimal impact on the inner arrangement. A similarly sized
>>>vent on the other end to allow air in would probably be a good idea.

[Markyt]

David,

There is a great deal of radiated heat being applied to that glass. Glass
is a relatively poor heat conductor which means unless the heat is applied
uniformly over the entire surface some areas will expand more than others
creating a stress that is breaking the glass. Adding a fan will carry some
convection heat away but perhaps not enough to keep the stresses in the
glass uniform.

In my response a few threads up you can see what All-Glass recommended that
I do for my Versa Top. Switching to tempered glass for this application
hopefully will eliminate the problem (for me). The tempered glass will
experience much the same heat stresses but will be much stronger and
resistant to cracking as a result of them. It cost me $36 for a single
35"x7"x3/16" tempered glass pane (which is being reimbursed by All-Glass).

The differences between my problem and yours are; you have a larger
aquarium, and your light fixture is home made, where-as mine are both
All-Glass products. I only raise this point because I believe that
All-Glass has some responsibility for my problem because the two products
should be compatible, this isn't the case for you.

You may want to give the tempered glass idea some thought. By the way, to
stave off this problem until my tempered glass panel arrives I have placed
pieces of 3/4"x3/4"x7" pine at each end of the light fixture (under it) to
lift it 3/4" off the glass. This has been in place for two days and no
crack. I might also note that my cracks were in the center where my two
lamps over-lapped each other,

Mark

"David" <David underscore J underscore Griffiths at yahoo dot com> wrote in
message ...
> Jeff,
>
> The ballasts is mounted above the relfector in a relatively open area.
> The problem seems to be heat build-up between the reflector and the
> glass top due to very little or no circulation of air in that space.
> Should have thought of it before I suppose but of course I was too
> excited by the pretty BRIGHT lights. Should be fine once I get a fan
> going. Although that will be a few days at least, what with Christmas
> coming up and all that jazz.
>
>
> David
>
>
> On Mon, 22 Dec 2003 16:06:39 GMT, Jeff Pratt > wrote:
>
> >David <David underscore J underscore Griffiths at yahoo dot com> wrote:
> >
> >>
> >>
> >> Eric
> >>
> >> Thanks for the response. Unfortunately the fixture is already quite
> >> open at the top, being only slats of wood supporting the ballast and
> >> reflector. The problem seems to be heat building up underneath the
> >> reflector. I'm thinking propping it up a bit and adding a fan would
> >> be the only way to sufficiently cool these lights. I shall report
> >> back on how things go.
> >>
> >>
> >> David
> >
> >Is it possible to separate the ballasts from the lights? If you can move
> >the ballasts out from under the reflector (I don't KNOW that they're
there,
> >but the description seems to point to it) that should help significantly.
> >Your reflector will reflect (radiant) heat as well as light, and the
> >ballasts are usually where the most heat is generated.
> >
> >HTH, Jeff
> >
> >> On Sun, 21 Dec 2003 01:15:36 -0600, Eric Schreiber
> >> > wrote:
> >>
> >>>David > wrote:
> >>>
> >>>>So here's my question. Is there any way to cool these guys without
> >>>>installing a fan in the hood. Everything is a really nice fit already
> >>>>and I don't think there is a lot of room for a fan.
> >>>
> >>>I am not speaking from experience here, so take with appropriate salt.
> >>>
> >>>Since heat rises, a series of holes drilled at the top of the back
> >>>side of the hood should help a lot. Being in the back they'd be out of
> >>>sight, since I'm sure you want your newly built hood to look nice.
> >>>
> >>>A fan may be your only option, however, if you have to move a lot of
> >>>heat (my 2x13 watt puts out a good amount of heat - I can only imagine
> >>>what a 2x96 generates!). You can get silent fans, and should be able
> >>>to mount one pretty flush with the wood on the side or back so that it
> >>>would have minimal impact on the inner arrangement. A similarly sized
> >>>vent on the other end to allow air in would probably be a good idea.
>

[T]

Here is a thought for fans... Have you thought about using a computor case
fan for drawing in cool air and exhausting hot air??

The Power Compact unit I was looking at had fans built in, not sure how
well they worked but the fixture was not covered allowing the heat to be
disapated quickly ( this was on a reef tank ).. Perhaps there might be some
more information on a Slat water or Reef Tank discussion board..??

Timmer...

"Christina James" > wrote in message
...
> David and Evergreen: I'm sorry for your unfortunate experience with tank
> lights, but I'm so thankful you mentioned it here. I had been wanting
> "better light" in my aquarium. Had I not read your posts, I doubt I would
> have given much thought to the heat generated by the "better light" - and
> now I sure will. (in my mind, anything non-incandescent was probably ok)
> Thanks for waking me up about lights.
>
> "David" > wrote in message
> ...
> > Ok, so I've learned my lesson.
>
>