turtle420
03-18-2006, 02:09 PM
Hello guys (and girls)!,
Hope you're all doing good. :)
I've been having this in the back of my head for some weeks now, and I must share and get your much desired input.
SUBJECT: Cooling HID Bulbs (Metal Halide MH, and High Pressure Sodium HPS)
As many of you know, there are many ways to run HID bulbs in your setup. Out in the open over the plants (with, or without a reflector), inside a hood, inside a sealed-hood, or with a cool tube. Many more variations to go around, but I think those are the basics.
In order for the HID bulbs to operate properly, they need a certain degree of cooling. But, how much cooling?
Well, let's use the CFM measurement.
[[[ CFM = Cubic Feet per Minute ]]]
I read/heard that 40CFM/W is a good cooling bench mark. You can see a very interesting thread below (link #1, at the end of this post).
Problem is, to make such an approach to "cooling HIDs" is, really a very bad engineering decision. There are many things that will alter how "effective" those 40CFM will be in cooling one watt of your bulb.
I'm inclined to think that a cool tube setup is better for cooling than a sealed-hood... but you've got the benefit of 'volume' with the sealed-hood.
Anyway, there are like 300,015 factors that can alter your CFM rating. My 550CFM Dayton, after running through my cool tube, has a VERY different CFM rating than those 550... and, quite obviously, much lower than those 500's. In the end, my cool tube isn't 100% cool.
So, what to do... ???
I further compound this "problem" by the fact that I read a post by Karmaxul the other day (link #2 @ the end of this post) that said that you shouldn't go too crazy cooling your HIDs... and, with sound reasoning.
The electricity is used to create a High Intensity Discharge inside the bulb... for example, in the Metal Halide, the electricity will be arcing on the small "pocket" inside the bulb. And, that means relatively "very high temperatures". So, if you cool your bulb waaaay too much, you'll be spending too much electricity trying to get your bulbs hot, so they can then arc and create our desired photons.
...... Ideas? Input? Suggestions? Comments?
I've been thinking that, in a super-uber world where we stoner growers do as we "say" we're going to do on these boards, we could create a data table with a couple of inputs from people here running enclosed-cooling for their HIDs.
We could get:
HID type - (HPS or MH)
Wattage
Inlet air temp
Outlet air temp
total CFM for HID
With this data, we could, somehow, create some sort of "knowledge base" to use for future growing setups. It could help us (and many newbs) to pick proper fans for the HID bulbs.
It's very simple to "over-engineer" something to make it work... just throw "more" into it until it works. It'd be very good to have some "data".
What'd you rather have in the costal roads... a 1970 Chevy Chevelle SS 454 LS6, or a Lotus Elise? (ok, damn it... I'd pick the LS6... but you get my point)
<o.o><o.o><o.o><o.o><o.o>
Aiiiight... turtle out. Hope there are some takers. Very stoned at the time of writing.
I think I'd might play with the 550 Dayton and the 6", 90CFM fart fan...
Peace people, may good grows find you all,
-turtle420 :cool:
.
REFERENCE:::
1- "" Anyone Help me with this cool tube question pls! "" http://boards.cannabis.com/showthread.php?t=51814
2- "" need help building copy of "mini caddy" from sunlightsheds.. "" http://boards.cannabis.com/showthread.php?t=53646&highlight=karmaxul
Hope you're all doing good. :)
I've been having this in the back of my head for some weeks now, and I must share and get your much desired input.
SUBJECT: Cooling HID Bulbs (Metal Halide MH, and High Pressure Sodium HPS)
As many of you know, there are many ways to run HID bulbs in your setup. Out in the open over the plants (with, or without a reflector), inside a hood, inside a sealed-hood, or with a cool tube. Many more variations to go around, but I think those are the basics.
In order for the HID bulbs to operate properly, they need a certain degree of cooling. But, how much cooling?
Well, let's use the CFM measurement.
[[[ CFM = Cubic Feet per Minute ]]]
I read/heard that 40CFM/W is a good cooling bench mark. You can see a very interesting thread below (link #1, at the end of this post).
Problem is, to make such an approach to "cooling HIDs" is, really a very bad engineering decision. There are many things that will alter how "effective" those 40CFM will be in cooling one watt of your bulb.
I'm inclined to think that a cool tube setup is better for cooling than a sealed-hood... but you've got the benefit of 'volume' with the sealed-hood.
Anyway, there are like 300,015 factors that can alter your CFM rating. My 550CFM Dayton, after running through my cool tube, has a VERY different CFM rating than those 550... and, quite obviously, much lower than those 500's. In the end, my cool tube isn't 100% cool.
So, what to do... ???
I further compound this "problem" by the fact that I read a post by Karmaxul the other day (link #2 @ the end of this post) that said that you shouldn't go too crazy cooling your HIDs... and, with sound reasoning.
The electricity is used to create a High Intensity Discharge inside the bulb... for example, in the Metal Halide, the electricity will be arcing on the small "pocket" inside the bulb. And, that means relatively "very high temperatures". So, if you cool your bulb waaaay too much, you'll be spending too much electricity trying to get your bulbs hot, so they can then arc and create our desired photons.
...... Ideas? Input? Suggestions? Comments?
I've been thinking that, in a super-uber world where we stoner growers do as we "say" we're going to do on these boards, we could create a data table with a couple of inputs from people here running enclosed-cooling for their HIDs.
We could get:
HID type - (HPS or MH)
Wattage
Inlet air temp
Outlet air temp
total CFM for HID
With this data, we could, somehow, create some sort of "knowledge base" to use for future growing setups. It could help us (and many newbs) to pick proper fans for the HID bulbs.
It's very simple to "over-engineer" something to make it work... just throw "more" into it until it works. It'd be very good to have some "data".
What'd you rather have in the costal roads... a 1970 Chevy Chevelle SS 454 LS6, or a Lotus Elise? (ok, damn it... I'd pick the LS6... but you get my point)
<o.o><o.o><o.o><o.o><o.o>
Aiiiight... turtle out. Hope there are some takers. Very stoned at the time of writing.
I think I'd might play with the 550 Dayton and the 6", 90CFM fart fan...
Peace people, may good grows find you all,
-turtle420 :cool:
.
REFERENCE:::
1- "" Anyone Help me with this cool tube question pls! "" http://boards.cannabis.com/showthread.php?t=51814
2- "" need help building copy of "mini caddy" from sunlightsheds.. "" http://boards.cannabis.com/showthread.php?t=53646&highlight=karmaxul