Air cooled lights: the right way - Growroom Lighting - International Cannagraphic Magazine Forums

badmf · 12-03-2004, 09:34 PM

Many of us use air cooled lights and lots of others have thought about trying them too. I wanted to address some points that will make this easy to do and more efficient if you have them already.

The distance between the glass sheild and the plants can be as close as 3-4" with a 600 or 6-8 with a 1K. As you know as light travels it loses intensity, for every foot away from the light a loss of 25% or more! So using air cooled lights benefits both usable lumens, lower room heat and longer bulb life!
1. One thing that is most important is the fan used. It must big a large enough and durable one or it will be the weak link! For 250/400/600 watt lights a Dayton 265cfm is more than adequate to cool to a level where your hand can be right on the hood over the bulb without feeling any discomfort! With 1000 watters, they produce a lot of heat so a better brand fan or added cfms are a must. Elicent fans are in-line centrifugal and have a higher static pressure( amount of air moved in a given period of time) and will work best here. If you go with a Dayton 465 it won't cool enough to max your distances. Rather use an Elicent 200b it moves 636cfm!
2. The placement of the fan is very important to lower duct drag or friction caused with in the ducts lining. Solve this by moving or adding the fan right next to the light, this will move the most air quickly and reduce the temps the most. If you have, as I have seen, placed the fan 8+ feet away your fans effiency is less. So re-configure your fans set-up next time you adjust your light.
3.Keeping the glass very clean will help cut down on the lumen loss as microscopic dust particles reflect light back into the hood. If you are using Co2 you will need to seal the edges around the glass to prevent the gas and room odors from getting sucked into the light.
4. Bringing in the coolest intake air will aid in lowering the lights and rooms temperatures. You can take it from inside a wall that has access to air from under the dwelling. And for exhaust either insert it into a dryer/chimmney or vent into a room you wish to heat during winter. Four 1K's kept my whole house quite warm though mountain weather with temps in the teens!
5. Run an oscillating fan over the plant tops between the light and you can lower even further!
To sum it up you will have a sealed room with contollable temps, bigger yeilds and co2 usage down. Your cool intake air goes through your light and exits never having any odor or co2 added, and thats a good thing!

12-18-2004, 04:19 PM

That is all very true, but one can drop about 3 to 5 degree's if they also insulate the out side of the hood, most noticeable temp change in summer heat.

I found the extra heat to be an added plus during winter as it help's keep a nice stable room temp.

On a sealed 400 watt system, closer than 5" gave bud's intensity burning, bud's turn white in color. The 600's I have also have a limit as how close they can get to the bud's, heat wise I can set them on the bud's if I wish, but light foot print decrease's as you lower the lamp on the grow, and again intensity light burn occur's on the bud's closest to the lamp, again I have found it to be with in 5" of the bud's, so in general my lamp's never get closer than 8" to the plant's as I like to keep a even foot print of light on the grow.

grow safe

realhigh.

A 4" duct can move only 120cfm of air flow in a 3 ft straight section tested, so if you use 4" duct, no reason for a fan larger than 140 cfm to cool a hood, just my opiniion about it.
6" is rated to move 200cfm of air flow thru a 3 ft straight section, and is being the recomended size duct to use for larger bulb's in sealed hood's, at least in my area.

Happy Holiday's to all.

12-18-2004, 05:34 PM

realhigh good info on the duct rating, I never thought of that and it was never mentioned in any of the grow books that I have purchased. It may have been in there I just flash read. Thumbs up for the good info.

Stay Safe.

Mo,

badmf · 12-18-2004, 10:19 PM

The footprint is a matter of preference to each grow, and I definitely agree with you using the space most efficiently! The air flow is deceiving though, as I said static pressure is what the issue is, and not so much cfms. If you were to take a set of fans rated the same cfms; such as the Elicent 150a cfm rating 247 and the Dayton 265 cfm you would notice the lower rated fan (the Elicent)having much superior air pressure. It therefore moves more air quickly across the bulb giving lower temps.

The newer hoods have larger duct openings to address the flow too, and an industrious type could enlarge the older 3" or 4" types. A great point you brought up! :wink:
realhigh; you are within the foot of distance to the bulb so you arent losing lumens as some, who must position their plants a greater distance away. A 24" distance = a loss of 50% lumens! :wink: But try out higher rated fans, ones with good static pressure before thinking a lower cfm would work the same. I have seen a much cooler room since I converted to better fans. The white tops are from "bud bleaching", when outdoors, plants get sometimes 15,000 lumens while indoors around 7250(with a hort 1k@ 20 sq ft) so light intensity isn't as much an issue as too much heat!

12-19-2004, 01:34 AM

Yes, one should consider the drop in air flow in the routed duct's, caused by static pressure, so one can increase the size fan to compensate for this static pressure and still move the max amount of air the duct allow's. This in turn can bring a cooler hood.

It is also easy to increase the 4" duct to 6" duct, flange's for hood are available at most hydro place's, and use the same fan as before, but due to less static pressure, the fan can move more air, less static pressure to deal with, so in turn a cooler hood.

No matter what, if you do not supply the fan with enough air flow that it is rated for it is over worked and it will use more energy and wear out faster.

grow safe

Happy holiday's

realhigh.

mybeans420 · 12-19-2004, 01:39 AM

great posts guys,
i'm sure that there many out there who will find this info quite helpful so kudos on the info and keep it coming fellas.

peace
beans

Harry Gypsna · 12-19-2004, 05:12 PM

great info, just what i need for my new year project, converting 6 X 400watt HPS low bays by remoting the ballsts and adding glass and air cooling them. I have got some nice enclosures to put the ballasts into, i am going to use 2 x ballasts in each enclosure so i will have 3 x twin 400 watt ballasts, i will use a pc fan on the enclosures just to cool em a bit. I was thinking about even adding a relay and timer to the enclosure so they a ready to plug and grow. And( I know, never start a sentence with and) thanks to the generosity of BV, i will be able to show how i do it.
I was going to use a "kettle" connection plug to attach the lamp to ballasts, which is what mozst hoods use anyway, but i am wondering if any1 has suggestions of connectors which are more secure? such as my 1000 power plant ballas6t, has a metal clip which slips over the lead when plugged in to preven the lead being pulled out.something like this would be better, as each of these sets of 2, wilkl be on a lightrail 3.5 so need to be connected securely.

badmf · 12-19-2004, 08:12 PM

I have always liked the Hydrofarm connections as they are very secure and have a lip to prevent any moisture from shorting out your enterprise. You spoke of cooling the ballasts but not the fans for the lights themselves, which fan(s) do you intend to use?
Just make sure in your blueprints you include some slack for the line as movers with air-cooled is not as easy to iron out all the kinks at first! Allowing enough ducting for lower light heights is a factor. I dis-connect some hose as they grow taller to lessen the run, less duct drag. A good fan is not much more than a cheaper one but will benenfit you in the short and long run(immediate cooler temps and long life). Good luck and keep us posted on your progress!

Harry Gypsna · 12-19-2004, 08:23 PM

I will be using centrifugal fans for the air cooling of the lights, i just got my TLC-direct catalogue dripped through the door, lol, u know, they guy at the grfow shop wanted to sell me a 6 inch centrifugal inline fan second hand for 80 quid, in this cataloogue, thats the price brand new, and i can get just abkoiut everything for a grow fro this cataloogue a lot cheaper.
For the cables connecting the hoods to the ballasts, i was thinking of using a plastic curtain rail alongside each lightrail with the cable, and the flexi-duct from the hoods, attached with those little plastic curtain hooks, thus allowing me to have just the right amount of slack, wiothout the leads and ducting being daragged back and forth atop the plants getting snagged, or trailing on the deck.

badmf · 12-19-2004, 08:43 PM

Sounds good! The tricky thing is to add enough flex-duct and not too much! I have sections that can be removed when it(the hood) gets highe. Do a dry run for a while to be certain of all connections and efficiency of the hose lengths. Most of us get fooled by cfms when deciding on fans. The cfms being equal we think the cheaper fan is the same, ahhh, but its not! The power or static pressure is what determines the force the air moves. The one with a higher force will remove more heat, although you are not in my neck of the woods, check out the time it takes to fill a large trash bag and compare if possible before buying. Brands with good pressure are Elicent and Hurricane, other fans local to your area will need to be checked or someone can add this info!

12-03-2004, 09:34 PM	#1
badmf Serving great bud since 65'! Join Date: Oct 2004 Location: Surface of a strange planet Posts: 908	Air cooled lights: the right way Many of us use air cooled lights and lots of others have thought about trying them too. I wanted to address some points that will make this easy to do and more efficient if you have them already. The distance between the glass sheild and the plants can be as close as 3-4" with a 600 or 6-8 with a 1K. As you know as light travels it loses intensity, for every foot away from the light a loss of 25% or more! So using air cooled lights benefits both usable lumens, lower room heat and longer bulb life! 1. One thing that is most important is the fan used. It must big a large enough and durable one or it will be the weak link! For 250/400/600 watt lights a Dayton 265cfm is more than adequate to cool to a level where your hand can be right on the hood over the bulb without feeling any discomfort! With 1000 watters, they produce a lot of heat so a better brand fan or added cfms are a must. Elicent fans are in-line centrifugal and have a higher static pressure( amount of air moved in a given period of time) and will work best here. If you go with a Dayton 465 it won't cool enough to max your distances. Rather use an Elicent 200b it moves 636cfm! 2. The placement of the fan is very important to lower duct drag or friction caused with in the ducts lining. Solve this by moving or adding the fan right next to the light, this will move the most air quickly and reduce the temps the most. If you have, as I have seen, placed the fan 8+ feet away your fans effiency is less. So re-configure your fans set-up next time you adjust your light. 3.Keeping the glass very clean will help cut down on the lumen loss as microscopic dust particles reflect light back into the hood. If you are using Co2 you will need to seal the edges around the glass to prevent the gas and room odors from getting sucked into the light. 4. Bringing in the coolest intake air will aid in lowering the lights and rooms temperatures. You can take it from inside a wall that has access to air from under the dwelling. And for exhaust either insert it into a dryer/chimmney or vent into a room you wish to heat during winter. Four 1K's kept my whole house quite warm though mountain weather with temps in the teens! 5. Run an oscillating fan over the plant tops between the light and you can lower even further! To sum it up you will have a sealed room with contollable temps, bigger yeilds and co2 usage down. Your cool intake air goes through your light and exits never having any odor or co2 added, and thats a good thing!
	Quote 1 members found this post helpful.

12-18-2004, 04:19 PM	#2
Guest Guest Posts: n/a	That is all very true, but one can drop about 3 to 5 degree's if they also insulate the out side of the hood, most noticeable temp change in summer heat. I found the extra heat to be an added plus during winter as it help's keep a nice stable room temp. On a sealed 400 watt system, closer than 5" gave bud's intensity burning, bud's turn white in color. The 600's I have also have a limit as how close they can get to the bud's, heat wise I can set them on the bud's if I wish, but light foot print decrease's as you lower the lamp on the grow, and again intensity light burn occur's on the bud's closest to the lamp, again I have found it to be with in 5" of the bud's, so in general my lamp's never get closer than 8" to the plant's as I like to keep a even foot print of light on the grow. grow safe realhigh. A 4" duct can move only 120cfm of air flow in a 3 ft straight section tested, so if you use 4" duct, no reason for a fan larger than 140 cfm to cool a hood, just my opiniion about it. 6" is rated to move 200cfm of air flow thru a 3 ft straight section, and is being the recomended size duct to use for larger bulb's in sealed hood's, at least in my area. Happy Holiday's to all.
	Quote

12-18-2004, 05:34 PM	#3
Guest Guest Posts: n/a	realhigh good info on the duct rating, I never thought of that and it was never mentioned in any of the grow books that I have purchased. It may have been in there I just flash read. Thumbs up for the good info. Stay Safe. Mo,
	Quote

12-18-2004, 10:19 PM	#4
badmf Serving great bud since 65'! Join Date: Oct 2004 Location: Surface of a strange planet Posts: 908	The footprint is a matter of preference to each grow, and I definitely agree with you using the space most efficiently! The air flow is deceiving though, as I said static pressure is what the issue is, and not so much cfms. If you were to take a set of fans rated the same cfms; such as the Elicent 150a cfm rating 247 and the Dayton 265 cfm you would notice the lower rated fan (the Elicent)having much superior air pressure. It therefore moves more air quickly across the bulb giving lower temps. The newer hoods have larger duct openings to address the flow too, and an industrious type could enlarge the older 3" or 4" types. A great point you brought up! :wink: realhigh; you are within the foot of distance to the bulb so you arent losing lumens as some, who must position their plants a greater distance away. A 24" distance = a loss of 50% lumens! :wink: But try out higher rated fans, ones with good static pressure before thinking a lower cfm would work the same. I have seen a much cooler room since I converted to better fans. The white tops are from "bud bleaching", when outdoors, plants get sometimes 15,000 lumens while indoors around 7250(with a hort 1k@ 20 sq ft) so light intensity isn't as much an issue as too much heat!
	Quote 1 members found this post helpful.

12-19-2004, 01:34 AM	#5
Guest Guest Posts: n/a	Yes, one should consider the drop in air flow in the routed duct's, caused by static pressure, so one can increase the size fan to compensate for this static pressure and still move the max amount of air the duct allow's. This in turn can bring a cooler hood. It is also easy to increase the 4" duct to 6" duct, flange's for hood are available at most hydro place's, and use the same fan as before, but due to less static pressure, the fan can move more air, less static pressure to deal with, so in turn a cooler hood. No matter what, if you do not supply the fan with enough air flow that it is rated for it is over worked and it will use more energy and wear out faster. grow safe Happy holiday's realhigh.
	Quote

12-19-2004, 01:39 AM	#6
mybeans420 resident slackass Join Date: Feb 2004 Location: somewhere that has a pool table Posts: 1,053	great posts guys, i'm sure that there many out there who will find this info quite helpful so kudos on the info and keep it coming fellas. peace beans __________________ "POWER TO THE PEACEFUL" micheal franti LET LOVE GUIDE YOU LEAVE YOUR CLOWNSHOES AND YOUR NEGATIVITY AT THE DOOR PLEASE.. THANK YOU "The prestige of government has undoubtedly been lowered considerably by the prohibition law. For nothing is more destructive of respect for the government and the law of the land than passing laws which cannot be enforced. It is an open secret that the dangerous increase of crime in this country is closely connected with this." Albert Einstein, "My First Impression of the U.S.A.", 1921 "Prohibition will work great injury to the cause of temperance. It is a species of intemperance within itself, for it goes beyond the bounds of reason in that it attempts to control a man's appetite by legislation, and makes a crime out of things that are not crimes. A Prohibition law strikes a blow at the very principles upon which our government was founded." Abraham Lincoln, U.S. President. 18 Dec. 1840 PLEASE don't PM me for seeds or cuts,.. Thank you
	Quote

12-19-2004, 05:12 PM	#7
Harry Gypsna Dirty hippy Bastard Join Date: May 2004 Location: Outside BodyShop, with a Tin Whistle and a dog on a piece of string Posts: 8,157	great info, just what i need for my new year project, converting 6 X 400watt HPS low bays by remoting the ballsts and adding glass and air cooling them. I have got some nice enclosures to put the ballasts into, i am going to use 2 x ballasts in each enclosure so i will have 3 x twin 400 watt ballasts, i will use a pc fan on the enclosures just to cool em a bit. I was thinking about even adding a relay and timer to the enclosure so they a ready to plug and grow. And( I know, never start a sentence with and) thanks to the generosity of BV, i will be able to show how i do it. I was going to use a "kettle" connection plug to attach the lamp to ballasts, which is what mozst hoods use anyway, but i am wondering if any1 has suggestions of connectors which are more secure? such as my 1000 power plant ballas6t, has a metal clip which slips over the lead when plugged in to preven the lead being pulled out.something like this would be better, as each of these sets of 2, wilkl be on a lightrail 3.5 so need to be connected securely. __________________ Clowns to the left of me, jokers to the right, and none of these people are very funny.
	Quote

12-19-2004, 08:12 PM	#8
badmf Serving great bud since 65'! Join Date: Oct 2004 Location: Surface of a strange planet Posts: 908	I have always liked the Hydrofarm connections as they are very secure and have a lip to prevent any moisture from shorting out your enterprise. You spoke of cooling the ballasts but not the fans for the lights themselves, which fan(s) do you intend to use? Just make sure in your blueprints you include some slack for the line as movers with air-cooled is not as easy to iron out all the kinks at first! Allowing enough ducting for lower light heights is a factor. I dis-connect some hose as they grow taller to lessen the run, less duct drag. A good fan is not much more than a cheaper one but will benenfit you in the short and long run(immediate cooler temps and long life). Good luck and keep us posted on your progress!
	Quote

12-19-2004, 08:23 PM	#9
Harry Gypsna Dirty hippy Bastard Join Date: May 2004 Location: Outside BodyShop, with a Tin Whistle and a dog on a piece of string Posts: 8,157	I will be using centrifugal fans for the air cooling of the lights, i just got my TLC-direct catalogue dripped through the door, lol, u know, they guy at the grfow shop wanted to sell me a 6 inch centrifugal inline fan second hand for 80 quid, in this cataloogue, thats the price brand new, and i can get just abkoiut everything for a grow fro this cataloogue a lot cheaper. For the cables connecting the hoods to the ballasts, i was thinking of using a plastic curtain rail alongside each lightrail with the cable, and the flexi-duct from the hoods, attached with those little plastic curtain hooks, thus allowing me to have just the right amount of slack, wiothout the leads and ducting being daragged back and forth atop the plants getting snagged, or trailing on the deck. __________________ Clowns to the left of me, jokers to the right, and none of these people are very funny.
	Quote

12-19-2004, 08:43 PM	#10
badmf Serving great bud since 65'! Join Date: Oct 2004 Location: Surface of a strange planet Posts: 908	Sounds good! The tricky thing is to add enough flex-duct and not too much! I have sections that can be removed when it(the hood) gets highe. Do a dry run for a while to be certain of all connections and efficiency of the hose lengths. Most of us get fooled by cfms when deciding on fans. The cfms being equal we think the cheaper fan is the same, ahhh, but its not! The power or static pressure is what determines the force the air moves. The one with a higher force will remove more heat, although you are not in my neck of the woods, check out the time it takes to fill a large trash bag and compare if possible before buying. Brands with good pressure are Elicent and Hurricane, other fans local to your area will need to be checked or someone can add this info!
	Quote