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Air cooled reflector testing with Digital footcandle meter
- Thread starter pico
- Start date
I HAVE FOUND A FLAW IN THE EXPERIMENTAL DESIGN OF THE HOOD COMPARISONS.
Ok, not a big flaw but I have some important input about what u are measuring. If this has been brought up a lot forgive me, there are an enormous number of replies here now. Also thanks for measuring this stuff, its great data, especially the graphed pictures.
Its something like this, whenever u test for something you have to be careful the question u ask. You are asking a question about who has the largest footprint at 4x4. And I think u have a way of measuring that pretty good. But if your question is what hood grows the most, best weed, then maybe there are different answers.
My exerience was that we measured radiants against daystars. The radiants were much better at footprint for 4x4. Yet sometimes we had heat burn under light. which traumatized product. Then we experimented with daystars and cool tubes. Immediately we dropped 5 degrees, This is with lens covers and insulated duct. The daysstars and cool tubes allowed much cooler temps. Furthermore, these hoods allow us to make a H shaped grow. A coliseum shape. Shorter plants in middle, taller on edges. Indicas in middle, OG along side in trellis. The daystar throws more light out at higher angles.
I did think there was alot of difference between hoods, but on further thought, the bulb is transparent so most light goes back thru bulb and back out. I think that a lot of the difference is light going off at angles to the hood. For instance the radiant light sits further in the hoods so light goes unifomlay down at maybe a 45 degree angle between down and sideways which is about a 90 degrees total footprint. The daystar light is maybe 25 degrees of sideways (or right angle to bottom of hood). That’s a total of 40 degrees on each side that the footprint is wider than radiant for a total of 140 degrees footprint. So thee would be a larger footprintwith daystar by perhaps 15% (my quick estimation). Now most of you might not be using this if u do not have canopy shaped grow, or if you do not grow next to another table.
the daystar has smaller distance to reflector so I think a smaller hood should reflect more light out AND be easier to cool. and use and manipulate.
I think that 2 similarly shaped hood must have about the same reflectivity as the aluminum is about the same. Maybe the one with less numbers are losing alot of the extra light out the side between 45 and 25 degreees. Of course there are some differences between hoods, but just cos one has lower avg number does not mean it reflects less.
The slightly better footprint of radiant in your survey, say 10% might be negated by temp difference. For instance the square footage of radiant HOOD and reflector surface is probably 2x or maybe even 3x. That surface heats up and can influence temperature by 11% to the negative.
The cool tube I am not sure how that fits in yet but it is even cooler. If you have 4 lights in cool tubes vs radiant AND heat is an issue I bet the cool tubes could really benefit you. Temperature and heat is the enemy as much as light is your friend.
To use an analogy with cars your measurements are like saying how many seconds to 60 mph. That says a lot, but so does braking, handling, roll protection and many other measurements.
Do this thought experiment. Say you have 2 hoods, a big one like radiant and a small one like cool tube. Lets say 1/2 the light goes directly down and is not reflected, this can add up to 1000 units (fc or par or lumens). The other 1/2 that is reflected we can imagine its path. Remember that light intensity falls at the rate 1/distance squared. This is say 1000 also. In 6 inch cooltube it travels a uniform 3 inches, is reflected and out the bottom of light with only 6 inched refected distance. The radiant light travels 4 to 10 inches before hitting reflector then bouncing down. Lets say average distance by the time light leaves lens in 12 inches. Without getting too algebraic that means the cooltube reflects more light than radiant. Total radiant light 1000+500 (reflected) =1500. Total Cool Tube light is 1000 +750 = 1750. So I think smaller hoods THEORETICALLY release more light. The bulb is mostly invisible except for filament itself and few metal parts.
The reason cool tubes do poorly is that the light angle is 0 degrees or right angle to hood. The hood provides a 180 degree footprint (maybe even 200 degrees.) This light needs to literally sit in the top of the canopy for your plants to catch all the light. Thats not easy to do, buts it all pretty uniform light.
An easy additional set of measurements include angle of footprint on sides and intensity there. Also temp of hood. Also cubic feet of metal surface of hood, lens and hood.
I applaud all the effort and think this is a real interesting thread. I hope that my input will help some of you, for instance those who are having heat issues or those who grow in a coliseum pattern might opt for smaller hood and those with massive fans or little heat issues can get bigger hoods.
Ok, not a big flaw but I have some important input about what u are measuring. If this has been brought up a lot forgive me, there are an enormous number of replies here now. Also thanks for measuring this stuff, its great data, especially the graphed pictures.
Its something like this, whenever u test for something you have to be careful the question u ask. You are asking a question about who has the largest footprint at 4x4. And I think u have a way of measuring that pretty good. But if your question is what hood grows the most, best weed, then maybe there are different answers.
My exerience was that we measured radiants against daystars. The radiants were much better at footprint for 4x4. Yet sometimes we had heat burn under light. which traumatized product. Then we experimented with daystars and cool tubes. Immediately we dropped 5 degrees, This is with lens covers and insulated duct. The daysstars and cool tubes allowed much cooler temps. Furthermore, these hoods allow us to make a H shaped grow. A coliseum shape. Shorter plants in middle, taller on edges. Indicas in middle, OG along side in trellis. The daystar throws more light out at higher angles.
I did think there was alot of difference between hoods, but on further thought, the bulb is transparent so most light goes back thru bulb and back out. I think that a lot of the difference is light going off at angles to the hood. For instance the radiant light sits further in the hoods so light goes unifomlay down at maybe a 45 degree angle between down and sideways which is about a 90 degrees total footprint. The daystar light is maybe 25 degrees of sideways (or right angle to bottom of hood). That’s a total of 40 degrees on each side that the footprint is wider than radiant for a total of 140 degrees footprint. So thee would be a larger footprintwith daystar by perhaps 15% (my quick estimation). Now most of you might not be using this if u do not have canopy shaped grow, or if you do not grow next to another table.
the daystar has smaller distance to reflector so I think a smaller hood should reflect more light out AND be easier to cool. and use and manipulate.
I think that 2 similarly shaped hood must have about the same reflectivity as the aluminum is about the same. Maybe the one with less numbers are losing alot of the extra light out the side between 45 and 25 degreees. Of course there are some differences between hoods, but just cos one has lower avg number does not mean it reflects less.
The slightly better footprint of radiant in your survey, say 10% might be negated by temp difference. For instance the square footage of radiant HOOD and reflector surface is probably 2x or maybe even 3x. That surface heats up and can influence temperature by 11% to the negative.
The cool tube I am not sure how that fits in yet but it is even cooler. If you have 4 lights in cool tubes vs radiant AND heat is an issue I bet the cool tubes could really benefit you. Temperature and heat is the enemy as much as light is your friend.
To use an analogy with cars your measurements are like saying how many seconds to 60 mph. That says a lot, but so does braking, handling, roll protection and many other measurements.
Do this thought experiment. Say you have 2 hoods, a big one like radiant and a small one like cool tube. Lets say 1/2 the light goes directly down and is not reflected, this can add up to 1000 units (fc or par or lumens). The other 1/2 that is reflected we can imagine its path. Remember that light intensity falls at the rate 1/distance squared. This is say 1000 also. In 6 inch cooltube it travels a uniform 3 inches, is reflected and out the bottom of light with only 6 inched refected distance. The radiant light travels 4 to 10 inches before hitting reflector then bouncing down. Lets say average distance by the time light leaves lens in 12 inches. Without getting too algebraic that means the cooltube reflects more light than radiant. Total radiant light 1000+500 (reflected) =1500. Total Cool Tube light is 1000 +750 = 1750. So I think smaller hoods THEORETICALLY release more light. The bulb is mostly invisible except for filament itself and few metal parts.
The reason cool tubes do poorly is that the light angle is 0 degrees or right angle to hood. The hood provides a 180 degree footprint (maybe even 200 degrees.) This light needs to literally sit in the top of the canopy for your plants to catch all the light. Thats not easy to do, buts it all pretty uniform light.
An easy additional set of measurements include angle of footprint on sides and intensity there. Also temp of hood. Also cubic feet of metal surface of hood, lens and hood.
I applaud all the effort and think this is a real interesting thread. I hope that my input will help some of you, for instance those who are having heat issues or those who grow in a coliseum pattern might opt for smaller hood and those with massive fans or little heat issues can get bigger hoods.
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did pico ever measure how much of a decrease in light happens when you put a glass lens onto a reflector vs. when its off? If not, i have some daystars and a light meter jus sittin around.
Also, can wind decrease lumens? This sounds so dumb i cant beleive im even asking it, but i just wanted other input.
I just wanna see if theres a differece in light output when a hood is being cooled vs when it not. And if there is a difference, does the temp and speed of the air cooling the lights play a role?
Has anyone tested how much of a light decrease there is when comparing the same hood design but one has aircool ports, and the other is completley enclosed? I.E. a regular enclosed daystar vs. a daystar a/c....?
Also, can wind decrease lumens? This sounds so dumb i cant beleive im even asking it, but i just wanted other input.
I just wanna see if theres a differece in light output when a hood is being cooled vs when it not. And if there is a difference, does the temp and speed of the air cooling the lights play a role?
Has anyone tested how much of a light decrease there is when comparing the same hood design but one has aircool ports, and the other is completley enclosed? I.E. a regular enclosed daystar vs. a daystar a/c....?
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^^^^ The accepted figure is 2% loss due to glass.
knna
Member
Who accepted that?
I though that glasses without chemical treatments block a minimun of 4% at each side of the glass, for about 8% total. And that for a high quality glass (very low iron content) and very clean.
Well i just picked up a super sun 2 and i got some daystar a/c's also, so i can check so that we have a second opinion.. How were u going about doing ur tests pico..? How do i measure it properly..?
ok ill get around to it when i get some free time.
Dr. Doesha
New member
Anybody try these 2 hoods Magnum XXXL 6" Air-Cooled Reflector or Great White® 6" Air-Cooled Reflector Largest reflector in the industry at 32 1/2" long x 26 1/4" wide x 7 3/4" tall.. They are new to the game. I was thinking about suggesting 2x 1000W for a 4'x8' but don't want to until someone trys them out to verify they don't have the flaws of the mondo hood. Thanks
Dr.
Dr.
Magnum XXXL seems to have a decent design. 6" vents with angled sidewalls and spectral aluminum all around. Same thing that makes the SS2 put out such great numbers. However, the thing is huge. What is the story there? I have a feeling it is marketing hype.
I want the smallest reflector on the market, not the biggest. I have to move these fuckers around. Unless the bigger one out performs the smaller one by a lot, I like the little ss2.
No data on those units, so I can't say if they are good. Seem to be more expensive than the SS2 as well.
I want the smallest reflector on the market, not the biggest. I have to move these fuckers around. Unless the bigger one out performs the smaller one by a lot, I like the little ss2.
No data on those units, so I can't say if they are good. Seem to be more expensive than the SS2 as well.
G
Guest
Sunlight Supply Magnums
Sunlight Supply Magnums
I spoke with a tech @ Sunlight Supply concerning the XXXL Magnums, by the way they're making a 8" XXXL Magnum with almost the exact dimensions of the 6".
I was told the Magnum's are geared for 1000 watt bulbs and will outdo the SS2 in a large 4' x 4' or larger area, not to mention with the SS2 (I own 1 & luv it!) it has to be at least 24" or higher from the canopy to get close to spreading enough light for a 4'x4' area, to where i hear the Mag can be like 15-18" over the canopy keeping lumens intense. The other thing i noticed too about the magnums is the light bulb socket / junction box is more out in the opening of the reflector opposed to being inside the port of the hood which i would imagine improves airflow & cooling.
Sunlight Supply Magnums
I spoke with a tech @ Sunlight Supply concerning the XXXL Magnums, by the way they're making a 8" XXXL Magnum with almost the exact dimensions of the 6".
I was told the Magnum's are geared for 1000 watt bulbs and will outdo the SS2 in a large 4' x 4' or larger area, not to mention with the SS2 (I own 1 & luv it!) it has to be at least 24" or higher from the canopy to get close to spreading enough light for a 4'x4' area, to where i hear the Mag can be like 15-18" over the canopy keeping lumens intense. The other thing i noticed too about the magnums is the light bulb socket / junction box is more out in the opening of the reflector opposed to being inside the port of the hood which i would imagine improves airflow & cooling.
bushdoctor215
Member
I just bought a new SS2 and a magnum xxxl 6". As soon as I pick up a decent light meter I`ll compare the 2.
G
Guest
El Koolzio
El Koolzio
being these two reflector dimensions are so drastically different, may i suggest maybe doin more than one footprint for this comparison..
just an idea but maybe try em at a square meter aka 3.25' x 3.25', 4'x4' and at 5'x5' to show the differences, cause the SS2 was built in mind w/the ability to be used in almost any application, to where of course the Magnum XXXL's are so big they'd only fit in a relatively large area nevertheless i am dying to see some results.
LBM
El Koolzio
being these two reflector dimensions are so drastically different, may i suggest maybe doin more than one footprint for this comparison..
just an idea but maybe try em at a square meter aka 3.25' x 3.25', 4'x4' and at 5'x5' to show the differences, cause the SS2 was built in mind w/the ability to be used in almost any application, to where of course the Magnum XXXL's are so big they'd only fit in a relatively large area nevertheless i am dying to see some results.
LBM
B
badugi
Thanks pico and darthvapor and others for this great informative thread! I chose the radiant 8 for my 1000w because of this thread.
That's interesting; what results about the Radiant 8 did you like?
D
dongle69
I noticed the Radiants seemed to have the best footprint...
I chose the SS2 because they were made better, though.
I chose the SS2 because they were made better, though.
