Cooltube Vs Easycool Vs Eurocool Reflectors .. And the winner is...

7th1der

Well-Known Member
Thanks for the information! I actually bought 2 of the bake-a-round pyrex tubes off ebay last summer. I was about to use them on my next grow. I'm in the middle of planning that, and you just saved me some light! I think I will quit sucking through my hood, and get rid of it. I have a 24" carbon scrubber, 400w light hood, 6' of 8" insulated ducting, and a 500 CFM fan, with temps at 85F!

Damn dude, all that and you still have temps in the mid 80's?
 

Hairy Bob

Well-Known Member
Just thought i'd throw this out there..

" 8% is a minimum light loss through glass transmission, but thats for aircooled hoods Not cooltubes. Only with perfectly clean and flat glass. As soon as the glass gets dusty (happens within a few weeks) then you start to lose even more 10-15% + the longer you forget to clean it the worse it gets. Most people clean their glass once a grow tops, and some don't even do that. By the time they hit flowering they're losing upwards of 10-15%

Cooltubes are even worse. Much worse. Especially ones that incorporate a reflector on the outside of the cooltube. Because not only is your light transferring through curved glass which further reduces light transmisson over flat glass, frequently the 50% of your light it thats hitting the reflector has to transfer through the glass 3x... Any decent professionally built cool-tube will include the reflector on the inside of the glass, eliminating part of the problem. But I've seen many many DIY cooltubes with reflectors on the outside of the glass.
Major light loss, possibly upwards of even 20% Or god forbid, no reflector at all,in which case your looking at a loss of 30% or more."


If you think you need a cooltube, or your having problems with temps, you really just don't have enough ventilation. a 2:1 ratio of lighting wattage to ventilation CFM will keep temperatures a few degrees above intake without the use of aircooling. You can keep canopy temperatures the same with ample interior fans blowing directly on the bulb. Its a pretty common misconception that cooltubes and aircooled hoods improve yield by allowing you to get closer to the canopy. This is almost never the case. Sure the inverse square law holds its ground. But getting closer to the canopy means most of your light is concentrated on the tops directly underneath the bulb, overpowering them and wasting it. Possibly even bleaching them. Its much better to have your bulb slightly higher up and get a much larger footprint and even distribution across the entire canopy, rather than blasting the plants directly below the bulb.

The only time i'd reccomend using an aircooled hood (note: I would never recommend a cooltube because of the curved glass, unless you feel like paying for special reflectorized bulbs) is when the loud ventilation causes a major security concern and all options for quieting it have been exhausted. Aircooled hoods do allow you to run less fans. Other than that, save your dough you were planning on spending on that cooltube and spend it on better ventilation."
Thanks for that, very informative. Just one small point, and it's really just a niggle that I can't keep myself from pointing out, but if there is no reflector above a bulb, surely at least 50% of the light emitted from it is wasted? For a conventional horizontally mounted bulb of course.
Inconsequential of course, but I couldn't help myself...
 

justatoker

New Member
Thanks for that, very informative. Just one small point, and it's really just a niggle that I can't keep myself from pointing out, but if there is no reflector above a bulb, surely at least 50% of the light emitted from it is wasted? For a conventional horizontally mounted bulb of course.
Inconsequential of course, but I couldn't help myself...

they make certain cooltubes with an INTERNAL reflector as stated above.. Its more effecient, but still not as efficient as just using a normal reflector
 

Hairy Bob

Well-Known Member
Yes yes I know this, I was referring to this part:
"Or god forbid, no reflector at all,in which case your looking at a loss of 30% or more."
Without a reflector the light coming from the top half of the bulb would just be wasted.
As I said, completely inconsequential since only a fool or a vert grower would use an HPS without a reflector in the first place.
Don't mind me, I just can't keep my mouth shut (or my fingers still) sometimes! :weed:
 

justatoker

New Member
haha.. Oh I get it now.. yea, why the hell would someone not use a reflector at all.. Well, unless they have a fixxed light that they dont raise and lower that is VERY close to the ceiling of the cab etc.. And if the ceiling is painted white or lined w/ mylar etc you wouldnt really need a reflector in that case.. But only if it were fixxed to the ceiling or w/e

peace bro
 

Hairy Bob

Well-Known Member
haha.. Oh I get it now.. yea, why the hell would someone not use a reflector at all.. Well, unless they have a fixxed light that they dont raise and lower that is VERY close to the ceiling of the cab etc.. And if the ceiling is painted white or lined w/ mylar etc you wouldnt really need a reflector in that case.. But only if it were fixxed to the ceiling or w/e

peace bro
Lol good point, I never thought of that!
 

Jash1297

Well-Known Member
well I found the best way to cool a cab with a cool tube, right now I have an intake coming in from the top of the cab the has ducting connected to a vent out side the cab on the wall above it, with a booster 250 cfm fan inside the cab to push cool air openly in the cab. ( I leave the thermostat off and let the fan run my apt is small and the light helps heat it.) and I have a 250 cfm booster pulling air out of the cool tube out of the cab and a centrifugal fan thats connected to a filter pulling air and heat out of the cab. so far its worked for me, temps are around 75 with a high of 79 and a low of 69
 

justatoker

New Member
so ur saying its connected to an AC vent? What kind of "vent outside the cab on the wall" do you mean? Can u post a pic?

thx
 

Jash1297

Well-Known Member
Here is a pick. the ducting that you see at the top is pulling air into the cab through the air vent. on my thermistate I can turn the ac and heat off and just run the fan, the air coming out of that is enough to control temps in the cab, and If you want you could just run the ac in the summer.
 

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