Cool tube also used as exhaust?

slinger36s

slinger36s

Well-Known Member
Whats up guys, Slinger here, first time using a cooltube reflector. My question is can I pull air out of the room through my cool tube while also cooling the light, thus removing the need for another exhaust point and using it as passive intake into the room?? I have a 220 CFM inline fan pulling air out of the room at the moment but my temps are running a little high (82-84F) as well as humidity at 35-40%. Currently have 3 plants in 7 gal containers, 1 week into 12/12. Any good info is much appreciated!

Room Specs
3x3x7ft Grow Tent
600w Cool Tube Reflector
440 CFM Can Fan (pulling air through the tube)
220CFM Inline Fan (exhaust)
 
SPLFreak808

SPLFreak808

Well-Known Member
I second that. Yes you can as long as it doesnt get hot. I can hold my hand all day on my 1000watt hood with a dedicated intake/exhaust though so sealed is much better.
 
malicifice

malicifice

Well-Known Member
You bet you can! I have a 4x4x8 with about that same size fan. It's pulling like this filter--1000watt cool tube--fan--outside. My temps are mid 70's with the lights on and mid 60's off. Humidity runs between 30 lights on to no higher then 50 lights out, depending on the weather but usually 40-50 percent. Cool the room the tent is in, open those vents at the bottom an exhaust the hot air out of both the tent and the room the tent is in.
 
O

orangesabc123

Member
slinger36s said:
What is not ideal about it? Thats kind of a general statement bro. Still appreciate the input :)
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Ideally you want to be running cool air over your lights, not warmer air from your grow room.

Also you get more fine-grain control of your bulb temps, room temps, humidity, co2 if you manage the grow rooms ventilation and the lightings ventilation separately.
 
SPLFreak808

SPLFreak808

Well-Known Member
slinger36s said:
What is not ideal about it? Thats kind of a general statement bro. Still appreciate the input :)
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You loose cooling efficiency
The hotter the exhaust temps the less air "cfm" can fit resulting in less air exchange per minuit.
The air getting sucked into the hood is the same temp as the room itself so it becomes a chain reaction if heat.
 
slinger36s

slinger36s

Well-Known Member
malicifice said:
You bet you can! I have a 4x4x8 with about that same size fan. It's pulling like this filter--1000watt cool tube--fan--outside. My temps are mid 70's with the lights on and mid 60's off. Humidity runs between 30 lights on to no higher then 50 lights out, depending on the weather but usually 40-50 percent. Cool the room the tent is in, open those vents at the bottom an exhaust the hot air out of both the tent and the room the tent is in.
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Thanks man, I forgot to put in that I exhaust strait out of the window so no hot air is being exhausted out into the room the tent is in. Also keep the bottom vents open and have a 10in fan blowing air across the top of the plants. I keep my apartment around 65-70 degrees year round. Will remove the intake ducting connected to the cool tube tonight and see what happens!
 
slinger36s

slinger36s

Well-Known Member
SPLFreak808 said:
You loose cooling efficiency
The hotter the exhaust temps the less air "cfm" can fit resulting in less air exchange per minuit.
The air getting sucked into the hood is the same temp as the room itself so it becomes a chain reaction if heat.
Click to expand...

That was my thoughts but I wanted to get second opinions, maybe ill just keep the temps lower in the apartment, still wanna test it out to see what happens, but your right, the light is what is making the heat, so blowing air the light has already warmed up across the bulb is just counter productive.
 
sworth

sworth

Well-Known Member
I've done this. Had plenty of temperature problems though, but managed to muddle along.
Strange...I was just checking out my hydro site for cool tubes, and it didn't cross my mind to run the carbon scrubber through the cool tubes again.
 
SPLFreak808

SPLFreak808

Well-Known Member
slinger36s said:
That was my thoughts but I wanted to get second opinions, maybe ill just keep the temps lower in the apartment, still wanna test it out to see what happens, but your right, the light is what is making the heat, so blowing air the light has already warmed up across the bulb is just counter productive.
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Yeah im actually running my 1000 without the intake hooked up because my fan slurped up something from outside! Waiting on replacement fan duct so i have the intake open. Temps are about 82-85f vs 76-80f
 
slinger36s

slinger36s

Well-Known Member
SPLFreak808 said:
Yeah im actually running my 1000 without the intake hooked up because my fan slurped up something from outside! Waiting on replacement fan duct so i have the intake open. Temps are about 82-85f vs 76-80f
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Maybe it's a miracle but my temps dropped from 82 to 77 and humidity from 45 to 38, makes me think I just needed more than 220 cfm as exhaust from the tent. Best of luck man!
 
SPLFreak808

SPLFreak808

Well-Known Member
slinger36s said:
Maybe it's a miracle but my temps dropped from 82 to 77 and humidity from 45 to 38, makes me think I just needed more than 220 cfm as exhaust from the tent. Best of luck man!
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im getting my air directly from outside. beats cooling the bulb with grow room air lol. im doing it backwards. im venting into my house and pulling from outside. only way to do it here without a/c. 70f is a cold day.
 
slinger36s

slinger36s

Well-Known Member
Yeah its starting to warm up here in Denver, but its not too bad, 70's right now, glad I dont have to deal with the heat in other parts of the country. Lived in Oakland, NYC, San Fran, Atlanta etc, this weather is perfect.
 
weedenhanced

weedenhanced

Well-Known Member
slinger36s said:
Whats up guys, Slinger here, first time using a cooltube reflector. My question is can I pull air out of the room through my cool tube while also cooling the light, thus removing the need for another exhaust point and using it as passive intake into the room?? I have a 220 CFM inline fan pulling air out of the room at the moment but my temps are running a little high (82-84F) as well as humidity at 35-40%. Currently have 3 plants in 7 gal containers, 1 week into 12/12. Any good info is much appreciated!

Room Specs
3x3x7ft Grow Tent
600w Cool Tube Reflector
440 CFM Can Fan (pulling air through the tube)
220CFM Inline Fan (exhaust)
Click to expand...
I go filter duct cooltube duct out of rom
 
Red1966

Red1966

Well-Known Member
slinger36s said:
Whats up guys, Slinger here, first time using a cooltube reflector. My question is can I pull air out of the room through my cool tube while also cooling the light, thus removing the need for another exhaust point and using it as passive intake into the room?? I have a 220 CFM inline fan pulling air out of the room at the moment but my temps are running a little high (82-84F) as well as humidity at 35-40%. Currently have 3 plants in 7 gal containers, 1 week into 12/12. Any good info is much appreciated!

Room Specs
3x3x7ft Grow Tent
600w Cool Tube Reflector
440 CFM Can Fan (pulling air through the tube)
220CFM Inline Fan (exhaust)
Click to expand...
I think the majority of growers do this : .....Filter>cooltube(or hood)>fan> exhaust.
 
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