Cool Tube with only exhaust..is it worth it?

[CannabisSativa]

If I decide to install a cool tube with an exhaust only and no cool air coming in, will it still lower the temperatures dramatically? My room runs at a constant 78 degrees with the closet door open, but raises the temps about 10 - 15 degrees once i close it. I would love to lower my temps to about 10 - 15 degrees with the closet door closed, so I hope this can help. I cannot get any type of cold-ac routed for the cool tube intake, I wish I had a means to do that. Also, I see that a lof of cool tubes have a crappy reflectors, can other reflectors be retrofitted or modified to fit these? Thanks.

 

[DeezyH]

Do you have any kind of intake into the closet (even a passive will work)? If not, a cool tube will do nothing for you.

You can have one end of the cool tube open and the other with a fan venting for exhaust, but you will still need some sort of intake into the closet. If the closet is sealed when the door is shut, all an exhaust fan will do is try to make a vacuum and do nothing basically.

 

[FreezerBoy]

you will still need some sort of intake into the closet. If the closet is sealed when the door is shut, all an exhaust fan will do is try to make a vacuum and do nothing basically.

Bingo.

No intake means no exchange means no cooling.

 

[CannabisSativa]

Do you have any kind of intake into the closet (even a passive will work)? If not, a cool tube will do nothing for you.

You can have one end of the cool tube open and the other with a fan venting for exhaust, but you will still need some sort of intake into the closet. If the closet is sealed when the door is shut, all an exhaust fan will do is try to make a vacuum and do nothing basically.

Hmm, so even if I leave the door cracked it wont be as efficient? I plan to keep the door cracked open about 1 - 1.5 inches, that way it can get plenty of fresh air and keep it cool.

 

[charlesweedmore]

i have 1 intake and 1 exhaust .cooltube works for me .

 

[DeezyH]

Hmm, so even if I leave the door cracked it wont be as efficient? I plan to keep the door cracked open about 1 - 1.5 inches, that way it can get plenty of fresh air and keep it cool.

You can try, but I wouldn't count on it working to well. Maybe if you put a small fan near the bottom of the door to draw in cool air, and then route the exhausted cool tube air up near the top of the door. That way you can at least get some fresh cool air in to replace the warm spent air from the cool tube.

Is there any reason why you can't put a hole in the wall for proper ventilation?

You may want to lose the cool tube all together and just go with a vented hood. Ideally you would have an exhaust near the top of the cab pulling through a carbon filter and at least one good sized passive intake near the bottom. With a decent fan blowing between the plants and the lamp you should be gtg.

 

[Vegan]

Hmm, so even if I leave the door cracked it wont be as efficient? I plan to keep the door cracked open about 1 - 1.5 inches, that way it can get plenty of fresh air and keep it cool.

thats xactly what I do and works fine for me

 

[CannabisSativa]

thats xactly what I do and works fine for me

Do you mean that you have a cool tube with an exhaust only and the door cracked? If so, how many degrees did you see it drop by?

My last grow I just left my closet door open with a small exhaust in the room and I got a very nice harvest. I just want to leave the door cracked a bit this time and not leave it fully open.

Is there any reason why you can't put a hole in the wall for proper ventilation?

You may want to lose the cool tube all together and just go with a vented hood. Ideally you would have an exhaust near the top of the cab pulling through a carbon filter and at least one good sized passive intake near the bottom. With a decent fan blowing between the plants and the lamp you should be gtg.

Well I do have a hole for exhaust since I was using a simple extractor for my last grow. I am thinking of making another hole that leads into another room to draw fresh air in via ducting and leave the closet door cracked a bit. I have so many options and I have until july to decide what to do.

 

[DiscoBiscuit]

How big is yer bulb? A fan blowing between/across the bare bulb and the canopy will probably work better than a tube w/o intake and/or exhaust.

If you go tube, you can hang a bat wing over it. Will improve the footprint better than a cool tube reflector.

 

[CannabisSativa]

Using a 400 w MH/HPS