Home made cooltube - need fan assistance

[the_panther]

Hi all!

 

This is one of my very first posts, so please correct me if i get anything wrong!

 

Now, I'm building up a little concealed greenhouse and i need a little help when it comes to the venting side of it.

 

Firstly, Should the intake pressure be higher than the exhaust vacuum, or vice versa? ie, should the fan PUSH cold air onto the light and out the other side, OR should the exhaust PULL the hot air away???

EDIT: Found this bit, Negative pressure is the key here, PULL the heat away, not push the cold in.

 

Secondly, (prays to the gods of green someone knows this) a 250 HPS doesn't exacly generate huuuuuge amounts of heat, however would anyone have any idea the CF/M output i would require to sufficiently cool the unit. The intake air will be from a fairly cool source.

 

I don't really want to buy anything expensive and deeLux (defeats the purpose hey) but it has to be stealthy ninja quiet, and i guess if i guess if $$ is whats needed..

 

I also have access to a fair few computer fans, could staggering a few of those through the ducting assist this endevour, or wouldn't it be worth it?

 

 

Much love all, & thanks for reading!

 

 

PS, when creating a post and 'Similar topics' comes up, AWESOME!!! Good work, hella usefull!

Edited May 14, 2011 by the_panther

[pot.head]

http://cannaversity.com/calculators/lighting.php

 

type your room size in here and will tell you the right lighting and ventilation needed

[the_panther]

http://cannaversity.com/calculators/lighting.php

 

type your room size in here and will tell you the right lighting and ventilation needed

 

Fantastic! I had a good look at that and i can see much use in the future!

Kudos to the creator!

 

However that is for general ventilation, where as this would be more, ummmm, light heat extraction only. Im having a really hard time trawling the interwebs for any relevant info, it may just be a mix and match kind of thing.

 

But if anyone has maguivered up a cooltube, please feel free to post your experiences re light wattage, fan size/flow rate & basic temps.

 

I know thats asking heaps, but if anyone could spare the time, thatd be awesome!

 

Thanks,

[The Hash Nibbler]

Heya Panther =) , Just rigged up a 600w Hps in a 125mm cooltube, open one end in the tent and other end having air pulled out of tent by a 150mm 25w computer style fan, works a treat, tent is running 6 degrees above ambient air temps, BUT, it's winter. in summer I might need to upgrade to at least a bigger wattage motor that moves more air.

So for a 250w , you would be pretty safe using a good computer fan just to cool the cooltube. Peace. gh72

[the_panther]

Heya Panther =) , Just rigged up a 600w Hps in a 125mm cooltube, open one end in the tent and other end having air pulled out of tent by a 150mm 25w computer style fan, works a treat, tent is running 6 degrees above ambient air temps, BUT, it's winter. in summer I might need to upgrade to at least a bigger wattage motor that moves more air.

So for a 250w , you would be pretty safe using a good computer fan just to cool the cooltube. Peace. gh72

 

Grasshopper, you provided precisely what I needed to know, thankyou!!!!

Very detailed specs, which will make my project a heck of a lot easier.

Much love!!!

Panther

[The Hash Nibbler]

No Wukka's Man. Happy Building! Peace. gh72

[shanetomlong]

Heya Panther =) , Just rigged up a 600w Hps in a 125mm cooltube, open one end in the tent and other end having air pulled out of tent by a 150mm 25w computer style fan, works a treat, tent is running 6 degrees above ambient air temps, BUT, it's winter. in summer I might need to upgrade to at least a bigger wattage motor that moves more air.

So for a 250w , you would be pretty safe using a good computer fan just to cool the cooltube. Peace. gh72

 

Just got a 600w kit with hps and hm globes and a 150mm cooltube. Got a 200mm exhaust fan, ducting and a reducer so it fits to the cooltube. I've got it pulling the air out of the tent through the cooltube like you said. Will I need a fan to push air into the tent or just a fan inside the tent? Tent is 1.2 x 1.2 x 2.0m I've given it a dry run with the MH globe and temps got to almost 30 degree with no fan or air in from outside, just the exhaust. Will that be too hot? Any help is appreciated, I've never done this before.

[The Hash Nibbler]

Just got a 600w kit with hps and hm globes and a 150mm cooltube. Got a 200mm exhaust fan, ducting and a reducer so it fits to the cooltube. I've got it pulling the air out of the tent through the cooltube like you said. Will I need a fan to push air into the tent or just a fan inside the tent? Tent is 1.2 x 1.2 x 2.0m I've given it a dry run with the MH globe and temps got to almost 30 degree with no fan or air in from outside, just the exhaust. Will that be too hot? Any help is appreciated, I've never done this before.

 

Heya shanetomlong =) , Good onya, ya on ya way to a good grow area. You will definately need a Oscilating fan inside the tent, really need air to flow around.

Mate if you have vents on the bottom of the tent, they will suck air in as the air is drawn from the top.

 

But, if you do have the extra $ and a ready made fan inlet hole on the bottom, spend $80-90 on a decent 125-150mm inline fan as well and use this to push cool air into the tent. with both fans running and the oscilationg fan inside, you should be apples. Keep the vents on the bottom of the tent as they are, don't seal em up, so you have extra air if needed, or if the fan fails/gets unplugged.

Here's a good tip, put some duct on the intake fan and duct it to the back of the oscilating fan inside your tent, that way cool fresh air gets to the whole tent.

 

Hope that helps, If you want some more info........

https://cannabis.community.forums.ozstoners.com/topic/32644-so-ya-bought-yaself-a-tent/page__view__findpost__p__297746

The fan setup/positioning may be slightly different, but this is my actual tutorial I did. laters.

. Happy Growing. Gh72

Edited September 26, 2011 by Grasshopper72

[shanetomlong]

Heya shanetomlong =) , Good onya, ya on ya way to a good grow area. You will definately need a Oscilating fan inside the tent, really need air to flow around.

Mate if you have vents on the bottom of the tent, they will suck air in as the air is drawn from the top.

 

But, if you do have the extra $ and a ready made fan inlet hole on the bottom, spend $80-90 on a decent 125-150mm inline fan as well and use this to push cool air into the tent. with both fans running and the oscilationg fan inside, you should be apples. Keep the vents on the bottom of the tent as they are, don't seal em up, so you have extra air if needed, or if the fan fails/gets unplugged.

Here's a good tip, put some duct on the intake fan and duct it to the back of the oscilating fan inside your tent, that way cool fresh air gets to the whole tent.

 

Hope that helps, If you want some more info........

https://cannabis.community.forums.ozstoners.com/topic/32644-so-ya-bought-yaself-a-tent/page__view__findpost__p__297746

The fan setup/positioning may be slightly different, but this is my actual tutorial I did. laters.

. Happy Growing. Gh72

 

Thank you Grasshopper for ya quick response. It does have a vent at the bottom Your tutorial was also very helpful. I'm still in the process of setting up feeding, ect so will most likely need more assistance. Thank you again for your assistance and I'll reply here when I need help!

[The Hash Nibbler]

Not a problem man. Get it all set up good before ya get ya plants in and you'll be laughing. Peace. Gh72