Tutorial Ventilation 101

[Amstel Light]

Damn... a 360 CFM centrifugal fan and a 200 CFM filter. Really? This is just bringing me down, I thought I was so close to being ready to go.

You have a great way with words man..

you are closer to a REAL harvest more now than ever... it's all relative...
Good luck with your op sincerely

Mole

Hey Mole all the years lurking was always mifted or amused by your avatar now you have changed it.... what was thge story with the cross dressing one?

Hey Ya'll ! I just got my cab all put together. I got my 400 watt HPS and Metal Halide Conversion bulbs yesterday along with the Batwing reflector, but I scratched that one after I saw how small it was. Instead I built my own reflector out of Hvac pipe which is the full width and depth of the cab (3.6' X 19"). I lined it with some Reflectix that I had laying around from my Rubebrmaid Grow. I built the Cool tube out of a Bake A Round from Ebay and initially had it hooked up to the exhaust with that crappy slinky type of dryer hose but was loosing pressure and so instead I hooked it up using 2 X Hvac 90 degree elbows. I just put in the 400 Watt Metal Halide bulb and DAMN this is BIG and definately BRIGHT!! I had to wear sunglasses in there. The bulb just barely fit inside of the Cooltube. I hope that the tube can withstand the heat. Anyways, I closed the doors to see if I had any negative pressure in the cab and guess what ? I don't. The doors no longer suck shut.
I got some heat coming off of the Cooltube but for only like a foot. I am sure that once I get some negative pressure back in the cab that heat will subside somewhat. I really need some advice on how to get the negative pressure back into the cab? Any one, please. As some may remember from my last posting I have 12 X 1.5" passive intakes in the bottom of the mother cab. From there I have 2 X 1.5" intakes through the Mother cab shelf and up and into the flower cab. Today though I put 3 more intakes into the flower cab to see if that would help but there was no negative pressure to be had. And so I closed them back up with reflective tape. Any sugesstions would be greatly appreciated. PUFF PUFF!!!

Sorry for the crappy pics.
My cat loves the herb just as much as I do!!

Halo...
atip..




if you spred the post ......




like this ......people will read more of it...



red will answer causre of his dedication to thread he ....

started but some of us are weary of....


embarking on that kinda journey

 

[rasputin]

You have a great way with words man..

you are closer to a REAL harvest more now than ever... it's all relative...
Good luck with your op sincerely

Thanks Amstel!

Big ups to Red and Hoosiers for setting me straight and helping to understand ventilation.

 

[BlueHalo]

Thanks for the tip Amstel Light.

Just a quick update: I closed up a few holes and got my negative pressure back but now my DIY Bake A Round of a Cooltube has turned into a bake it yourself of a Cooltube. My temps are 111 a foot below the tube. I have alot of air going into the tube but too much heat. Got the S&P turned all the way up but no go. PUFF PUFF!!!

 

[DontBeEvil]

excellent post!



edit: it didn't need to be intelligent, I'm just stating its a good post, didn't try to up my posts, I'm finally able to post, so I'm posting.

 

[guest 77721]

This is like a shopvac with a tennis ball stuck in the hose. I think you'd be better off to just mount the light and run without the cooltube until you can get a bigger one that will let the air flow around it.

This is a good example of a cooltube made by BonsaiGrower
http://www.icmag.com/ic/showpost.php?p=893301&postcount=11

 

[tommyboi_420]

This is like a shopvac with a tennis ball stuck in the hose. I think you'd be better off to just mount the light and run without the cooltube until you can get a bigger one that will let the air flow around it.

^^^^ i dont know the size of your bakearound,but maybe this is a lil bigger???<<--->> http://www.save-on-crafts.com/glcycash10in.html hope this helps ya BlueHalo

 

[BlueHalo]

^^^^ i dont know the size of your bakearound,but maybe this is a lil bigger???<<--->> http://www.save-on-crafts.com/glcycash10in.html hope this helps ya BlueHalo

Thanks for the address tommyboi. The Bake A Round that I had was 4" but with 5" ducting which meant that I had to put a reducer on it. I think that this may have caused me a little bit of drag as well. I took out the
MH and put in the HPS and there was more airflow as the bulb was not quite as big but the temps still reached 117. I did away with the whole

system because I couldn't get the temps down immediately and so I had to put the girls to bed under a 150 Watt HPS while they flower. For my next grow I will definately get one of the 5" glass tubes you recommended and try to run cooltube MH and a HPS on each end of the cab. Thanks again for your help. PUFF PUFF!!!

 

[tommyboi_420]

your welcome BlueHalo good luck with your grow!!!

 

[1hitter]

Hey Red, Great thread I have learned alot from it. I have a 7" hole in the side of my cabinet with a blue furnace filter covering the hole while it dose give me a good air flow it does not block light very well any suggestions maybe something I could make myself ?



rasputin, I bought the same fan from Home Depot and did not think the airflow was all that good so I went to the maker of the fans website and read some more info on it and found out it is only 140cfm. The 250 cfm is the max the fan can do.

 

[rasputin]

Hey Red, Great thread I have learned alot from it. I have a 7" hole in the side of my cabinet with a blue furnace filter covering the hole while it dose give me a good air flow it does not block light very well any suggestions maybe something I could make myself ?



rasputin, I bought the same fan from Home Depot and did not think the airflow was all that good so I went to the maker of the fans website and read some more info on it and found out it is only 140cfm. The 250 cfm is the max the fan can do.

Thanks for that info, 1hitter! I've decided to place the duct fan in the v/c space hanging from the ceiling, circulating air. In the flowering space I'm going to go with a 6" fan, not sure which yet, likely S&P for the speed changes, and possible a DIY filter.

 

[nephilthim]

bumpedy bump

 

[retawgnob]

Appreciate the intell. I have a cab thats 4x2x4 and with a 6'' can fan and 3 x 2 3/4" holes for intake.
According to the chart, that is not enough; however there is no scrubber on the inside and the pressure seems to be at the proper level. Any advice or aspect i maybe overlooking?

 

[Dr420CloneX]

Excellent thread. Helped me out a lot. Got my temps killin over here . Fricken 97 day and 57 nights. Crazy. But yes. definitley a help on reading up on this. I think im going to make sure to get on running inlines and a vortex through my lights to get the heat out of the room.

 

[petemoss]

Excellent thread! Thanks for taking time to write this informative tutorial, red!
All cab/micro growers should read this. Ventilation is just physics and not a "black art".

 

[DIRT DIGGLER]

good job great....very informative.thanks

 

[pontiac]

Great effort

 

[smurfin'herb]

great thread

 

[Hundred Gram Oz]

Hey man I got a question, I'm building a cab 10Lx5Wx6H Foot, I'll have 3 600w hps in there. What foot per hour or m3 per hour extractor fan should I have in there to have good temp control? And what intake should I have

Much respect

HGOz

 

[jchesmore722]

hey Dr420, try putting your light on at night time when its cooler and make the darkperiod during the day when its warmer. It should balance out your temps a little bit. Since its colder at night it will keep the heat in check in your box and its warm during the daytime so this should help keep the plants from getting to cold.

You want to keep as small a gap in temperature as possible. It keeps plants from stretching and they will have tighter internodal spacing. Ive also heard it encourages more males if the day/night temps are too far apart.


sorry to rant, just my 2 cents.

 

[jchesmore722]

hey red, this is an awsome thread. props for putting this together.

btw, i was wondering if you think this would work well or if you had any suggestions or coments.

I was plannign on building a speaker grow box w/ a 150w HPS
i wanted to keep the light seperate from the plants with tempered glass and use a 200mm 100cfm pc fan to exaust the light. the grow room itself would be exuasted by (2) seperate 120mm pc fans with carbon scrubbers. these fans take the air from the grow room and suck it up through the carbon scrubbers into the lighting/electric housing. then it gets pulled past the bulb(cooling it) and out the 200mm fan.

the fans are set up in parallel and series if that makes any sense. (first two w/ scrubbers are parralel to each other but in series with the main exaust.)

sorry if i wasnt clear enough. maybee this diagram will help.

(air)--->Intake---> Grow room-----> Carbon Scrubber--> 120mm Fan--> HPS bulb---> 200mm fan