Advice for venting a DR120.. 4x4x7

Hey Guys,

I ordered a DR120 that's coming at the end of the week and wanted to get your input on my venting plans. My area is 4x4x7 and I will be using one 600W HPS.

For my 600w HPS:
duct-hood-duct-fan-exhaust

For the tent:
duct-fan-exhaust

My question is:
1) If i am using minimal ducting (less than 2 feet) for the hood, do you think a booster fan would be enough to move the heat?

2) since the ventilation will be separate, will a 4" can-fan be strong enough to ventilate the tent itself? I may be adding a small diy carbon scrubber after a couple weeks of flowering.

3) OR should i use a closed system for venting and get a 6" can-fan?
filter-duct-hood-duct-fan-exhaust

I am more concerned about the sound than smell or anything.

Thanks RIU! I would be so lost without you !!

soooo noooo one has any idea??

I use 2 can fans on my dr120 one intake one out both 400 cfm and I run a 600 watt hps

I used to use the same tent with a 3x3 ebb and flow tray. Here's a pic of my setup.

it took some searching but i found an old post where i attached a diagram of my setup

fisk - do you think the intake fan is really necessary? i hear a lot of people say the intake should be passive and i've always used that too, any reason other than more air circulation?

noman - thanks for the diagram!! that's exactly what my setup will look like.. is your 184cfm fan enough to move air efficiently through your 200cfm filter? i plan on rigging up on diy one.. but i'm not sure what diy carbon filters would be rated cfm-wise.. i went to look at a 6" can fan today and it indeed sounded like a 747 taking off. i need to use a 4" if possible!!!

Sorry I didn't really look close at the setup. After I dialed it in I changed it up some and had better results. I used the 184cfm fan for the intake and a 240cfm up top as my exhaust. It kept everything cooler since more air was being pulled through my light and kept humidity down.

here's an old post from when I swapped fans: https://www.rollitup.org/general-marijuana-growing/147355-best-fan-ever-extremely-quiet.html

I just set up a small 32x32x60 tent with a 400w hps cooltub and use 2 4" vortex fans, one for intake, one for exhaust. I can control my temps easily with variable fan controls. My tent is inside a large closet and no noise with the doors closed. Both my fans are ducted from/to the outside of a crawlspace.

thanks for the input i will probably get a small intake fan on whatever budget i have left

nomaninsf said:

Sorry I didn't really look close at the setup. After I dialed it in I changed it up some and had better results. I used the 184cfm fan for the intake and a 240cfm up top as my exhaust. It kept everything cooler since more air was being pulled through my light and kept humidity down.

here's an old post from when I swapped fans: https://www.rollitup.org/general-marijuana-growing/147355-best-fan-ever-extremely-quiet.html

Click to expand...

hey oldreefer, do you have a filter running in there? i was curious if a 4" fan is strong enough to pull through one (a small diy one).

Oldreefer said:

I just set up a small 32x32x60 tent with a 400w hps cooltub and use 2 4" vortex fans, one for intake, one for exhaust. I can control my temps easily with variable fan controls. My tent is inside a large closet and no noise with the doors closed. Both my fans are ducted from/to the outside of a crawlspace.

Click to expand...

Check out the 1st page in my signature there is a pic of my setup... 110CFM axial fan providing fresh air when light is on it turns off when light does ~190 CFM running at 3/4 speed with a 400W HPS in a 3'x3'x6' tent

If you need a small powerful fan I would go with a 4" can fan HO version. I think HO is for High Output. They're quieter than the vortex and move more air. They're not too loud when hooked up to ducting. Ducting will knock down fan sound a lot but will also reduce the strength of the air current the longer it gets.

Avoid using dimmers on fans and blowers. Look for a fan that is the perfect cfm while maxed out for your environment. When you dim a fan it creates a humming sound that may raise curiosity if you have close neighbors.

edit: just saw Weedler's post. the dimmer pictured on his first page is the one i used. avoid using them and avoid the buzz. the reason for the buzz is because a fan's motor is designed to run at a specific Hz, 60 Hz i think. when you dim that it's not running at the cycle it's designed for and it buzzes or hums. the same thing happens with lights in a living room on a dimmer.

calidankkk said:

hey oldreefer, do you have a filter running in there? i was curious if a 4" fan is strong enough to pull through one (a small diy one).

Click to expand...

Yes, I have a 4" charcoal cannister that I bought matched with a 4" vortex which works very well. I am able to turn the controls down to a low setting and still move plenty of air....the exhaust setup is: c.can-duct-400w hps cool tube-duct-fan.....the fan is actually located outside of the tent.....intake fan is also outside the tent and ducted into a bottom vent. I've been very happy with my temps AND the stealth it allows...............I purchased the fan and cannister combo off amazon.....
I do use fan controllers and have NO buzz whatsoever......

I have the Jardin 120 4' x 4' and my temp stays no higher than 80 with a 600W HPS. Like the OP, for the cooled hood, I went:

vent > duct > REFLECTOR > duct > 6" 160 CFM inline booster > Vent.

This is plenty of air to cool the bulb. I have my 600W HPS 12" from canopy and no heat issues with plants. For my exhaust I went:

6" C.A.P. Active carbon scrubber > duct > C.A.P. 6: 450 cfm Vortex > duct > vent

I use a passive intake, a 6" drop ceiling louver vent attached to a short run of duct. The tent has neg pressure and you can see the sides of the tent gently pushed in. If you open the side, you can't smell the plants because of the negative pressure. The fan is attached to a variable speed controller, and I only use about half speed.

calidankkk said:

fisk - do you think the intake fan is really necessary? i hear a lot of people say the intake should be passive and i've always used that too, any reason other than more air circulation?

noman - thanks for the diagram!! that's exactly what my setup will look like.. is your 184cfm fan enough to move air efficiently through your 200cfm filter? i plan on rigging up on diy one.. but i'm not sure what diy carbon filters would be rated cfm-wise.. i went to look at a 6" can fan today and it indeed sounded like a 747 taking off. i need to use a 4" if possible!!!

Click to expand...

I like using an intake fan I find my tents stay much cooler then they did when I used only an out take fan my dr120 stays about 2-4 degrees warmer with both fans then the temp of the room where before they with just one they where about 10 degrees warmer
the 2 fan system causes more air pressure in the tent cuasing it push the warm air up and out better

hey guys thanks for all your help, i ended up going with this:



i have it as intake-duct-hood-duct-4"HO can fan-exhaust. my ballast is the 600w quantum one and is dimmable, luckily it is extremely quiet! i also have a oscillating fan in there and right now with the light output set at 75% (for the first few days), the temps stay at 82.
i live in san diego, which for some reason has been fucking 85 degrees for the last week. i have my 12/12 light cycle set that so the light is on during the day, maybe i should flip the cycle so there's more cool air being drawn in at night when the light is on? anyone have particular times they prefer?

when i add a filter i'll try to run it like old reefer suggested. if the 4" isn't enough cfm i will vent that separately. also will be adding a small intake fan, thanks fisk..