Ventilation

[johnbs8]

i have a 10x4x7 grow closet. i need to run ventilation. the room is air tight. ill be using a 1000w HPS with a hood that has a 6" tube for cooling. just curious on what and how i should do this. also money is tight so cheap cost is a factor. i was thinking for the HPS i could run a 6" duct booster fan that will run continuously while the light is on. they are rated at 160cfm. will this do for air exchange?

[Royal Smoke]

i have a 10x4x7 grow closet. i need to run ventilation. the room is air tight. ill be using a 1000w HPS with a hood that has a 6" tube for cooling. just curious on what and how i should do this. also money is tight so cheap cost is a factor. i was thinking for the HPS i could run a 6" duct booster fan that will run continuously while the light is on. they are rated at 160cfm. will this do for air exchange?

 

I don't think that's enough. Because the space is so small and you have a 1000 watt light.

 

I think I'd go minimum 250 cmf.....

 

Don't take my word for it though....

[knottwhole]

I agree with Royal Smoke on this. You want to do an air exchange every minute if possible. Sure, you can get away with less, but going with the larger fan won't set you back that much. Also, you say the room is airtight? You'll need a passive intake except when using CO2. And don't forget, your plants want fresh air around the clock, not just when the lights are on. Let the fan run.

[Royal Smoke]

Thanks knottwhole!

 

And to add to this just a bit.....

 

You're going to need two fans of this type, probably 3.

 

You say your closet is air tight, right?

 

 

You'll need your inline fan to exhaust the air cooled hood, which could also work to exhaust the room, if you're broke.... lol It'd be better to have a fan room exhaust too, but I know money's tight....

 

Plus, you need air coming into the room through another fan.....

 

If money's a huge issue. Use the one to exhaust the hood first. Then add the one to bring fresh air into the room, and lastly one to exhaust the closet room air....

 

While you're waiting on the funds for the fan to exhaust the room, just keep the door cracked when you can...

 

I think I got it right...

[knottwhole]

 

Plus, you need air coming into the room through another fan.....

 

 

One fan can do it all. All vented hoods can pull the air out of the room while pulling the heat away from the light. A passive vent near the floor will provide plenty of intake if large enough. I've never used more than 1 exhaust on any of the rooms I've built. I have used variable speed fans for less draw during lights out though.

[Royal Smoke]

One fan can do it all. All vented hoods can pull the air out of the room while pulling the heat away from the light. A passive vent near the floor will provide plenty of intake if large enough. I've never used more than 1 exhaust on any of the rooms I've built. I have used variable speed fans for less draw during lights out though.

 

I hear ya.... That's how I'm running it now....

 

It's just that it's a small closet with a 1000 light in there. Does he have air conditioning? I don't know. I just think in the summertime, you made need the added exhaust.

 

Get the fan with the largest cmf ya can afford.

[Kingdiamond]

The Vent fan isn't going to cut it my 1k is aircooled by a 442 cfm in a similar sized space and on a speed controller its wide open all the time and my temps hover around 86 degrees.

 

Hightechgardensuply.com

 

The above company sells the 442 cfm inline for $109 shipping is free via ebay,.

 

Knottwhole

 

I tried going that route utilizing passive air vents and the temps got in the low 90s

i fixed it by putting a dryer vent through the passive air vent to the outer room hood pointing down to prevent light leaks and inside the flower room i used the above mentioned vent fan to draw kool air in it works perfect.

[knottwhole]

The Vent fan isn't going to cut it my 1k is aircooled by a 442 cfm in a similar sized space and on a speed controller its wide open all the time and my temps hover around 86 degrees.

 

Hightechgardensuply.com

 

The above company sells the 442 cfm inline for $109 shipping is free via ebay,.

 

Knottwhole

 

I tried going that route utilizing passive air vents and the temps got in the low 90s

i fixed it by putting a dryer vent through the passive air vent to the outer room hood pointing down to prevent light leaks and inside the flower room i used the above mentioned vent fan to draw kool air in it works perfect.

Hey King.

To each their own.

I'm fortunate to have built all my rooms in basements. I also direct vent to the outside. That way I'm not recirculating used warm air back into the room. Many direct their exhaust into a side room, and eventually back into the grow room. That's the killer. Many worry about wasting warm air during the winter. It's cheaper to grow healthy plants than worry about heating bills in the long run. Venting to the outside cost are so minimal that more people would do it if they knew. Now, if we can only get people to quit worrying about the smell, and leo, and neighbors. You know where I'm going.

In the end, what works for me, may not always work for others.

Peace as always.

[Kingdiamond]

I forgot to add that my hood is filter + ducting + hood + fan + ducting running directly out my basement window sry.

 

Yes i worry sometimes because i have two jkasses living on both sides of me but im legal under my limits so if they do come i have my defense in line for court.

[johnbs8]

thanks for the replys guys. ill be using an portable AC unit for heat controll. i figured i need 280 CFM min so ill have to figure out what fan or fans to get. you say ill need a passive air intake except when using CO2. whats a passive air intake? and how do i use utilize it while using CO2?

[mibrains]

passive air intake is as it sounds. a hole cut to let air in. no fans.

i vent my rooms outside in the summer and then into the house in the winter with a simple movement of my output duct.

i learned the hard way venting into the house and drawing air from that source for cooling will eventually overheat you.

my fresh air intake comes directly from the crawlspace always and i only redirect the output line for seasonal changes.

 

this is my first winter in this house, but it seems to be working awesomelyistic...

 

my input for you, is to get the strongest fan you can afford, and put it on a variable controller. that way you can "grow" if you need to expand later...

get a thermometer and experiment until you can keep your temp consistent between 70 and 80

i try to hit 70 in the dark, and no more than 80 when lights on

i run an axillary oil heater in the winter and a air conditioner in the summer to maintain the rooms ambient temp.

good luck

it's not difficult, just time consuming to regulate air. think outside the box literally and you'll do fine.

[johnbs8]

thanks for the heads up on the controller switch. how do i vent without venting out all the CO2 in the room?

[mibrains]

thanks for the heads up on the controller switch. how do i vent without venting out all the CO2 in the room?

 

 

thats a great question, i don't have / want a co2 system right now.

so i can't answer that LOL

but i would assume you would have to switch off the room exchange / circulation air while the co2 is running...thats not for me...

i am a fresh air freak so i like tons of air movement.

I'm not happy unless theres several fans blowing the girls around.

but i switch them on and off daily and move them around regularly.....i like to pretend i am a summer storm or whatever sometimes and blast the girls....

imagination is the key to happy girls...

theres very few times when theres no fans running in my space....

i would say theres always at least 1 going.

if not 6 LOL...

but i am a total newb with 1 yr experiance..so defiantly don't take my word for it LOL

 

peace

[johnbs8]

Thanks for all the help guys!! anyone out there that can answer this question? how do i vent without venting out all the CO2 in the room?

[johnbs8]

ok so ive been doing some research, correct me if im wrong. so if im to use CO2 then i want to vent just my light. i have a portable AC/heater to take care of the rest of the heat/moisture build up. if im not running CO2 then i need a passive air intake and exhaust the room once every 5 min for proper air exchange.seeing i have 10x4x7' room 280 cubic feet. i need at least 280CFM exhaust fan to achieve this. this doesnt include counting the bends. so 450cfm should do the trick either way. hit me, is this correct?

[knottwhole]

If you put your fan at the termination of the exhaust run, you should still be able to achieve proper ventilation with a smaller unit. You're correct about only needing to vent the light during CO2 operations. The plants can also handle higher heat during CO2 infusion. Some say the temp can go up to 90 without any problems.

Many, including myself, have not found CO2 to be cost effective. That's why you're not getting many responses. I used it in the past, and it just didn't add up to a great enough advantage over traditional grow methods.

Best of luck though if you do.

[MR GREENTHUMB]

your on the right track johnbs8 with co2 vent the lights and use air cond/ heater.