newbie help with ventilation

[drizzy]

Hello everyone
I'm finaly ready to begin growing after years of reading tru these forum..
Here's what I have so far: xtrasun 6 coolable hood,600w hPS,extrasun dimmable ballast and timer.. the tent will be a hydro lab 2'7"×2'7"×5'11"
I'm thinking of getting a s&p td 6" silent,
Any suggestions on how to set up this grow tent:
Intake / exhaust ,ducting ect. The tent will be in my bed room and will be running at night. I need it to be silent. Thank you...

 

[Jnugg]

I'd get a inline rated for more cfm...like an 8".

Read the ventilation 101 thread.Best bet is two fans.One for just air cooling the light,the other for ventilation/odor scrubbing.

 

[seeingthings]

If you have the funds, always go with bigger / more power.

Ability to move more air is never a bad thing with ventilation. You can always use a fan controller to dial it down.

 

[seeingthings]

Also...... (wish I could edit posts!)

I've got a similar sized tent in my bedroom in flowering right now.

*What kind of climate do you live in? What temps are you going to see in your bedroom for the next 6 months?

*What's your budget? (I cheaped out and wished I wouldn't have!)

I'm using a 400W hps with a modded stanley blower cooling the light and exhausting the room. I used 4" ducting originally as I was just running ~300W CFL in veg...and wished I would have gone with 6" as the temps did start to get high (low 80's) once I swapped in the 400w HPS. Now that I'm flowering at night it's cooling perfectly with a max temp of about 77. It is VERY quiet though, just a slight whooshing air sound.

Anyway- My advice to you. Get a proper inline fan rated for more CFM than you "need." You should also take into consideration adding in a carbon scrubber for odor control which will increase static pressure to an extent (more load on the blower).

There are some quiet blowers out there, check reviews or spec sheets for dB levels. There might be a tradeoff with price and noise. The blowers marketed as 'really quiet' seemed to always cost a premium.

As for ducting I've read nothing but good things about Thermoflo. It comes insulated and bare. I'd suggest insulated for lowering dB levels as well as shielding from leak. The cheap insulated shit I got at the local home improvement store kept on ripping.

 

[drizzy]

Thanks guys
temp for the next 6 moth is winter..
Jnugg: I don't think I'll have room for two fans
Can I just use one: filter>fan>hood>exhaust>bedroom
What about intake..what exactly is passive intake..
If get an td 8" what filter will I need ..

 

[Jnugg]

You can use one fan...read ventilation 101 seriously!

Calculate how big a fan you'll need to cool the light (roughly 3cfm per watt of lighting,then calculate how big a fan you'll need to ventilate the grow tent 2-5x per minute....Add the cfm's together...get next fan up to account for duct losses and carbon filter.

If you use an 8" fan you'll want an 8" filter.

The way I would set it up would be filter>hood>fan>out.Try not to dump the hot exhaust air back in to tge same room the tent sits in and draws it's fresh/cool air from as this will raise the temps of the room thus raising the temps in the tent.Exhaust to a diffrrent room or outside.

A passive intake is a hole with no fan.Passive intakes should have twice the area if the exhaust.An active intake is an intake with a fan...I wouldn't recommend that.


Seriously,read ventilation 101...there's a link to it in my signature.

 

[drizzy]

OK..I will read vent 101..
How do I prevent light leak with a passive intake..
How about this set up :
6"td silent >6" scrubber>exhaust
6"axial /computer fan>hood without glass(pulling air from outside..

 

[oscarthegrouch]

You can use one fan...read ventilation 101 seriously!

Calculate how big a fan you'll need to cool the light (roughly 3cfm per watt of lighting,then calculate how big a fan you'll need to ventilate the grow tent 2-5x per minute....Add the cfm's together...

That seems excessive, are you sure thats what you meant to say? I really cant see anyone running 3000cfm+ to cool a 1000w light. There tent would implode. I use 420cfm to cool a 1000w gavita pro in a tent with no problems....

 

[Mr. Krinkle]

here's a great link for you to read ----> http://urbangardenmagazine.com/2010/07/planning-your-grow/

 

[drizzy]

OK..thanks everyone for your time
I've read vent 101 and Mr.krinkle recommended thread ..valuable info
OK...here's what I got out of it..
Volume :2.6×2.6×5.9=40
Extractor: 1.25×40(v)=50cfm
Coolbulb:3.16×600w)÷20delta=95cfm
Total cfm=95+50=145cfm] scrubbed cfm=145×.75=108cfm
Intake:108×.85=92cfm..
Am I on the right path and go by these numbers on choosing fans..
Choose the next up cfm fan.
Can I get away with a 4" s&p 203cfm

 

[Mr. Krinkle]

round up

so go 3 x 3 x 6 = 54

54 x 1.25 = 67.5

so go like 70 cfm exhaust and if its too much you can always pickup a fan speed controller to dial down a little - better more than not enough

 

[Jnugg]

Get a 6" just to be safe,you can always use a solid state speed controller to dial the fan down.There are some things in life that are better ti have and not need rather than need & not have...catch my drift?

 

[Granger2]

Krinkle's numbers work except that you want to exhaust the volume of the tent multiple times/minute. Three per minute is kind of a min. I'd get a 6" centrifugal fan. You can speed control it down if you want to, like in cooler months. One thing to consider is that with your sq footage, 400 watts is plenty, and will cause less heat. -granger

 

[drizzy]

OK .. thanks
I'll go with the 6".. where can I get a good speed controller and what Brand.
I'm going with an active intake, what size u guys recommend.
Also where can I get a good scrubber..
What set up is best: FILTER>HOOD>FAN>EXHUAST OR FAN>HOOD >FILTER >EXHUAST..
THANKS EVERYONE ...

 

[Mr. Krinkle]

can fan and can fillters - and get whatever speed controller they got at the store...no big deal there..

you're practically in a closet so uhhhh - idk what to tell you as far as hoods go...

 

[Granger2]

I got a speed controller here, I'm content. If you have Amazon Prime, free 2 day shipping. Also, check Harbor Freight. You may have one locally.

http://www.amazon.com/SE-Step-Speed...d=1376710513&sr=8-1&keywords=speed+controller

At least 10 bucks cheaper than the one's that Hydrofarm had their supplier put "Hydrofarm" on.

I'm reasonably sure that all the one's this style come out of the same factory, or by the same mfgr, probably in China. The one I got doesn't even get warm while running a 6" centrifugal fan at less than half speed. A good sign. -Good luck. -granger

 

[Granger2]

Oh, and whether to push or pull thru the filter? - I don't want to get into that argument again. Engineers still argue about this. I'll just link to Can's FAQ. You decide. Consider your priorities, like smell, etc.

BTW, I'm not endorsing Can products. I've never used any. They have a fairly informative FAQ is all. There may be others. Good luck. -granger

http://canfilters.com/faq.html

 

[drizzy]

Thanks Granger
yeah, I've seen the forums on either to push or pull through filters
I need it to be silent and smell less.. I'm thinking at 4" Axial/ computer. For intake..

 

[Granger2]

A 4" axial fan, regardless of the cfm rating, won't even come close to doing the job. For one thing, axials have little if any ability to handle static pressure. You can't supply a 6" centrifugal fan with only a 4" axial. Totally inadequate. You're better off using 2 6" passive openings, or equivalent. If you want to have powered intake, you'll need a 6" centrifugal fan, or 2 4". The 2 4" fans are only enough because you're lessening the exhaust by drawing it thru a filter. Good luck. -granger

 

[drizzy]

OK..now I'm confused
How can i use passive intakes with out light leeks ..I thought the intake need to be less than the exhaust.. 2 4" centralfungal?..
Thanks in advanced ...