Tutorial Ventilation 101

[gkoat]

Try using the 6" for cooling the light and the 4" for ventilation,and vice versa and see what works best for you.

Definitely a good way to determine which works better, but I'm hoping someone can dose me with some science.....i'm working my way through the thread and intend to gain a greater understanding but figured it couldnt hurt to ask

 

[gkoat]

ok i have made real progress and have returned w a revised set of questions that perhaps are more specific....

1. Is the effect of a reducer on air flow best measured by [v * A = 4005 * SQRT(Vp) * A]?? And even then, if i'm reading correctly, a 8" fan blowing into or intaking from a 6" with higher pressure will outperform a nonreduced 6"?

2. Is there a way to determine K without measuring exhaust? Specifically, the 1st page of this thread had some numbers assigned to various ducting bends and openings and assigned values to it which suggested numerical values attributable to exhaust imperfections.....how were these values determined? Were they just used as an example?

3. Does the "bend" in the growzilla hood mandate a centrifugal? Or could I get away w an axial? would I need a fan on each side or just one for ~2' of ducting going off each side?

http://www.planetnatural.com/product/growzilla-dual-bulb-reflector/

4.It seems that while these rules apply to my chamber, they will also apply to the closed off closet in which the chamber is in.....so if my intake in my cab is a 4" fan, that 4" acts like an exhaust for the closet, so in order to efficiently exhaust my closet air through a 4" duct, I need to have intake area = to 2(pi*2^2) that serves the closet which houses the chamber.

5. Where can i buy a bell mouth inlet????

6. Do the fans that sit in my cab moving air around contribute to the ACpm that might stress my plants?

 

[LexLuthor]

Thank you for posting this resource! Very helpful!

 

[gloryoskie]

Here:

parts-express.com

Designed for sub woofer boxes. Fits into 4" pvc pipe.
It will improve airflow dramatically.

 

[jaygr0w]

Grow Cab still too hot

Grow Cab still too hot

Hi all. Im germinating Auto Kush Ryder seeds right now and i'm about to plant themin Coco (coco tek) soon. I will be using Jungle Juice from AN and will use the H3ad formula. I have another post up about this but in the wrong section. Here goes....

Made a grow cab with dimensions of 10 1/2 x 23 x 27 inches. 3.87 Cubic ft. At first I had car sun reflector on the walls with 8 14w CFL lights *only thing I can afford for now), a DIY carbon filter, a pc fan with a 48cfm for the exhaust and passive intake holes. The cabinet would go up to about 85f.

This was the setup



Got some advice from the other post. Changed to mylar for the walls since it seemed like the car sun shades were insulated. I also removed the filter for more air flow and got an 87dfm fan. I also added bigger intake holes. This is now the set up



I added more holes and still nothing. I have higher cfm and still goes to 83.5. Should I add another fan of the same CFM parallel or in series? Does anyone think that would help? its a very small space. I have another pc fan with the same supposed speed and another with a speed control but its highest cfm is about 48. I dont want the plant in soo much heat.

The help will be greatly appreciated!

 

[mojave green]

7x7x7 flower room, 2x400w + 3x600w vertical. i started with a 10" max-fan for exhaust. passive intake was 2x10" duct + 1x doran light baffle (12.25" x 12.25".) temps getting to 82/85. not like. installed another 10" max-fan for intake. much better, now tops out at 78 or so. ventilation would be easy if ya didn't have to worry bout light leaks! it does take alot of air to cool that room!

 

[Hydrosun]

Time to subscribe and read. I love how much info is available here at the mag.

 

[gus738]

Hi everyone im trying to learn about air movement on a indoor . how much air intake and exhaust for a large room i do not plan to have ac. .

im trying to exchange air and out without stressing plants out. My main goal would be to clear out a capacity of 10 ft x 10ft x 10 ft without stressing plants out.


I currently have 2 oslating fans 16 inch each i have 1 600w horti with a magnum xxl6 without the sealed glass . i placed the ballast outside of the room bolted on the 2x4. now the room has 1 window that is 4ft wide and 5 and half ft in height . as you leave the room to the right walk 1-2 ft i have a window door into back short patio.

i read paragraph of this thread so correct me if im wrong but my theory is that i need one 4 inch inline fan for intake and one 6 inch inline fan for exhaust. ? or would i need an 8 inch for intake and 12 for exhaust?


i like the room to bring air in and out at the recommended minutes per air exchange .
also if it matters i'd like no smell during flower so i rather have something that is for sure in a sense to guaranteed that i wont smell a cannabis plant.

 

[gus738]

bump

 

[mojave green]

Cheap Humidity Controller

Cheap Humidity Controller

this:

$115.95
plus this: http://brainytrade.webstorepowered....archPage=1&searchRank=salesrank&searchSize=12
$27.39
plus a $30 pc fan
plus a rubbermaid and some ducting make a great humidifier!

 

[Ghost25]

I have some questions about ventilating a shed about 420 cubic feet. Light is 1000 watt HPS. I had orignally planned on getting a large inline fan >700CFM but according to the OP such a high flow rate would stress the plants.

What about a 6" inline fan like this 400CFM: http://www.amazon.com/Hydrofarm-Active-Air-inch-In-Line/dp/B002JQ14F8/ref=sr_1_1?ie=UTF8&qid=1386030351&sr=8-1&keywords=inline+fan pulling through a carbon filter? Apparently a filter reduces effective CFM by 50% so that would leave 200CFM, one turnover every 2 minutes.

My hood isn't a cooltube but I was thinking about cutting a hole in the side and attaching an inline duct fan like this 100CFM http://www.amazon.com/LEDwholesalers-Inline-Booster-Inches-GYO2405/dp/B0069GE9N8/ref=sr_1_4?ie=UTF8&qid=1386030507&sr=8-4&keywords=inline+fan or this 240CFM http://www.amazon.com/VenTech-DF6-Duct-Fan-240/dp/B005KMTYFK/ref=sr_1_3?ie=UTF8&qid=1386030507&sr=8-3&keywords=inline+fan. Would this be beneficial? Also would I be OK running this directly out without a scrubber or would I have to attach a small scrubber?

 

[medicalmj]

I have some questions about ventilating a shed about 420 cubic feet. Light is 1000 watt HPS. I had orignally planned on getting a large inline fan >700CFM but according to the OP such a high flow rate would stress the plants.

What about a 6" inline fan like this 400CFM: http://www.amazon.com/Hydrofarm-Act...TF8&qid=1386030351&sr=8-1&keywords=inline+fan pulling through a carbon filter? Apparently a filter reduces effective CFM by 50% so that would leave 200CFM, one turnover every 2 minutes.

My hood isn't a cooltube but I was thinking about cutting a hole in the side and attaching an inline duct fan like this 100CFM http://www.amazon.com/LEDwholesaler...TF8&qid=1386030507&sr=8-4&keywords=inline+fan or this 240CFM http://www.amazon.com/VenTech-DF6-D...TF8&qid=1386030507&sr=8-3&keywords=inline+fan. Would this be beneficial? Also would I be OK running this directly out without a scrubber or would I have to attach a small scrubber?

Buy the biggest fan you can afford along with a $25 speedster fan speed controller. Personally I can't see a 800 or 1200 cfm fan causing issues in a 420 cf enclosure. If neg pressure is the issue install a couple intakes with a damper. Or you can dial to whatever floats ur boat for $25 extra bucks.

.On the cool tubes or any vented light for that matter, spend the 50-75 bucks and buy a real 4" or 6" inline fan. Those duct booster fans don't work for shit. Then install as close to the exterior as possible (outside the enclosure if applicable) with the intake toward exterior and push the air to the light. If the air then exits you will have near zero smell emitted.

So no need for a scrubber. The key here is anything before the fan (ideally it'd be mount to the exterior wall and sucking fresh air) is sealed and must also be hard ducted. Once the air is being pushed to and through the light, no stink can enter the flow. It simple passes through the duct and light w/o mixing.

 

[gus738]

would 700cfm exhaust fan be over kill for my 10x10x10? im getting vortex 8" s line series unless i get recommendations . i live in a condo so noise /sound is somewhat of an issue...

 

[smokadepep]

I am sorry if this is the wrong thread or it's been answered already. Here is my situation.

I have one window and 3 tents in my grow room. 2 flower and one veg. The flower tents each have a 600w hps and the veg has a 400 cmh. I am thinking of getting a dual window fan to extract out of one port and intake into the room through the other. I want to run both my flower tent exhaust to y joint and out through a six inch vent. Each tent has a 6 inch phresh filter and a 6 inch vortex s-line fan. I Might even add a muffler after the y joint to help reduce the sound. My question is will this put a strain on my fans motor? Will I have any back draft from one to another? Should I increase the size at the y joint to 8 inches?mAny issues this setup may run into?

 

[messn'n'gommin']

Hi everyone im trying to learn about air movement on a indoor . how much air intake and exhaust for a large room i do not plan to have ac. .

im trying to exchange air and out without stressing plants out. My main goal would be to clear out a capacity of 10 ft x 10ft x 10 ft without stressing plants out.


I currently have 2 oslating fans 16 inch each i have 1 600w horti with a magnum xxl6 without the sealed glass . i placed the ballast outside of the room bolted on the 2x4. now the room has 1 window that is 4ft wide and 5 and half ft in height . as you leave the room to the right walk 1-2 ft i have a window door into back short patio.

i read paragraph of this thread so correct me if im wrong but my theory is that i need one 4 inch inline fan for intake and one 6 inch inline fan for exhaust. ? or would i need an 8 inch for intake and 12 for exhaust?


i like the room to bring air in and out at the recommended minutes per air exchange .
also if it matters i'd like no smell during flower so i rather have something that is for sure in a sense to guaranteed that i wont smell a cannabis plant.

Using a 600w lamp, a 4x4 tent, and a smaller exhaust fan is probably a better option, unless you have a plan for light leaks, via the room's windows.

Carbon-filled air filters will take care of any aroma's.

I am sorry if this is the wrong thread or it's been answered already. Here is my situation.

I have one window and 3 tents in my grow room. 2 flower and one veg. The flower tents each have a 600w hps and the veg has a 400 cmh. I am thinking of getting a dual window fan to extract out of one port and intake into the room through the other. I want to run both my flower tent exhaust to y joint and out through a six inch vent. Each tent has a 6 inch phresh filter and a 6 inch vortex s-line fan. I Might even add a muffler after the y joint to help reduce the sound. My question is will this put a strain on my fans motor? Will I have any back draft from one to another? Should I increase the size at the y joint to 8 inches?mAny issues this setup may run into?

The wye will be a choke point. It effectively reduces two 6" fans down to one. A ventilation system is only as large as its smallest aperture.

hth!

 

[gus738]

the wye? choke point? i plan to put my 5.5 mil panda film black /white . for light leaks . im thinking an exhaust inline vortex s line fan will work?

 

[smokadepep]

If the wye joint was a 6 to an 8 would it still be a choke point? Area of 2 6 inch circles= 28
Area of an 8 inch circle = 50 so it's about a 6sq inch difference

 

[messn'n'gommin']

the wye? choke point? i plan to put my 5.5 mil panda film black /white . for light leaks . im thinking an exhaust inline vortex s line fan will work?

Oscillating fans will help to stir the air, so it doesn't get to hot in just one spot. Where do you plan on exhausting the hot air?

Panda film will work, but, before you put any plants into flower, you might want to spend a half hour or so in the room with the lights off, to let your eyes get used to the dark, and check for light leaks.

If the wye joint was a 6 to an 8 would it still be a choke point? Area of 2 6 inch circles= 28
Area of an 8 inch circle = 50 so it's about a 6sq inch difference

Not exactly the same, but it might work. It's cutting it a bit thin, so, it doesn't allow much room for error. The length of run might have to be figured in there, as well.

 

[gus738]

one of the choices i have is through the window another option is to get thermalflow 2000sr and vent out of room to heat the condo
oh and i do not want to get a tent

Oscillating fans will help to stir the air, so it doesn't get to hot in just one spot. Where do you plan on exhausting the hot air?

Panda film will work, but, before you put any plants into flower, you might want to spend a half hour or so in the room with the lights off, to let your eyes get used to the dark, and check for light leaks.



Not exactly the same, but it might work. It's cutting it a bit thin, so, it doesn't allow much room for error. The length of run might have to be figured in there, as well.

 

[messn'n'gommin']

IMHO...That's probably the best option. I exhaust to my basement and it doesn't really hurt the A/C all that much in the summer. But, it makes a good bit of difference in the winter!

After your next to last post, I figured you didn't really want to go the tent route, hence the suggestion of an oscillating fan or two stirring up the air to even out the room temps.

Sounds like a plan! You're on your way to self-sufficiency!