Need help with ventilation

BluJayz

BluJayz

Well-Known Member
acekard said:
So will it be enough to have this fan to fully ventilate 4x4 grow tent? http://www.ebay.co.uk/itm/4-Hydroponic-Grow-Room-Fan-Inline-Tent-TT-Extractor-For-Duct-Carbon-Filter-/221233778407?ssPageName=STORE:HTMLBUILDER:SIMPLEITEM&refid=store As I understood it can push air in & out, is that correct? Or only out? Thanks :)
Click to expand...
Is it enough, not sure.

Although 100mm is 3.9inches. That's like a CPU fan. 110cfm is not much more than a larger cpu fan. Why not just use one or two of those?

Everything here does the same cfm is not higher and might be less electricity.
http://www.frozencpu.com/cat/l3/g36/c435/s1104/list/p1/Fans-12_Volt_Fans_by_CFM-100_-_119_CFM_Fans-Page1.html

Turn any fan around and it will push in the opposite direction, so yes.
 
lamopa

lamopa

Active Member
What is the height of your grow room? You need it to measure the cubic feet (width x length x height). If I assume it is 6 feet, you are looking 96 cubic feet. For that all you need is a simple 6" duct fan that pulls out 180 cubic feet per minute (cfm). Something like this is fine:

http://www.homedepot.com/p/Suncourt-6-in-Duct-Fan-with-More-Powerful-Motor-DB6GTP/202797339#.UewGAY2kol8

This should be installed above your lights (heat rises) and set on a timer or a temp controller. For intake a simple fan that you can get at WalMart is fine, put it on the ground near an intake (if it is a tent). Finally buy a small clip-on fan that you can hang form the ceiling if you have to. This fan should be mounted at a height where it is blowing right over the bottom of your light.

With this set-up you should be good to go!
 
rwbrock

rwbrock

Active Member
I use a 4" inline 160 cfm fan for my 400w light vented hood. Are you running a cool tube for your vertical grow or just open light? You need to pull hot air and exhaust out of your tent. You should be able to get by with a passive intake. Meaning the negative pressure pulling out will pull fresh air in. The fan recommended above is more of a booster fan and won't be enough. I recommend cooltube and a fan at least 160 cfm a larger 6" fan even better. You will also need a carbon filter at some point.
 
A

acekard

Member
I will be running just open light. My room dimensions are 2x3x7, I will be placing fan under the bulb, shouldn't that booster fan supposed to be more powerful than 4 inch 160crm? Or am I mistaken?
 
rwbrock

rwbrock

Active Member
My closet is 4x2x8 and I basically utilize a 2x3 area for my grow. Not vertical and I have a vented hood. I duct from carbon filter to hood to fan and pull heat and smell and exhaust into attic. Ambient temps will play a part but my closet runs 76-82 depending. In summer as it heats up the spare room it gets warm. If I take out the glass in my hood it raises temp another 3-4 degrees. I ended up buying another fan for intake to help with air exchange. I thought that 6 inch booster fan would work great. It was weak even though rated well. A 5-6 inch computer type fan was way better but kind of loud. I tried and returned both and actually found a 5 inch fan from local store that worked well and was quite. The 4" vortex fan 160 cfm I use to exhaust is a lot more powerful than the 6" booster fan. I tried that exact same fan he linked too from Home Depot too.
 
lamopa

lamopa

Active Member
rwbrock said:
My closet is 4x2x8 and I basically utilize a 2x3 area for my grow. Not vertical and I have a vented hood. I duct from carbon filter to hood to fan and pull heat and smell and exhaust into attic. Ambient temps will play a part but my closet runs 76-82 depending. In summer as it heats up the spare room it gets warm. If I take out the glass in my hood it raises temp another 3-4 degrees. I ended up buying another fan for intake to help with air exchange. I thought that 6 inch booster fan would work great. It was weak even though rated well. A 5-6 inch computer type fan was way better but kind of loud. I tried and returned both and actually found a 5 inch fan from local store that worked well and was quite. The 4" vortex fan 160 cfm I use to exhaust is a lot more powerful than the 6" booster fan. I tried that exact same fan he linked too from Home Depot too.
Click to expand...
My tent is 32" x 32" x 5' H and I run two 150w HPS lights during flowering. My exhaust fan is a simple 4", 80cfm that I run off a timer (on for 15 min every hour during lights on, for 10 min every 2 hours during lights off). I also have a circulating fan down below near an intake flap. Finally I have a clip fan that I mount on the frame just below my lights so it blows air over them. In this set-up heat has never really been a problem. Then again I also have the tent in my cellar, which never gets above 75 in the summer and 50 in the winter!
 
rwbrock

rwbrock

Active Member
You were on the right track with your first post. You want an inline fan. I would go bigger and buy a speed control so you can dial it back or run full throttle if needed. Those little computer fans, duct or booster fans will work well for intake or small cabinets but if your using a 400 veritacle open light it is going to put out some heat! Maybe even something like this


http://www.saferwholesale.com/product-p/6 ventilation system 440 cfm.htm?vfsku=6+ventilation+system+440+cfm&Click=35179&gpla=pla&gclid=CO7ho4CHwbgCFYdQ7AodTUIAgQ
 
lamopa

lamopa

Active Member
rwbrock said:
You were on the right track with your first post. You want an inline fan. I would go bigger and buy a speed control so you can dial it back or run full throttle if needed. Those little computer fans, duct or booster fans will work well for intake or small cabinets but if your using a 400 veritacle open light it is going to put out some heat! Maybe even something like this


http://www.saferwholesale.com/product-p/6 ventilation system 440 cfm.htm?vfsku=6+ventilation+system+440+cfm&Click=35179&gpla=pla&gclid=CO7ho4CHwbgCFYdQ7AodTUIAgQ
Click to expand...
For odor control I simply attached a 4" flex duct from my duct fan into a lint dryer vent that I have chock full of activated carbon. I change it out about once a month or so and have never really experienced that bad of an odor problem. This one to be exact:

http://www.acehardware.com/product/index.jsp?productId=1273083
 
rwbrock

rwbrock

Active Member
As Lamopa pointed out ambient temps play a big part too. I am in a spare room that gets sun all afternoon. In summer I have to run AC or that room can get up to 80. But I am usually in The mid 70s and my closet runs about 4-5 degrees warmer than the room it's in.
 
A

acekard

Member
Sorry for so many questions guys, first time grower here ;) I'm just being afraid that 170cfm fan won't be enough to cool down 400w hps in vertical grow, or shouldn't be I be afraid? And how many fans do I actually need? 1 for cooling down the bulb and that's enough? I would need another one in order to receive fresh air, that's right?
 
lamopa

lamopa

Active Member
acekard said:
Sorry for so many questions guys, first time grower here ;) I'm just being afraid that 170cfm fan won't be enough to cool down 400w hps in vertical grow, or shouldn't be I be afraid? And how many fans do I actually need? 1 for cooling down the bulb and that's enough? I would need another one in order to receive fresh air, that's right?
Click to expand...
You should be fine!! Run it off a temp controller if you're that worried. Also make sure you have a circulating fan and a fan blowing over your lights. These don't have to be huge room fans, small 6 or 8 inch personal fans you can get at your equivalent of WalMart.
 
You must log in or register to reply here.
Top