Advice please on a new grow tent project

[TD.]

I may be wrong but this mixed flo fan is inline yes ?

I have a westaflex centrifugal (the yellow 200mm one) strapped to my carbon filter.

Just letting you know in advance, inline fans dont work well with carbon filters, either they cant do the job to start with or the motor on the fan burns out from trying to overcome resistance.

 

There is no fan that can work with a carbon filter that is under 40db, its just not going to happen, you can take proactive steps to make everything whisper quiet.......just change your exhaust fan to a 150mm or 200mm centrifugal fan.......also if u go for the canfan brand be warned they sound like a small jet taking off...

 

Also i just realized that if you go with LED's your wasting your money on odor control. The power of the fan that you need to overcome the resistance of the carbon filter is also powerful enough to cool your tent....if your using a cooltube with CFL or HPS....since LED's dont pump out heat u dont need a big fan...but without a decent fan you cant use a carbon filter properly....and no one wants to do a half ass job, it only leads to half assed buds...at best

Edited March 20, 2010 by TD.

[pug1010]

Hi TD:)

 

Thanks for the reply mate. Yep...you were right, it is an inline not a centrifugal fan. I have done some searching, because noise might be a bit of an issue and have come up with the following package: a HVK100A1 Fan (175m3/hr) (103 cfm @ 34 dB) and a PHAT FILTER 100MM X 300MM Carbon Air Filter. Sadly, I can buy the whole lot from the UK (including shipping) for the same or cheaper than in Oz - http://www.progrow.co.uk/acatalog/info_4495.html. If the Phat Filter is too big for the fan, I could go down to a 200 cfm Mountain Ait, mabye an Elf or something around 150cfm - I think. That would hopefully solve the problem of too big a fan for such a small space.

 

Just a question that might seem really dumb and might only affect grow tents with little heat issues from the lights. Would it be possible to reverse the whole venting system? If the air from outside was sucked into the tent via ducting attached to the intake fan, then the air inside the tent would be sucked out into the room via the carbon filter. Wouldn't that mean that the exhaust air, would have been filtered so that there was no smell, no mould or spores and also it would contain a shit load of oxygen?

 

Sorry again for all the questions...especially the ones that show my limited knowledge. I really appreciate all the help though, as without it I would have spent a lot and got poor results.

 

pug

 

PS: also throwing around the idea of a small portable air-con with an odour sock attached to the air con exhaust ducting

[TD.]

Hi TD:)

G'day Champ

 

Just a question that might seem really dumb and might only affect grow tents with little heat issues from the lights. Would it be possible to reverse the whole venting system? If the air from outside was sucked into the tent via ducting attached to the intake fan, then the air inside the tent would be sucked out into the room via the carbon filter. Wouldn't that mean that the exhaust air, would have been filtered so that there was no smell, no mould or spores and also it would contain a shit load of oxygen?

 

Im not too sure i understand what your getting at...you lost me after intake fan. either way grow tents are made with the intention that hot air is being sucked out of the tent thru the ducting holes provided and cool air being being sucked in either passively from the Velcro slots at the bottom or thru an intake fan which has ducting leading into the tent.

 

PS: also throwing around the idea of a small portable air-con with an odour sock attached to the air con exhaust ducting

Sounds like a good waste of money, you do understand the exhaust fan motor in the portable air con is not under any circumstances designed to handle any form of back pressure...i own one myself...a 3.5kw portable aircon/heater and it states in the instruction manual that having the exhaust ducting placed too high can cause problems with the flow...and its the flow that draws cold air over the condenser(which is a fluid radiator) then throws it out as hot exhaust air.

Confusing ? maybe you should try and go for a simple setup....simple is best.

Edited March 21, 2010 by TD.

[Reverend]

You are growing under lights, so you are hydro doesn't matter what medium you are going to use.

 

"4. Plant Pot (Au): Autopot Single 12" pot (grown in soil to fulfill the non-hydro requirement)"

 

I don't know how successful you will be using soil in auto pots, they are designed to work with perlite from what I can gather.

[pug1010]

Thanks TD and gills:)

 

I will try and go the simple road and avoid the aircon and weird ventilation setup.

 

Just another question....when sucking air out through the ducting holes at the top of the tent (using a fan and carbon filter) and also at the same time sucking air in passively from the velcro slots on the bottom...does any smell come out of the tent through the bottom velcro slots at the bottom of the tent?

 

pug

[mull]

As long as you keep negative pressure in the tent, smell should stay in the passive vents.

 

If fan goes off in tent they'll leak, or force smell out if you run positive pressure.

[TD.]

Just another question....when sucking air out through the ducting holes at the top of the tent (using a fan and carbon filter) and also at the same time sucking air in passively from the velcro slots on the bottom...does any smell come out of the tent through the bottom velcro slots at the bottom of the tent?

As long as you keep negative pressure in the tent, smell should stay in the passive vents.

If fan goes off in tent they'll leak, or force smell out if you run positive pressure.

 

Mullaway is correct, as long as you are sucking air out of the tent you have negative pressure. When the fan is turned off smell can escape, but you want your fan on 24/7 to maintain proper air flow, which is vital to keep your plants alive...if your fan is off for more than a few hours air start to get stale.

[pug1010]

Thanks TD and Mullaway...nice one.

 

Appreciate all the great advice.

 

I'll let you know how things go, once everything is bought and under way.

 

pug

[Amos]

Mullaway is correct, as long as you are sucking air out of the tent you have negative pressure. When the fan is turned off smell can escape, but you want your fan on 24/7 to maintain proper air flow, which is vital to keep your plants alive...if your fan is off for more than a few hours air start to get stale.

 

Yeah these guys are on the money.

Personally though, i have never had an issue with only running the fans when the light is on. Sure the c02 wont be constantly pumped in, but i think you'd only be losing a few grams at the most here....(haven't tested this though , but have always managed good yields this way). I would however be running the fans constantly when the girls start to really pong.... neighbours .

I'd probably run the fan 24/7 if you could live with the noise at night time.

 

I have recently set up a tent, 1.2*1.2*2.0, with 400w hps, 150mm centrifugal w/ carbon filter. It works brilliantly, and the temps are great (ie not in the slightest bit hot). You'd be able to get away with 400w in your setup, but id def. use the cooltube. Don't bother with anything less than 400w.

ATM the inlet is passive (only 1 inlet 150mm ducting), but the fan is powerful and it'll definitely require 200mm ducting, coming in from 2 separate passive inlets. The airflow is great and no need for inlet fan. Using a silencer on the exhaust side of fan, however the noise from the exhaust fan sucking through the carbon filter is the only noise issue now. Can't be helped/ rectified though but its not that loud....