Small Grow Box Ventilation.

[Danolo]

I'm building a small grow box : 2' deep. 4' wide and 6' high. I'll dividing it into two room, each one with a 2' by 2' footprint and 6' tall.

That's approx 100 cubic feet.

I'm planning to put my fan and filter outside the box... actually, through a window in its own box outside. So my fan will suck from the room and blow it out through the filter.

I've been looking at 4" and 6 ' fans.. you can find them easily on amazon. Some of them come with speed controllers, some you can buy add-ons.

My goal is to change the room air in one minute.
A popular 4" fan has CFM of 150, which, if I factor in the filter and a couple of 90 degree bends, I should be pretty close.
Or I could get a 6" fan that runs at 250 CFM and then I'd need a speed controller.

But there is a blog here about the risks of using some of the speed controllers.

My questions are:
1. Are the fans that have built-in speed controllers going to work better/longer than an add-on?
2. Have you guys any experience with the add-on speed controllers?
3. If I dumb-down and 25o - 300 CFM fan to an effective rate of 100 CFM, what will that do to the life of the fan, the filter, and the speed controller?

If you have any advice, I'd be glad to hear it.

Thanks

 

[hiboy]

Why two rooms

 

[Tat2420]

Are ya gonna feed and vent each side separately?
With the size of the box it would prolly be more effective use of space as one chamber rather than 2 and cheaper on the wallet.
Did you mention your lighting? What are you using? That's gonna make a big difference here.
Your gonna have to regulate 2 different exchanges of air, heat, and humidity.

 

[Danolo]

Why two rooms

Are ya gonna feed and vent each side separately?
With the size of the box it would prolly be more effective use of space as one chamber rather than 2 and cheaper on the wallet.
Did you mention your lighting? What are you using? That's gonna make a big difference here.
Your gonna have to regulate 2 different exchanges of air, heat, and humidity.

Yeah, I know...two rooms is problematic...

The plan is (was) to do an auto for quick results in one room, and then germ and grow a regular photo strain, scrogged and flowered that way. Hoping to get some perpetual harvest going.

I'm looking at lights, in particular, the Perfect Sun Mini...start with one over my auto and a second when momma is big enough.

My hope was to use one fan and filter to exhaust and clean both rooms, hence the fan/filter box outside. Inputs Y'd into one duct going out to the fan. And perhaps some baffles in the input ducts to moderate the air flow in either room.

This is a first grow box for me, and I haven't grown for 24 years. So there's lots of new technology I must learn. My last grow was 12,000 watts of HPS in a flood and drain setup.

So, I'm a bit stuck in my "old school" with a mother and clones.

I'd be glad to hear your suggestions..

 

[Danolo]

I know the integration of one fan and filter may not work for both rooms...
The alternative is two fans, two filters, two ducts...

Or, one room....

I had hoped to get a scrog vegging in one room, while flowering the previous scrog in the other..

The space noted is the absolute maximum available..

Help me solve this, folks...

 

[Tat2420]

I'd do one room honestly...run 3 autos.
Although I don't have much experience with autos but I'd think that would be the way to go

 

[Danolo]

I'd do one room honestly...run 3 autos.
Although I don't have much experience with autos but I'd think that would be the way to go

Yeah, you may be right...Just buy seed...quicker harvests...

I could stagger the germination dates and get a crop every month.

Hey Tat, thanks, you have opened my brain!

 

[Danolo]

I'm obviously getting old... :)

I was stuck in mother/clone/scrog mode. I was gonna grow an auto for a quick harvest... DUH!!! Three autos!

I may even be able to do a bit of LST on them and increase bud sites.

It teaches me that I need to "think outside the box". Why not take advantage of modern technology?

Thanks guys...

Now I gotta see if I can change my seed order.. :cool:

 

[HailTheLeaf]

I'm building a small grow box : 2' deep. 4' wide and 6' high. I'll dividing it into two room, each one with a 2' by 2' footprint and 6' tall.

That's approx 100 cubic feet.

I'm planning to put my fan and filter outside the box... actually, through a window in its own box outside. So my fan will suck from the room and blow it out through the filter.

I've been looking at 4" and 6 ' fans.. you can find them easily on amazon. Some of them come with speed controllers, some you can buy add-ons.

My goal is to change the room air in one minute.
A popular 4" fan has CFM of 150, which, if I factor in the filter and a couple of 90 degree bends, I should be pretty close.
Or I could get a 6" fan that runs at 250 CFM and then I'd need a speed controller.

But there is a blog here about the risks of using some of the speed controllers.

My questions are:
1. Are the fans that have built-in speed controllers going to work better/longer than an add-on?
2. Have you guys any experience with the add-on speed controllers?
3. If I dumb-down and 25o - 300 CFM fan to an effective rate of 100 CFM, what will that do to the life of the fan, the filter, and the speed controller?

If you have any advice, I'd be glad to hear it.

Thanks

Hey Danolo, you should pull air through your filter not push it through, and also about the fans, i have a 6in can fan max with a 3 speed controller and i love it, its very quiet. Maybe something to look into for you, you cant go wrong with can fans or can filters imo.

 

[Danolo]

Hey Danolo, you should pull air through your filter not push it through, and also about the fans, i have a 6in can fan max with a 3 speed controller and i love it, its very quiet. Maybe something to look into for you, you cant go wrong with can fans or can filters imo.

I've seen Can Fans... they seem good. I'll have another look at them, thanks

As for the push/pull, I've seen a few sites that indicate there's no difference, the same CFM is moving through the filter.
For me its an issue of noise... the box in in my bedroom, right next to my bed (doesn't everyone sleep with their garden??). So the fan noise will be harder to muffle.
So, my plan is to duct the output, out through the window and into box on my balcony. And I was planning on putting the fan and filter in that box and sound insulating it.
I'm in an apartment building and I must be careful of neighbours and what they may hear and smell.
I may even have to add an additional filter inside the box the get 100% smell reduction.

 

[HailTheLeaf]

I've seen Can Fans... they seem good. I'll have another look at them, thanks

As for the push/pull, I've seen a few sites that indicate there's no difference, the same CFM is moving through the filter.
For me its an issue of noise... the box in in my bedroom, right next to my bed (doesn't everyone sleep with their garden??). So the fan noise will be harder to muffle.
So, my plan is to duct the output, out through the window and into box on my balcony. And I was planning on putting the fan and filter in that box and sound insulating it.
I'm in an apartment building and I must be careful of neighbours and what they may hear and smell.
I may even have to add an additional filter inside the box the get 100% smell reduction.

When you pull through the filter you are using the carbon more evenly that pushing air through. Also its like having no prefilter then, and the prefilter helps to keep dust and other bs from clogging up the activated carbon inside the filter. It could also make the fan work harder depending on fan speed and size of filter.

 

[Tat2420]

I would have to agree to pull air through rather than push it out...it would seem to me that it would be less taxing on the fans motor...i don't know just a thought.

 

[Danolo]

I know what you mean... it does seem like that doesn't it? But if you check out this link:
http://www.phreshfilter.com/page/phresh-frequently-asked-questions
And check item 12, the guys at Phresh say you can run the as suck or blow. In another site, they suggest rolling the prefilter and inserting it into the centre to prefilter the air coming in.

I've seen other suppliers say the same thing.

In the final result, I don't think it will make a huge difference, because I will likely need two filters, one input and one output, just to control the smell.

I don't have to commit to this yet, so I'll do some more research and letcha know.

Thanks for your inputs,

 

[Farmer P]

I say if you can, make the box taller and put the filter on the inside. I tried it both ways and sucking through the filter is much better. Good luck and look forward to seeing your grow.

 

[Danolo]

Ok, I'll see if I can put it inside....

 

[Danolo]

Ok, I've been doing research on various fans and filters... with a view towards getting something that won't take up a lot of space when I hang it from the ceiling of my box.

So far, the fan I like best is the Hyper Fan 6" with the built in speed controller.

Now I have to hunt down a retailer here in Toronto that will order one for me.

I was gonna visit a local hydroponics store, but when I arrived there was a notice on the door that they had closed the store for two days to attend the O'Cannabiz Conference here in Toronto.
I was going to go, but the tix and $25.00 US!

I may still go...