Need extraction advice for my first growbox

[JimApple]

Hi all,

I need advice on what fan and filter setup I should use for my first growbox, a stealth one. The internal dimensions are 470w x 390d x 680h / 18" x 15" x 27" (see photos below).

My intention is to grow 2-3 plants in this (will it take it?) and use 2 x 42W CFLs per plant, so will have 6 sockets.

I've lined the box with panels made of card, silver-backed bubble wrap and Reflex Diamond Reflective Sheeting. It's location is a shed with a RH of around 60% and temp of 18C. I plan to introduce a thermostat and heater to raise the temp of the shed slightly, which will bring down the RH by a few points.

The exhast hole is 100mm diam while the intake is passive and 4x that. I was planning to buy a 100mm in-line fan and filter set (LTI Systemair RVK100 + matching CF160 filter.) This fan extracts 175m3/h. Both would be outside the box as shown below, both acting as a light trap (will that work?) and saving space inside.

box - duct - carbon filter - duct - in-line fan - duct - big wide world

My concern with this is will I be drawing out too much heat and have to heat the box more, which will both cost more and be visible via IR cameras. Is this a valid concern?

Can I make my own filters (are they as effective as the pro ones?) Either way, how effective are filters - if I decided to go down the PC fan route housed in the box and venting into the shed rather than the big wide world, would there be any smell at all? I am looking for zero smell.

Any advice would be gratefully received.

Regards

JA

 

[David Bowman]

The whole idea behind a carbon filter is so you can vent into a living space with zero smell. Assuming you purchase a quality carbon filter or properly build one for yourself - check out Do It Yourself, you should have no problems venting your grow space anywhere without smell issues. My 6" Carbon Filter/Fan combo, which I vent from my grow box back into my grow closet, has completely eliminated all smells from my grow.

 

[Farscape]

Nice little set up you have there. Your not going to be able to grow the super massive strains of weed because of height constraints but you should be able to produce some good quality dwarf plants. Agree with ColoradoHigh you shouldn't have any smell issues even with a small carbon filter. If your shed gets cold and you dont want to heat the entire shed for the sake of warming your cabinet you can get small greenhouse heaters.......

Easier to show you.....

This is my stealth grow box made out of an old fridge probably about the same space as yours. The long tube you see at the back of the fridge is a small greenhouse heater, between the 2 pots you can just make out air intake hole (bathroom fan) and behind the rear led panel an air outlet (atm its a passive air outlet but i might fit a carbon filter if i ever have the need).

Your lights will produce a fair amount of heat themselves (my led panels bring up the temp to low 30's deg c so i put in a thermostatic controller which kicks in the heater when its cold (usually only in winter here) and kicks in the air intake when it gets too hot. It all works pretty well.

Downside is always space constraints, ive grown quite a few plants in it now with the occasional plant growing too big for the cab, keep an eye on your strains even some that say dwarf plants can surprise you

IMHO a 4" carbon filter should be fine for smell issues. mount the filter at the top of the box through a hole in the side or top with a nice inline fan in another sound proofed box next to your cab. Vent the exhaust back into the cab if it gets too cold (which i doubt) or straight to the outside.