First Grow

Hey, my friends and I are planning our first grow pretty soon. We are running into issues as to how we should rig up the ventilation. We are working with a 4.5' x 3' x 2.75' (HxDxW) and will be running a 400w HPS/MH conversion light set up. We would also like to run a carbon scrubber.

With such a small space I assume we should air cool the light. How should we do this? We were thinking about getting this hood from HTG (http://www.htgsupply.com/viewproduct.asp?productID=49541). Would it be best to just have a seperate intake/exhaust for the light alone? Could someone maybe attach a simple diagram to explain the setup, if possible.

Next as for ventilation in the box we were thinking about running a 180 cfm computer case fan (120mm) for the exhaust, and about a 100 cfm fan for intake. Would this be ideal, if not what should we shoot for?

Thanks in advance, sorry I'm a noob, just want this grow done right.

You can exhaust "through" the light, no need for extra exhaust. Basically, your fan pulls the air through the light and exhausts it to the outside. But the box is way too small. The reflector which is 7" high must hang somewhere, so there's 1 foot. Your pot or container another foot. Your light needs to be away from the plant tops about a foot. No you got 1.5' left for the plant... can't you built a higher box?

FileError404 said:

You can exhaust "through" the light, no need for extra exhaust. Basically, your fan pulls the air through the light and exhausts it to the outside. But the box is way too small. The reflector which is 7" high must hang somewhere, so there's 1 foot. Your pot or container another foot. Your light needs to be away from the plant tops about a foot. No you got 1.5' left for the plant... can't you built a higher box?

Click to expand...

Thanks for the quick response. As for the size, we were going to grow in a closet. We have other options, and I will investigate and see what we can do.

So your saying, I can just use the same intake/exhaust from the light for the box? If this is the case...would I run Intake ---> Light ---> Scrubber ---> Exhaust (--> indicates duct)? What kind of fans would you recommend then?

Also, forgot to mention, we are growing a shorter strain (misty) as well as possibly complementing that with LST. Do you think that the 4.5' height limitation will be a really big problem? I've seen a number of grow boxes that have been less than 3' tall...thanks again.

you will want as much height as possible. op for a cooltube must u keep it at your size now... and for venting, your intake does not need to duct to the light. maybe use those baby pc fans to have small intake on both sides of the box.

the only thing ducted is your carbon>>light>>fan>>exit>> also since this is the way most people do it, u might wanna think about pushing threw the carbon on the outside because again space is gonna be your main concern.

stop knocking his size lol and feel free to check out my link we have a pretty similar setup are u doing hydro or soil ? and what are u trying to accomplish yield wise any goals

Yeah, light>Hose>Scrubber>Hose>Fan pull>hose>output. The fan can be on the outside. The fan size depends on the scrubber, Can fan has good combos. Fan should be able to exhaust your room in a few minutes. You'll need around a 175cfm fan but I always go bigger than I "have to".

Never really grown that small, or with LST, closets are usually higher. If you spend all that money why not grow em as big as possible?

stop knocking his size lol and feel free to check out my link we have a pretty similar setup are u doing hydro or soil ? and what are u trying to accomplish yield wise any goals

Click to expand...

We will be using soil. Goal wise we just want to grow a successful plant, we're not in it for the profit or anything, just personal use and experience .

If you spend all that money why not grow em as big as possible?

Click to expand...

I live in a house w/ 8 guys so we are confined to our room space and we have a lot of traffic through our main areas so that is why we are growing in my closet. Our house is an older style house and my closet specifically has slanted ceilings which are hindering our height. If the ceilings were normal we would have a 5' x 4' x 6' high grow room, but like I said since its slanted the most efficient box size was what I mentioned earlier.

Yeah, light>Hose>Scrubber>Hose>Fan pull>hose>output.

Click to expand...

Just to clarify are you only using one side of the reflector hood then and blocking off the other end? Would there be a duct on the opposite side of the light that pulls in or would the small intake computer fans be used as the only intake (thus blocking off the other end of the hood)?

Also, how would this fan/scrubber fare in my box? http://www.htgsupply.com/viewproduct.asp?productID=52609

Ok, so just to clarify...are we only using one side of the hood opening and blocking off the other end or should the intake be connected to the light via duct as well (versus just placing it in the box and only running the exhaust/scrubber through the light hood)? Will the intake and exhaust from the light should be sufficient enough for the whole box? We are looking at this fan/scrscrubber combo (http://htgsupply.com/viewproduct.asp?productID=52609).

As for the intake, should we invest in a cpu case fan rated at like 100 cfm, or no and just have an opening (light sealed though). Thanks for the help!

You don't need an active intake. Just take a length of flex duct, bend it twice (snake it) to prevent light from going out or coming in. That combo looks great, very good price for such a strong fan + filter. And yes, just leave the other side of the light fixture open.