Main room re-design

Redesigning my 'main' room these days, and have a question or two for the good people of AZ Rollitup. Air flow, mainly, but CO2 also, and other topics as confronted. This maybe should be a grow journal?

Anyway, starting with a 10x 10 bedroom, installing low 4x10 table, with pass-under to access both sides of what I hope will become worthy of the ambitious name, "the hedge".


Above the hedge, I've got attic-air input and exhaust cycling through 2 1k lights ducted up thru the ceiling to the open-air in the attic. both ballast mounted in the attic. insulated ducting in the room. "Sun shield" reflector covers (dont laugh...did i get taken or do these work? anyone used them? i dont think ive seen them in anyone's pictures, ever, probably not a good sign.) as my hoods were hot to the touch last grow, and hoping to control the heat mainly thru duct air flow rather than added ac.


all that to say that I have 6" 440 cfm inline fan to power the air movement in the ducts...with a cutout section of a house air filter fitted over the entry-hole (not much impedance to air flow but keeps bugs and insulation out) and the fan positioned at the exit-hole sucking the air thru the whole deal like a wide u-shaped straw and blowing out into the attic.


Q1: am I doing this right or could it be improved? (Am JUST about finished building, so it's still theoretical as to how effective the new design will be...had un-insulated ducting running around the room, making turns and incorporating a carbon air filter before so I'm sure the new straighter, insulated, run without air filter will flow faster and cool better but hoping drastically better)


Q2: Anyone else cycle attic air thru the hoods, does that become a problem when using summer air to air-cool hoods?


Q3: With my air-cooling air now separated from my grow-room air I think I may have an easier transition to co2 enrichment. Anyone have CO2 lessons or advice to share?

this project will receive pictures after a while but let's talk theory until then.

THANKS and be well my civil-disobedient peers!

You are using a room similar to mine.

Q1: I think you need a bigger fan.. I use a 8'' 675CFM Max fan to cool my two 1000W air cooled hoods. My hoods are never hot to the touch, and they shouldnt be.

Q2: You are definitely going to run into heat issues cycling attic air through your hoods. Its well over 100 degrees in the attic during summer months. You need to pull from another room in the home ( thats what I do )

Q3: You should be fine using co2 but I would seal up the doors with weather stripping and add one of those draft blockers underneath the door.

Basically you need a bigger fan, and you need to pull air from somewhere else its all good for now but come May you are gonna have problems unless your attic is 75 degrees all the time.

same here, i pull air from the grow room through 2K with an 8" and vent to the attic, you do need a bigger fan 8 or 10 even.

this creates a negative pressure and always pulls cool air into the room through the a/c duct, but it's harder on the A/c and the rest of the house. I might cut another hole and pull from the attic also, just haven't yet because I rent this house. what's the difference i guess, i already cut one. removing the neg pressure, and constant cooled air will make my room heat up and i may need to supplement with a small a/c unit. but imo, thats better than spending extra money on your power bill every month, cause the a/c is on overdrive, only to have it take a shit in the middle of summer, fry everything in your room, and have a stranger climb into your attic and ask what all that noise is. ...uhmmm..you're hearing things


beav is right, your attic will be about 150 all summer. but in comparison your bulbs are way hotter, i dont think it would make much difference, but my room isn't vented that way so I can't say for sure. you could always seal the intake hole and pull from the room if it doesn't work as well as you'd hoped.

My room is

pull air from closet in bedroom next to grow room ----------> cool house air goes through ducting -----> through hoods ----- Exhausted into attic.. So when lights are on and the fan kicks on I'm constantly pulling cool house air ( 70-75 degrees ) through the hoods and exhausting through the attic.


Red Bird --- Fuck it dry wall repair patches do wonders lol!!!

Seems to be the main issue folks have... Air Exchange

Your CFM is too low. Way too low.

I would put (2) 1k lamps on a intake/outtake setup. no interference with the room air - outside air cooling the lamps.

Then your room itself will need a separate intake/exhaust system. When the fan to exhaust the room air turns off that is when you want your CO2 to kick on and fill the room.
Will need to make a intake/exhaust setup for the room that exchanges the air often.

HB DC said:

Seems to be the main issue folks have... Air Exchange

Your CFM is too low. Way too low.

I would put (2) 1k lamps on a intake/outtake setup. no interference with the room air - outside air cooling the lamps.

Then your room itself will need a separate intake/exhaust system. When the fan to exhaust the room air turns off that is when you want your CO2 to kick on and fill the room.
Will need to make a intake/exhaust setup for the room that exchanges the air often.

Click to expand...

If he's running Co2 in a sealed room and using AC he doesnt need to exhaust / intake any air from the grow room itself.. He's working with CEA (Controlled Environment Agriculture ) The plants will produce fresh new oxygen and the AC brings in new fresh air. I pasted below a CEA article from cannabis.com

In a truly sealed room the ballasts will also be housed in the growroom. Preferably, higher up on a shelf out of harm’s way, yet accessible for maintenance and routine inspection. This does create a lot of additional heat in the growroom versus remote ballasts outside of the growing area. However, it would defeat the “sealed” principle of this room to house the ballasts elsewhere. By centralizing the operation, you are consolidating all your eggs into one proverbial basket. It is also a well understood fact that longer lamp cords diminish the lumen output of most HID lamps, so shorter runs are preferred. If you mount sturdy shelves high up around the perimeter of the growing area, there is seldom any need for lamp cord lengths of greater than 18’. For many good reasons, it is recommended that you run enclosed ballasts (boxed and louvered).

Since there will be no intake or exhaust, you will need to manufacture healthy air for the growing environment. The first step in maintaining clean, odour free air is an active carbon filter. There are many applications for active carbon filters, in this instance it will be installed with an inline centrifugal fan acting as a “scrubber”. Basically, for a 10’ X 10’ area, a three foot or four foot activated carbon filter will be plenty. Just sit a eight inch or 10” centrifugal fan on top, plug it in, and let run 24/7.
Air from the growing area will be continuously drawn through the activated carbon, and discharged and circulated through the growing environment. The activated carbon will trap unwanted spores (i.e. powdery mildew), dust, odours, and other airborne contaminants (well, except for Jim’s cigars) leaving the growroom air fresh and clean.
A de-humidifier is typically required for dark cycles. Note that in a sealed room the DIF (day/night temperature differential) can be controlled very precisely, so there is often less of a drastic rise in humidity from day to night cycles. RH (relative humidity) should be maintained between 45 to 65%. Higher humidity levels (80%) will decrease the effectiveness of the activated carbon scrubber.

Great advice so far throughout, 6" fans are fine for 2 1000ws if you are running an open design, but they need to be nice hoods that allow proper air flow and the air they intake, whether from the grow room or outside of the grow room, the intake needs to be cool.

Is the top of your hand hot 12" under the glass? upgrade your fan or upgrade your reflector if that is the case.

I run 4 1000ws : 2 each thru 6" exhaust in my grow room and I never go above 75 degrees but I supplement with a 12k BTU A/C that feeds the room cool air and a commercial humidifier to keep my Humidity up (it lowers temps a couple degrees as well).

If you go sealed, don't fuck around: get a co2 monitor that can tell you the exact ppm of the room, and that can control the ppms precisely. take the glass off your hoods, blast your a/c , set the co2 to 1300ish ppm , exhaust up high if temps go above 90 degrees, and get a humidifier / dehumidifier on a controller that you can dial into an exact percentage. In a sealed room humidity / mold will be your biggest enemy.


Without all the proper equipment I listed above you will be lucky to push anything close to what you can do just running unsealed 24/7, which is cake in my opinion.

Just know that cannabis like 77degrees/50% RH in an unsealed environment with lots of air flow : This can be achieved numerous ways here in the desert especially since we can use humidifiers.

In a sealed environment she likes 80-90 degrees/50 % RH/ 1300-1500 PPM Co2 - Equipment can be bought to control all these things to the tee.

OK so have decided to pull air for cooling lights from the room next to the room, take that thru the lights and vent that into the attic, good call Beavr, summer would have caused problems.

Gonna run a 5k btu window ac in a cutout in the closet and blow a tower fan across the coils in the closet on the other end. Will keep a close eye when test runs begin for any light leaks in or condensation issues in other room.

very excited to see how much improved my temps will be using:

A shorter route of insulated ducting, with faster-flowing external air thru lights, ballasts removed from room to attic, and the sun shield reflector cover. No one said anything about that product, so I guess it's not popular but I'm hoping for lasting value as a temp mgmt tool - may prove redundant if I can keep 2 hoods w 1000w bulbs cool just by moving my air better. Still I'm gonna put a layer of reflectix insulation on the other hood in the room and see if either or both work to remove heat from the room. I gotta think it will.

Maybe run room w/out ac or at least on a light diet of ac. My hippy mom gets mad cause growing is not a very 'green' hobby. I'm trying to do better ma! Lol

if your fan is exhausting well enough, then there's no need for insulating the hoods. they'll barely be warm.


organics is green... we can't do much about the electricity we use for lights and a/c, but you can make up for it with a simple compost bin.

I use compost to amend my dirt with fresh humus, aact's, mulch. (i've been using the same 4 bags of roots for over a year)
I cut-up and reuse the banding on packages when I order equipment online and use as strain labels.
if running hydro, i'll distribute last weeks nutes to all the shrubs in the backyard when changing buckets (so they don't go down the drain)
you can dump used carbon filters into your soil mix, use fish tank water on plants
use ladybugs instead of chemicals

turn garbage wood into biochar https://www.rollitup.org/organics/615900-biochar-burner.html

Ive used the empty soil bags to cover 7 gal outdoor pots from the sun, just think, what would macgyver do? lol

Redbird1223 said:

if your fan is exhausting well enough, then there's no need for insulating the hoods. they'll barely be warm.


organics is green... we can't do much about the electricity we use for lights and a/c, but you can make up for it with a simple compost bin.

I use compost to amend my dirt with fresh humus, aact's, mulch. (i've been using the same 4 bags of roots for over a year)
I cut-up and reuse the banding on packages when I order equipment online and use as strain labels.
if running hydro, i'll distribute last weeks nutes to all the shrubs in the backyard when changing buckets (so they don't go down the drain)
you can dump used carbon filters into your soil mix, use fish tank water on plants
use ladybugs instead of chemicals

turn garbage wood into biochar https://www.rollitup.org/organics/615900-biochar-burner.html

Ive used the empty soil bags to cover 7 gal outdoor pots from the sun, just think, what would macgyver do? lol

Click to expand...

Yeah man when I used to run DWC I would throw my old " nute soup" onto my Palo Verde tree out front...

i had a picture of 2 HIDs chained together with fan and filter inside a tent. i lost that picture and i want to show somebody what im thinking of doing.

do any of you have a good picture or a link to something like this?

i was thinking of two 600s in a 4' 9" square tent. i want a fan to suck air in from another room, and another to work with the filter to take hot air out of the tent and into the attic.

i forget the size, but i have a fan and filter set up that clears a 10 x 10' room in a few seconds. it sounds like a wind tunnel without the muffler.

Its not sealed tent but something like this? [video=youtube;-b0AhVPSDgs]http://www.youtube.com/watch?v=-b0AhVPSDgs[/video] about a minute 15 secs he stars showing the lighting set up. I got to try one of these nano ballast they look so cool. The 1000 watt version of the nano only ways 2.9lbs