Duct Sizing for Light Ventilation

The AC is 11,000 btu

 

You should not have any heat issues with that unit.

 

This is a perpetual grow, so there will be two lights, are you suggesting that I use a 600W for veg AND a 600W for the flower? I have not purchased the light for my flower space yet...so does it make sense to move my 600W to the bloom room and buy a big-ass T5 light for VEG?

I am not sure what to do at this point. If I use a T5 for veg then my ducting becomes much simpler and the grow will be substantially cheaper. I want to reduce costs wherever possible (of course) but it is crucial that my setup produces potent high quality plants. These buds are going to fight cancer! Having T5s in veg would reduce all of my costs, but are they intense enough to bring out the best in the plants?

Great discussion so far, please keep it coming!

 

My room is roughly 6 ft by 6 ft and I run a 600 over a 2x4 table and a 400 over a 2x2 table. Both have 6 inch exhaust that downsizes to a 4 inch line and with ac my temps run max of 80.
You could run two 600s in line on the right side of the room with that ac unit with no heat problems.
You can use T5s for vegging too.

 

Thanks MGJ. Would you go with T5s or another 600W in my case?

 

I see no reason why you can't run two 600s that shamelessly cover the right side of room. Are you kidding reflective Mylar on the walls that helps a lot. I would just run the T5s left side of room.

 

Thanks Nippie, there is one main room, but the bloom space (not completed yet) will be in a tent. Thanks for the feedback on the T5s. I'll wait on buying any new lights until it gets closer to bloom time. I'll set up the 600W for veg and get it going!

Thanks tons! I'll post a few pics of the setup when it's done.

 

Run the T5 for veg, it will work just fine and use one six hundred for flower. And I'd veg in the tent and flower in the room. These are seeds started in end 0f july and have been under a T5 24x7 for two weeks now. I have a 10x10 room and two 1kw's. I grow only with an 4ft 8 bulb t5 in the summer and just use the regular house ac to cool the room. In the winter I switch over to veg in the garage in about middle of October and use the room for flower exclusively. In the room I have a 10 inch duct bringing in outside air with a small fan attached to it. I'm getting a line voltage thermostat today and am going to hook it to the fan and use it to keep the room cool by switching the fan on and off at 75 degrees. I had a blower motor contraption that I took out of an old furnaceI rigged up doing this the last couple of years without a thermostat and just using a pin timer set to on every 30 minutes for 15 minutes and it was overkill and too hard to regulate.

now


and various iterations

 

Your duct sizing and cfm are all wrong insofar as cooling your lights is concerned. (I do this for money)

one 600w light needs 300 cfm of air when there are no turns or obstructions in the duct. you have the light and I am sure some turns.
one 1kw light needs 350 cfm of air "
your min required airflow to cool your lights is 650 cfm. "
Your vortex fan has a cfm range of 400-600 cfm but is rated at 452cfm on high.
one 6 inch round flex duct is rated at 12ocfm

Based on that diagram I would do it this way...

All calculations/cfm are based on 100 foot max duct run at .5 inches water column and 1000cfm vortex fan.

1. Use something like this for the airflow (it's variable speed). http://www.homedepot.com/p/Vortex-8-in-Low-Powerfan-Inline-Duct-Fan-VTX800L/204262767?cm_mmc=Shopping|THD|G|0|G-VF-PLA-D26P-Plumbing|&gclid=Cj0KEQjwg8i_BRCT9dHt5ZSGi90BEiQAItdjpC5-3s38cH28QkFgcK2f33e3NBcL51mJ-nm4uHR6eSsaAsGO8P8HAQ&gclsrc=aw.ds

2.You must start from the floor with a 16inch round flex duct (1000cfm) then reduce it with a 16" to 10" Y or use this plenum and attach two tens to it, I'd use the plenum because you need to filter the air (even though it is only theoretically going thru the lights), also, this plenum is sized for aprox 1000cfm input http://www.homedepot.com/p/Master-Flow-16-in-x-25-in-Dual-Filter-Plenum-Kit-PK1625DF/205430361?cm_mmc=Shopping|THD|G|0|G-BASE-PLA-D26P-AirCirculation|&gclid=Cj0KEQjwg8i_BRCT9dHt5ZSGi90BEiQAItdjpCUHkofd7MnQ0dyqdnOV8OLxmNpeBZPG8wSGG7LAzlsaAhvL8P8HAQ&gclsrc=aw.ds

3. Come out of each light with a ten then couple them together with a 10" x 10" Y and run that to the vortex fan. The ten run to the fan will be a little large (because you started with 1000cfm in and theoretically only have 800 cfm out, maybe less after length and turns of entire run) but it will work and at worse just cause the fan motor to load a little more but that's doubtful.

http://www.waptac.org/data/files/website_docs/training/standardized_curricula/curricula_resources/duct system sizes and airflow quick chart.pdf

Once you get the lights cooled then you need 3500 btu per 1kw light to cool the room.

or you could just skip all the above and install a 1.5 ton dual zone mini split and be done with it.

 

lmao. I was high as fuck trying to write that and it's the readers digest version, but yeah, that's kinda what I said. And the funny part is I'm like the mechanic that never has time to work on his car so always rigs it, but.... my shit works.

The 600w needs 300cfm, that's a 9 inch duct minimum, if you try to pull air through the 6 inch duct with a 1200cfm fan it will not deliver the required cfm. What it will do is cause extremely high water column and load the fan motor, but you won't get 300cfm out of the duct. Short answer is like Dolly said. You're trying to get 50 pounds of taters in a 25 pound sack.

 

Taters, what a nice way to describe a blivet...

 

so did you ever figure this out?

 

He's got the 600 for veg and the 1000W for flower.