New Tent Build and First Post.

[Untchbl]

Hello GWE folks!

Gearing up for my first grow after reading here for the last month and have a few questions on final tint build out and environment control.

Here’s the setup 30 x 60 x 80 tint. 1 Nanolux CMH 315. 4” hurricane with large carbon filter exhausting into the room. Currently set up for passive air intake. Upstairs bedroom that averages 68-75 degrees and a RH of around 40.

With the tint zipped up it can get as warm as 85. Turn the exhaust on and I can pull it down to around 80-82. Overall room temps still hang around 73. It for sure has negative pressure even with a bottom sock open and a 6” hurricane clip on pulling air in.

With tint open and just the ceiling fan blowing it never gets hotter than about 78. Thats where I’d like to be at max
with the tint zipped up.

So, exhaust out the window? Add 8” inlet with a passive fan inside pulling air through inlet? 8” duct fan on the inlet? I want to keep it simple as possible.

I’ll be starting with 4-6 photo plants in 5 gallon fabric pots.

Let me know your ideas.

[az2000]

The LEC 315 is sufficient for a 36x36" tent. You're going to need to supplement the sides of your 60" wide tent. (And, you're not making the best use of light with 30".).

I would in smaller containers and transplant. It's hard to keep a soil uniformly wet while not too wet (too long) when a plant's in a disproportionately-sized container. I'd start in 20oz seedling cups, transplant to 1gal, then 3gal, then 5 gal.

You said "4” hurricane" and "6" hurricane." If it's 4-inch, that's probably not enough capacity for that tent. 6" is. You probably don't need a fan pushing the inlet side, if that's what you were talkingabout doing with an 8"? As long as you're moving enough air to replace the full volume of the tent every 5 minutes (bare minimum), and moving enough air to keep the temperature/humidity where you want it (while moving the bare minimum, at least), that's all that matters.

[az2000]

EDIT: There is a CMH hood that has the bulb sideways, not vertical. The vertical hood is a square footprint suitable for 36x36". The horizontal hood seems to be more rectangular. That might work better in your 30x60. It might fit the 30 a bit better, and go 40" to the sides (something like that). I'm positive you'll still need to supplement the sides. Ultimately a 315 CMH is good for about 9sq ft. Your tent is 12.5sq ft. So, you'll definitely need 50-60% more light.

[Untchbl]

Just crunched some numbers. This hurricane 4” in-line is good for 170 CFM. The tent is about 81 cubic feet. Thinking this should be sufficient if I can just get some cool air in?

[Untchbl]

I’m actually not planning to utilize the full footprint of the tent. Only a 3x3 or so.... the rest of the space will just be additional room for things like a humidifier or some seedlings to hang.

Just looking for some direction on temperature control with what I have. Thanks.

[az2000]

Sure, if you ran a 4" on the input, slightly slower. That might be enough. Or, get a 6 for the output, and use your 4" for the input. The larger the fan, the slower you can run it, and the quieter. I have a 4" an 6" ActiveAir. I like my 6" much more. I can dial it down to low volume, moving as much as the 4", and it's whisper quiet. (Speed controllers are a different story. Maybe your Hurricanes come with a speed controller.).

[az2000]

I’m actually not planning to utilize the full footprint of the tent.
Just looking for some direction on temperature control with what I have. Thanks.

It seems to me 5 5gal plants would take up about 30x60. (I typically do four 3gal containers in my 48x48.).

Did you get a CMH hood with a remote-mount ballast? That will make the most difference. They make an air-cooled/sealed hood too. I haven't tried one yet. With the ballast outside the tent, I don't feel like air-cooling the hood would make that much difference (not like removing the ballast). There is some light loss from the glass front of the reflector. I don't think my CMH is warm enough to warrant that light loss. With the filter right next to the hood, it sucks the air from the hood (essentially).

If you can't manage the heat, you can run a 6" exhaust fan, and 6" intake (just a little slower than the exhaust, to maintain negative pressure). You can move a lot of air.

[Untchbl]

Here’s the ballast and reflector. The bulb is vertical. I guess if I can’t control heat with this stuff I bought I can buy 6” stuff for exhaust, sell the filter and use the 4” for the inlet. Next step would be to go to a Quantum board setup.

Agreed on the 5 pots and just rotate them. In my mind I was going to have a 3x3 grow for 4 pots and 2 strains with extra room in the tent for gadgets and such.

[Untchbl]

If you can't manage the heat, you can run a 6" exhaust fan, and 6" intake (just a little slower than the exhaust, to maintain negative pressure). You can move a lot of air.

Hey AZ2000 what 6” would you recommend? Not really worried about cost, just want to do it right.

After tinkering some yesterday with the current 4” just exhausting in the room it didn’t even warm the room up, so thinking I may just sell this 4” stuff and go with the 6” exhaust now.

[az2000]

IMO, 6" is more suitable for that size tent. I use a 4" for my 24" x 48" (48" tall) tent. I'd prefer using a 6" for that, running slower and quieter. I've never used an 8", but I wouldn't mind trying that with my 4x4 tent (instead of 6"). I think larger/slower is quieter. You can get flanges that clamp onto the side of your tent, and you cut out the center hole (if your existing holes didn't accomodate 8" tubing).

I don't have a recommendation for brands. I use the old-school green Active Air. I spend $70 USD for a 5amp (or 3amp, I forget) variac. That's a very quiet way to slow those fans. The inexpensive speed controllers make those fans buzz/hum loudly at lower speeds.

There's a lot of newer fans out there with integrated speed controllers. Those might be a better choice. I like having a cheap fan. The bearings can be replaced. The speed controller is separate. If I ever need to replace the fan, it's just $70 for the fan. I already have the speed controller which will last forever unless I try to drive something outside it's capacity.

Something I should have mentioned about pushing more air through your tent: the carbon filter operates better when the air spends more time in the filter. If you needed to move a lot of air, you might need a larger filter. If you have unwanted odors, it could be that you're moving too much air.

[Untchbl]

Thanks so much! Can you give me a link to the controller that you have?

[az2000]

It's a 3amp, model SC-3M. Amazon ASIN: B006NGI8VS . But, if you search Amazon, you'll find a couple other brands that are 20% less expensive. Those weren't available when I bought mine years ago. I might have bought one of those instead. However, the other brands look a little cheap (construction) to me. To me, this part is a long-term investment. It may be worth the extra $15-$20 USD.

There are different kinds of fan motors. Apparently some work with the inexpensive speed controller (without buzzing/humming). I don't know how those motors would work with a variac. All I know is that the variac works very well with the motors that buzz/hum with the cheap, dimmer-like speed controllers. I can dial mine way down and hear *nothing*.

I mentioned earlier that the minimum air flow should replace the entire volume of the tent every 5 minutes. Figure out your cu ft space in the tent, divide by 5 (minutes), and convert that to gallons. Then use a large trash bag (like 40gal?) on the end of your exhaust hose. and see how long it takes to fully inflate. My 4x4 tent should inflate one of those in 15 seconds. That gives you a concrete idea of how much air needs to be flowing. (But, if you have to manage heat, you'd move more air.). They sell CFM meters. I've thought about buying one. They have a fan blade on one end. You hold that over the end of your exhaust hose and let the air spin the blade. The meter tells you how much CFM that is.