Need Ventilation advice 315cmh in a 3x3 tent

IndoorScore

Active Member
Hey Guys,
Brand new to cmh but it's looking like the best way to keep temps in check and still get results close to that of a 600w HPS in a 3x3 space (supposedly the perfect coverage area for these lights).

When I was looking at the 600W, I assumed I would have to get a 6" inline @~450cfm, fan controller and 6x12" carbon scrubber. Now that the light will be what I hope significantly cooler, even with an open air bulb, I wonder if I'll really need all that fan for a 3x3x6 tent.

Anyone running these lights in a tent, would love to hear about your exhaust system. I will unfortunately be exhausting directly into an attached bedroom from a walk-in closet... so no true exhaust for the heat other than an AC controlled apartment, thankfully the AC can keep a decent consistent temperature throughout so I should be okay I think.

Also, if anyone is using the nanolux 315cmh fixture with the attached ballast, let me know how thats working for you. Included the picture below, I thought that at ~350 all in with phillips bulb, i'd be in for about as cheap as possible with a decent reflector.

NEWB, so any and all advice welcome with open arms.
Thanks!
IS
 

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Growdict

Well-Known Member
you could certainly get away with a 4" fan. however if you got a 6" with a (separate or inclusive)variable speed controller, you can turn it down and it would be quieter, if that is an issue. i have the sunsystem 315 with built in ballast and the 4" does a good job as long as you arent venting into the same room. if you can set your a/c to always circulate house air at low volume, you would be able to close your bedroom door, if not, you may need to keep it open during lights on.
 

IndoorScore

Active Member
Thanks for the quick reply man.
I have about 550sf total in my place and it has it's own forced air heating and air-conditioning. I'll have to obviously check temps in the closet compared to at the wall where the thermostat is now, but I haven't had any issues with raising and lowering ambient temp in the apartment as a whole.

I may just go for a 6" combo just to be safe. As I am growing in tight spaces to my neighbors, I would like to keep the odor minimal. If it's pushing a bit too much air, I can always just turn down the fan a bit. Better safe than sorry in this regard?
 

IndoorScore

Active Member
And I forgot to ask, what sized space are you in?

I'm trying to find the cheapest 315 combo (or remote ballast for that matter) with the phillips bulb.
So far it's looking like 260 shipped on the fixture and 75 on the bulb to get me something decent
(IE not the HTG or similar conversions with regular ballasts, which I assume drops efficiency.) You're still using the included bulb in your rig?
 

Growdict

Well-Known Member
i have it in a tent thats 4x4. i think it works better in a 3x3 or 1m (39x39") tho. still using the 3100k bulb it came with, 1 year old now. I hear 2 years is replacement
 

IndoorScore

Active Member
yeah, the phillips 3100 seems to be the bulb to run if you're just going to run one ( and it seems much more even than MH/HPS in terms of serious switch benefit). I'm just struggling spending 3-400 on CMH when I could probably spend about the same and get a decent COB setup for the same sized space... decisions decisions.
 

IndoorScore

Active Member
Yeah, found a pretty barebones 315 kit on eBay for $250 bucks with the phillips 3100k bulb. Probably no way to touch that with led in terms of cost vs energy savings.
 

visajoe1

Well-Known Member
You have 54 total square feet. A rule of thumb is being able to change air once per minute.

My tent is about 40 square feet. I run a 6" 240cfm booster fan pulling through a 6" carbon filter (with the outside foam removed) and it still sucks the sides of the tent in a little. Even if I lost 50% of my cfm due to the filter, I'm still changing air 3x per minute. You can still use a speed controller with this fan too, and they are MUCH quieter and cheaper than an ipower or similar fan.
 
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