Hey there. I'm building a cabinet based a lot of what I have seen here on GC. I have finally finished making the cabinet, and am trying to make everything about as good as possible without breaking the bank, but not skimping on quality. I DIY'ed a DWC out of a 30 gallon storage container, put 6 pots in it, and made the grow box the right size to fit it and sit nicely in my closet. This is meant for stealth. Inside the box, I have a 400 w ballast w/ a cheapo wing reflector (no air cooler) to run inside (both MH and HPS, some CFL's too for the whole spectrum). I caulked up all the edges and weatherstripped the door so that all the air will be coming from the under part of the door, and so I can run the ballast outside to lower heat. The box's dimensions are: 21" W x 38"L x 66" H The storage container is about 19" W x 30" L x 17" H Trying to SCROG this guy too. Now. I need to decide how to ventilate. I've heard you need to circulate out the air once every 5 minutes, and the inside of the box is about (edit) +/ 28-31 ft^3, meaning i'd need a ridiculously low CFM to keep that. But, heat, obviously, it will probably get pretty hot in there, and I'm going to be safe and at least carbon filter it, maybe do the ONA bucket in conjunction based on smell. So, to keep temps in there any sort of reasonable with a bigger light like that, whats the best way to go about ventilating it? Here's the two option I have so far. 1.) 4 inch 110 CFM computer fan, attached to a PVC pipe grate attached to a DIY carbon filter +/- $70 and is relatively quiet. 2.) Something like this, HTG Supply - GrowBright 4" Inline Fan & Carbon Filter Combo A bit more pricey, likely offers better airflow, and the carbon filter looks legit. But, I'm sleeping nearby, and if its real loud, I would not be a happy dude. The other option is to consistently place frozen water bottles by the intake, so the air would be cooler inside etc etc, but is a bigger pain in the ass, but also super cheap! I'm going to make a screen out of PVC and twine, and keep it in place by drilling some bolts through the sides to secure it between the two bolts. But i have time for that part. Let me know what you think! Any help or advice is greatly appreciated, I'm trying to get it all right!
If you plan on putting a 400 watter in there, you need AWESOME ventilation and a nice fan (350-400 cfm I would think to be safe). And that fan will not be quiet whatsoever. I have a 250w HPS light and even my 200cfm fan mounted right above the light can barely handle her (and it sounds like a little blowdryer running in my room 24/7). I would say get a 250w HPS with a REMOTE ballast, not ENCLOSED and a 200 cfm fan with 4 or 5 2" passive intake holes on the bottom with flat black 2" PVC pipes to block light leaks. And whatever room the cab is in better be under 70-ish degrees or have AC near at all times.
Hmmm. The thing is, I already have the light. I got a 135 CFM Fan HVACQuick - S&P TD Series Inline Fans And some carbon filter off eBay. Does the size of the intake holes really matter? I was just hoping that there would be more air flow from under the door. I have a remote ballast luckily, and can keep that and the air pumps outside the box to keep it cooler, maybe add some frozen water bottles. Also, I was planning on keeping the door open as often as possible, besides when there is a girl over or something I even have 2 small and 1 medium sized fans to help circulate air in there, so hopefully it will work!
Thats an awesome quiet fan, but the CFM ratings low. Passive intake holes should be *2x* the size of the exhaust. A 6" exhaust/fan would "require" six 2" holes or three 4" holes. Yours would need 8" in holes if that makes sense, four 2" or two 4" holes. I have 4 2" holes and PVC pipes so theres no light leak and I REALLY wished I had made 5 or 6 2" holes because that would help with getting all the hot air out faster, and pulling in cooler air. Test temperature and humidity levels before wasting seeds. Good luck my man.
Hmmm thanks for the advice! If only you had said something sooner, I would have picked up a larger one... I guess I will have to rely on hoping and praying then, or return it, lose like 20% on restocking, and get a larger one. But, if im not correct, isn't a large part of the reason for the noise the "WOOOOOOSH" of the air? And, should I be ok if I open up the door when I can, and put frozen water bottles in the res? That way maybe they will turn purple, water stays cooler longer than air, etc. But, if I definitely should step up to the 5" (197/149) or 6" (293/218) tell me and I probably would, as long as there isn't the sound of a crazy blowdryer going in my closet 24/7 ! Or then, should I look into an air duct muffler? Ahhh. Complications...