Hey fellow blades. I'v been working on a small grow box for my own personal supply lately and im just about ready to get started. I just need to figure out my ventilation system and then I can finally start germination of my seeds. My grow box dimensions are 55 inch H x 20 inches W x 20 inches D. I will be using a single 250 watt Feliz CFL bulb with a Sun Systems reflector for vegitative growth then I'll switch over to a 400 watt HPS system for flower. I plan on building a 4 inch cool tube using the Pyrex Bake-A-Round DIY method. I plan on growing 2, maybe 3 plants at a time in 2 liter pots in FFOF soil mixed with some Light Warrior and maybe some perlite/vermiculite (dont know if i should). What I am having issues with is that my grow needs to be stealthy and noise/smell is a major concern for me. I have a ventilation plan in mind but would like to know whether it is good, bad, overkill, or simply not enough. The plan is: Using a Dayton 10 inch Axial exhaust fan which is rated at 665 CFMs and about 52 dBs. Here is a link to the fan in question. Dayton Blowers: DAYTON® AXIAL FAN 10 inch - .23 AMPS - 26 WATTS - 665 CFM [736911] - Fans, Blowers & Ducting - Environmental Control - Discount Specialty Farm, Greenhouse & Garden Supply Store - Horticulture Source What I plan on doing is mount this fan in the attic as my exhaust fan while using 1 or more (as needed, dont know) passive intakes. I really want the fan in the attic for obvious reason/security. Smell, noise, etc. What I really want to do is: 1: Lower static pressure 2: Increase velocity Apparently, this will make the fan run more efficiently due to lower static pressure and also create a better enviroment for air exchange due to the higher velocity. Please correct me If I am wrong as I am still learning. Besides, if I had a 10 inch pipe running down from my cieling, it would really defeat the purpose of being "stealthy". Do do this, what I intend on doing is build my own exhaust reducer which will lower the size of of the piping from 10 inch (fan) to a 1-2 inches immediately after the fan in the attic. Then take the 1-2 inches piping straight down from the attic, through a small hole in the ceiling directly into the top of my grow box. From the fan in the attic to the grow box in my closet, directly below will include 100% straight piping. Not rippled ducting, but actual straight through piping for smoth air transport and no bends. I'm thinking stainless steel, aluminum, or PVC piping, which ever conducts less heat. Then, once I have the the piping connected to the grow box, I will do 1 90 degree turn from top of grow box to one end of cool tube by making one more reducer from the 1-2 inches of piping from ceiling to a 4 incher to connect to 1 end of the 400 watt cool tube I intend on using for flower. This way, I, in theory, should be able to do both, cool my grow box and cool my 400 watter. For odor control, I will attach a 4 inch car intake filter filled with activated carbon to the other end of the cool tube. Entire ventilation system will be 100% air tight so that any air that the fan pulls has no choice but to go through the carbon filter. My home is always between 68-78 degrees F and would like to know if this system I have conjured in my head will work. If it helps any, my grow box is 100% sealed air tight and completely light proof. So the only FRESH air coming in would have to go through the passive light proofed intakes. Also, I plan on having some super quiet PC fans (1-4 small fans) inside the grow box for circulation but I am still not sure how to go about that. I know this is a seriously a long read but I want to make this grow a success as I am sick and tired of the shady, unreliable dealers down here in Texas. Well, here it is, I may be going about this completely wrong so any help, advice, thumbs up, criticism, insults, flaming are ALL welcome. Help a new grower out please! -Alter
Also, thinking about using 3 of these PC fans inside the grow box for air circulaton, stem growth, and imitation wind. 39 CFMs each, at only 9 dBAs, and 600 rpm fan speed. 2 in and around plants and 1 in between the lights and top of canopy to keep the heat away from the plants. 140mm Silent Series Cooling Fan EDIT: DITCHED THE 1000WATTER FOR A 400WATTER