We have a black plastic curtain lined with mylar completely splitting a small bedroom, leaving the "useful" area about 7x4... There is a window in the room, but outside of the curtain. Inside, we are running a 400w HPS hortilux and 4 CFL's. We made a pretty good air tunnel using a fan and some supplies, and this is set up so as to pull cool air in from outside (from open window) and blow it into the room, above the HPS. It will work well when its really cold in a few weeks, but for now its not helping much. The problem is that the side w/ the lights is around 92degrees when everything is on, and this is obviously waaaay too high. Now, we have not yet set up the rest of our air circulation system, which will involve a small fan to blow hot air from the light area out into the rest of the room (thru hole in curtain) where there will be a carbon scrubber hanging + blowing the air through a tube and back out the window (at opposite side of the intake for our "air tunnel"). might sound complicated but anyone familiar with air pressure or convection currents should probably understand why we're doing that. We also plan on putting extra fans in the lit area, but that doesnt do much. Does anyone have any good suggestions for how to help cool the room? I know it may improve once we finish setting up, but i dont see it helping enough to drop it by the 15 or so degrees that i'd like to see ANY HELP APPRECIATED ps. havent started anythin in the room yet, just setup
you should have your intake fans on the bottom of your grow room. And the exhaust fans at the top of your room. Hot air is lighter than cooler air. So the hot air will rise.
the intake comes from the window, through the air tunnel (which passes through the curtain) and is blown into the room directly toward the HPS... we are gonna put the fan that blows the hot air out on the ceiling for the reason you just mentioned
dude.. I had a 400 that I just recently switched to a 600 in my shed.. like your bedroom I have half of it walled off with that black and white poly.. all I did was run a 6" flex duct from the window across the shed and put a 265 blower pushing the air through.. I took the duct all the way to the window, I would just go get a duct rather than making a airway it's much more productive.. also a good 465 dayton or even a 265 would probly do.. just gotta get that air exchanged.. with my 265 and my 600 on I get it about 76 at night and 82 during the day.. is it still hot there during the day or what?
Its not really hot here during the day but its been like 70 That sounds like a good idea, and somewhat fits with the plan we already had... I hope that having a carbon scrubber w/ fan (i know nothing about the fan yet, so cant describe it) and flex duct exhausting out the window will be strong enough to lower the air pressure a little on that side of the curtain so the hot air will come out through the small desk fan we plan on mounting to the ceiling. I'm gonna take a photo soon of what we already have set up but ideally the air will move like this: Outside--> "Air Tunnel"--> Growroom---fan-in-upper-corner-of-curtain---> Room--> Carbon Scrubber--> Flex Duct/Dryer Duct--> Outside BTW "Air Tunnel", which i'll take a pic of, is basically just something we made... It is an 8 or 10 inch fan mounted insde a cone-shaped thing like 3ft long so the the air is pulled into the narrow end and blown out the wide-open end. Doesnt push a ton of air, but it sucks a good amount of air in from outside, so once winter rolls around it should help a lot more than it is right now.
still seems strang to me.. it's like 80 here during the day.. and my 600 keeps it at like 82 in my shed.. How is it getting so hot in there with a 400 if you have that 70 degree air coming in? Do you have the ballast right there ? If so I'd run it across the room, far away from your little room you made as posible.. a blower would help drastically ...
Mobitsfa answered half of your problem (whether you acknowledge it or not), and I've just enboldened the other half. Little fans and home made "air tunnels" aren't going to be up to the job. I've tried to resist, but it's no use; I'm gonna have to tell you... Your whole ventilation system sounds half-arsed. There. I've said it. Sorry.
Rabiez, you arent hurting our feelings by saying you think it sounds half-assed. If you are going to say sorry, allow it to be for the fact that you didn't say much to help us. I agree with you that our device to bring in the cold air is pretty bootleg, but it does its job fairly well. That's about the only piece of equiptment that we're using that is home-made... We just went out and got flex duct/dryer duct to place near the ceiling, with fans on both ends of it to draw the hot air out and back into the non-grow area and then will be setting up a carbon scrubber (purchased, not home-built) to push the air through more flex-duct and back out the window. Also we have 3 oscillating fans in the corners of the room... I guess we wont know how well the system works until we get the carbon scrubber set up, but if anyone has any good suggestions besides what has been said, its much appreciated
I built my own little ventilation system using just two small fans to vent a 4x5x7 ft.^3 growing area with a 400W HPS running 21 hours a day. The temperature ranges from about 78 to 88 degrees depending on outside temperature. I think the only problem with your set up is you're trying to cool your light, which, if you think about it thermodynamically, isnt a good place to direct your air flow. Set your intake fan so it blows air right below the bulb and across the top of the plant. This way, you're constantly replacing the air above the plants with ambient air(which largely controls the temperature of the plants). The exit vent should be located as high up as convinient for your setup. Of course, if you're pulling air in from the outside, the lowest temperature you can reduce the room to, is whatever temperature it is outside. So if the temperature outside is 90, the temperature inside will be at least 90 degrees. GL
Ah. Ok. I'm sorry that you think my post didn't help much. Initially, I had intended to point out every little nuance, and give helpful comments about each, and formatted the post as such. Then I noticed the dismissal of Mobitsfas' advice, and wondered if I should bother. After an hour of drafting responses that were dancing around the truth to protect your sensibilities, I decided that they may be taken as sarcasm, and that straight talking was the way to g. I'm pleased I didn't hurt your feelings, as that wasn't the intention. However, it'd be worth browsing the Grow Room Design section to get a feel for what other people have had to do to overcome their problems. Inevitably, most end up spending cash on decent inline fans and ducting, and wishing they'd done it right, from the start. The sad fact is that it's very hard to offer any help when your terminology is ambiguous (at best), and your system is cobbled together from household supplies. By my reckoning, your 4x5x7 growroom gives you 140 cubic feet of space. Ideally, you want to exchange the air in your growroom 3 times a minute. So you'd need at least 420 CFM blowers, based on active intake/exhaust on reasonably short ducting runs. So, answer me this basic question, and I'll try to help; How many Cubic Feet per Minute can your system currently push?
