Is this enough exhaust?

Discussion in 'Grow Room Design/Setup' started by GrowMeowMeow, Aug 2, 2008.

  1. My flower room is having 2 1000 watt HPS lights in a Sunhut, 4ft x 8ft (7ft High). I plan on connecting the lights with ducting and air cooling them with a Fan/carbon filter combo (passive intakes a the bottom of the hut).

    Is this enough to keep temps down and air smelling clean?

    It's a 660 CFM fan, but a 400CFM rating after filtering? What do you think?
  2. First of all you dont need a carbon filter for air cooling the lights if the air is coming form one end and going out the other.

    Second that wont be enough.
    You will have to have a separate exhaust for the room itself. thats where you will need the carbon filter. Preferably an air intake also to compensate for the exhaust.
  3. That will be really close. I think you will be fine if you can keep the room ambient at 72. That will be very difficult however if you exhaust back into the room.

    I dont see how that fan and filter are rated that high personally. Doesnt look like much froom for a motor that pulls that type of static pressure.

    If i had to bet i would say that would be 200cfm at most.

    Dude by the name of august west on here has a similar set-up but 1 1000 i think . I think he uses a canfilter 50. Search for his name on the forum. He is a cool dude and thinks logically, he will set it staright.

    I think your biggest need is to have whatever vents those 2000w vent outside if the room the passive intake is pulling from.
  4. Sorry i guess i didnt explain but yeah fullmetaljacket is right. You want to vent the the 2 exhausts out of the room where the tent will be in. Or the inside room temps will get too hot and your tent temps will sky rocket. Eventually canceling out the fact you have any sort of exhaust at all.
  5. get a larger outlet than your inlet and that creates better suction
  6. Im in a 10x10x8 room with a can 50 (all 8" duct) scrubbing the rooms air,cooling my single 1K and exchanging the rooms air VERY well in all temp conditions but also with the aide of the homes AC,i use a speed controller to adj the fans movement and use a HUGE vortex 8" 747cfm fan which with all the ducting and filtering still exchanges the room air many times more than i need.

    I'm thinking the 8" size is a big part of why this system is so efficient,@200 cubic feet and two 1Ks i would also go with a big can fan with a speed controller.

    The biggest question is whats the temps going to be in side the room just outside the tent?

    Using one big fan to do everything im sure would work if you duct your exhast outside both rooms and the outside rooms temps are less than 78F. at all times,unless your getting the intake air from outside and those temps are lower.

    2000 watts is allot inside a 200 square foot tent and heat will be your biggest factor,unless you live in a cool place i see an AC in your near future.;)
  7. Wow, I appreciate all the helpful responses. Thanks, +rep.

    My grow will be done in a California climate, so temps might be a problem in the summer time, but this winter should be alright.

    Trogdor seems to think I'll need a separate exhaust for the lights alone. I can definitely do that if it's necessary, and I could duct it to vent out a window of the room. What kind of fans would be recommended for that and for my Fan/Filter combo that would be venting the area?

    I'm somewhat concerned about fan noise, would this bother someone in adjacent bedroom?

    Futhermore, there are two windows in the room. I could vent the lights and room exhaust out of one of those windows. Should I leave the other window open as a passive intake for the room or what? Should I use a house fan blowing inwards? Do i need to be concerned about pests with open windows?

    Thanks for the help.
  8. The very best set would be using a HO 8" Vortex in line fan(10 year warr.) 747cfm starting with the scrubber up high in the tent (8" flange ) to 8" ducting then to both lights again with 8" light flanges (the larger sizes move more air quieter using less power when a speed control is added),then out the tent and out the window with the vortex at the end and a silencer at the very end to muffle any sound left prior to exiting the window,all ducting runs should be as short and straight as possible to keep up the CFM.

    Vortex #2 intake fan should be mounted just outside the tent as low as possible (A Vortex 6" with 6" duct is fine,6" duct straight out the window for freash air intake is great for cool air and abundant C02.

    Both fans should be set up with a therm. controler or a simple speed controler to move the right amt. of air for the season and to keep the sound level as low as possible.

    An outside fan loop to cool the lighting would also work but cool c02 added to the tent would be a must as would be a quality carbon filter,(i will suggest a can 38 from for the best price you will find,like $90.00 for 1-2 years of flower scrubbing,i use the can50 in a 1000 sq. ft. room with great results.

    Good luck and if you need anything just let me know man,have fun bro.!!!:hello::D
  9. Thanks Ocitown.

    I'll get a Vortex 8in 747CFM fan to exhaust the room, 8in ducting out the window. I'll duct it through both 1000HPS lights to air cool them, and then attach a Can-66 Carbon filter. So the air should travel through the Can-66, through both lights, through the Vortex fan, and then through the ducting and out the window.

    I see you recommended a 6in Vortex fan for intake. Do you think that I can get away with a passive intake instead for the 4'x8' x7'high room?

    If you think I absolutely need the two fans, wouldn't it be better to run the 6in Vortex through the lights to air cool them on a closed circuit, and exhaust the room with the 8in vortex and carbon filter with a passive intake? I dunno, do i really need an intake fan?

    Trogdor, I love your purple wreck grow, it sucks you got a bunch of hermies.

    Do you think I should get the SunHut 4'x8'x7' or the Darkroom 4'11''x9'10''x6'7'' for two 1000w HPS lights? I'm kind of concerned about the low ceiling, i dunno?
  10. #10 ocitown, Aug 7, 2008
    Last edited by a moderator: Aug 7, 2008
    It really all boils down to what will exchange air in the room faster,using the 6" for cooling in a closed circuit is good thinking but then the 8" will draw even more vacuum requiring still another intake fan for the exhaust to function right,a big exhaust will move way too much air with a passive intake unless you dial it in and leave it w/o any speed controller.Which you will want as temps will change with the seasons,to cool effectively two 1K lights,scrub the air and exchange co2 and hot air you will need a big fan with a feeding intake fan moving just a small amt less air to create a constant vacuum in the tent to scrub and work well and still have the adjustment you will need as seasons change the ambient temps around the room and tent.Try anything you want,hey it may work fine for you as there are too many variables were dealing with here,just how i would do it,2 fans and 2 speed controllers.....DONE.
  11. I always say get the highest tent you can afford,im cramped at times with 8 feet.

Share This Page