Best way to setup Inline axial fan

Discussion in 'Grow Room Design/Setup' started by Deleted member 826314, Mar 4, 2015.

  1. #1 Deleted member 826314, Mar 4, 2015
    Last edited: Mar 4, 2015
    Hello everyone,
     
    I just started my second growth (the first one was pretty successful with 220 g from 3 plants!) and for this second growth I wanted to make some changes to improve the quality of my growth. 
     
    Since I had problems with the grow tent overheating (I use a 400w Hps), I decided to purchase a cooltube for my next grow in order to control temps better, also because summer is approaching.
     
    Now, I used to have a 4" inline axial fan that was out from the room and acted as exhaust. However, right after I set up the cooltube with it, after a few hours it stopped working (I assume the quality of the fan was one of the reasons). 
     
    I now purchase two 5" inline axial fans. I decided to buy two because I felt that I could either setup up just one and use the other one as a replacement, or two setup both of them at both ends of the tube in order to improve the airflow. 
     
    Now I was thinking that probably the best solution is to mount both of them, what I want to ask you guys, is if you think that that is the best solution and if that would reduce the chances of the fans breaking since they would be working together and probably would have less resistance.
     
    Thanks in advance!
    .

     
  2. As with all exhaust and heat issues i need to know a few things.
     
    1.)Size of the tent
    2.)Temp of the tent
    3.)Temp of the room outside the temp
    4.)Sealed or Unsealed set up
     
    Once you reply ill be able to more adequetly assist you. I dont want to tell you the best way without knowing the basics for your set up. It could end up pullign to much air or too little air.
     
  3. #3 Deleted member 826314, Mar 4, 2015
    Last edited: Mar 4, 2015
    1) So the tent is 80X80X160 cm   so the volume is 1,024 m^2
     
    2) The temp of the tent now without fans going is around 34 degrees celsius
     
    3) The temp of the room where the tent is oscillates between 20-25 degrees celsius depending on whether it's a sunny day or not (I know this is not ideal but I was quite limited in the choice of the room, also it is the only room that allows me to exhaust the air in the tent outdoors with little ducting)
     
    4) I am not sure what you mean exactly by sealed/unsealed. Now that I have no fan and I am waiting to setup the new ones I am leaving the "doors of the tent" open to allow some air exchange and control temperature. But I would like to close everything once the fans are set up.
     
    The tent has several intake/exhaust holes, I left the two at the bottom open, one mostly for cables and the other for intake. The ones on the top have been all closed apart from one which is on the "ceiling" of the tent, that's where I am planning to install my ducting and make it go to a window for exhaust.
     
    Also, since that is my only hole for exhaust, I was planning not to get the air through the cooltube directly from outside the tent, but leave one of the fans hanging so it could suck some air from the grow tent and allow better circulation. The other fan would replace my previous one, so it'll be on the other side of the tube sucking air from outside the tent.
     
    I hope this is clear enough, in case it isn't I can make a drawing for you, it's probably easier to understand. 
     
    The company that manufactures the fans that I bought claims that their air flow is 200m^3/h, but if I understand correctly, inline axial fans are quite inefficient.
     
    Thank you.
     
  4. with inline fans they are usually better at pulling air rather than pushing it so it is best to have the fan pulling air in on the inside and the fan pulling air out on the outside.
     
  5.  
    I thought of that, the only problem is that both fans have the same cfms and the one that is supposed to exhaust air runs through ducting and sucks air from the cooltube.
     
    So I am afraid that the exhaust fan won't be able to work at its fullest meaning that there would probably an increase of pressure in the tent created by the intake fan. I'd rather go for passive intake.
     
  6. The above answer of pulling air threw a cool tube is wrong. If you pull hot air into your fan and exhaust it outside your going to over heat the fan and kill it. The correct set up for a cool tube is. Secondly the end you place the bulb at is very important. you dont want to blow hot air back into the bulb you want to blow it away from the bulb. Using two fans on 1 cooltube is over kill especially for a 400w bulb.
     
    I run a 6" stealth fan at 450 CFM over a 1000w bulb in a 4x4 tent no issues at all, but i also have venting for the tent itself.
     
    FAN - Ducting - Tube (bulb at the end closest to fan) - ducting straight out of the room. 
     
    Also i read your post there and you said you had 1 fan hanging to create circulation? for what? use a small fan not a 200 watt fan. you should have a tent exhaust and a dedicated cool tube exhaust dont mix them, you dont want the load of a carbon filter on your cool tube system it will just bog it down.  With that said there are methods of setting up your tent venting with your cool tube i wouldnt suggest it tho. 
     
    and just so you know inline fans are propulsive and built to push air not pull it. they are normally used to move AC or heated air long distances threw ducting by PUSHING it. 
     
  7. https://www.youtube.com/watch?v=UUxsPDwVcD4 - Setting up an Air-cool grow light - The Right Way
     

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