Cooltube-Push or Pull Air?

Discussion in 'Grow Room Design/Setup' started by HansMoleman, Apr 11, 2009.

  1. #1 HansMoleman, Apr 11, 2009
    Last edited by a moderator: Apr 11, 2009
    The title says it all...I have a cooltube set up going 3 feet across...should I have it set up blowing air through and over the light or sucking the heat from the light and pushing it out?
     

  2. Suck it from the light.
     
  3. Yes. Definitely SUCK air out of it rather than push it through.
     
  4. as above.... pull the air thru the cool tube
     
  5. Hey there Bro all the above posters are wrong there you should blow the air throutgh the cool tube as for this reason bro cold air will move more efficiently than hot air as cold air is more dense than hot air the fan will be more efficient and shift more Air. This in turn will cool the lights more as there is more Air flow over the units.

    Eather way you can get those babys right over the girls and get some mental Buds.
     
  6. #6 ricard0, Apr 13, 2009
    Last edited by a moderator: Apr 13, 2009
    Wait....... So, we're all wrong, but either way will work? :confused_2:

    I believe the reason most folks pull air through them is because fans inherently pull air more efficiently than they push it. As for air temp and density, that can be a floating variable depending on where one chooses to vent exhaust air and to introduce intake air.

    OP, this guy could be right...... despite what the overwhelming majority has to say about it. It's entirely possible he knows some Top Secret fan stuff....... either that or he's "pulling" from limited experience. You decide for yourself though..... don't let me steer you in the wrong direction...... what do i know. ;)
     
  7. if you dont have a filter attached to the line that is cooltubed, it probably doesnt make much of a difference.

    if you do have a filter attached, then you would be wasting energy pushing air over your light and out of the cab through the filter. The air is going to slow down as distance from the fan increases....so youd have to generate more cfm from your fan to have the same extraction force through your filter

    this means more electricity, and more noise.

    besides, given that air IS circulating in the tube, temperature difference becomes moot once the fan is on. If there really was an advantage to pushing, it would dissipate as the temperature stabilizes with room temperature. 5 degrees above ambient isnt going to decrease air density much, at all.

    so, waste your cfm if you really think its a good idea....
     

  8. I knew i was missing some punctuation there amoril.
    Thanx for the "Exclamation Point"! ;)
     
  9. why not use a 90mm pc fan to push air into it and have a exhaust fan with filter for exhaust. so push and pull.
     

  10. Mine actually has a little 12v 65cfm fan pushing air across it and an inline pulling from it. Just as you state. It works quite well :)

    My understanding of an air-cooled fixture may be a bit narrow i'll admit. For a Cooltube or any other vented reflector to achieve the intended results it must be completely removed from the grow IMO.

    I realize not everyone is afforded this option when setting up shop. But. Connecting the filter, light and fan in series to serve as light cooling and room cooling is not very efficient IMO. Not only is your fan hindered somewhat by the filter, but now you're cooling your bulb with the hot air from the room itself??:confused: Watch the temps on your fan :eek: Most are only rated for 140º fahrenheit.

    To properly remove the bulb from the grow, it needs its' own intake. You can mix the exhaust after it passes through your space if you want, just make sure you have a decent fan. Of course, as i've said before, what do i and the collective knowledge of thousands of GC members know. ;)

    -Peace
     
  11. I may have been wrong here as i run a complicated syestem whare i extract the bad air into a room that is filtered throutgh a carbon filter 12" then throutgh to two 6 " outlets. Eather way you are running the better system there so get those lights right ontop of those girls.

    AND SMOKE SOME NICE WEED> LOL:smoking:
     
  12. #12 cameron__666, Jun 5, 2010
    Last edited by a moderator: Jun 5, 2010
    dont think anyone else mentioned this, but when your using a cooltube if you are sucking warm air through the cooltube and out of the fan, this is reducing the lifetime of your fan due to the heat, ive always read the best was is to have the fan pushing the air over to try and stop the fan getting warmer and reducing the chance of heat damage.
     
  13. #13 Bohbo, Jun 5, 2010
    Last edited by a moderator: Jun 5, 2010
    One of reasons to pull air is less air loss. If you push air you push air out of leaks so the farthest lamp receives less airflow (minor see further). If you are pulling you pull from intake but you can also pull in from leaks rather than pushing hot air out the leaks thus releasing it back into the room. IMO the best reason not to push is not pushing hot air back into your room.

    Definitely pull if your setup allows.

    EDIT: Nice Simpsons Reference =)
     
  14. Assuming no filter on the air, and that the air is both gotten from and released to a seperate area from the plants (and the input/exhaust) Then by pushing you might save some life of the fan's motor by introducing room temp air (rather than cooltubed air that is what, 30+++ degrees warmer at the 600W/1000W levels?) AND you're not going to draw in air from the plant room to be exhausted unfiltered into the outside world? (smell issues come to mind)

    Then I have to say, why on earth is pulling so popular? assuming you're properly venting the room, the little air pushed into the room from the cooltube won't adversely effect temps too much, but the little air pulled from the room might adversely effect your freedom of movement as a good number of people growing things they shouldn't are caught via the nose of a nosy neighbor ;)

    I think perhaps I will play with fan placement in a controlled environment to see for myself sometime...
     

  15. A long time ago I read a study done on the HID bulbs and within this study they found that when the HID bulb was kept cooled below normal operating temperature it not only lowered it's intensity, but shortened it's life as well.

    So I believe this is where it become common knowledge from the experienced growers that you should suck the heat away from the lamp, as opposed to pushing (blowing) cooler air into the lamps..

    Another reason, if there is any leaks within the ducting or lamp's hood, if there is positive pressure on the hood (blowing into the hood), it will leak the heat into the chamber, but if you're sucking from the hood/ducting and there is a leak, then you're just removing chamber heat which is why we use cool hoods in the first place...

    Yes, if there is a leak and you're sucking from the hood/ducting you will suck out the smell and vent it into the surrounding area, so you better have a sealed hood/ducting... But really if you're growing illegally, "don't do the crime, if you can't do the time"....


    Personally when I only use one fan on a lamp it's behind the lamp..
     
  16. Um, but if pulling the heat away causes the bulb to be cooler than pushing the air through (as the fan is more designed to pull supposedly, which results in more airflow and a cooler bulb) then wouldn't it be worse for the life of the bulb to pull rather than push? I mean either way you're still getting air that is X degrees cooler than the bulb, but by pulling you're getting theoretically more of it...

    Still, things to think on, thanks for the reply :) When the little ones are ready for the 1KW I'll check the temps (and get another spare bulb in case the coolness sucks the life away quicker than I usually replace them).
     

  17. No, what I read is that blowing into the lamp (or on the bulb) causes a cooler bulb, as opposed to pulling the heat away from the bulb...

    But I will say that I have NO DATA to back this up, nor did the article give any specific data results, and again it was a LONG time ago...

    So IMO, I don't trust anything which does not supply any data facts..
    But personally I have always pulled when using one fan...


    Why.... Not really sure to be honest... LOL
    Guess that is the way I have always seen them setup, and kind of followed the chain of command over the years...
     
  18. I know this is an old thread but that is what I do because the exhaust run is so long, 25'
     

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