Ventilation Question - Is this fan the right size for my 12X16 coop?

Discussion in 'Coop & Run - Design, Construction, & Maintenance' started by Engteacher, May 22, 2010.

  1. Engteacher

    Engteacher Poultry, Poetry, and Prose

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    It's a Maxxair heavy duty exhaust fan with integrated shutter - 14" fan diameter. Rough opening is 20.5" X 20.5". Hubby says it's way too big, but "Ask your friends on that chicken website."
    Here's the link to the Tractor Supply fan:

    http://tinyurl.com/23m6whm

    Here's my coop under construction. I was thinking to mount it in that upper right corner facing the camera.

    [​IMG]

    Oh, and only half of this building is my chicken coop. Hubby gets the other half as his workshop.
     
    Last edited: May 22, 2010
  2. patandchickens

    patandchickens Flock Mistress

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    I'm not certain what size your coop is, but let's pretend it's 10x10 and 8' high. That's 800 cubic feet. The website says this fan runs at 1400 cfm (cubic feet per minute). You would be doing 1.75 air exchangs PER MINUTE. It would be a veritable whirlwind in there. Even if you could modulate the fan down to only 1/10th of its specified running speed, that's still a total air turnover every five minutes or so, and quite a strong breeze.

    I really really wouldn't do it.

    Honestly I do not see any virtue in using a fan AT ALL in a coop, unless you are in a super hot climate where you expect the chickens may want to actually sit in front of the fan (for which a regular household fan is FINE, properly mounted and carefully maintained, and only run during the hottest part of the days). Or possibly a swamp cooler type fan in a hot-deserty kind of climate.

    A fan FOR VENTILATION, specifically, is hardly ever really appropriate for a backyard coop. Just having a generous amount of wall openings is far, far better -- more effective, more all-purpose, and more foolproof.

    JMHO, good luck, have fun,

    Pat
     
  3. BankerJohn

    BankerJohn Chillin' With My Peeps

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    There is nothing wrong with an electric exhaust fan. 1400CFM is an average sized fan; some are larger and some smaller. How many cubic feet are in your coop? How often do you plan to run the electric fan? Some have installed vents like these:
    http://www.airvent.com/homeowner/products/staticVents-windTurb.shtml

    The wind turbines require no electricity.
     
  4. Neil Grassbaugh

    Neil Grassbaugh Chillin' With My Peeps

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    Quote:Calculate the volume of the area the chickens are to inhabit.
    Divide the Cubic Feet (of air per) Minute capacity of the fan (stated as 1,400) by the volume of the room expressed in cubic feet. The result will be the number of air chages per minute within the room.

    High density cage layer hens with a years worth of manure stored in the building with them and broiler chickens on litter that has been used for three flocks are raised with one air change per minute in the hottest and/or most humid places on earth.

    You did not state where you are located but in the northern US we never go below 0.25 CFM per bird no matter how cold it is. Generally the air change rate is higher than that because of air quality issues. So on the minimum side you have enough fan capacity for 5,600 birds and, using another rule of thumb, you have enough air for 200 birds at the highest level of demand.

    I suggest that you admit to your husband that he is entirely right and you are wrong.

    Then get more chickens to make better use of the fan. Everybody wins.

    Perfomance wise where the fan is placed on the exterior wall is of little consequence in your situation. I would place it so that the noise and dust it produces will be of the smallest annoyance.

    Where and how the it enters the room is a far more important issue.
     
  5. Engteacher

    Engteacher Poultry, Poetry, and Prose

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    Hastings, MN
    I just drove over to TSC and looked at it. You're right. It's way too big.

    So then I drove over to the hardware superstore, Menards, and looked at their attic vents. I saw the turbine style and that would probably work. We always have at least a soft breeze because we're on high ground. Can those be side mounted instead of on the roof? I also saw an attic fan that was for a gable end. That might work.

    My coop side of the shed is 12X16 with the tall wall 7'8" and the short wall 5'8". We have a north and south facing window and a 5' sliding barn door yet to be mounted. We'll wrap the whole shed in steel with a white roof to reflect heat.

    Thanks for your wisdom. I appreciate your advice!
     
  6. JanetSmithery

    JanetSmithery Out Of The Brooder

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    Quote:I'm a little confused...this type of fan looks like it's mounted to suck air out, which lets fresh air in...not create an internal breeze.

    My parents have a house that uses a series of similar fans instead of air conditioning. They set a time to turn on all the fans in the early hours of the morning. There's a small roar, and then a few minutes later, you feel the temperature drop. It usually keeps it pretty cool in the house for most of the day, afterwards. There's no real draft felt or anything...just new air. Isn't that desirable for ventilation?
     
  7. patandchickens

    patandchickens Flock Mistress

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    Quote:IMO there are three main things wrong with 'em (for a backyard coop) -- 1) they don't work when your electricity fails; 2) they are a totally-unnecessary safety hazard (fans are a nontrivial fire risk in a high-dust environment, I know of a couple barn fires started that way); and 3) they are just UNNECESSARY because you can get JUST AS GOOD OR BETTER air quality by properly designed *passive* ventilation, i.e. intelligently-made large openings in the coop walls.

    Some have installed vents like these:
    http://www.airvent.com/homeowner/products/staticVents-windTurb.shtml
    The wind turbines require no electricity.

    Yes, but they only work when the wind is blowing, and if the wind is blowing then PASSIVE ventilation will work even BETTER. (The wind turbine things are excellent aids for situations where passive ventilation is grossly inadequate b/c you canNOT have large openings in the sides of the bldgs, e.g. an attic or a workshop or storage shed, but coops are well-adapted to having large openings in the sides)

    Quote:Well, first, if you suck air out, you get vast amounts of chicken dust fouling the fan. Secondly, it doesn't matter a great deal whether it's blowing in or out, the same amount of AIR MOVEMENT still occurs -- the air is coming in SOMEWHERE (one would hope [​IMG]) and will be whirling around in the coop.

    My parents have a house that uses a series of similar fans instead of air conditioning.

    Yup, I grew up in a house with a whole-house fan, they are GREAT, but it do get rather WINDY near the windows [​IMG] If yours was not, then it was a pretty small whole-house fan... if it were doing almost 2 complete air exchanges PER MINUTE, like the o.p. is proposing, believe me, you would be reporting something verrrry different [​IMG]

    Just sayin',

    Pat, headed out of town for a while to visit family, y'all have fun and I'll be back here next weekend [​IMG]
     
  8. WoodlandWoman

    WoodlandWoman Overrun With Chickens

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    Have a good trip, Pat!
     
  9. Engteacher

    Engteacher Poultry, Poetry, and Prose

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    Hastings, MN
    Okay, so here was our solution. We went with an attic fan for mounting in a gable with a shutter which closes when the fan is not operating. The cost was $90.

    [​IMG]

    [​IMG]

    We'll be sure to let you know how it works for us.
     
  10. paaschjc

    paaschjc Just Hatched

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    Sorry to pull up this old thread but I'm wondering how the exhaust fan worked out for your coop. We converted an old shed to a coop and it doesn't have any windows and we need to improve the ventilation. Adding windows is not a good solution in our case so we were thinking an exhaust fan would help with the air exchange. How did it work out for you? was the fan you used a good size, too big, too small, too much or little air movement? Do you have any specifics on the fan you installed. Size, CFM? Your feedback would be greatly appreciated. THanks :)
     

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