Barn Fan - Help!

Ontario Chick · Post by **Ontario Chick** » Sun Feb 21, 2016 11:21 am

So I am going to buy that darn barn fan, set out to do the research, holy cow....
No way can I figure the main barn and the addition as one building, so will start with the addition which is
10' wide , 8' high and 34' long.
Now the "Farmtek" info sheet tells me I need to create a slight negative pressure by installing air inlets of a certain size....
I can only assume that if I get this wrong, I will either not move any air at all, create a vacuum or suck the chickens right out of the barn, or at least strip their feathers off.
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So Ross, since this is your fault, isn't there enough "natural" air intake in my barn and by that I mean all the gaps here and there, or can I just open the door opposite the fan???
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and for all you mathematical geniuses, instead of counting you bananas and coconuts, how about figuring out what capacity fan I need?

Post by **poultry_admin** » Sun Feb 21, 2016 11:41 am

We have this one:
http://www.princessauto.com/en/detail/2 ... -p0772210e

CFM is for cubic feet per minute. So in your case (10x8x43=2720cfm) it would exchange the air in the barn every 47 sec.

Place it on top under the peak to get all the warm air out.

The air intake comment IMHO is so that people don't forget to put one in. Some seal up everything and then put up one fan and wonder why the barn is still hot.
Yes, across from the fan is a good spot for the inlet to create a good flow. You don't want the air to make a u-turn right out the bar again.

We have two additional fans in the loft under the roof to help with the moving of the air into the direction of the exhaust fan. Mainly because the layout makes the loft into three sections/tubes. The middle one has the exhaust, the two on the outside have the "pushers".

ross · Post by **ross** » Sun Feb 21, 2016 11:59 am

No matter how many holes/gaps in barn it doesn't hurt to have what they recommend as well .But if you have amount of fresh air coming in as they say as long as doesnt whistle your ok .As far as a door open , will it be open 24/7 & fan on 24/7 . Mfgs recommended air inlet is for a new completely sealed barn . In ventalation you treat the blg barn/house as a envelope & in cross air ventilation you you need to provide the amount of fresh air in as your pumping out . Hope helps . Luck

Ontario Chick · Post by **Ontario Chick** » Sun Feb 21, 2016 3:22 pm

Thank you gentlemen, your input is greatly appreciated.
I am planning to run the fan in winter only while I am in the barn, 1 hour in the morning and 1 hour in the evening.
In the summer as needed depending on temperature.
The metal door is open during summer and the screen ( 1'x1" wire) door is closed at all times.

In the winter the screen door has insulation inserts, which could be opened to provide air intake of the size needed.

The fan would go in to the top right corner window space.

: Barn quonset summer .jpg (30.61 KiB) Viewed 4504 times

ross · Post by **ross** » Sun Feb 21, 2016 3:27 pm

My opinion waste of money . But wish you luck .

Post by **poultry_admin** » Sun Feb 21, 2016 4:30 pm

ross wrote:QR_BBPOST My opinion waste of money . But wish you luck .

If you have NO wind due to the trees around it, maybe. Otherwise I second Ross' opinion. You have just about the best natural ventilation setup possible.
How much warmer does it get inside compared to outside in the summer midday? If within 5degC without a fan, it won't get much better.

But those are just opinions from afar. You know best, you are right there.

Jaye · Post by **Jaye** » Sun Feb 21, 2016 5:26 pm

OC, are there ventilation issues you are trying to correct?

TomK · Post by **TomK** » Sun Feb 21, 2016 5:47 pm

OC...in my recent energy assessment foray with NRCan i depressurized houses to see what the infiltration leakage of a home was...easy if you have the right equipment...it can be calculated to the sq in just how big a hole in the wall equivalent the building leakage is...it was almost impossible to get a reading on old farm houses with laid stone foundations because the houses leaked so much...and that was using an industrial 24" dia exhaust fan...I'm guessing that if you are trying to ventilate a barn building of older vintage that you wont have an issue with the airflow...what you'll be trying to suck out will readily be replaced from all the existing apertures...just a thought

Ontario Chick · Post by **Ontario Chick** » Sun Feb 21, 2016 5:53 pm

My main problem is dust, the summer heat isn't that much of an issue.
I was hoping to move the dusty air out when I fluff up the bedding, instead of raising the dust and then having it settle down in a fine layer over everything.

ross · Post by **ross** » Sun Feb 21, 2016 6:18 pm

Sorry OC I was confused . Sucking dust out at bedding time only & ventilation for air improvement for livestock or people are 2 different things . If your only using to remove dust at bedding time just stick in window of barn & suck out dust or at barn door outside like yu see fire crews drawing smoke out of bldgs. If your looking to bring fresh air in & stale air out on a regular basis that's totally different . .think I misunderstood I'm talking bldg ventilation your talking short term dust removal . Your hook up should work . Luck