We at SV Enterprises have seen that the new pig barns in double wide configurations, hallway in the center, have exhaust and inlet operations very close to each other. Under cold conditions, while Stage 1 is operating at minimum, the air tends to circulate around and head back up into the barn. This will rust the soffit, fascia and roof steel prematurely and possibly compromise the trusses. Besides the health of the barn, there may be animal health issues due to the re-introduction of moist, dirty, re-circulated air. Wall fans also can be hampered by strong winds that restrict air flow to almost nothing. Why not give your wall fan the advantages of a wall chimney? With the unit you see pictured to the right, you will eliminate the wind effect on your fan. Two, three and four foot extensions can get us to the height we need to be. Routing the dirty air above the eaves will protect your barn investment and save a lot of trouble down the road. We have found with wall chimneys, we can remove the louvers in the fan (since the wind effect is gone) and this allows for natural chimney draw in a power outage situation giving extra time for generation to resume.