The hot weather is now upon us in the Northern
hemisphere. Travelling the world, it surprises me that more producers aren`t
using Airbag Ventilation, this valuable ventilation system either as a back-up
method to alleviate hot weather stress, or as a full-time device to get over the
common problem of over closed-up nurseries (to retain heat) when an icy wind
streams around the building in the depths of winter.
The hot weather is now upon us in the Northern hemisphere. Travelling the
world, it surprises me that more producers aren`t using Airbag Ventilation, this
valuable ventilation system either as a back-up method to alleviate hot weather
stress, or as a full-time device to get over the common problem of over
closed-up nurseries (to retain heat) when an icy wind streams around the
building in the depths of winter.
Why is it so useful?
- It is simple to install.
- Air can be placed exactly where it is wanted.
- The farmer can make 80% of the gear himself, given
simple instructions.
- Thus it is cheap.
- Maintenance is easy and accessible.
- The fan(s) runs at a high speed thus overriding
outside wind pressure, so the system is windproof.
- The fan is linked to a temperature sensor(s) in the
normal way.
- On a permanent installation the system can be
designed on a recirculation basis so that in cold weather heat is conserved
with a minimal but adequate supply of cold air introduced from the outside.
- In very hot and still conditions the air can be directed directly on to
the pigs, thus delaying the introduction of evaporative water cooling. This
saves water - expensive to remove as slurry.
What does it consist of?
An ordinary, and cheap propeller fan/fans are situated at
the top of a gable end. This leads into a simple air-straightener cylinder
inside the building (which can be home-welded). This is needed to remove the
twisting of the airbag tube due to the torque from the fan. A tapering tube made
from heavy duty (500 gauge) polythene is clamped to the cylinder with a
loosening nut to rotate the tube so as to allow the air to be directed where it
will do the most good in hot weather or cause least discomfort in cold
conditions. The tube runs the length of the piggery. In wide-span buildings more
than one airbag is used from their own fan. Tapering the tube ensures the same
exit air pressure is obtained both close and far distant from the fan. Given the
correct design pattern the producer can easily make the tube/airbag himself -
further cost savings. D-shaped holes (called `sipes`) are cut at prescribed
intervals down the tube - this ensures even and correct air projection and
volume.
Obviously from the above description some design specifications are needed.
These I will provide in my next blog.
This system deserves far better recognition than it seems to be getting. I
hope I can encourage you to try one and see.