| Buildings
Ventilation is far more
than just volume of air in
a building, it is the rate
of air exchange
To go back to the beginning, we have to look at what
animals do when exposed to nature and their rate of
survival when left to the elements.
ome modern
breeds would find
it very difficult to
live outside all
year and cope
with the vagaries
of our weather systems. Animals
out in the open will always look for
natures shelters, just like humans
do. We will always look for simple
shelter were ever it can be found.
Do you stand talking to someone
in the middle of your farmyard on
a wet & windy day or, do you
move and stand around the corner
of a building to shelter from the
wind and rain? likewise, when the
sun is burning down how often do
you find shade to get out of the
heat. Animals left to nature always
try to find shelter in the basic form
as well. They use hedges, walls &
natural hollows to get out of or
reduce the impact of the winds.
Likewise, they use trees for shade.
So, when we look at buildings
we need to stick to the basic
principles of nature. All animals
want shelter from the wind and
rain, shade from the sun and
plenty of fresh air. Air movements
ideally want to be above animal
height so as not to create a draft.
There are very few days in a year
that we as humans are glad of a
small breeze, how many days do
we complain about the chilling
effect of the wind and say it would
be grand if the wind dropped,
animals are no different they need
shelter from those chilling winds
as well.
S
32 | Farming Monthly | August 2018
All animals need a shelter wall
to be able to lie behind with a
decent air gap above for air to
pass over. Depending on the
height of the wall, the gap above
may need some wind break
material above it to break wind
speed on bad days.
When designing buildings, we
need to think about all the factors.
The No 1 factor for livestock
buildings is the purpose of the
building. Is it for Adult Cattle,
Yearlings, Young Calves or even
Sheep. Whichever group, they will
all have different needs regarding
optimum sizes and feeding
systems.
There are many guide lines on
volume of air per animal, the best
form of ventilation is and probably
always will be natural ventilation
with gaps at the eaves and open
ridges. This will undoubtedly be
the cheapest form of ventilation
you can get, no fans using
electricity, no moving parts &
nothing to go wrong. In high
rainfall areas, where people panic
about open ridges special
cappings can be applied. The best
is still simple, upturned flashing to
make the outside air lift over the
ridge of the roof, yet most people
(probably myself included in the
past) don’t fit the flashings right.
The big trend is always to try and
close the gap up with these
flashings and consequently the
base of the upstand ends up being
further up the roof than the end of
the roof sheet. This doesn’t work
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