Ventilation
Ventilation is absolutely vital on a greenhouse. It¹s not just to keep the
greenhouse cool, although that is of course, important. It¹s also to
create a movement of air that helps to prevent powdery mildew and damping
off. The ideal ventilation in a greenhouse would have about twice as many
roof vents as side louvre vents. The roof vents will allow hot air out of
the top of the greenhouse, but if there are no louvres in the side of the
greenhouse these will not perform as well as they could in conjunction
with louvres. The cool fresh air would be sucked in through the louvres
and warm air would then rise easily through the roof vents. One of the
first items on your shopping list for a greenhouse must be automatic
openers for your roof vents. These superb inventions work by heat
expansion alone and will open your roof vents gradually as the greenhouse
warms up. That way you never have to remember to open your greenhouse
vents or close them again at night. All the different models of auto-vent
will lift the same weight of about 7 kg (ample for all our greenhouses)
but the stronger ones perform better in the wind.
