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.