Ventilation

The coarse filter in the outlet should have at least a minimum of ¨÷ m©÷ filter surface per 100 m©÷ growing surface. This will prevent over pressure in the growing room becoming too high. It's better to replace the filters each growing cycle. The (relatively costly) fine filter in the inlet can be replaced at a later stage. Replacing it too soon is an unnecessary expense, but leaving replacement too long also means air resistance becomes too high - with all the inherent consequences. The only safe option is to measure filter resistance with a pressure meter at full ventilation levels. If maximum filter resistance has been reached (depending on the type of filter around 250 Pascal), it's time to replace the fine filter.

Jan Gielen, specialist climate & energy, C point