Climate & Ventilation — 250-400 m³/h

This is the largest of the six bands and the figure most growers arrive at: one well-filled 100x100 or 120x120. There are so many fans and filters here that it is tempting to compare on the number alone. That is exactly where it goes wrong, because the two numbers do not mean the same thing.

Two numbers, two meanings

A fan's figure is what it moves in free air with nothing attached. A carbon filter's figure is how much air it can clean without odour passing through. You hold the two up against each other, but you do not add them and they need not match exactly: the filter may be generous, the fan must be.

Fans: the widest choice in the shop

From Vents there is the VK in several versions, the VKO, the TT and TT Pro and the Quietline DUO. From Can-Fan, the RK 125 L and LS. Alongside them G-Tools with two speeds or a temperature controller, Secret Jardin with the DF16E350 that steps down on temperature, and Prima Klima with the PK125EC-TC.

Filters: well supplied, including at Ø125

This band holds the Prima Klima Eco and Industry lines, the Can-Lite in its smaller sizes, the Can-Filters Inline that may sit anywhere in the duct, a Rhino and the largest Secret Jardin DF16. So you need not move to a larger diameter in order to filter, which this page long implied otherwise.

Or fan and filter together

Because this is the most common band, complete combinations are supplied on it: the G-Tools kits with a Prima Klima filter, with or without a controller, and the Prima Klima PK 125 EC-TC with a matching filter. That saves working out whether the connection sizes line up.

Frequently asked questions

Must my filter carry the same number as my fan?
No, the filter may be more generous. A filter that is tight for your airflow lets odour through while still looking new.

Which tent size suits this band?
Usually a 100x100 or a 120x120, depending on how much light is in it.

Why are there so many versions?
Because this is the most common size and manufacturers supply their whole programme on it. Compare on airflow and on how you want to control it.