This is the band for one small tent, usually on Ø100 or Ø125 mm. The question here is rarely whether enough air moves through, because at these figures you almost never run short of capacity. You hear the fan long before you miss it, which is why noise matters more than power here.
Quiet is a product choice here
The Vents Quietline is built around silence and gives up airflow for it, which in this band is no drawback. The VKO is axial and simple, meant for short runs. The VK is centrifugal and pulls better against resistance, which counts the moment a filter goes behind it. Alongside them sit Garden Highpro with the Profan and Proline and G-Tools with the mini extractor.
What a filter costs you, and why there is no rule of thumb
A carbon filter takes capacity off your fan, and at this scale there is little margin to absorb it. How much it costs depends on which filter you hang, how long your ducting is and how many bends it has, so there is no fixed percentage. Check the stated airflow on your filter's product page and choose your fan above it.
The filters in this band
The Secret Jardin DF16 CTC80 filters are chosen on airflow rather than diameter, which suits this band because you are searching on capacity anyway. Alongside them, the smallest Can-Lite, the plastic Can-Original and the Prima Klima Eco. Note that the number on a Can-Original is a type number and not a capacity.
Turning it down is the norm here, not the exception
Most fans in this band are generously sized for the tent they sit on. That is fine as long as you plan for it: set low and running continuously is quieter, cheaper and better for your plant than hard and intermittent. Do check per model whether an external speed controller is permitted.
Frequently asked questions
How much capacity does my filter cost?
That depends on the filter and on your whole run, so there is no fixed figure for it. Choose your fan above your calculation and you absorb it.
What is the quietest fan in this band?
One built around silence, or an ordinary one turned well down. Turning it down costs nothing and gains the most.
Which tent sizes does this suit?
Roughly 60x60 up to 80x80, and a sparsely fitted 100x100.
