An 80x80 is nearly twice the volume of a 60x60, which puts it squarely in the range Ø 100 mm is meant for. Not surplus capacity you have to dial back, but a good match. That makes this the tent size where a 100 mm system works best, and at the same time the size where you should stop shopping at the bottom of the range.
Why the filter pushes you up a step
This is what changes compared with a smaller tent. A carbon filter costs static pressure, and on an 80x80 with a filter a just-adequate fan really is too small, where the same fan would still have done on a 60x60. So choose deliberately from the upper end: the Can-Fan RK 100 L at 270 cubic metres per hour, or the AC Infinity CLOUDLINE Pro S4 or T4, rather than the smallest version.
Everything in one size
The filters in Ø 100 mm connect straight onto these fans, so you need no reducer. That is worth more at the smallest diameter than at any other, because there is little in reserve to absorb pressure loss. AC Infinity also supplies complete air filtration kits in this size, with fan, filter, ducting and mounting together.
Buying adjustable still pays
Even now the size fits well, a fan you can turn down beats a fixed one. You run it higher by day and lower at night, you hear it less, and when the filter loads up after a few months you still have room to compensate. Note that not every fan may take an external controller; that is stated per model on the product page.
What this selection does not include
There is no silencer and no odour control at this tent size. For noise, turning the fan down is usually enough here, and otherwise the silencers sit in their own group. At this scale the filter does the odour work; sprays for the room itself are under odour control.
Frequently asked questions
Is Ø 100 mm enough for an 80x80?
Yes, provided you do not take the tightest fan. With a filter on it, the upper end of the Ø100 range is the right choice.
When do I move up to Ø 125 mm?
When the tent stands in a warm room, carries a lot of light, or needs a silencer as well as a filter. Then Ø 125 gives you more headroom.
Do I need a circulation fan?
Yes. Extraction refreshes the air in the tent but does not move it past every leaf. One clip fan is enough at this size.
