Sizing a grow room dehumidifier
Capacity is sold in litres of water pulled per day under a test lab's conditions. The Trotec TTK 100 E is a 30L/day unit; the DH 25S is 40L. Those numbers assume warmer, wetter air than a typical grow room, so you will see less in practice. Pick the larger machine rather than the smaller one, especially in a sealed room or when a late-flower canopy is dumping water.
Where the moisture comes from
The plants. A canopy puts most of what you feed it back into the air as vapour, so bigger plants and heavier irrigation mean more work for the dehumidifier. That is why a room that felt fine in veg starts fogging up in late flower on the same kit.
Ducted, VPD-aware or portable
The AC Infinity Hydrone 5 is a dual-duct unit with VPD control built in, so it can join an existing duct run and chase a VPD target instead of a humidity number on its own. The Trotec machines are portable and simple to park. The Quest 70 Hang Kit lifts a Quest unit off the floor — useful only if you already have a Quest 70, because that machine is out of stock here.
Monitor with a hygrometer, and see humidifiers if the room is too dry rather than too wet. Extraction does some of this job as well — see fans and blowers.
