My current setup for the GF is to use the supplied hose, and unfortunately there are 3 different 90-bends in this hose to get to a outside window. Total hose distance is ~7 feet.
I’ve tried three solutions for exhaust from the GF:
Hose out the window. Results in a lot of smoke from the unit itself as apparently its fan just can’t push through those bends and distance. Smoke is not from window area, but from around the GF. There are no hose leaks, and joints are all sealed.
I bought a 4 inch computer fan ( Zhanye 120mm Fan Computer AC 1238, Axial Cooling Exhaust 110V by 125V, High Speed with Metal Net and 4-feet Power Cord - amazon). I mounted this fan in a 3-d printed fan-hose connection (see picture), and added a cleaner and more sealed port through my window. Result: less smoke, but still not clean enough. The air flow wasn’t enough through this fan. The fan was rated at 120cf/min, but I seriously doubt it was anywhere close - maybe it could without any air resistance. However, this fan did cause the off-GF’s fan to slightly turn, but not by much.
- I then bought a larger DUCT fan (TOPHORT Inline Duct Fan GDF100-4inch 203CFM Ventilation Fan HVAC Exhaust Blower Replacement for Grow Tent - amazon). This one is rated at 203cfm. I fitted this to my sealed port in the window and now I have very little smell from the GF. The potential downside is that if this fan is on but the GF is off, the GF is actually has a high amount of noise because the fan is pulling air out of the GF, and the poor GF fan, which is off, is spinning like crazy as air is sucked through it. I’m assuming that this is not a very good condition for the GF fan.
So, far I am satisfied with my #3 solution.