This is the fan I used for mine, it's borderline leaf blower status and fits 4" flexible dryer exhaust tube perfectly. Draws 2.5A. Highly recommended.
Attwood Quiet Blower Water Resistant (White, 4-Inch) https://www.amazon.com/dp/B003EX02DA/ref=cm_sw_r_cp_api_9XLCzbD3X657Y
Using a float switch is also a good idea, so you don't run it dry and burn out your pump.
The more holes you can drill in the bucket (without compromising its integrity and leaving a reasonable volume for water at the bottom) the better. More surface area means more evaporation.
I had issues with mine leaking the first year. I found I had much better luck cutting the outer pad so that it's pushed against the inside of the bucket. I put the vinyl tube hoop on top of the inner pad, and tied it with thread so it can't move. It doesn't leak at all using this method, as the outer pad only gets damp by soaking up water from the saturated inner pad. And it works better, because there is no gap between the pad and the bucket for air to go through, it has to all flow through the pads.
awesome! yeah I'm going to be using that on the random hole around the machine that let smoke into the room and Weather striping on the lids to block it so that it ONLY goes through the exhaust!
any suggestions for blowers? I was looking at https://www.amazon.com/attwood-Quiet-Blower-Resistant-4-Inch/dp/B003EX02DA/ref=sr_1_4?ie=UTF8&qid=1542672858&sr=8-4&keywords=4+in+blower+fan
You could use that along with some aluminum tape to seal it to the back of the cutter.
I use this blower: attwood Quiet Blower Water Resistant (White, 4-Inch) https://www.amazon.com/dp/B003EX02DA/ref=cm_sw_r_cp_api_3L18BbTB6G1FB
Along with this vent hose: White Flexible Pvc Vinyl Vent Duct Hose, 4 in. x 20 ft. https://www.amazon.com/dp/B01G198P5A/ref=cm_sw_r_cp_api_4R18BbNJ19ANP
These clamps: Cambridge Tension Clamps, 2 Pk, Zinc Plated Steel https://www.amazon.com/dp/B07737XRRH/ref=cm_sw_r_cp_api_SS18Bb12827MZ
And this quick disconnect: Dryer Dock Dryer Vent 6" for 4" Tubes, White https://www.amazon.com/dp/B0028BAAWW/ref=cm_sw_r_cp_api_4T18BbV6CJ1TW
If you put the blower near the window it will keep negative pressure upstream which helps put less smoke into the room.
I don’t exhaust out a window, but something like this might do the trick for you: Window Dryer Vent (Adjusts 24 Inch Through 36 Inch) by Vent Works https://www.amazon.com/dp/B01M17V4CO/ref=cm_sw_r_cp_api_AW18BbDW0592D Though there may be cheaper or better DIY options for that part.