Airbrush Spray Booth Dilemma

Another option is a bilge blower and a laptop ac to dc transformer, I use a 130cfm one on my homemade booth and it removes 90% of the fumes unless im drenching a model in future wax. It is also ignition protected so if you are spraying laquers and other flammables there is no risk of explosion. The longer hose will increase resistance especially if it is the ribbed style dryer hose. A larger cfm rating may be needed to overcome the resistance.

You can have the booth vent into a bucket of kitty litter.  

Get a 5 gallon bucket with a lid, cut a hole in the lid so that it is just big enough to allow the vent tube to pass through.  

Pass the vent tube through the lid 3-4 inches.  

Fill bucket half way with kitty litter.

Attach lid with vent tube to bucket.

Allow for a little air to escape from the bucket when the lid is on by having a few vent holes drilled into lid of bucket or make the hole for the vent tube a little big so there is some gap to allow a little air flow.

Every 3-6 months shake the bucket to stir up the kitty litter.

I did this for years till I moved to another house.  I was in a similar situation, window was too far from spray booth.  I put a box fan on a small table in front of the window drawing air out the window and with the combo of the bucket and box fan, never got complaints from the misses that the house stunk like paint.

If you decide on a bathroom extraction fan, just make sure the venting tube is a close match to the diameter of the fan. In addition try to find a fan that has a minimum of around 200 cfm air movement. These type of fans dont have the ability to push volumes of air through a smaller tube as I discovered when I built me airbrush booth.

I did an airbrushing class, where the extractor hoses were dropped onto a bucket filled with shredded paper, no residue on the bucket.

My own home-brewed extractor, I used the fleecy mesh for filters, &even after 3 years of use, there is no residue in the hose, but I still pop it out the window if spraying Future or varnish or large projects.

In the wintertime I do not connect my booth to the window vent.  It puts a little more smell in the air, but not much. If you have a good filter in the booth, that will at least get rid of all the particulates.

Even a small fan should be able to push the air through a dryer hose. I'm not expert on physics and all that, but since it is a constant size, the tubing shouldn't have much of an effect on the ability of the fan to draw air out of the booth. The booth I cobbled together uses an exhaust fan and some flexible dryer vent hose, and I have no problems.