Finally, got it together this new year to order and install an exhaust fan for my studio. The 3 speed fan is from TekSupply and it goes from 555 cfm ( cubic feet per minute) to a high of 1,115 cfm. So far the fan is working well and I hope it last for a good while. Also, I think it will work as an all house fan to cool my studio/apt. come summer. On low it takes most of the fumes out from heating wax for encaustic painting or any other artwork smells and if not, medium takes the fumes out for sure. When I turn the fan on, the shutters open to take air outside and I usually put on a fan or window behind me to blow air past my face. But the exhaust fan works so well that it sucks most everything out without the other fan on. And it passes the incense test also. I really should have got this fan sooner but I am glad I took the plunge to buy it. Framing the fan in the hole and bolting it in was a little work but things went fairly smooth. And I truly recommend a good exhaust fan to take care of one's lungs whether painting in any medium especially encaustics.