I have used Factory Direct
I have used Factory Direct for about 5 years now, for both my air cleaner and for some custom filter boxes I built to protect my mini-splits. Had annual service this week ( been over a year), and the tech told me how shocked he was at how minimal the dirt on the coils, fins, etc was for a woodshop. He said they are usually a nightmare, but mine was not an issue. I will continue to use FD!