Model CM3000 I Use Model CM3000 I for installation in unconditioned spaces such as an attic, crawl space or garage. Mounts horizontally or vertically. Use independently or on an existing forced air furnace or air handler. Fantech’s Whole House HEPA installs on your home’s forced air furnace/air handler or can be used as an independent system mounted in the attic, crawl space or closet. The unit is small, compact and very affordable. A powerful 240 CFM fan directs air through a series of three filters then delivers clean, safe, healthy air back into your entire home. CM3000I 20.6" X 17" X 11.2" - insulated For use in unconditioned spaces such as attics and garages. Insulated outer shell prevents condensation problems.