Wow, that may cost them more in the long run on a busy place. I know they promote that its cost effective when they take in consideration of the cost of roof damage and labor to clean the filters. Most accounts I have the roof is shot already from poor grease containment systems, but the ones that have a grease capturing devise stay pretty clean. kinda seems it can work against me & them to promote them, and if it will cost them a lot more including hood cleanings even if they reduce the intervals! Mikey