Porcupine coils take low water pressure volume helps from the inside out. And seeing some of the fins on the ground is typical.We have the same problem with cottonwood trees, so I purchased both intake and exhaust screens for our Trane AC condenser. Put the exhaust screen on in the spring to catch the helicopters coming off of our neighbors trees and then install the intake screen when the cotton starts falling. Just remove that screen last week. Even with a strong shop vac, that cotton is very hard to remove from the screen. The Trane Spin Fin technology on the condenser tubing is very susceptible to fowling with the light weight cotton. All over until next year.