A polymer having two different sets of repeat units consisting essentially of:In this polymer, R1, R2, R3 and R4 can be independently selected from the group consisting of alkyl group, alkoxy group, aryl groups and combinations thereof. Movement sensor signals are filtered in different ways. During cooling operation of the unit, the unit blower creates a negative pressure inwardly adjacent the hole which draws return bend condensation from the outer longitudinal pan portion into the inner longitudinal pan portion for drainage outwardly therefrom, with the condensate received from the balance of the coil, via a drain line connected to the pan.