This York E1FH has an outside unit and an inside the attic unit. Its a slpit heat pump unit. In the attic, the coil is very cold and is sweating normaly, however the vents in the living space are blowing at 79 degrees when the outside temp is 95 degrees and humid. My question is, is there a filter in the attic coil secion. If so could that be my problem since it was never cleaned?