Pull the cover off and look.

When was the last time you pulled the cover off your window air condition unit?

What have you been breathing?

Has the air you've been breathing coming through this?  

Allergies, Respiratory troubles?

This sure doesn't help.

Slow draining bathtub

Did you ever try removing the drain cover and plunging? Love it when customers send us pictures, not sure what the black stuff is but tub drains faster.