Is this mold/musty smell
I live in an old 2 story farmhouse built in 1901. HVAC system in the basement, A/C unit outside. Installed in 2017 not sure what used to be in its place. A couple of the runs for ductwork is old, most are new. Most of the return duct is old but I stuck a camera down the run and found not much of anything. Stuck a camera down one of the old runs and nothing alarming.
I’ve been getting a musty smell when the A/C kicks on. Got it a little bit in the fall when the furnace first kicked on but didn’t notice it again until we swapped to A/c. Correct me if I’m wrong, this is my A-coil or Evap coil for the handling system in the basement? And is this bad enough to cause that smell? I get the smell through the whole house. But worse the closer you get to the air handler. Change filters religiously every 3 months. Stuck a camera up the Condensate line and it seems to be okay. How hard would this be to clean myself?