The dust allowed the air ducts not to work

I have been told by both our neighbors & our repair businesss that I live in a particular ly dusty environment.

Many have urged myself and others to keep our windows at home closed as often as possible, & to vacuum & sweep officially to keep the pesky particles out of our air & away from our Heating, Ventilation, & A/C system. I have tried to abide by those easy rules, but I can’t seem to make headway on removing the continual onslaught of dust that I’m faced with each week inside this house. I dust surfaces, furniture, knick knacks—you name it. Next, I vacuum all of the carpet, & after that I finish with sweeping & mopping the tile floors. But, no matter how much care & detail I put into the work, the dust returns within a morning. Finally, I decided to have our entire Heating, Ventilation, & A/C plan evaluated by a odd dealer. The 1 I had been using kept telling myself and others that our complications were from dust getting in our front door, but I quit buying that excuse. My persistence paid off, because the first thing the new professional noticed was how dirty the inside of the air handler looked at immediate glance. He even showed myself and others some of the grime & dust buildup right around the evaporator coil. To little surprise on his end, he found caked on dust all throughout our ventilation system. I had to make an appointment for HVAC duct cleaning immediately. I can’t think I have been breathing this particulate every morning for so long. It horrifies myself and others to guess about it & angers myself and others that our previous Heating, Ventilation, & A/C professional ignored it the entire time.
furnace/heater