Just bought a house built in 1979. The house has a packaged HVAC unit outside. I went to replace the filter for the first time and noticed some insulation that sits in the “air intake” portion of the unit behind the filter. At first, I freaked out, worrying that it was asbestos. I took a sample to a local lab where they identified it as glass, not asbestos. That relieves my initial concern, but then I started thinking that having fiberglass sucked into the system is not the best thing either. Any thoughts on whether this should be removed, why it’s insulated in the first place, and whether I should replace it with another material.