Hello, I have a older EB12B Coleman indoor furnace. Below my A-coil tray around the blower is glued on insulation. I pulled my blower cage out for cleaning and noticed a white mold in various areas on the insulation. I found a replacement insulation kit for around $50+ shipping including the door. I see no way to clean it, a vacuum would tear it apart... Is this insulation really needed? If it is needed what's the best procedure for removal without making a dusty mess? I thought about lightly misting it with water prior to removal. Any suggestions?

The history is, an oldish (15 year) AC unit, that's worked fine for a long time. (Lenox elite CB29N 21/26, and I need to go outside when I can for the outside unit, but Lenox also) Starting perhaps six months ago, it'll blow uncooled air now and then. Fidgeting would fix it, and over time, I learned it wasn't the fidgeting, it was the resting, so now, mostly, turn it off for an hour or two, and it'll work fine again, until the next time. It varies from every few days to a few weeks of working right. What we've tried: [LIST] [*]I did have an AC repairman come out. He confirmed the refrigerant wasn't low. It was all working reasonably well the day he came too. He inspected the coils (looked fine, not frozen), the filters, etc. He didn't see anything obviously wrong. [*]The capacitor was working, but old/dodgy. I agreed to replacing it, but in the end, that didn't resolve the issue. [*]AC repairman said something about a valve, I forget the name, that might be the issue. [*]I'm in Florida: The AC industry has everyone convinced that everyone needs a new AC every 8 years. This person was better than most in that respect, he didn't turn on his 'replace' sales pitch too much. [*]When working fine, if I touch the tube from the hot side leading into the house, it's cold. And of course, when not working, it's not. [*]My other unit turns 25 years old this year. That one maybe, I should do something about... :-) (In fact, this one started acting up just this morning, but it's less of a mystery there, what's wrong. but it reminded me to ask about the other unit) [*]Turning off for about an hour: that seems to reset it until next time. [/LIST] Any ideas or suggestions? Thanks in advance!