I did this duplex last week and found the duct work to be quite odd, I thought at first they were popping jiffy pop popcorn:roll: I then soon realized that the whole entire duct system was wrapped with of all things aluminum foil. :shock: it was a very extensive wrap.
I found out why it was wrapped today, it turns out the owner was trying to hide the fact that the entire system was rusting through and their were holes everywhere. So let this be a good lesson if it looks weird and smells like popcorn there must be something wrong. I wonder if the owner owned stock in aluminum foil, ya think??. Or better yet here is a thought could they have had a growing operation in the ducting?? :roll: Or could it have been aliens taking over??:roll: when it comes down to it its just freakin wierd.