[masraum]

I've got a normal 2 part AC unit. Outside is the compressor/condenser and inside is the furnace, evaporator and fan. We had the evaporator replaced a year or two ago. I was up in the attic the other day and noticed that there are a few places in the housing where cold air is being blown out. The goop that's currently sealing most of it is like a cross between bondo and flour/water. It's a plasticy white goop. I'd like to properly seal the unit. What's the best way to do that/best stuff to use?

I noticed because I am tinkering with some weather software. I put temp sensors in the house, attic, and outside and noticed that when the weather is just right, the temp in the attic can actually be lower than inside the house and outside.

I'd like to minimize how much I cool the attic.