We actually spent 4K and replaced our old oil furnace chimney, which was a metal Faux chimney, with this Class A one. This is not our house, but it looks like this. Supposedly lets less air in and out especially when the furnace is on. We definitely hear the wind less. We keep our real brick chimney damper shut when not used. We had a door blower test done (you probably did too) and found where the issues were. When the damper was open it was incredible what it pulled in. The electrical outlets were also allowing a lot in from in between the walls so they all have those children safety plugs on now which cut that way down though not a seal. Our house is mid 60's. I love it. Not a fan of the new house look (no offense to anyone.) I so wanted to do the seal in the attic instead of blown in, but our roof guy said that if we do, the 50-year roof warranty is gone.