Hey all! I was thinking about installing a block-off plate this year. I'm not really sure it would have much effect, though. It is an interior chimney, right in the center of my house, between my kitchen and living room. It is open on both sides, so access is super easy. I'm just not sure it will have much positive effect,though. I have a 6" double-lined , stainless liner, and no creosote problems to speak of. Does anyone have any 'before and after' performance experience when installing a block-off plate in an interior chimney?