Any way to extract more heat from the exhaust?

sunlight33

The exhaust flue of my condensing boiler goes through an insulated (not heated) laundry room in my garage before exits the house, the flue feels warm to the touch and has kept the room a couple of degrees warmer than the rest of the garage (the room actually doesn't need to be comfortably warm, I just need to keep the pipes from freezing during the coldest nights here in NY). I know this has already been done by the condensing boiler but can more heat be left in that room before existing? By the way I was inspired by noticing the fins on the baseboard heater the other day. lol!

Charlie from wmass

not safely

the boiler does it's job pretty well, that is why it can condense the flue gases.