My wood stove is in my dining room. It is on a raised brick floor. The wall in back and one side is also brick. I just had a door blower test for my house prior to air sealing and insulating it. I just noticed that there are gaps / tunnels on the bottom row of the wall brick. They seem intentional, and every other brick has a little tunnel gap. It turns out - surprise to me - that there is a huge air flow coming into the house from these gaps. What is also probably happening is that when the stove is not being used, the oil heated air (or a/c air in summer) is sucked out of the house during windy days (this happens with air going out and up the wood stove chimney due to a bit of warping in the doors that I seal when not using the stove). d I am assuming these gaps ensure good air flow to the wood stove. But I am now spending a lot of money to air seal and insulate the house to save on energy costs. I am thinking of plugging up the gaps in the brick. This is a 100 year old Victorian house with an old stone foundation, and everyone says you will never 100% seal it, it will always have some leakage - so the wood stove will always have a source of fresh air. Any thoughts your way on sealing up the brick gaps and their purpose?