How to work with an OAK

Aside from extremely minor leakage into the system, why would you expect this to lose so much heat? The air enters from outdoors and exits outdoors - not really going to cause a noticeable effect.

We recently built a new house with a freestanding wood stove, and also had it installed with an OAK. In our experience it was the right thing to do, and would do it again if we built another house.

It does not appear to cause any heat loss when the stove is not running. The only thing I have ever noticed with it is that when it is really cold (say, 10 degrees or less) that the inlet pipe would build up frost while the stove was running. To prevent that I wrapped it with a thin layer of pipe insulation and that seem to did the trick.

Ironically if the stove was not running, not enough air went through it to build up frost or even really notice anything.

But like Brant says - it is just a portal to your stove separate from the air in your house. Without it, you'd be pulling outside air into your house before it went into your stove and up the chimney anyways. Therefore IMO it can only be a benefit to have it.

Hope this helps.

I too have an OAK and agree with the others. Heat loss is negligible. When not burning the stove, I close off the air intake completely to minimize air movement. Another option would be to stuff a bit of fiberglass insulation into the chimney, just dont forget to remove it before burning.

You can buy a 3 or 4" damper at HD and put it in the air inlet just prior to the stove connection. I thought about doing it but I burn 24/7 so it was not worth the effort in my case.

I too have a very tight house and an OAK for the small woodstove I use mainly just in the evenings for 5-6 hours. I have a double-walled ICC damper installed in the pipe just below ceiling level. Those come with some minimal opening (forming the letters "ICC"), which I had a welder close off for me. I open the damper all the way for a burn, close it completely the next morning after verifying there are no glowing embers left. I anticipate adding a damper on the OAK inlet duct where it comes through the wall.

As it is, when the stove is not in operation, there is a very slight leakage around the door gasket and air controls, which aren't super tight, if I feel for it. But in general this is not a problem for me. I like having the OAK, as it lets me burn while the range hood or clothes dryer is running. When lighting off the stove, if either exhausting device is going I have to crack open a window nearby, with the stove door closed, until the fire warms up the flue to establish draft. Otherwise I can get backdraft and a smoky room.