Mad Tom said:
I have an Oslo with about 20' of pipe. One elbow going into the thimble and a urn to head straight up. Someone told me I could heat better if I put a damper in. I have double walled leaving stove for 3 ' before the elbow. It is a adjustable pipe and at about full extension.
Unless you have an overdraft problem, I don't think you need one. I had a long straight run of chimney, so I had a damper added to my
initial installation (double walled). There were no overdraft issues, so I took it out the next year. In our current house, I have a couple of
turns like you and didn't even consider a damper.
Do you have a sputtering fire? Do you have a fire that burns wildly even after the primary is shut all the way off? The damper can help in
the latter circumstance.