I'm an OAK believer now!!

[SmokeyTheBear]

35% isn't really that moist, the recommended indoor relative humidity is in the 50% range.

Ya didn't follow the link I gave. (broken link removed), which agrees with advice I've found elsewhere. The important measure isn't the relative humidity inside the house, but what the relative humidity would be of the same air if chilled down towards the current outside temperature. They give a nice chart:

Outside Temperature                        Inside Humidity

20º to 40ºF                                     Not over 40%
10º to 20ºF                                     Not over 35%
0º to 10ºF                                      Not over 30%
-10º to   0ºF                                   Not over 25%
-20º to –10ºF                                   Not over 20%
-20ºF or below                                  Not over 15%

In other words, when the inside relative humidity is 35% (as mine is) and the outside temperature is under 10º, a typical house can start to see problems from the dampness in the areas exposed to the inside air that are chilled significantly by the outside temperature, which is what causes the condensation, followed by mold, rot, rust. That said, I think I'm getting away with the 35% relative humidity in the house in winter, since the days at least are usually over 10º. But 35% is on the high side, especially in an older house such as mine.

Very little (far less than is chilled by the replacement air drawn in by not having it) of the inside air is going to get chilled down by an OAK. For starters I have one and just a short length of it gets any condensation on it, if you insulate it none of it does. The primary condensation issue with an OAK is during the off season when the relative humidly is high and the air is being drawn through the stove and the deposits still on the internal surface remove the moisture.

This can be dealt with by blocking the OAK, the vent, placing a dissect in the firebox, or just spraying all of the interior surfaces with a light oil.

I did follow that link you provided. This is not a case of indoor humidly levels but inside the stove humidity levels. They are not one in the same.

Cold air has very little moisture in it and what little it has is quickly vaporised by the fire in the stove and sucked out the vent.

 

[ivanhoe]

i've just recently installed a OAK and have noticed less draft seeping about. it's a diy 3" tied into my venmar 6" piping which i don't use to often. it's a trial set-up for now and will modify it when the need for the venmar arises. i will keep a eye on the condensation in the heating and unheating seasons!

 

[save$]

Someone mentioned Damp Rid for inside the stove and the hopper. I tried it and got no visible rust issues. My stove is in the basement level of my raised ranch. Area is finished. I have to run a dehumidifier in the summer, but in the winter I have to add moisture with a humidifier. Comfort. warmth and no wood cracking is best when I keep the humidity around the 50% level.
My dealer didn't go along with OAK, but then again, he left without leaving a copy of my stove's manual. Why any dealer would go against the owner's manual is a mystery to me. I installed my OAK for about $60. Got a lot of good advice here about materials to use with OAK. NO pvc.