My OAK Experience

[MacGyver]

Controversial subject, I'm told.

Anyways, I just wanted to share my OAK experience since installing it on my Eco-65.

The one comment I heard a lot (including from a Drolet technician) is that the colder the air outside, the more BTUs my stove will produce. I can't really say that I am seeing that result so far. If anything, the colder it is outside the stove seems to run slightly less hot - at least by what my exhaust temp is reading on the stove. On milder nights it seems to be about the same temperature as it was before - maybe a degree or two hotter.

The big impact however has been with drafts. Since installing the OAK, the drafts in my home have almost entirely disappeared. The stove is in the basement and upstairs are all old single pane windows that I have covered in plastic for the winter. Drafts were so bad before that at night you could actually see the plastic crinkle and move with the drafts coming in. Now they are still as can be.

So while I'm not sold on the the claims of "colder air = more btus", installing the OAK was well worth it for the draft situation.

One question though: I'm noticing ice build-up around the housing for the air intake on the stove. Is this normal?

Thanks.

 

[moey]

Glad its working for you. I dont think anyone on here as ever said things were better before a OAK. Some say no difference most cite some improvement with something.

 

[heat seeker]

Icing is normal. Some insulate the OAK to reduce condensation/freezing, but it's not necessary.

 

[haff99]

I'm on my second stove and the second time both the store and installer said we don't need OAK. I read the pro's and con's and it has to get air from somewhere, but I noticed I get a slight draft nearest the door to the pellet stove and that is all I noticed ever. It is a slight draft too and we never had any issues with stove and no OAK. I just assume this is the air getting used by the stove, so no big deal. I'm assuming it isn't that much air either because I could barely notice the draft and I never felt a draft anywhere else.

 

[bogieb]

Somehow I've never gotten the impression that people thought you would get more BTU's with an OAK, but maybe that is because I didn't read closely enough.

Definitely cut down on drafts when I installed the OAK on my Harman.

Haven't gotten ice build up on either stove, even when -18. The Harman's OAK is insulation wrapped for the first 18" or so just because I hated the cold being released into the basement - right onto the bags of pellets - but the last 18-22" is un-insulated. The St. Croix has a very short OAK and is completely un-insulated. Just sounds strange to me having ice build-up, but maybe my climate isn't cold long enough for that to happen.

 

[heat seeker]

Back in 2012, 9º outside. It's had more than this on occasion.

 

[bogieb]

Back in 2012, 9º outside. It's had more than this on occasion.


View attachment 151379

I wasn't doubting it happening, just seems strange to me. Maybe part of the reason the St. Croix doesn't do it is because it has a combo thimble (separate OAK, but on the same thimble, so it probably gets a nominal amount of heat from the exhaust pipe.

The Harman OAK is separated from the exhaust by over a foot, and is also into the prevailing wind, so maybe it is that way under the insulation and I just don't see it.

 

[Tonyray]

I wasn't doubting it happening, just seems strange to me. Maybe part of the reason the St. Croix doesn't do it is because it has a combo thimble (separate OAK, but on the same thimble, so it probably gets a nominal amount of heat from the exhaust pipe.

The Harman OAK is separated from the exhaust by over a foot, and is also into the prevailing wind, so maybe it is that way under the insulation and I just don't see it.

P61A With OAK..Facing prevailing winds..
Never get any Inside or outside Ice...
Air comes in right under that flap//

 

[TimfromMA]

My OAK pipe before and after insulating.

 

[chken]

The one comment I heard a lot (including from a Drolet technician) is that the colder the air outside, the more BTUs my stove will produce. I can't really say that I am seeing that result so far. If anything, the colder it is outside the stove seems to run slightly less hot - at least by what my exhaust temp is reading on the stove. On milder nights it seems to be about the same temperature as it was before - maybe a degree or two hotter.

I'll guess and say that they may be referring to the fact that cold air is more dense than warm air. Being more dense, means there is more oxygen in the same volume. On the other hand, for the stove to produce more BTUs, you have to not just add more oxygen, via cold air, but also more fuel. So, unless you were adding more fuel, you probably shouldn't see more BTUs, at least not that you would notice.

 

[Wilbur Feral]

Ice / frost is simply warm, moist air coming in contact with very cold surface. Very normal if cold enough and enough humidity in air. Insulation prevents the two from coming in contact, and fixes it.

 

[bogieb]

Ice / frost is simply warm, moist air coming in contact with very cold surface. Very normal if cold enough and enough humidity in air. Insulation prevents the two from coming in contact, and fixes it.

That makes sense - plus, I'm at less than 20% humidity in my house, so less humidity to get to what is exposed.