Too much wood, or too much draft?

In answer to your question I think it’s draft. Your setup makes a standard pipe damper difficult.
I have similar height chimney and similar draft

 

On the old noncat heritage, all intake air including secondary air, came through that sealed 3" intake connection so putting a damper on the OAK "hose" would work. Is that hose vinyl or mylar, or is it the appropriate metal? Yes, one of my last resort measures to stop a runaway was to smash the intake hose flat. On my heritage I used semi rigid aluminum tube.

 

Ahhh, super interesting. You're confirming something I've been wondering.

The tubing I'm using is insulated dryer venting rated for about 300*F. I've been watching it closely for signs of heat stress like melting or brittleness, but so far it looks good. I wanted to go with this tubing vice the flexible aluminum because of its insulation, but have been nervous about the heat.

I figure I could easily insert a damper into this hose to control flow, and hearing your opinion was helpful.

 

First of all, welcome to FHC looks like you've been here a while, but I haven't seen you yet, so a belated welcome. Secondly, I don't own a Hearthstone, but I just read up on them a bit and it sounds like they are a similar stove to the hybrid stoves that Woodstock also produces and I do have two of those.

It surprises me that the stove itself can't control the stove draft. On my stoves, one Catalytic and the other Hybrid Catalytic/Secondary Burn like yours) there are 2 controls. The first control is to engage the Catalytic converter, and then the 2nd is to control the draft. How many controls do you have on your stove? When you talk about the "Stove Damper" are you talking about the draft control? If so, there must be a 2nd control that engages the cat, while open it bypasses the cat for that timeframe when you are starting and getting the stove up to temp, usually about 250 Stove Top Temp. Once the stove gets to a 250+ STT it's time to engage the cat.

Do you have 2 controls? Are you engaging the cat as a cold start gets up to temp? If you are engaging the cat, the stove will get really hot as the cat ignites and then you should drop the draft control down to a very closed down about and the high flames should minimize and/or bring the flames down to almost zero and just cause a smoldering burn, where the primary heat comes almost completely from the cat.

PS If you're in the Monadnock Region, we're neighbors, I live in Ashby Mass.

 

Just spoke to Jim...

He said inserting a damper into my outside air kit would not work because the secondary burn pulls air from the room (not the outside air kit), so therefore a damper on the outside air kit would not be effective.

He also said a slowly rising STT which exceeds 600* for short periods is not concerning.

He felt my draft was probably on the strong side, but not so much of an issue that a damper would be required.

So I guess I'll press on like all is normal.

 

Yes, our stoves are very similar (but I suspect yours is built a little better than mine. I would have loved to have a WS!).

I do have a second control to engage my cat, and I using both controls (stove damper/draft control, and bypass) as you describe. My problem is that when the draft control is at it's lowest setting, STT slowly rises. The amount it rises is dependent on the amount of wood I have in the stove. With a FULL stove for an all-night burn, the temp gets pretty darn high.

And howdy neighbor!

 

It sounds pretty normal that the stove is getting that warm, even with the draft control at its minimal setting in the first 1/3rd of the burn life-cycle and especially if you have nicely seasoned dry wood. But then as the wood gets mostly "gassed off" you should be seeing a lengthy decrease in STT for a number of hours until the wood pretty much turns to coals. Even then the coals and now the soapstone should continue to keep the house warm into the morning hours if it is an overnight burn.

How big is the firebox on that stove? The 600' Temp sounds like a typical burn for me with my Ws Fireview. With really dry wood, even when I set my draft to very close to the minimum, the CAT gets hot and gets up there toward 700'F. I have never found it to be as manageable as, for instance, my oil burner thermostat.

 

Your stove and mine sound operate in the exact same manor. You're confirming as 'normal' what Jim the Heritage SME told me. Good to know.

The Heritage is their middle sized stove with a 2.2 cf box. I couldn't be happier with it, and going from a traditional fireplace burner to this stove has been mind opening haha!

 

Takes time to refine a whole cycle of a full load burn. Then it takes time to come up with a daily regimen of 3 or 4 burns to take you through a 24-hour period. Which also includes the outdoor-to-indoor transfer of the wood, and also the disposal of ash in a safe and sufficient manner.

It's work. Once you get it down, it's pretty easy to do. Still, takes time to get it down. Oh, and this doesn't count the added who world of harvesting the wood if you are doing that. That's a whole world of its own.

One of the things you'll hear a lot about here is getting on a 2 or 3 year plan. So the wood you are burning this year was purchased or harvested 2 or 3 years ago. So it's really nicely aged, cut/split/stacked, and covered.

But it is really nice keeping the oil man at bay.

 

I love cutting and splitting my own wood. The idea that I would pay someone for something that grows in great numbers all around me seems crazy.
That said, I'm about to purchase a cord to get me though this season. When we decided to pull the trigger on the stove, my wood supply was immediately not enough.

I scrambled and have about four cords split and stacked for next year, but will probably be a cord short there, too. BUT, by the year after that, I'll be ready!

 

You can still gather dead and down wood all the way through the summer for next winter. My favorite are dead oak branches that the sapwood has completely rotted off of and have recently fallen from their seasoning spot high in a tree. Those lose any residual moisture quickly and burn HOT!!

 

To each his own. There are lots of guys here who are experts at it. The key is to get ahead of the burning season by a couple to three years. Especially here in New England where most of our wood is hardwood that takes a year or more to really get dry enough to make great fuel. Then just stay ahead of it.

This place is as much if not more a wood-harvesting forum as much as a wood-burning forum. So you're in the right place.

 

If you have options for multiple wood suppliers pick the one with wood that tests best! Split a couple pieces and test on the spot prior to purchase. Keep in mind that cold splits will test drier than they really are. There is a temp to moisture scale easily found online for reference.
Otherwise, you may be buying fuel that is no drier than what you recently split/stacked yourself! A very, very likely possibility.
Good luck!

 

I wasn't implying that the pipe damper go into the outside air vent. I meant that the damper go into your six inch vent pipe.Both of my Hearthstones have pipe dampers and work very well.Now looking at your set up I can't see where or if you can access your vent pipe.How are your burn times with the new Cat system ?

 

Mine hits 600° STT with every fire.
That's how it works.
A flue damper might help if you have too much draft.
Are the secondary flames rolling lazily around the top of the firebox, or does it look like a blast furnace ?

 

The secondary air always lets in air, no matter where the main air setting is set.

 

Totally agreed, which is why I'm going with kiln dried wood. The supplier guarantees mc below 20%, which it better be if it's kiln dried.

Good, I guess, though I don't have much experience or frame of reference. Loaded the stove about 3/4 last night at 9:30 and came down this morning at 6:00 to the fans still blowing and relight with nothing except splits. I do believe I have a slightly excessive draft, so it probably burns a little hot and a little fast.

 

Just had another thought.
The highest STT I've seen (800°) was with the air control set almost closed. This gives the cat time to burn all the gases off completely. (I would think the cat temp would be 1500° in this condition.)
When i set the air at 1/4 i usually hit 500-600 depending on the weather.
Try giving it more primary air.

 

Not trying to dampen your enthusiasm but kiln dried many times means the wood is bug free and the outer surface is dry! Basically useless in a stove. If your seller is guarantying 20% or less on a few splits you guys knock apart and test on the freshly exposed inner face right there, then kudos. Buy a bunch!
Best of luck.

 

I'm fairly certain all of Pacific Energy's stoves with the "single lever control" controls both primary and secondary air.