Wood stove usage and sizing for highly insulated, airtight home

[EbS-P]

@EbS-P its a ~2008 double door that was in service as a primary stove from 2008-2022.

I thought about the clearances issue, but my flue would a pretty tall, interior, top vent so I think a single wall offset wouldn’t be too hard to install for this ‘test drive’ plan?

It’s probably due for a minor if not major rebuild. I’d be hesitant to put it into service, expecting/wanting lower output without throughly assessing for possible air leaks.

You know how F400 runs. You probably have a good idea being able to compare old house to new house now that you have a manual J and utility bills from the old house to say, I want something longer burning with lower output or I want to use the heatpumps down to 30 or 25 or xx degrees and think the loading cycle of the F400 fits.

I bet you could sell the F400 now for $1000. More if it’s enameled and in good shape.

 

[xshmoox]

I’d would say ashford 30 would be a pretty perfect fit. The cast iron jacket does buffer the heat a good bit. And to get all the heat out you really need to utilize the fan kit. So there’s a bit more flexibility there for you. So especially in the shoulder months running it on low shouldn’t overheat the space. Plus if it gets a tad warm you could run the fan on the heat pump to circulate the air around to dissipate the heat in the main area.

 

[John Lehet]

I have friends with a similar house in Southern Vermont, in Guilford. I can't remember the name of the outfit that engineered/built the shell -- that outfit is in Walpole NH. I don't know their square footage.

They use a heat pump 99% of the time. This is a weekend house for them, so they turn the heat down during the week, and then they only use the woodstove to get it up to temp when they arrive on Friday evening. I think the stove they have is a Quadrafire, but that's neither here nor there, as it's just a burst to get it up to baseline for the heat pump to take over.

I had a superinsulated house once, years ago. It was before heat pumps were any good. My solution was a masonry stove. Mine was a Tulikivi, 3500 pounds of soapstone. My ex and I built it ourselves, directions all in Finnish, one of the first Tulikivis in the US. Used that for almost 15 years I guess. It was perfect. I could modulate the small amount of heat over 24 hours, have a perfect, clean, super efficient fire once a day. I burned 25 pounds of wood usually, in the one fire a day. I had a dairy scale in the woodshed, so I could measure the carry-bag of wood.

I would really lean on the heat pump and any wood stove would be either super small or a big mass you could modulate. Has anyone recommended a Jotul 602? I had a 601 once, amazing little stove.

These friends also, it turns out, have a Tulikivi in their Monday-Friday house, which is NOT superinsulated. I think they've got the wrong stoves in the wrong houses.

 

[DBoon]

my flue would a pretty tall, interior, top vent

I have a 27' tall double-insulated exhaust pipe going straight up. There is one pipe damper in it. I had a top-vented Lopi 1750 tube stove in this location during construction, and that tube stove would go nuclear no matter what I did to shut the air down early, load it tight, etc. The combination of a 27' chimney vent with no bends (even with a pipe damper basically closed) and a tube stove just meant a crazy-fast nearly uncontrollable burn.

The nice thing about a catalytic stove is that the catalytic converter has a significant impact to the exhaust velocity, and it gives me a lot more control. My setup is pretty ok with a cat stove and a pipe damper - sometimes when it is below zero it burns a little faster than I'd like but its nothing like the old tube stove.