So, after many years burning wood in an old coal insert (not a lot of wood, mostly ambiance and emergency backup), in 2020 I pulled the trigger on a new Fireplace-X Large, nextgen fyre, with a 2020 EPA cert and a very big pretty window. And secondary combustion tubes. LOL.
They installed it in May 2021, and I cured the paint on the last couple cool days before it got too warm to burn.
I have been learning my way around this thing for the last couple months, burning more than a half a face cord of well seasoned Ash (cut, split and stacked under a roof for 14 mos) on cold days, and trying different control settings.
The good news: The stove behaves as you expect, lights right up, I have figured out how to do reloads with only little/no smoke spill (my old stove had a lintel plate that dropped down when you opened the door, which made spills really unlikely). I can run it with the primary all in, and get a bright fire, pull it out and the stove gets darker and switches to secondary only (so the door doesn't obv leak too much). I get slightly higher temps (measured by IR temps off the window) and slightly longer burns with the air pulled out slightly (decreasing the primary air). Window temps on the IS are maxing out in the low 900s °F. (Assuming standard emissivity, temps of the glass may be higher, ofc).
My wood is mostly blocks, so my fires are generally of the 'short hot' variety, not densely packed, and going to coals in 3-4 hours.
The problem you say? I don't think I'm getting as much heat as my old stove!! The backstory is I have a sense that a box of wood in the old insert can heat my house 100% at 30°F outside for x hours. When I crunched numbers years ago, I worked out that so many lbs of wood per hour and the known BTU load of my house worked out to be 40-50% efficiency for the old stove. Nerd.
This stove should be BETTER than the old one, and has a bigger fire box and secondary combustion... it should easily heat my house using the same or LESS wood. Instead, my HP is working harder (still cycling versus shutting off) with the new stove.
Am I sure, comparing new to old over the course of years? Yeah, I'm sure.
My theory: MY old stove had a hard block off plate that I installed and sealed and leak checked myself. The NEW stove does not have a hard block off plate, the the installer swore the top of the chimney would be sealed airtight around the liner adapter (to a terra cotta chimney), so a blockoff plate would be unneeded. (the old system was a direct connect, which is why I did the blockoff plate).
Two bits of data:
1) if I burn for hours with the blower on med, my finished walls around the chase around the interior masonry chimney get barely warm. Can't feel it with my hand, but I can see the chimney flue with a FLIR, barely. If I then turn OFF the blower, an hour later the chase is very warm to the touch, even in the upper story where the insulated liner and flue are. My interpretation is that the chimney is drafting cool room air up around the outside of the liner, keeping the chase cool (the liner insulation is thin, its hard to imagine the chase being so totally cool otherwise. When I cut off the blower, the firebox now heats up (ofc) and now preheats the same air drawn up outside the liner.
2) When I am burning, and turn off the blower, there is air getting sucked in around the surround. Enough to draw in a match flame or smoke from a blown out match. Not a HUGE amount, but probably more than several cfm. This is not convection, the draw around the surround is inward all around its periphery. That is my smoking gun.
3) Part of my lost heat might be me running the blower on low, to reduce noise. The window is huge and radiating a lot of BTUs. I figure that the heat in the box has nowhere to go but into my house (tall interior chimney), so lower blower just means hotter air out of the blower and more radiant. But it is clear that lower blower gets me a lot less heat (more HP cycling). Cranking the blower (which is annoyingly loud on high) I get enough BTUs (finally) to get my HP to shut off, at least while the stove is cranking. Which never happens on med blower. I think this is suss.
Sound sensible to you guys?
Course of action with installer? Haven't been on my roof in years. Did he blow off sealing the adapter on top? Do a chitty job. Did the seal break?
What do I do now?
They installed it in May 2021, and I cured the paint on the last couple cool days before it got too warm to burn.
I have been learning my way around this thing for the last couple months, burning more than a half a face cord of well seasoned Ash (cut, split and stacked under a roof for 14 mos) on cold days, and trying different control settings.
The good news: The stove behaves as you expect, lights right up, I have figured out how to do reloads with only little/no smoke spill (my old stove had a lintel plate that dropped down when you opened the door, which made spills really unlikely). I can run it with the primary all in, and get a bright fire, pull it out and the stove gets darker and switches to secondary only (so the door doesn't obv leak too much). I get slightly higher temps (measured by IR temps off the window) and slightly longer burns with the air pulled out slightly (decreasing the primary air). Window temps on the IS are maxing out in the low 900s °F. (Assuming standard emissivity, temps of the glass may be higher, ofc).
My wood is mostly blocks, so my fires are generally of the 'short hot' variety, not densely packed, and going to coals in 3-4 hours.
The problem you say? I don't think I'm getting as much heat as my old stove!! The backstory is I have a sense that a box of wood in the old insert can heat my house 100% at 30°F outside for x hours. When I crunched numbers years ago, I worked out that so many lbs of wood per hour and the known BTU load of my house worked out to be 40-50% efficiency for the old stove. Nerd.
This stove should be BETTER than the old one, and has a bigger fire box and secondary combustion... it should easily heat my house using the same or LESS wood. Instead, my HP is working harder (still cycling versus shutting off) with the new stove.
Am I sure, comparing new to old over the course of years? Yeah, I'm sure.
My theory: MY old stove had a hard block off plate that I installed and sealed and leak checked myself. The NEW stove does not have a hard block off plate, the the installer swore the top of the chimney would be sealed airtight around the liner adapter (to a terra cotta chimney), so a blockoff plate would be unneeded. (the old system was a direct connect, which is why I did the blockoff plate).
Two bits of data:
1) if I burn for hours with the blower on med, my finished walls around the chase around the interior masonry chimney get barely warm. Can't feel it with my hand, but I can see the chimney flue with a FLIR, barely. If I then turn OFF the blower, an hour later the chase is very warm to the touch, even in the upper story where the insulated liner and flue are. My interpretation is that the chimney is drafting cool room air up around the outside of the liner, keeping the chase cool (the liner insulation is thin, its hard to imagine the chase being so totally cool otherwise. When I cut off the blower, the firebox now heats up (ofc) and now preheats the same air drawn up outside the liner.
2) When I am burning, and turn off the blower, there is air getting sucked in around the surround. Enough to draw in a match flame or smoke from a blown out match. Not a HUGE amount, but probably more than several cfm. This is not convection, the draw around the surround is inward all around its periphery. That is my smoking gun.
3) Part of my lost heat might be me running the blower on low, to reduce noise. The window is huge and radiating a lot of BTUs. I figure that the heat in the box has nowhere to go but into my house (tall interior chimney), so lower blower just means hotter air out of the blower and more radiant. But it is clear that lower blower gets me a lot less heat (more HP cycling). Cranking the blower (which is annoyingly loud on high) I get enough BTUs (finally) to get my HP to shut off, at least while the stove is cranking. Which never happens on med blower. I think this is suss.
Sound sensible to you guys?
Course of action with installer? Haven't been on my roof in years. Did he blow off sealing the adapter on top? Do a chitty job. Did the seal break?
What do I do now?
