20 pounds of eco brick burns for 5 hours in my stove, 2 hour of flame and 3 hours of coal with reasonable heat output. Compare to my small split softwood not super dry, it has a much much longer coal period. Next I will try big split softwood.
Am I doing this right
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20 pounds of eco brick burns for 5 hours in my stove, 2 hour of flame and 3 hours of coal with reasonable heat output. Compare to my small split softwood not super dry, it has a much much longer coal period. Next I will try big split softwood.
Das Jugghead
Burning Hunk
To answer your question regarding my non-cat stove burn times:
- I load my firebox with approximately one cubic foot of wood. Couldn't tell you the weight of the wood but it is a mix of ash, oak, walnut, maple, birch, and hickory - all of it properly seasoned.
- I see flames for 2-3 hours after a reload. When I reload the previous charge has burned down to ash and coals just about level with the bottom lip of the door opening. I sift/rake the ash and coals to bring the coals to surface and allow the ash to filter down to the floor of the firebox. I remove ash a few times a week.
- My stove still puts out reasonable heat 8-10 hours after a reload. Last night I loaded at 11 pm and reloaded at 8 am this morning. House temperature was 68 and outside air temperature was 22 degrees.
It sounds like you have some of the same issues I had in terms of wood quality and over-drafting. This is further complicated by the absence of effective intake controls on your model of stove and the fact that it is an insert which makes experimenting with methods of controlling the intake virtually impossible. The only thing I can think of that might help you (outside of the aforementioned wood issues) would be to have an outside air intake that could be adjusted to control the amount of air being drawn into the stove.
Here is a thread on my stove/learning experience: https://www.hearth.com/talk/threads...all-challenges-questions-observations.173074/. You may be able to get some ideas from it, but again, the fact that you have an insert makes everything more challenging.
Thanks bro, I read your thread and learn quite a lot. An out side air intake could be useful. Should the outside intake be really outside the house? I am thinking drawing air from my garage or basement; easier access and closer to the stove. Also if I am drawing air from a somewhat enclosed area, that should create negative air pressure in there and reduce the draft?
Das Jugghead
Burning Hunk
I absolutely believe the intake should draw from outside the conditioned house envelope. Heating exclusively with a wood stove really highlights the crucial element for top-notch insulation/weather-proofing. I am not sure what you can gain from drawing intake air from a basement or crawlspace - in fact I would wager that doing so will equate to an overall loss in terms of heating efficiency. Having said that, in insofar as it relates to slowing down your intake velocity, I would think that using a smaller diameter intake tube would gain you the reduced draft by virtue of greater laminar resistance.
Care to explain more? I have no idea but my stove is at least 15 feet away from nearest build exterior wall though.
Das Jugghead
Burning Hunk
Drawing intake air from inside the building envelope such as a basement necessitates that the air is replaced by air presumably - from outside. That cold outside air will cool down whatever space it is traveling through such as a basement or crawl space.
I must have missed where you described the location of your insert and the distance to an exterior wall. Is it possible for you to run a 4" metal pipe (similar to a dryer vent) through the basement to an exterior wall? If so, you may want to experiment first with using a short length of smaller diameter intake pipe to see if that slows down the draft. If it works you could explore running a long insulated pipe through the basement to provide intake air for your insert.
I know it does little good for you at this juncture but it has been mentioned before by others and I wanted to reiterate that your wood is probably suspect here as well. I had a similar situation last year and tried everything I could think of to get through the season as best as possible including splitting the wood down to smaller splits to increase the surface area of each piece and laying them on the hearth in front of the stove to try and dry them out and pre-warm them before loading them in the firebox. This season I found that the only thing that works is to use properly prepared wood - seasoned, correct length, all hard wood, etc.
My garage is already cold; it is unheated but warmer than the outside though. Basement is also unheated but warmer than the garage because being underground and having my furnace in it. Drawing from the basement is probably not very nice because it is quite sealed up and that air has to come down from the house. I think drawing from garage may be nearly the same as drawing from the outside because the garage is quite leaky. So if I do that my garage will be colder still; I can live with that.
I can get through the season with my oil furnace and the stove already gives me warmth in my living room when I burn it. I just want to have better return from the wood.
I wouldn't want to draw from the same space as your furnace. That could lead to draft issues from the furnace and possible combustion gasses from the furnace not venting properly.
You cannot pull from a garage it is a code violation. Basement is fine if there is decent air supply
Thanks. My basement most likely don't have decent air supply; I think the furnace pull air from somewhere else. So no for both then.
Intrepid Flexburn question: what is the purpose of part #20, the stainless steel retainer/gasket? This looks more like it is to function as a air flow restrictor on the five holes in the "engine". I think by default this would increase the air flow to the air wash on the doors? This plate restricts the size of three of the five holes by about half. Why didn't they just make the holes in the porcelain that size to begin with unless this was an after thought after testing? Do the other V C flexburns have this? Any thoughts welcomed?
Doesnt the Montpeiler II have an air start up control? If so I think the knob is on the bottom right and closes on a timer. Did you check to see if that was closing?
SculptureOfSound
Feeling the Heat
Original Montpelier owner here. I get about 3-3.5 hours of useful on 4 medium-small splits of pine.
I think the lack of air control is going to lead to shorter burn times and wasted heat. The EPA specs for btu range on the original Monty was like 10,000-27,000 btu an hour. The low/high range for the Montpelier II is listed at 24,000-27,000...aka it's burning almost full out the whole time. The problem with that is at such a burn rate a lot more heat is wasted up the chimney (and a lot more air is going up the chimney too which means more cold air being pulled in the house to replace it)
I think the lack of air control is going to lead to shorter burn times and wasted heat. The EPA specs for btu range on the original Monty was like 10,000-27,000 btu an hour. The low/high range for the Montpelier II is listed at 24,000-27,000...aka it's burning almost full out the whole time. The problem with that is at such a burn rate a lot more heat is wasted up the chimney (and a lot more air is going up the chimney too which means more cold air being pulled in the house to replace it)
Yes, it is closing. The ACC control a separate air intake at center front bottom. Primary is somewhere else, I am guessing right side top. If acc is engaged you can clearly see coal behind the andiron bright up. As long as you have a small pile of coal at that spot your wood will catch. Coal at other place does not matter. This is also why the stove always burn from front to back and from center to both sides.
I always thought hot burn is the more efficient burn. To harvest the heat I have to turn blower to max though.
I am not sure how big is your split; my split is about 3~4 pound each. If I put in 3 splits or ~10 pounds I get useful heat of ~1.5 hours. 10 pound more will get my another hour, upto 30 pounds at 3.5 hours. more fuel is longer and hotter burn with a higher burn rate. below 10 pounds the flame will be a little pathetic, at 30 pounds the peak heat is a little scary to me; but probably nothing out of ordinary. For one thing The tube did not glow; so it is still below 1200F.
SculptureOfSound
Feeling the Heat
The cleanliness of the burn is usually higher at high burn rates (you can see this when looking at detailed EPA burn reports....this is also why single burn rate stoves burn at a high rate) but that doesn't mean it's the most efficient at heat transfer.
I don't know the physics of it all but I find I get the most heat from a load when I get the whole load burning at once (not just the front of the load or one side) and then cut the air as low as I can. Tons of secondaries and a slow burn, stove top will go 700+ and heat is incredible for a couple hours, then tapers off quickly (this is with maybe 1 to 1.5 cu feet of pine).
Getting only part of the load going leads to a slower burn with less of a peak output but also seems to be like less heat overall (although the coals last maybe 25% longer).
More air leads to a faster burn but the heat output is still less than with the air down when it's just all secondaries all over, and it also burns down quicker.
Heat transfer efficiency seems highest when burning with the minimal air you can run with while maintaining enough of a burn that heat at the top of the box stays warm enough to sustain vigorous secondaries.
I don't know the physics of it all but I find I get the most heat from a load when I get the whole load burning at once (not just the front of the load or one side) and then cut the air as low as I can. Tons of secondaries and a slow burn, stove top will go 700+ and heat is incredible for a couple hours, then tapers off quickly (this is with maybe 1 to 1.5 cu feet of pine).
Getting only part of the load going leads to a slower burn with less of a peak output but also seems to be like less heat overall (although the coals last maybe 25% longer).
More air leads to a faster burn but the heat output is still less than with the air down when it's just all secondaries all over, and it also burns down quicker.
Heat transfer efficiency seems highest when burning with the minimal air you can run with while maintaining enough of a burn that heat at the top of the box stays warm enough to sustain vigorous secondaries.
I see what you are saying. The best way to burn is to somehow deplete the wood from air and let them just emitting gas, only to be ignited at the tube. What I am seeing are columns of flames, which means wood getting too much air and the gas is already burning right off the wood. And the extra air is taking away my room heat up the chimney. However, that balance sounds very tricky to me; I would not only need air control, but also some form of thermostatically feedback air control. Also if the wood should be air depleted, how does the coal burn then? Wouldn't you need to shut the secondary air and reopen primary air once the gas run out? Or you will sending unnecessary air up the chimney, but through secondary tube instead, and with some unburnt coal at the bottom?
Can you run a fresh air duct along the common garage wall to the exterior wall for the air intake?
Maybe, however, that will be 2 holes on brick walls, one 90 degree turn and fifteen feet long air duct; and I am not sure if it can help. My plan is to improve insulation like some other people on this forum did. I am not sure how much that will gain me but at least it must be a net improvement.
therealdbeau
Burning Hunk
I don't think the Montpelier is set up to allow for a fresh air intake so I don't know how you'd make that work anyway
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