A tight wood stove in the hands of an experienced user is a remarkable thing. The amount of heat that can be extracted from a large oak log is nothing short of remarkable.
Sadly, most wood stoves are not tight, nor are most users experienced.
Best fireplace in terms of efficiency is a rocket mass heater. It burns the wood gas in a secondary burn chamber and then routes the exhaust through a lot of thermal mass. One 2 hour fire a day will usually heat 2000 sq feet of house. 3m video explains the concept; longer videos will better explain it https://youtu.be/fwCz8Ris79g
This is 50% of the reason why pellet stoves were created, with the other 50% being you can burn scraps instead of large oak logs that could be used for furniture etc.
Pellet stoves sound nice in concept but my experience with them (n=2) has not been good. The hoppers break and jam, the fans die, and they’re generally just a pain in the rear. Usually happens right when you need them most, too.
I only have n=1 experience here, but I've been using a pellet stove for years, burning a ton (50 bags) of pellets each year. I buy quality pellets which avoids having clinkers and keep them dry in the garage.
It does require yearly maintenance to grease the motor and I had to undergo some repairs when we bought it (used, it came with the house) because the previous owners did some really dodgy stuff like using a completely wrong sized fuse and taping it in with duct tape, mangling the fuse holder, but it has been reliable for over a decade now.
Cold climate here (Quebec) and we heat with electricity usually. Many people have an electric furnace (forced air) or even baseboard (what I have for example). We also have a heat pump (heats the upstairs very well until about -15C and provides awesome AC for the entire house in summer).
For Power outages and also coz its just awesomely warm: propane fireplace. All the benefits of a wood fireplace with none of the downsides.
What this means is that we don't worry about "oh how about we all go ice skating" just turn the fireplace off without worrying about a fire. No indoor air quality issues. Electricity is out? Sure no fan but who cares. Still warm (and some have battery backup fans). Have to start it up without electricity? No problem, pilot lights w/ piezo starter. Propane delivery isn't that different from having to stockpile the firewood.
LPG or Propane is awesome down until -42 celsius. Then it’s basically useless as it won’t vaporize. Live in Quebec too and my backup is a dual fuel generator. Propane and then regular fuel if it’s too cold or I’m out of propane. Never too careful!
You do have us on the regular fuel backup :) don't have that but we also don't have a backup generator in general. I wanted to last time we had a >12 hour outage but couldn't get the expense approved by the "finance minister" (i.e. the SO). When the electricity goes out for more than an hour or so the neighborhood is suddenly very loud though coz several next door neighbors go and bring out their generators so I'm not too worried about our survival and there's always the firewood pile in the backyard.
I haven't downvoted you, but it's perhaps because the LPG tank is usually outside with a rather large surface area, so if -40 degree days are rare, insulating the tanks and providing a heater might not be very cost-effective vs. having multiple fuel jets in your burner for multiple viscosity fuels.
Also, either the "way to keep the tank warm" would probably be an electric heater (which would fail in these corner cases) or else a small burner... next to your tank of highly flammable gas with lots of no-smoking signs around.
Though, I would guess in colder climates, if you really wanted to use LPG, you could put an electric fuel pump in your tank (so it doesn't rely on vapour pressure to feed) and have a burner that pre-warms the fuel and includes a small electric heater for starting.
> it's perhaps because the LPG tank is usually outside with a rather large surface area, so if -40 degree days are rare, insulating the tanks and providing a heater might not be very cost-effective vs. having multiple fuel jets in your burner for multiple viscosity fuels.
It's more or less a one-time cost and you might want the simplicity. Tradeoffs rather than it being inevitable.
And multiple fuel jets aren't enough. If you can't depend on the propane, then you need a lot of backup fuel.
> small burner... next to your tank of highly flammable gas with lots of no-smoking signs around.
You have fire that's not very far anyway. It's not hard for an expert to design something that's safe, since you don't need all that much heat.
> Though, I would guess in colder climates, if you really wanted to use LPG, you could put an electric fuel pump in your tank (so it doesn't rely on vapour pressure to feed) and have a burner that pre-warms the fuel and includes a small electric heater for starting.
If you prefer keeping the tank design the same, that sounds fine. A tiny pump would take barely any power, so a cheap solid-state generator attached to the burner could run it and charge your phone too. You don't even need a battery to get things going; a 1 pound tank could be warmed by hand if everything else goes wrong.
They also change the composition of at least Diesel at the pump. Not sure on fuel oil which is essentially the same as Diesel at the pump, save for possibly things like that (definitely the color)
Yes, most of my relatives on my mom's side are farmers in the upper Midwest. They have separate (gravity fed) tanks on their farms for #1 and #2 diesel, and the tank they use for filling the tractors depends on the season.
(Farmers buy diesel in bulk and don't pay road tax on it. It's illegal to put the untaxed diesel into a pickup that ever leaves the farm.)
What's a good place to learn the art, do you know? I'm not in Texas, but I have two woodstoves now, and my one experiment with them thus far has taught me only that I have a lot to learn.
Other poster covered it well, but one thing to add. There are the kinds of wood burning stove. Old simple, pre EPA mandated high efficiency stove, efficient stoves with a catalyst to provide the clean burn, and efficient stoves that use secondary air injection to provide a clean burn. The new efficient stoves are a bit more forgiving for throttling them down for long burns without producing too much creosote they can cause chimney fires.
I just replaced the old stove in my house with a new catalyst model and I burn 30% less wood while providing more steady even heat. I am heating 4000 sqft 2 story with only wood heat, one load every 12 hours, house between 80 and 64 degrees depending on location.
Are you aware of any high-efficiency wood burners that don't require electrical power for the secondary air injection? If they do all require electrical power for secondary air injection, if power is lost, do they quickly foul the burners with soot, or do they just gracefully degrade to running at a lower efficiency?
The secondary air combustion for wood burning stoves usually doesn't require electricity. At least, we shopped for an EPA 2020 compliant replacement wood stove a couple years ago, and I don't think I came across that needed electricity for combustion. Pellet burning stoves often do, and there are often add-on kits for wood stoves to provide greater air circulation for the room, but the primary and secondary combustion use the natural "draft" from the chimney. I guess it's possible that even higher efficiency would be possible for bulk wood with a forced air design, but I don't think they are common. We ended up with a Progress Hybrid Soapstone, and have been happy with it.
Other reply covered it nicely. I am not aware of any conventional high efficiency wood stove that requires electricity to run. I do have blowers on mine to circulate air over the convection deck, which also reduces clearance requirements to the rear of the stove.
I opted for a blaze king catalyst stove. It’s probably the nicest stove utilitarian stove you can buy if you want to heat a large space and want to control temp outputs. Downside is cat replacements every 5 or so years, but that’s not a big deal and worth the benefits.
Wood stoves are charcoal breeder reactors powered by their own vaporized wood gas. The re-radiated heat from the ironwork is what gives them their extreme warmth. They are like many other fuel burners — stage one vaporizes the fuel and stage two burns the vapor — it’s just that both stages are in the same iron firebox.
When you start a fire you want to quickly get the stove up to temperature. Use small split logs and kindling sticks along with some kind of “candle” that burns long enough to get the flames going. Commercial fire lighters (kerosine wax bricks) or even just a bit of kitchen towel with a tablespoon of vegetable oil will do.
The kindling and your first log will burn hot and bright with an attractive yellow flame — like a campfire. At the end of this first burn you will build up a layer of red hot wood embers in the base of the firebox and the ironwork will be about half way to temperature.
The next stage and each stage after that is to put on a much smaller load — often I will just use a single large log — and leave the air intake or door ajar, temporarily. The hot embers will rapidly get the new log hot and the whole thing will instantly go from glowing red to an inferno in under a minute.
At that point you have achieved a self sustaining reactor. You can leave it running full throttle if you want the pretty yellow flames. It will only last 20 minutes though and all the energy will blast up the chimney.
Much better, and indeed the whole reason for having a wood stove over an open grate, is to now shut off almost all of the airflow to the firebox. Low airflow means the combustion goes right down — you may not even see any flames if you go super low — but it also means the stove isn’t being constantly cooled by a high volume of airflow.
If you balance it just right then the flame front of burning wood gas will sit above the logs and permeate the whole chamber. It looks like a cross between Aurora borealis and a Backdraft (1991) slo-mo sequence — a deep red wraith that flaps around slowly, completely unlike the sooty yellow flames you began with. You get a real feeling for how it’s the gas not the wood that’s burning. (Having a stove with a glass viewing window really opened my eyes to their operation.)
A single 10” log — quarter split from a 20” diameter ash tree and air dried for 18 months to <20% moisture content — will now produce 10kW for an hour or more and stay burning for eight. The fire will “keep” overnight and in the morning you can put on a new log, fire it up with the door ajar, and be back at full capacity in minutes.
What’s interesting is that if you run the stove in pretty mode — like a cartoon open fireplace with crackling and burning and yellow flames with the vents or even the whole front door open — you’ll notice that parts of the stove might not even get hot. The iron air intake grill on mine will remain at room temperature because although the flames are vigorous, the airflow is so fast it keeps the stove body cool.
Conversely, once the stove has been running for an hour in slow burn mode, the entire body is practically glowing and requires thick gloves to handle. It is wonderful.
Exactly this. Wood stoves operated in this manner are extremely efficient, and generate particulate emissions comparable to an oil-fired furnace, maybe 100x less than an open-hearth fireplace.
> It looks like a cross between Aurora borealis and a Backdraft (1991) slo-mo sequence — a deep red wraith that flaps around slowly, completely unlike the sooty yellow flames you began with. You get a real feeling for how it’s the gas not the wood that’s burning. (Having a stove with a glass viewing window really opened my eyes to their operation.)
Would love a video if you can find one to see exactly what you're talking about.
After a quick search on YouTube I was somewhat unsatisfied; the few videos I looked at showed the effect only partially. People do sometimes like to bias the burn towards the yellow flame, either for entertainment or to keep the temperature of the stove down. Also it's hard to capture. My own attempts to photograph the effect haven't been successful due to the movement of the flame and the gentle low red glow that it gives off.
I've never seen it before (so I'm not 100% this is the same thing), but did find a picture that I think is similar to what they're describing - the red glow in the top window of the picture here: https://commonsensehome.com/masonry-heaters/
The trick is to start it up hot and then reduce down the airflow to near zero. The knowledge was passed down in the tribe, so I don't know where one learns the art.
Sadly, most wood stoves are not tight, nor are most users experienced.