New, modern yurt build in Mongolia

[UKadventurer]

Originally Posted by Bob Rowlands

Thanks for update. Very nice place you have there UK.

My Hungarian friend Bela heated his small mountain house with coal burned in an old school late 1970s Fischer wood stove, that he retrofitted into his old fireplace. He burned wood in that fireplace many years. His old wood bin got turned into a coal bunker.

Burn time differential wood to coal I do know know, he just said coal burned longer. Cost wise beats me, I never asked.

Heating

with coal was a WHOLE lot less work vs cutting and splitting wood. He was fit in his retirement years, but regardless, making a wood pile is a LOT of work.

You're welcome. I was starting to feel it had been a long time since I posted anyway. Your reminder prompted me to post. Cheers for that.

The general rule of thumb is you can get a far longer burn with coal/coke than with wood. Unless you have a very sophisticated wood boiler.

We have unlimited fallen wood in the forest next to us but the whole process of cutting, splitting and seasoning is a massive amount of labour. My back isn't great either so I'd have to pay somebody and that defeats the savings of doing it myself. Firewood is widely available but I don't think it's properly seasoned and/or stored here. It costs $2 per 10-12kg (22-26lb) bag. The last batch was a bit damp. Maybe they didn't store it well over the wet summer months. I don't have a

moisture

tester so I'm unable to test the

moisture

content.

In contrast, semi-coke costs about 20% of firewood by weight and burns longer and cleaner. It's essentially smokeless once going. Firewood is nice in a glass fronted stove and we'll still use it as a backup and some is needed to start the semi-coke burning.

By the metric ton (2200lbs) the price here is:
firewood = $200.
semi-coke = $40.

However, it's all about availability and price. You can't use what's not available and you don't want to pay too much for your

heating

unless there's huge benefit like convenience. I'm definitely willing to trade a bit of inconvenience for huge savings. But the inconvenience of dealing with semi-coke is nothing compared to making our own firewood.

Coal/coke price depends on whether it's local or how local. Mongolia has massive coal reserves but no gas/oil production. So coal - processed into semi-coke briquettes - is a no brainer and is the most used energy source that powers and heats the entire country. We can buy semi-coke bags from a store about 5 miles from our place once per week. I can pickup and deliver it myself which is also a big saving.

Wood is mainly used by nomads and other yurt dwellers, but is probably imported from Russia, just like LPG (propane) and oil, benzine, diesel. So it's expensive. LPG and diesel are about $1 per liter or $4 per US gallon. I use diesel for my truck and LPG for cooking and backup heat. It's costly so I try to limit my use.

Some folks swear by wood pellet stoves because they can have auto-feeders (augers) which can give you all night and day burns, but their mechanical complexity means they are prone to breakdowns. We don't even have a good supply of wood pellets so it's not even an option here.

So far, our coke boiler with radiators seems to be promising but it's not super cold yet so we won't really know if it's sufficient for our needs until December/January. If not, we have multiple supplementary means of heating.

[Jafo]

Originally Posted by UKadventurer

Some folks swear by wood pellet stoves because they can have auto-feeders (augers) which can give you all night and day burns, but their mechanical complexity means they are prone to breakdowns. We don't even have a good supply of wood pellets so it's not even an option here.

I have a pellet stove in my home, though I hope to retire it now that I have mini-splits (we'll see). Mechanically, I have had little problems over 12 years. I had to replace the igniter once (should always have on on backup anyway) and the auger motor and blower motors. That was for 12 years worth of use. Only the igniter went out without warning. The motors let you know that they are on the way out generally just by listening to them.


If you can get the pellets and have the electric to run the stove, they are a good option.

[UKadventurer]

Originally Posted by Jafo

I have a pellet stove in my home, though I hope to retire it now that I have mini-splits (we'll see). Mechanically, I have had little problems over 12 years. I had to replace the igniter once (should always have on on backup anyway) and the auger motor and blower motors. That was for 12 years worth of use. Only the igniter went out without warning. The motors let you know that they are on the way out generally just by listening to them.


If you can get the pellets and have the electric to run the stove, they are a good option.

Well, they always say YMMV.

I was just going by what the "Embers Living" YouTube channel says. They are a retail BBQ and fireplace store in Denver, Colorado.

From my impression, they sell all kinds of stoves and fireplaces but report far higher failures on wood pellet stoves. I mean it stands to reason since they have far more moving parts. The most basic stove has few or no moving parts.

His points on long term reliability:

-WOOD
- Its pretty hard to beat the reliability of a wood stove. The reason is, there isn’t much to them, and very few moving parts. So you won’t get stuck in the cold in the middle of winter without any heat.

PELLET-
- This is where pellet stoves become a real pain. There are so many moving parts and electronics, and the issue is. If just one of them goes out, the pellet stove is completely non functional. Which is a huge drag if you wake up in the freezing cold, and then could be out a heater for a month or so if parts needed to be ordered. So it turns into a giant paper weight.


My thoughts, I suppose if you handy with maintenance and spare parts are easy to come by, have electricity, and a good source of pellets, they are worth considering.

We can't consider them at all due to no supply of pellets locally. I don't think they even sell pellet stoves here but I suppose you could import one. Then you wouldn't be able to run it.

[Bob Rowlands]

I know zip about pellet stoves.

We have ~ 3.5 cords of ponderosa pine stacked out back. My labor got it from where the trees grew to those stacked cords. A LOT of work, but good healthy outside work in fine clear crisp fall weather.

We just harvested a bushell of apples last Sunday at an orchard up north of us. In fact this morning my wife and I made up a pot of apple sauce in the slow cooker right now. Pork chops and apple sauce tonight. Man I LOVE this time of year. And our son cbow shot his 6x6 bull elk last Sunday night. MMMM mmm that is gonna be some PRIME eating.

[UKadventurer]

Country life is pretty amazing.

I’ve no idea what a cord of wood is. I thought the UK had weird, archaic measurements but the USA leads the way.

Luckily there are converters online. It seems like 3.5 cords is 12.8 metric tons. That’s enough to heat an Arctic village. LOL.

I love burning wood and I wish it burnt all night. Unfortunately it doesn’t. So we use it while we’re awake. While we’re asleep semi-coke should do the job.

[Jafo]

I have a couple full cords at my yurt camp. We do about 1 cord a season there in my wood stove.

I think the pellet stoves are not ideal for yurts because they are forced air heat, whereas coal and wood stoves are radiant. Much better solution for that use case. If you were in a tightly insulated house like most new construction in the US is, then forced air is actually much more efficient or so I am told.

[Bob Rowlands]

UK, the dimension of a cord is 4x4x8.

My small 'fireplace insert' size (~1.5 cu ft) air tight 1980s era Sierra Cricket wood stove I used in my yurt would burn about 1.5 hours damped down. Doors open and fire raging it would burn about 3/4 hour. All night burn ain't gonna happen with that little twinkie.

Some bigger air tight old school late 70s early 80s no catalyst, no secondary burn, stoves were not all nighters either. I worked out of a welded steel stove manufacturing shop my boss owned in 1980-1982. I was a carpenter working out of his shop and not involved with the stove end of things. But those air tights beat the heck out of any open fireplace for burn time. Our non airtight fireplace blows through our wood pile. I go through a couple dozen of sticks a night, and WAY more over all day burn during holidays.

[Bob Rowlands]

My wife and I lived in an apartment back in the 80-82 period in WY that had a non airtight Franklin stove in it. It also went through the wood pretty darn fast, but not as fast as an open fireplace.

Old school all brick and masonry fireplaces like my parents had were great for holding the heat in the huge masonry mass though. Once warmed up it didn't take all that much wood for a nice long evenings fire.

Our open fireplace in this house I built in 2000 is a manufactured POS unit that was fast install and very little mass except for firebrick. It >totally sucks< in comparison to the old school masonry fireplace I grew up with.

Lastly assuming money is no object, a Rumford all masonry is the winner. Very old design and as perfect as can be for open fire.

[UKadventurer]

Yes, thanks for the explanation. A cord is an archaic but still useful measure of a volume of a wood pile. It works well for people who cut and store wood.

Wood stoves / furnaces have come a long way in terms of efficiency but we still have the issue of energy density.

Here are some interesting numbers from a scientific study - the numbers give an indication of energy density in Millions of Joules per kilogram:

Smokeless coal
28Mj/Kg
Kiln dried wood
15Mj/Kg
Seasoned wood
15Mj/Kg
30% Wet wood
12Mj/Kg

Local pricing is:
Semi-coke briquettes
$0.04 per kg.
Firewood (unknown moisture content, might/might not be seasoned)
$0.21 per kg.

But to get the energy density of semi-coke, I'd have to get 2kg of wood compared to 1kg of coke.

Smokeless coal (I think my semi-coke briquettes are a similar coal product) has roughly double the energy density of the best wood. Kiln dried or seasoned doesn't seem to make much difference.

Then we get into stove / furnace efficiency which is important too. Good numbers are >80%. I believe my wood burners are in that range.

Obviously, operator efficiency is important too. There seems to be quite a bit of skill in controlling airflow with flues and flaps, etc.

Locality makes a huge difference. In our case, coal products are cheap and available. This is not the case everywhere. In fact, it may be banned in some regions, even "smokeless". Firewood is much more expensive unless you have "free" supply. We do but I can't manage the work involved. It's a major commitment and when compared to semi-coke briquettes at $40 per metric ton (2200lbs), I can't make a case for it.

In the end, we'll use both firewood and semi-coke. Firewood for a quick warm-up of each yurt and semi-coke for central heating which is slow to warm up but burns all night. Actually, we need a bit of wood to start the coke burning so we'll always use a bit of wood.

[UKadventurer]

How's your winter going?

I was enjoying my winter, even modifying my electric dirt bikes to work on snow and ice with ice screws. Lots of fun.



Then disaster struck. The local power station had a failure in the night. Unfortunately, I was fast asleep and couldn't take any steps to mitigate any problems. Off course, Murphy's law dictates that this would happen on one of our coldest nights. About -39C which is a nice temp because Fahrenheit and Centigrade agree on the number more or less. Very cool.

Totally oblivious to what had happened the night before, I went to the boiler room to maintain the fire. To my horror, there'd been a literal meltdown.









Behold various melted plastics next to some unaffected plastics. Interesting. Also the root cause is the pipe going into the boiler tank melted and separated.

The evening before, I had started a coal fire for the central heating. While also running electricity (an immersion coil) to keep the boiler temperature stable. Our system has an electric pump to circulate the water in the pipes to the gers, insulated container and well house.

This is what I think happened: when the power went off the pump stopped circulating the water. The fire doesn't care about that so it overboiled the water, melting the pipe connecting the water supply to the boiler then probably steaming off any water left in the system. Various plastic components melted.

Now with the water just sitting in the pipes it did what water does in these temperatures, it froze. Despite

insulation

. We'd originally had anti-freeze in the system but due to several over boil incidents, it'd had all leaked out and I had to replace it with well water. Anti-freeze in those quantities is really, really expensive.

My handyman came up on his day off (Sunday), first going shopping for replacement components. That's a big deal and very nice of him since he's very religious.

We worked together all Sunday afternoon and half way through the night to get some semblance of a system going. We thawed out accessible pipes with a blow torch. Bypassed the well house completely because it has 40m of buried pipe with no easy way to thaw them out. He replaced all of the damaged components: a heating coil (now upgraded from 4.5kW to 12kW), a timer, a relay, various melted plastic electrical components, sections of pipe cut out or bypassed.

What have I learned?

You can't depend on the electric grid.

Our boiler is too basic and is incredibly labour intensive. I may upgrade to one of with thermostatic and barometric automation. Also, more capacity for a larger load of semi-coke.

I need a reliable UPS backup for the pump (12v battery, charger, inverter).

Also, some sort of alarm that would wake me up if there's a temperature spike or power outage.

We can survive any temperatures that nature throws at us because we have our dumb stoves and plenty of solid fuel. Or just simply lots of bedding and shared body warmth.

However, the systems with water in them are really susceptible to freezing and I need to be constantly vigilant to keep them above freezing. It's stressful. Maybe the Mongolians got it right by keeping everything basic and no reliance on electricity.