Making Wood Stoves Great Again!

Not all that I work on is distilling industry related. Sometimes my mind wanders off in other directions. Last week it wandered towards the issue of my wood stove not performing as I want it to. This iStill Blog post (and two more, that will follow soon) informs you on how I improved my stove's performance to the extend that I am now very happy with it. Information that I hope most of you find interesting ... and maybe helpful. It should be a good read, as it was a nice little quest, full of discoveries. Well, to me at least ... so here I go:

We have a JAcobus 12 wood stove. A beast of a thing. A stove that actually only runs well when it can burn 10 to 14 kW per hour. When it's on, it's ON! First around the stove and soon throughout the entire living room it's warm, then hot, and then sweltering.

Less wood on it then? Or less air? Then JAcobus starts spluttering and smoking … and goes out. And when it's off, it's cold 20 minutes later. Not a JAcobus problem, actually just a convection wood stove problem.

Today I came up with a solution. What if I put soapstones on the stove? After all, soapstone stoves have been around for ages. And those stones should enable the JAcobus to store energy (making it less hot) and radiate it out later (making it less cold).

And … does that work? It works fantastically. Better than expected, even! The stove heats up less quickly. It gets less warm. How long the radiating will take, once the stove is off, I won't know until tomorrow morning, but I estimate: 5 to 6 hours. Maybe 7 to 8 hours. But there's more:

The stove uses much less wood. For the first time, I can close the air valve halfway. The chimney gets much less warm. The combustion is cleaner and more efficient - probably because of the insulating effect of the stones. The subsequent higher combustion temperature should ensure fewer PACs, so less pollution. One advantage reinforces the other. And so you create a virtuous cycle (yes, the opposite of that vicious circle).

How many soapstones? Twenty-four pieces. That weighs 27.84 kilos. Such a weight of soapstones has an energy absorption capacity of 1,420 kiloJoules per degree Kelvin. Converted to power, the stones store 0.4 kWh of energy for every degree that they get warmer.

How warm they get, I don't know yet. My heat meter will not arrive until tomorrow. But an initial estimate (and adequate calculation) shows that an increase in the stone temperature of 150 degrees enables an energy storage of 60 kWh.

That is why the stove is much less warm now, starting up, but will be warm for much longer: I estimate that 2/3 of the 12 kWh that JAcobus supplies goes into the stones, to continue heating the room later, at a slower pace. When? When the heater goes off, around midnight, and the coldest part of the night begins, until about sunrise.

The JAcobus 12 with 24 soapstones on top ...