I'm a total newby on rocketstove mass heaters, been watching plenty of youtube today!
I'm wondering is, once the fire is going, a rocketstove mass heater can handle wood that is wet or recently cut and has not yet dried, and whether it would render the exhaust dirty. In other words, how picky is a rocketstove mass heater in terms of its fuel to burn clean?
Rocket stoves want DRY !!! wood, they will burn any species of wood but if its not dry you will have problems and not be happy . Broken branches , wood pallets, pine cones , douglas fir , larch, oak, maple and any other wood you can name , BUT IT NEEDS TO BE DRY! If your wood is wet it will not burn well at all, you will get smoke and creosote and ash build up ! All the things that a good running RMH does not have !
We currently have a stove. According to the manufacturer, for our stove not dry enough is no good, but too dry is no good either. We season our own wood, and can't measure the water content to know for certain our wood is in the stove manufacturer's range.
So for our RMH project, I wonder how "dry", in practical terms, it needs to be for a RMH?
If your wood has moisture in it, it cools down the fire because the fire has to heat the water into vapor first before it can get to the wood. A cooler fire is less efficient at releasing all the BTU's stored in the wood. This would be true for any sort of wood-burning device.
For a rocket heater, the dryer the better. Buy a cheap wood moisture meter like this one and don't use fuel that brings more than 15% on the display. I've tried to figure out what the difference might be using, say, fuel containing 25% moist and came out as 40% efficiency loss as compared to 10% moist.
I guess this goes beyond my original question, but I read that air dried wood has a moisture content of about 20 to 30% (depending on variables). How does one dry wood to 10% moisture content in a home/backyard setting?
Woodworking forums have ideas about drying wood. There are solar kilns with fans, for example. Moreover, I think your 20-30% is incorrect. Our air dried wood was 15% and I live in a very humid climate.