will always be the chunk of fire wood. Once burned the energy starts slipping away. First the process of combustion, I suspect at least 20% goes up the flue, even with the best of gassers.
Then the heated fluid needs to be circulated somewhere, somehow. you lose some there through to piping, and the best of the wetrotor circs run maybe 25% efficiency, on the sweet spot of their curve. many are not running at the best efficiency point. Then you need to store the 180F or so fluid and try to minimize the loss. you will never insulate 100%.
Then it needs to be circulated from the buffer to the emitters, with some losses again.
Ideally the wood fire would be built exactly to the load. not easily accomplished, as most have discovered. Although the pellet/ biomass boilers are fairly capable of adjusting, stopping and starting to the load.
So buffers become a common addition to wood fired boilers. But don't over do the capacity. Of the dozens of brands I looked at in Germany at the ISH show, most had 1000L storage tanks. Most had at least dual, often triple coils in the tanks.
Always keep boiler return temperatures in mind. Many boilers have 240F aquastats to pulse the boiler circ to accomplish this. I prefer variable speed circs. better yet the new delta t & P ECM circs. Must less power consumption.
Expansion tank size will surprise you when you start adding hundred's of gallons of fluid.
Primary secondary piping really makes the most sense to keep all the sources and emitters happy in their ideal temperature and comfort zone.
Some of the new hydro separators work nicely also. smaller package with factory insulation. most of the hydronic components from Germany and other Euro countries have nice foam jackets. it's a code in many areas and a standard exisits for the insulation spec.
That's what I know so far. Anxious to learn more.
3 rd season on a EKO 40 with 500 gallon LP buffer tank.
BR
Then the heated fluid needs to be circulated somewhere, somehow. you lose some there through to piping, and the best of the wetrotor circs run maybe 25% efficiency, on the sweet spot of their curve. many are not running at the best efficiency point. Then you need to store the 180F or so fluid and try to minimize the loss. you will never insulate 100%.
Then it needs to be circulated from the buffer to the emitters, with some losses again.
Ideally the wood fire would be built exactly to the load. not easily accomplished, as most have discovered. Although the pellet/ biomass boilers are fairly capable of adjusting, stopping and starting to the load.
So buffers become a common addition to wood fired boilers. But don't over do the capacity. Of the dozens of brands I looked at in Germany at the ISH show, most had 1000L storage tanks. Most had at least dual, often triple coils in the tanks.
Always keep boiler return temperatures in mind. Many boilers have 240F aquastats to pulse the boiler circ to accomplish this. I prefer variable speed circs. better yet the new delta t & P ECM circs. Must less power consumption.
Expansion tank size will surprise you when you start adding hundred's of gallons of fluid.
Primary secondary piping really makes the most sense to keep all the sources and emitters happy in their ideal temperature and comfort zone.
Some of the new hydro separators work nicely also. smaller package with factory insulation. most of the hydronic components from Germany and other Euro countries have nice foam jackets. it's a code in many areas and a standard exisits for the insulation spec.
That's what I know so far. Anxious to learn more.
3 rd season on a EKO 40 with 500 gallon LP buffer tank.
BR
