I have used two approaches to measure efficiency involving weighed wood burns, using the figure of 6050 (or 6040) of available btu's per pound of wood at 20% MC and 400F stack temperature. I have calculated the total available btu's by weighing the wood in a burn and then by measuring the increase of temperature in a known quantity of water.
Alternatively, where I have been able to determine flow rate by differential pressure, and logging output and return temp delta-T, I also have calculated btu's to the system divided by btu's available in a known weight of wood to determine efficiency.
As to ewd's critiques, at times I have bristled a bit under my breath at his comments on some of my posts, but in the end I take them as learning opportunities to expand or challenge my understanding. It doesn't mean we will agree in the end, although we usually do, and I respect the comments of all who do their best to share knowledge so that we all come out ahead.
Today I traveled to Lamppa Manufacturing in Tower, MN, 150 miles from my home, and visited with Daryl Lamppa. Lamppa is the maker of the Kuma Vapor-Fire wood furnace. I will be posting soon regarding my visit, and I suspect some info from my visit may offer more perspective on efficiency.
Alternatively, where I have been able to determine flow rate by differential pressure, and logging output and return temp delta-T, I also have calculated btu's to the system divided by btu's available in a known weight of wood to determine efficiency.
As to ewd's critiques, at times I have bristled a bit under my breath at his comments on some of my posts, but in the end I take them as learning opportunities to expand or challenge my understanding. It doesn't mean we will agree in the end, although we usually do, and I respect the comments of all who do their best to share knowledge so that we all come out ahead.
Today I traveled to Lamppa Manufacturing in Tower, MN, 150 miles from my home, and visited with Daryl Lamppa. Lamppa is the maker of the Kuma Vapor-Fire wood furnace. I will be posting soon regarding my visit, and I suspect some info from my visit may offer more perspective on efficiency.