This is our Central Boiler outdoor wood furnace that we use to heat our house, my parents house next door, and Dad’s workshop. Not only do we use it in the winter for heat but it is our every day source for hot water so we burn wood in it year round.
The capacity of the water tank in the furnace is 393 gallons, so it does use a lot of wood throughout the year. We like to save the higher quality wood for the winter time since it will provide more energy to heat the water for a longer period of time between stoking the fire. The water in the furnace cools quicker in the winter so the damper opens more frequently to let air in for the fire so the larger pieces of wood do not cool to the point that it takes a very long to go from smoldering to a fire again.
There is a nearby sawmill that we get log slabs from to burn during the summer. The damper on furnace does not open as much in the summer time to heat the water up in the furnace since the water does not cool as quickly. Since it takes less energy to heat the water up we can use lower quality of wood and also use smaller pieces. The smaller pieces of wood have more surface area so they will go from smoldering to burning quicker than a larger denser piece of wood. This is ideal for summer time wood since there is a longer frequency between times of the damper opening.
