Do some research on the Kuuma Vapor-Fire Wood Gasification Furnaces:
.45 Gr/HR. Emissions
.01 Gr/MJ. Emissions
99.4% Combustion Efficiency
84% Overall Efficiency
99% Smokeless Burns
What I need to know about BTU ratings?
A lot of people are mixed up on the BTU's required to heat a home because oil and gas furnaces do no run steady hour after hour. If they did you'd spend $20,000/yr. to heat a home. As it is some people are spending over $4000/yr. to heat their homes. They cycle on and off. Your BTU needs are delivered intermittently. If your home is poorly insulated, or if for some reason you let it cool down, your oil and gas furnace would then run steady. Generally, a furnace rated at 100,000 BTU/hr. runs from 1/4 to 1/3 of an hour on the coldest of MN. days delivering about 30 to 40,000 BTU's/hr. to maintain a comfortable heat level for your home, i.e. 70 degrees F. Most people feel cool in their homes in between the on and off cycles of the oil and gas furnaces, therefore many people prefer wood heat because it's continuous.
Now, heating a home with our KuumaVapor-Fire furnaces is really special because they deliver very even continuous heat hour after hour. They don't smolder the wood and then blast the wood (the two extremes) like other wood furnaces. Instead, its unique automatic draft system avoids these extremes with a continuous front to back burn pattern that allows the user to adjust the burn rate, which in turn varies the BTU output. In mild weather you use a low setting for 15-25,000 BTU's/hr., in moderate weather a medium setting for 25-45,000 BTU's/hr., and in cold weather a high setting for 45-60,000 BTU's / hr. It adjusts simply by turning the knob on the computer from low to high and anywhere in between. Most people never go above the medium setting all winter long.
Keep in mind that all wood has the same # of BTU's pound for pound. The heavier more dense wood (oak, hickory, maple) have more available BTU's/piece than the lighter less dense wood such as poplar and pine, only because each piece weighs more. Every pound of wood that is 100% dry has approximately 8,600 BTU's /pound. Say for instance your home needed 100,000 BTU's/hr. to heat, it would take 11.6 pounds/hr. of 100% dry wood to heat it. Now, if your wood has a 20% moisture content, each pound of wood has only 6,880 BTU's in it (it's 8600 x .80). Then if your wood furnace is only 60% overall efficient, your BTU's would only be 4,128 BTU's/pound (that's 6,880x.60). This would result in a ridiculous amount of wood, 24.2 pounds/hr., to get the needed 100,000 BTU's/hr. In a 24 hr. period that would mean 576 pounds of wood needed for 100,000 BTU's/hr after hr. This would result in probably more than 20 cords of wood to heat your home for one winter. It makes more sense to say that most homes in the coldest of weather only use the 30-40,000 BTU's/hr and probably use 7-10 cords of wood/season to heat their homes. With our KuumaVapor-Fire furnaces that are 84% overall efficient and 99% combustion efficient most people use only 3-5 cords of wood to heat their home/season and that's what makes our furnace very special. To top if off we also have the clean burn of less than 1 gr. emissions/hr.
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