I got thinking about heat loss of an OWB sitting out in the yard and ran a rough calculation on my heat loss software. If the jpeg screen shot attaches here you'll be able to see the calcs for each surface of the OWB. I figured the unit to be 4 feet wide and 6 feet long with a side height of 6" and the ends at 7'. I used R19 in the side walls and R-11 on the ends with a 3'x4' door also at R-11. The top was R-28. I think this pretty much reflects the insulation on a run of the mill OWB. I calculated the heat loss at -6* outside and 180* (that would be the water temperature) inside the structure. I used a poor air change per hour figure that is in reality probably pretty generous.
So just for giggles let's knock it down to 5,000 for easy figuring and also to reflect the fact that the whole winter is not -6* and see how much wood that adds up to over a heating season.
5,000 x 24 hours in a day = 120,000 btu/day. If our heating season is roughly 200 days like here, that's 24,000,000 btu's lost. Factor in an efficiency of 50% (again generous) and you are looking at 48,000,000 btu's worth of heat. That's the equivalent of about 2-1/2 full size cords of wood.
I kinda enjoy helping the boys do their wood (all 4 of em burn) but cutting hauling splitting stacking and then loading that much extra wood every year.............just sayin' ........
Consider all the factors before you make a decision.
So just for giggles let's knock it down to 5,000 for easy figuring and also to reflect the fact that the whole winter is not -6* and see how much wood that adds up to over a heating season.
5,000 x 24 hours in a day = 120,000 btu/day. If our heating season is roughly 200 days like here, that's 24,000,000 btu's lost. Factor in an efficiency of 50% (again generous) and you are looking at 48,000,000 btu's worth of heat. That's the equivalent of about 2-1/2 full size cords of wood.
I kinda enjoy helping the boys do their wood (all 4 of em burn) but cutting hauling splitting stacking and then loading that much extra wood every year.............just sayin' ........
Consider all the factors before you make a decision.
This give it a higher efficiency rating. They (EPA)know thats the problem but have not came up with a way to solve it. This stove highlights Heatermans point on heat loss sitting outdoors. It has no insulation on front , back or bottom. In my opinion for what it is worth. This furnace is the poorest insulated furnace out there.
