Optimizing efficiency of an Outdoor Woodfired Boiler

[veggies13]

Hey Folks:

I am moving into a new house that comes with a HeatMaster MF 5000e furnace. I have never heated with an OWB before, and am shocked at reports of people burning 10+ cords of wood per year. I know that burning seasoned wood makes a big difference. Loading a smaller amount of wood twice a day vs. a full load once a day also seems to be recommended. My question is, does anyone have any experience increasing the efficiency even more by loading smaller loads even more frequently, like 5 or more times a day? Would keeping the fires smaller minimize the amount of time the combustion air damper is closed? I don't think I would mind the extra work.....yet!

Thanks

 

[NSMaple1]

The biggest hit to OWB efficiency, can often be the use of inadequate underground piping. In which case it won't matter how you operate it, you will still lose heat to the ground. Any idea what it has? Pics of where it goes in & out of the ground should tell.

Aside from that, sounds like you are on to things to try. Different boilers can respond a bit differently, so it will likely be trial & error until you sort out things that work for you and it.

(10+ cords can be very real, yup...)

 

[homemade]

I don’t think the several smaller fires or one big loading make a difference. It’s all based on the demand for heat. The 10 cord per year people are usually in a drafty farm house with old single pane windows and little to no insulation in the walls, and trying to heat a shop or shed. And like above. What is the temp difference between the water leaving the stove and coming into the house. Cheap lines will also eat wood. And so does green wood.

 

[NSMaple1]

I don’t think the several smaller fires or one big loading make a difference. It’s all based on the demand for heat. The 10 cord per year people are usually in a drafty farm house with old single pane windows and little to no insulation in the walls, and trying to heat a shop or shed. And like above. What is the temp difference between the water leaving the stove and coming into the house. Cheap lines will also eat wood. And so does green wood.

I think it can make a difference in some case, but yes it does come down to heat load. Loading to minimize time spent idling will usually help. Frequent small fires would get pretty old pretty quick into a winter though - with me at least.

 

[cumminstinkerer]

@NSMaple1 I actually just tested that theory last night with my crazy contraption of a boiler and I for sure found that loading smaller more frequent loads, like four or five splits every hour, will keep the combustion more efficient and temps way up, I also get way lower levels and duration of smoke at reload that way. Loading a big every say eight hours, the thing will smoke for maybe ten minutes, not horrible choke you but smoke, but small frequent loads and there is maybe a minute after closing the door that it has any visible smoke. Now I am not sure with the model the OP has it will do much good but with mine it does, and after visiting with Warno from another site, lol maple knows, his is the same way.

 

[Marley5]

Loading your wood furthest from exhaust, usually the front.

Had a friend recently report burning 23 cords per winter " that's what he said "
And after questioning him....he was throwing everything to back of stove where all the heat exhausted up the chimney while keeping his stove pipe glowing .