Heating 2300 square feet.

Greetings all! My Wife Ashley and I are new to permies.com. We live with our 4 children Ezra 7 Joran 5 Noe 2.5 and Ellowyn 9 months in a 1960's church that was converted into a home in the 90's on an acre of land. Needless to say it is big! W have lived in the house for almost a year. The old furnace was shot so we put in a new Goodman. It's only purpose is secondary  heat. Being a church we have a stage in our living room,  on it use to sit a wood stove insert. It has seen better days. as part of our 203k we just removed in instead of having to frame it in. That being said this is a big house the upstairs alone is 2300 sf and basement is the same. This is a larger residential space than most RMH are used. We would like to put one in.

first thing I would want to do is figure out your heating load so; where abouts is the property?... Next would be how insulated is the building? what is the foundation or basement and is it insulated? what is the quality of the windows what is the general ceiling height?

David Baillie wrote:first thing I would want to do is figure out your heating load so; where abouts is the property?... Next would be how insulated is the building? what is the foundation or basement and is it insulated? what is the quality of the windows what is the general ceiling height?

The property is in in Olivet, Michigan. On Duck Lake just 30 minutes south of Lansing. The Roof was redone in the 90's and they added insolation. Our outer wall is red brick and inner was in concrete brick. We covered the inner walls with 2x4 wood frame walls with r17 insolation. Windows are newer circa early 2000's. The foundation is cinderblock construction. The basement is not insulated. The entire basement is cement. The walls are cement block and the ceiling is 12 inch thick reenforced iron segments that are hollow allowing a portion of the HVAc to run trough them. The technology is called a hypocaust. One thought of mine was if I heated the basement it would warm the upstairs in radiant fashion to some degree.

that's a lot of space for any heat source to heat.  Is there a way to block off un-used rooms in the winter?

Is there an existing chimney where the wood stove insert was?

my priority would be:
1. reduce heated square footage
2. improve air-sealing and insulation (look into utility rebates)
3. select and install an appropriate heat source

I'm testing the same concept inmy build but with far less square footage. I think heating the basement will help the upstairs, but either way it will have to be supplemented with the current heater. Is it a walkout basement our fully covered? Do you use the basement and is it wide open? I'll be finding out the limits here soon with my experiment? I'll let you know. I'm also in Michigan, northern lower.

Here is a load calculator for you. https://www.loadcalc.net/load.php
there are dozens online. One thing to remember is RMH heaters are good but are not magic. 1lb of wood has about 7000BTU of energy in it if you were able to use 100% of it which you cannot. Any idea how much heating oil you used to heat the structure? Oil has a heating value of about 140000btu per us gallon so for every gallon on oil you burned you would need 20lbs of wood. Its not a one to one comparison of course but its somewhere to start. Personally I would start with insulating the basement from the outside to turn all that concrete into my mass. A large block basement like that in that climate has to have heat load in the tens of thousands of BTU's let alone the house above it.
Cheers,  David