My coal furnacewas built in 2014, I bought it in 2018 on clearance. I didn't pay anywhere near $4,000. With sales tax it was nearly $800.
Originally with sales tax, it would have been just about $4,000.
I didn't buy the coal in new mexico it's very hard to get unless you are over by Arizona or the 4 corner area. I collected over the course of several road trips returning home
through central texas.
I use some where around 1.5 mm btu of coal last year.
Around 90% of what goes into the coal furnace is construction waste lumber, pallet pieces. Most importantly it's free, but lots of nails.
Most of the remaining 10% is plain firewood from chopped up trees, then almost all of those were cut down by the electric coop.
The anthracite coal I use burns far cleaner than any of the wood I burn.
I will probably use the kill-a-watt meter to track power use by the furnace. It knocks at least a mega watt hour or 2 off the monthy power bill running the coal furnace compared to the heat pump with electric heat enabled.
The coal furnace blowers use almost no power compared to the heat pump.
It will have definitely paid for its self in its 2nd year of operation, if it gets cold this year like it did last year, in the 2nd week in October it will pay for its self before the end of this year.
This winter I am going to make the coal furnace closed loop. It will greatly boost efficiency. Less fire wood to collect, less coal to buy. I bought a metric ton of coal and that should last around 10 years, baring no unusual events like another week of -10F nights.
I got the coal furnace because it was almost the same price as the more lightly constructed equivalent model of wood furnace. Plus I can burn the hottest and fastest burning types of coal if I want. I have heard they can burn tires too.
Plus just saying the words "coal furnace" sets people off.