Contractors build what customers buy, not what is smart. I'll give you a great example.

If you are surrounded by free trees, you might consider a wood-burning stove, like the Franklin style.

But what size to buy? Plus you have to gather and chop the wood. People buy the large one because it "looks right", and they have yo keep adding wood frequently.

Where does the air come from that feeds the fire? There is n adjustable opening right now the lower front, so...it takes-in air from the room. Air that you burned wood to warm.

The fire is 1500F, so it doesn't care if you feed it 20F air from outside, or 70F air from the room. People heat the air in the room, and then throw half of it away up the chimney.

Duct some air from the outside to the intake, and you will only need to burn half the wood.

The wood is free, but, you just cut your gathering and chopping in half.

Plus now, you realize you can buy the smaller stove, and sell the big one.