You can make them pretty much invisible, if you build them as an integrated part of a new house.
You can even use them for baking bread or pizza.
Personally I prefer a central heating system, because it is easier to regulate the temperature.
I think you, as a chimney weeper, would love my furnace set-up.
It measures temperature and water content in the smoke and adjusts the amount of air to fit whatever I'm burning at the time.
Once it reaches working temperature, you can't even tell it is running, no smoke at all.
Since I have a large buffer tank with water, it runns flat out all the time, untill that water is hot, then shuts off.
The water lasts me a day in winter, so I have to fire it up when I come home from work.
Spring and fall it lasts 2 days.