We had a wood burner out on the farm. The house was always warm even though it wasn't insulated well. Stoke it up with some oak logs and there was always glowing coals in the morning. Stir them up and throw on a few more logs. (rarely bigger than your thigh) Dad would come home for lunch and fill it for the afternoon and evening. If I was home from school I would do it. Cleaning out the ashes was my job as a kid.