Open fires are very attractive but they tend to be poor at distributing heat within a room, let alone around a house.
Today’s invention is a device which allows a single fireplace to provide more uniform home heating.
A mobile robot (ideally with stair climbing ability) carries a metal plate on its back. It is programmed to hold the plate in contact with the flames until its temperature reaches a target value). The plate is withdrawn inside a wire mesh box and the robot then moves to a region of the home where the ambient air temperature is detected to be low.
Air passes through the mesh cover, across the vertical plate and becomes warmed. When the plate temperature has decreased by a certain amount, the robot returns to the fire.
You could have several of these devices per house, coordinated to appear at the fireplace in turn. Use Pleos and it might even resemble the disputed cooling fins of certain dinosaurs.