Aside from keeping the warm air from escaping, the doors act to keep the hearth clean just as a fireplace screen used to do in the olden days. With the doors closed, ashes and embers don't scatter about the room, keeping the carpet or rug clean and scorch-free. The doors also have built in devices that divert air towards the bottom of the fireplace. These vents make the fire burn brighter and easier to light.
Works perfectly as a real cooking stove. Some modern wood burning stoves are designed to work as cooking stoves. All you need is to install the cookware and adjust the temperature and you are good to go. With a good wood burning stove, you can thus reduce your expenditure on cooking gas.