Does the fireplace have to have a flue?

The fireplace must have a flue. If there is a flue, there will be no smoke back, so that heat will not be lost.

Fireplace is an independent or wall-mounted indoor heating equipment, which uses combustible as energy and has a chimney inside. Heating facilities originated in western families or palaces. Because its fuel is a renewable resource, it is still widely used in the west, especially in the higher education class that advocates environmental protection. Fireplaces are divided into open and closed, and the latter has much higher thermal efficiency.