However, it is not a big problem because you can always buy special cleaners for fireplace screens and glass doors. More often the construction of furnaces have special channels that send air flow along the inner surface of the door, and don't allow the soot particles settle on the glass. If your fireplace has no doors at all, you can use a variety of nets and shutters that can be installed directly in front of the firebox. They help to manage the air flow and thus regulate the heat level.
A corner fireplace door is somewhat smaller than an ordinary fireplace door. They usually come in the traditional accordion-type frame because of the limited space offered by the walls. In choosing a fireplace door from the rack, the purchaser has to ensure that the door is big enough to cover the widest area of the fireplace opening without covering the whole mantle design. The door should overlap the whole fireplace opening in order to serve its purpose, but should not keep the fireplace itself from being seen and admired.