A fireplace glass door is installed on a fireplace to keep the room warm longer when the flames die down. Whether a wood burning fireplace or a gas burning fireplace, heat radiated into the room escapes through the chimney. One does not notice this while the fire is burning brightly, because of the heat from the flames that radiates into the room. However, when the fire starts to die down, the hearth becomes cold quickly as the heat escapes through the fireplace opening. To stop this from happening, a fireplace glass doors blocks the opening, keeping the warm air from leaving the room.
While modern fireplace gives us some benefit, it can do as some hassle also. Firstly, it is a little bit expensive. Also, if they are not properly being taken care of, they may be prone to failure because they are mechanically-oriented. Since it is a mechanical machine, it needs electricity to power up the various parts of the machine such as the fans, motors, etc. So, this device cannot be used if there is power brown out.