A gas log set is a kit that consists only of a burner, logs, and any included accessories that are assembled into an existing fireplace. Because the appearance of the opening is unchanged, a gas log set allows you to keep the fireplace’s viewing area intact. However, they are not designed to heat a home like an insert. A gas log set is for a homeowner who would like to improve the interior appearance of their current fireplace and increase convenience, but is not concerned with heating or efficiency.
There also exist unvented log sets that are designed to be burned with the damper closed, but there is misinformation about their usage. CLICK HERE to learn more!