Which of the following statements about direct vent gas fireplaces is false?

The statement regarding gas fireplaces having an adjustable air damper is not true because direct vent gas fireplaces are designed to be sealed systems that draw air from outside for combustion and expel exhaust directly outside, eliminating the need for an air damper. In direct vent systems, the flow of air is precisely controlled through the venting process, and there is no requirement for an adjustable damper to manage airflow as in traditional fireplaces.

Conversely, the other statements provide accurate information about direct vent gas fireplaces. These units can indeed vent both horizontally and vertically, which allows for flexibility in installation depending on the layout of the home. Additionally, because they are designed to pull air for combustion from outside, they do not require a traditional chimney, using a vent pipe instead. While they are safe to use in various environments, it is essential to follow specific installation and manufacturer guidelines to ensure safety and efficiency. Thus, the correct identification of the false statement focuses on the misconception about the presence of an adjustable air damper in this style of fireplace.