Vented gas logs will have a higher flame, owing to their higher BTU ratings. They are great for appearance purposes, but must be installed into a fireplace with a working chimney. They are not designed for heating.
Vent free gas logs will have a lower flame pattern, as they are limited to 40,000 BTUs. However, because the system is designed to be operated with the damper closed, they are excellent supplemental heaters. It is important to service and clean vent free systems on a yearly basis, as buildup of dust and cobwebs within the burner assembly can cause it to release undesirable odors.
on December 1, 2015