The best logs for an existing fireplace depend on whether you need vented or vent-free gas logs. Vented logs create large, realistic flames and require an open chimney or flue. Vent-free logs produce more heat and don’t need a venting system, making them ideal for efficient heating. Your choice should also consider the look you want—traditional or modern—as well as the type of burner your fireplace is designed to support. Selecting the right combination ensures safe, efficient, and visually appealing performance.
The need for venting depends on the type of gas logs:
Vented Gas Logs: Require a functioning chimney or direct vent system to exhaust combustion gases. They produce a realistic, high yellow flame but are less heat-efficient since some warmth escapes through the vent.
Vent-Free Gas Logs: Do not require a chimney and operate with a high-efficiency design. They burn very efficiently, but proper room ventilation is necessary to ensure safe indoor air quality.
Vented and ventless gas logs serve different functions:
Vented gas logs require an open chimney or flue, directing combustion gases outside. While they provide a natural-looking flame, they are less heat-efficient since warm air escapes through the vent.
Ventless gas logs operate with a closed combustion system, retaining nearly 100% of the heat inside the room. However, they produce small amounts of water vapor and emissions, requiring adequate ventilation and compliance with local codes.