About Gas Logs (Ventless and Vented)
Vented Gas Logs
Vented gas logs, when burned, create exhaust which must be vented out through a chimney. Because of this, they cannot be installed in fireplaces which do not have a functional chimney, and must be burned like a traditional wood fire, with the damper open. This means much of the heat from these logs will vent out the chimney with the exhaust! On the bright side, vented gas logs burn more brightly than their vent-free cousins, with larger, yellower flames which “dance” more. Because they are run with the damper open, there is less likelihood of exhaust products building up in the room. The logs are generally more visually interesting as well.
Pros:
- More realistic logs and log arrangement
- Larger, yellower, more lively flames
- Less intense smell
- Less likelihood of exhaust buildup
Cons:
- Lower heat output than ventless logs
- Slightly less fuel-efficient than ventless logs
We carry R H Peterson, Monessen, and Hargrove gas logs, in vented, vent-free, natural gas, and propane.
Ventless Gas Logs
Ventless, or vent-free, gas logs use specially designed burners to burn gas cleanly, emitting no, or almost no, exhaust. They can be installed in fireplaces whose chimneys have been damaged or blocked — or in “vent-free fireboxes” with no chimney at all. Because they are run with the damper closed, most of their heat stays in the room, and they produce more heat than vented logs.
However, ventless gas logs can have a lot of down sides. Because they use room air to burn, they cannot be run for more than about two hours without having to crack a window to let some fresh air in, reducing their heat efficiency. Their byproducts of combustion include water; the excess moisture in the air can cause mold or mildew to form. In order for the burner to burn cleanly, the logs need to be sized and arranged carefully on the burner, and may not look as realistic as vented logs. The flames will not burn as high or as brightly as those on a vented set, because if the flames touch the logs they cool off and do not burn cleanly, forming soot deposits and other exhaust products. Ventless gas logs burn very hot; they cannot be installed in all systems, and sometimes hoods or other items must be installed to protect nearby furnishings from the heat.
Ventless gas logs are not legal in all states, due in part to the potential complications (i.e., exhaust buildup) which can arise if the log set does not burn efficiently.
Pros:
- Higher heat output than vented logs
- Burns more cleanly (less pollution)
- Slightly more fuel-efficient than vented logs
- Can be run in a system without a working chimney
Cons:
- Less realistic logs and log arrangements; less realistic flames
- Cannot be burned for extended periods (more than about two hours)
- Since there is no venting, “kerosene” smell of the logs is somewhat stronger
- Moisture in exhaust products can form mildew
We carry R H Peterson, Monessen, and Hargrove gas logs, in vented, vent-free, natural gas, and propane.
Installation of any gas log set should be performed by a professional who can ensure the installation conforms to building codes.
In general, we recommend vented gas logs in most applications. They are safer, more aesthetically pleasing, and do not smell as strongly as ventless logs. We recommend ventless gas logs only in cases where it is not feasible to repair a damaged or deteriorated chimney (it is too small to take a liner or a liner is not economically workable) or where no chimney is present.
Many alternatives exist for both options: direct vent gas inserts make better room heaters than either type of logs, for instance, and some models can be installed even in rooms where no fireplace exists.
