Vented and Ventless Propane Fireplace Logs Explained

A fireplace.

For those looking to have the authenticity of a real fire with the convenience of a gas heating system, the answer could be propane fireplace logs. These nifty little devices resemble wood logs but are actually lit by gas. There are two different styles of gas logs: vented and ventless. How you choose between the two depends very much upon how you will be using them, and where.

Gas Logs

Gas logs are the ideal indoor heating devices. They have the look of a real fire, but produce no sparks, embers, or other fire-producing dangers. They are also more environmentally friendly than firewood, producing around 40% fewer greenhouse gas emissions than everyday firewood, and they have no harmful matter. They also help to keep the air clean and prevent the logging of forests. Propane logs can also help with allergies and asthma. The additional advantage is that gas logs turn off at the press of a button.

Vented Propane Logs

These logs are typically factory installed logs built into a vented fireplace. They produce an attractive yellow flame which makes them seem as though they were glowing. It is also much taller than with the ventless logs. In vented propane logs, the flame also 'dances' around the logs, much like the flame on a real wood fire. However, the heat which they produce is also vented, or taken straight up the chimney. The only way to prevent this is to turn on the damper and chance that you are not going to be trapping toxic gases in the room.

Ventless Propane Logs

Often known as vent-free logs, these have specially created burners that heat off the gas, rather than producing an exhaust. This means that they can be burned safely with the damper closed. Almost all of the heat produced by ventless gas logs goes back into the room, so they are warmer than the vented versions.

They also consume slightly less gas than their vented counterpart. On the downside, ventless logs can create a pool of moisture which can lead to mold. They also produce a smell similar to burning kerosene, and the flame which burns in them is much less authentic than on the vented.

Vented vs Ventless

The most significant problem with the vented propane fireplace logs is that they can be dangerous if you do not have a proper chimney system. With a working flue, the gases produced by the gas logs will be pulled out of the room, and sent into the open air, but if the flue is damaged or blocked, or you simply don't have a chimney, then dangerous gases such as carbon monoxide can be released into the room.

Ventless gas logs are intended to be used indoors, so they don't deplete oxygen, nor do they emit toxic gases. Vented propane fireplaces, however, are much more realistic in the flame-production, and the burning smell is taken up the chimney, rather than trapped in the room as with the ventless. The difference is mainly aesthetic if you have a working fireplace, but if not, then there is no option but to choose the ventless logs.