Vented vs. Vent-Free Gas Fireplaces

Vented vs. Vent-Free Gas Fireplaces

If you are hoping to install a gas fireplace, you likely have some key questions: What are the differences between a vented fireplace and a vent-free fireplace? Which fireplace is right for you and your home? This blog post compares the two different models and details the advantages of each so that you can make an informed decision.

Vented Gas Fireplace

A vented gas fireplace is just what it sounds like—any fireplace that requires a ventilation system to exhaust combustion byproducts, such as carbon monoxide and water vapor. This ventilation could take a few forms.

Traditional vented systems (also called B-vent or natural vent) utilize ductwork that is routed through a masonry chimney or a chase and terminated above the roof. These systems ventilate by drawing warm air from the living space to feed the fire and circulate through the ductwork.

A direct vent, on the other hand, expels combustion byproducts directly through the wall of a house, and uses the same vent to draw fresh combustion air into the firebox from outside. Direct vent systems require a sealed glass front to work properly.

Vented gas fireplaces work similarly to a wood-burning fireplace and safely expel unwanted combustion by-products. If you are installing a new gas firebox into an existing fireplace and chimney infrastructure, vented is the way to go. Otherwise, the installation of the ductwork and ventilation system will be more costly.

Because a direct vent system runs directly through the wall, installation is much simpler and less expensive than that of a traditional vented system.

Vent-Free Gas Fireplace

Vent-free gas fireplaces are fireboxes that operate without any ventilation system. In order to do this safely, vent-free fireplaces are designed to a standard of near-perfect combustion.

Because of this, vent-free systems offer 99%+ heat efficiency and produce a negligible amount of potentially harmful combustion by-products (like carbon monoxide). These fireplaces require special vent-free gas log burners in order to achieve this efficient combustion.

Vent-free gas fireplaces are particularly if you are looking for maximum heat efficiency, hoping to avoid the costs of installing a ventilation system or wanting to install a firebox where no ventilation system can conveniently be installed.

However, although these models are 100% efficient (no carbon monoxide problems), they do release non-harmful combustion by-products into the home, such as water vapor and carbon dioxide. These by-products could lead to added humidity and air quality issues.

As a result, a vent-free fireplace is not ideal for a room with many windows or for residents sensitive to smell or allergies. Some states have regulations for vent-free fireplaces, and some consumers fear that, if not properly installed or operated, these systems could release harmful substance into the home.

As with most home improvement decisions, the right answer depends on your individual needs and priorities. Already have the ductwork, chimney and infrastructure in place? Sensitive to smells? Go for a vented gas fireplace. Looking for maximum heat efficiency? Limited in terms of infrastructure or budget?

Consider going vent-free. Your local Chimney & Masonry Outfitters would be happy to talk you through your options and provide a consultation anytime to help you make the best choice for you!