Fireplace Knowledge

Vented/Wood-Burning

Arguably the most common kind of fireplace, especially in our region of the United States, is also the most confusing. A vented fireplace is also referred to as a wood-burning fireplace. This style of fireplace has the ability to accept a gas line, either to use to install gas logs or to use to help start your wood fires. Don’t get confused - this does not make it a “gas fireplace”! This is still considered a wood-burning fireplace, and all regulations, clearances, and specifications must be followed that a wood-burning fireplace requires.

Vented/wood-burning fireplaces fall in to one of two main categories: 1.) open-hearth fireboxes that are used for recreational burning, and 2.) high-efficiency wood-burning fireplaces that are EPA compliant.

• Open-hearth fireboxes provide around 10% heating efficiency, due to the amount of heat loss up the chimney, and constantly adding fuel. All vented fireplaces should have a mesh spark screen or mesh curtains for safety, and can also have glass doors for additional safety. If you have gas ran into the firebox, installing a set of gas logs is an excellent way to increase your heating efficiency.

• High-efficiency fireplaces typically provide around 60-75% heating efficiency, and undergo rigorous testing to meet or exceed stringent emissions limits to ensure efficient and responsible wood burning. These are designed for constant use as a supplemental heat source for your home, and are more commonly installed in very cold climates.

Most wood-burning fireplaces are offered in a front-open configuration only. With today’s focus on tighter, energy-efficient construction, configurations such as see-through and multi-sided openings tend to perform poorly and can spill smoke into your home. Consider a direct vent gas fireplace if one of these opening styles is what you are looking for.

Direct-Vent

A Direct-Vent system operates uses two vent pipes. One pipe draws air in from outdoors to support combustion. The other pipe exhausts the by-products of combustion to the outside. The two vent pipes may be co-axial (exhaust pipe within a larger intake pipe) or co-linear (separate pipes of about the same size).

Combustion takes place inside a sealed chamber. In the case of a fireplace, this means behind a glass front. A DV system will always have a sealed, solid glass front. Furthermore, all DV systems manufactured after 2015 will have a safety barrier in front of that glass front. This is typically a fine mesh screen. Air circulates around the combustion chamber, and radiant heat transfers through the glass front to warm the room. Additional convective heat may be supplemented by a blower; a fan installed within the appliance to circulate warmed air out into the room.

Direct-vents systems are available as fireboxes, inserts, or stoves.

A DV fireplace is often installed along an exterior wall to simplify the installation of the vent run,
but it can also be installed elsewhere in the home and vented through the roof. They can operate via remote control or wall-switch, and do not necessarily require house power electricity. Although, if connected to house power, a battery pack is often included to serve as a back-up power source for instant heat during a power outage.

Generally speaking, a DV system provides good efficiency – usually around 60 to 80%, because they are warming the room without taking air from the surrounding space. There is also little-to-no worry about poor drafting, because it does not rely on positive house pressure to naturally move air through the firebox like a traditional fireplace does. A DV system is very popular in new construction, as it is able to perform well with today’s tightly built, spray-foamed homes.

Ventless

A ventless (or vent-free) system operates just as the name indicates; without a vent! It pulls room air for combustion, and delivers 99.9% of the available heat energy directly back the room. VF systems are safe thanks to their clean-burning technology and required Oxygen Depletion Sensor, which instantly shuts off the gas valve if oxygen in the room drops to an unsafe level. Although, VF systems can be known to produce an odor while burning.

Indoor VF systems are limited to 40,000 BTUs of gas, and must be operated as supplemental heating sources in conjunction with a central furnace that circulates air. These fireplaces do not accept a glass front, although a screen barrier is usually an option for additional safety.

Ventless systems are available as built-in fireboxes, gas logs, or stoves.

Typically, VF systems are more affordable, due to more flexible installation methods without requiring a vent. They can operate via remote control or wall-switch, and do not necessarily require house power electricity. Although, if connected to house power, a battery pack is often included to serve as a back-up power source for instant heat during a power outage.

Generally speaking, a VF system provides excellent efficiency – nearly 100%, because there is little-to-no energy loss from the fireplace.

Electric

An electric fireplace provides a wonderful ambiance with mesmerizing lights and optics to give the illusion of fire, but without a real flame. These fireplaces do not require any venting considerations, and simply require a standard electrical connection.

Nearly all electric fireplaces include a heater, which you can engage or disengage depending on the season! Most models operate off 120v, but some can be set for 240v to provide stronger heat output.

Electric fireplaces are available as built-in fireboxes, gas logs, or inserts.

Usually, electric fireplaces are the most affordable of all fireplace types, and can be installed virtually anywhere, but do rely on electricity for operation and provide very little heat, since there is no real flame.