Masonry Fireplaces

Open pit masonry fireplaces, also known as Conventional Fireplaces, have a long history of beauty and realism that only a real masonry fireplace and true wood burning fire can create. There is no substitute for the charm and atmosphere created by an open fire which is why masonry fireplaces offer a fireside experience that is like no other.  These types of fireplaces are intended only for fire viewing and do not include the features needed to convert the fuel to useful heat.

Masonry fireplaces are beautifully sculpted out of mortar materials such as concrete blocks, bricks, stone and other materials that will stand the test of time and offer a lifetime of beauty and service. Worldwide, wood burning in a masonry fireplace has become a tradition. Masonry fireplaces are not just seen in old homes but are also built in newer homes and the tradition of the masonry fireplace is still carried on today.

That being said, conventional masonry fireplaces also pollute the indoor and outdoor air more than advanced wood heating appliances.

Anatomy of a masonry fireplace

A masonry fireplace’s main functions are to control fire, heat, and smoke, and the inner shell is made from fireproof materials. The outer shell of the masonry fireplace supports the inner shell providing overall structural stability. Some fireplaces may have fewer or more individual parts than others but generally a masonry fireplace will consist of the following parts:

• Mortar Crown –The mortar crown is the concrete like surface at the top of your chimney. Its job is to shed water away from the flue and also keep water from entering the chimney chase.
• Flue –The flue is a vertical opening through the chimney, extending from the smoke chamber to the top of the chimney. Its primary function is to create a draft for proper ventilation, and to discharge smoke.
• Smoke Chamber –The smoke chamber is the transition area in a masonry chimney that starts directly above the damper and continues to where the first flue tile is installed. Shaped like an up-side-down funnel, smoke and hot gases are in direct contact with the tapered smoke chamber walls as you burn your fires. The smoke chamber is a hot oven where much of the creosote accumulates and many chimney fires start.
• Smoke Shelf –A horizontal surface directly behind the throat of a fireplace to prevent down drafts.
• Lintel –A horizontal, non-combustible member that spans the top of the fireplace opening.
• Damper –The damper is a mechanical device which opens and closes to regulate the draft and airflow to the firebox. The damper also stops heat from escaping up your chimney when the fireplace is not in use.
• Firebox –The part of the masonry fireplace where fuel is combusted.
• Hearth –The fireproof area directly in front of a fireplace. The inner or outer floor of a fireplace usually made of brick, tile, or stone.
• Ash Dump – Some masonry fireplaces will have an ash dump where ashes can be collected and removed through an ash dump fireplace door.
• Foundation – The foundation of a masonry fireplace is often referred to as a “footing” in some building codes. Codes will specify that the foundation must be a certain thickness and width with proper reinforcement.

How to make a masonry fireplace energy efficient

Although newer masonry fireplace models have come a long way since the days when they provided more ambiance than heat and are more energy efficient than they used to be, the fact remains that an open masonry fireplace is hands down the least efficient wood burning fireplace out there.

Despite their popularity, one setback of traditional fireplace construction is that approximately 90 percent of the heat from burning wood goes right up the chimney. Masonry fireplaces have actually been proven to be a heat loss since heated air is allowed to escape out the chimney.  A damper can help partially solve this problem however the damper must remain open all night while you sleep so even as the wood burning fire dies down, warm air will still escape the chimney throughout the night. Masonry fireplaces can be made more energy efficient by following these simple steps:

Close your room doors

When burning a fire, shut the doors to the room where the fireplace is located. Doing so keeps that room heated and prevents a roaring fire from drawing warm air out of the rest of your house (and replacing it with cold outdoor air). Also crack open one nearby window to give the fire just enough air to burn.

Buy a great fireplace grate

Fireplace grates differ greatly in structure and style. Ensure that yours either holds logs in a manner that maximizes heat flow to your room or has C-shaped parallel tubes that point toward the room, thereby recycling warmed air back into the room.

Enclose the fireplace

Many metal-and-glass fireplace enclosures come with a fan that circulates heated air into the adjoining room.  Even models without this feature save you energy by keeping cool outside air where it belongs—not in your home—when your fireplace is not in use.

Put a damper on it

The easiest way to prevent cold air from entering your home when your fireplace is idle is to close your damper. This can save you up to 15 percent of your total energy bill.

Seal it up

Applying caulk manufactured for use around the hearth and firebox is another simple, inexpensive way to keep cool air out and warm air in.

Upgrade to gas

If you are not satisfied with your current wood-burning fireplace, you could consider converting your existing fireplace into a gas burner. These prefabricated inserts with their faux logs can save you money because they allow you to control the heat and eliminate firewood expenses, and they also burn more steadily than traditional hearths.

Consider other options

Other energy-efficient alternatives to the traditional fireplace include wood burning stoves.

Wood stoves may or may not provide you with energy savings, depending on where you live and whether you have a cheap and abundant supply of firewood.

How do fireplaces compare to wood stoves?

Generally, fireplaces are not an efficient means of burning wood.  They do not burn as cleanly as a certified wood stove.  Furthermore, fireplaces provide less heat to your home, since most of the heat from a fireplace goes out the chimney.  Most fireplace owners do not use their fireplaces as a primary source of heat.  They may burn wood in their fireplace as supplemental heat on chilly days, or to provide ambiance to their home.  For more efficient heating with less smoke, consider having a gas, pellet, or a certified wood fireplace insert installed in your fireplace.