How an Outdoor Fireplace Works

Styles

Outdoor fireplaces can be as simple as an open fire pit, or exactly like an indoor fireplace, complete with hearth and chimney. Freestanding fireplaces are much like the standard indoor fireplace. They have sloping inner walls, a hearth and a chimney with a damper. The chimney is usually much shorter than an indoor fireplace, however, but still tall enough to carry smoke away from the area.

Other outdoor fireplaces are designed as portable fire pits. They feature large, metal bowls on legs. The fire is made in the bowl, where it is contained. Some of these portable fire pits also have a wire cover. Because metal conducts heat, they can get quite hot. Many are placed inside a stone surrounding built specifically for that purpose. Still other fire pits are designed solely of stone, in a simple circle with a dirt or stone floor. All types of fireplaces are usually wood-burning.

Smoke

Traditional freestanding outdoor fireplaces carry the smoke away from the people next to the fireplace by use of the chimney. When the fire is started in the firebox, the air inside the fireplace becomes warmer, causing it to rise up the chimney. This action allows cooler air to move in beneath it, feeding the flames of the fire. The hot air and smoke rises up the chimney and out the top.

Indoor fireplaces have dampers, which can be pulled down to block the flow of air in and out of the chimney. This is to prevent cold air from entering a house. Outdoor traditional fireplaces usually do not have dampers.

Metal and stone circular fire pits do not have chimneys, so the smoke can sometimes bother people who are sitting around the fire.

Cleaning

Like indoor fireplaces, outdoor fireplaces and pits need to be cleaned of ash before each use. Metal fire bowls can simply be lifted, dumped and rinsed clean with a hose. Traditional outdoor fireplaces, made of brick or stone, may have an ash pit underneath the grate where the fire is built in the firebox. This can be swept out and also hosed down. Circular stone fire pits are harder to clean, as the ash is usually trapped in the stone surround. A dustpan and broom are needed to remove the ash, then they should be hosed down as well.