Chimeneas made of clay come from Mexico. Chimineas are small fireplaces with an egg shaped firebox and a smoke stack. Originally it is said that chimeneas came from Spain and were brought to Mexico centuries ago. These small fireplaces were used for cooking and heating indoors or out. Centuries ago and today in some areas in Mexico homes had dirt floors and a hole in the center of the roof for the smoke to exit. Chimeneas made of clay are baked in the hot Mexican sun. These clay chimeneas are inexpensive. Clay chimeneas can crack and break with temperature changes.
Today you can still purchase clay chimeneas but because of the breakage the cast aluminum and cast iron chimeneas are more popular. Chimeneas are widely used outdoors on the patio as a small fire pit. Pinion wood is popular because the smoke wards off mosquitoes. Cast iron chimeneas will scale to a reddish brown color but it will be years and years before it rusts through. When looking at cast iron chimeneas made sure the smoke stack is cast iron as well. Many Chinese manufacturers are using sheet metal for the chimney and this rusts out rather quickly. Cast iron takes awhile to heat up but it holds the heat long after the fire has died down.
Cast aluminum chimeneas have gained in popularity. Cast aluminum will not rust, it is light weight compared to cast iron so it is more portable. The aluminum casting must be thick. Too many manufacturers are making the casting thick by the openings and thin around the fire box. Cast aluminum will burn through at a low temperature always burn small fires in them. Cast aluminum will tend to warp under heat if the casting is too thin. Did you ever have a gas grill that after a short time the cooking grids shrunk and kept falling down? The cooking grids didn’t shrink the aluminum grill head warped from the heat. The same thing holds true for the chimeneas as they can reach higher temperatures than a grill if over fired.
Most chimeneas have a small opening on one side. Since they are primarily used for cooking and heat it makes sense. The viewing of the fire is limited through the small opening. Some chimeneas have been made that are open on all sides for viewing and are more popular for patio fires. If placing on a deck or patio a hearth pad is recommended for protection from sparks, heat and any rust marks. Chimeneas make great patio heaters.