How to Insulate a Firebox
You can prevent heat loss in your smoker grill by insulating the firebox. Also referred to as barrel smokers, these types of grills feature a short tube, or firebox, connected to the grill's longer tube, or cooking chamber. The firebox feature is for slow-cooking and smoking projects, such as smoking ribs. The firebox is used for fuel while the cooking chamber cooks the food. Fast-cooking projects do not require a firebox because coals are placed in the cooking chamber below the meat. Some smoker models are made of thin metal so that heat escapes quickly. Insulating the firebox will prevent this.
Use firebricks to line the bottom of your smoker's firebox. Firebricks are thin, ceramic bricks made for oven use. Purchase enough bricks to cover the bottom of the firebox.
Wrap each brick in aluminum foil. With foil-covered bricks the cooking chamber will take longer to heat up but will retain heat longer. They will also distribute the heat evenly, help dampen temperature spikes and prevent heat from escaping from the bottom of the box.
Place each foil-wrapped brick in the bottom of the firebox until it is lined completely with one layer of bricks.
Kent Page McGroarty has worked as a writer since 2006, contributing numerous articles to various websites. She is a frequent contributor to the health and fitness sections of the online magazine EDGE Publications and holds a Bachelor of Arts in English from Saint Joseph's University.