About Firepit BTUs

Newcastle Fire Pit FirepitOften enough when choosing the right gas fire pit, our customers wonder: What is a BTU?

BTU stands for British thermal unit, a unit measure of energy. One BTU is equal to about 1055 joules, and represents the heat needed to warm one pound of water by one degree Fahrenheit. In this case it is used to describe the heat value of firepit fuels: one standard cubic foot of natural gas yields approximately 1,000 BTU, and one cubic foot of propane equals about 2,500 BTU. The higher the BTU, the more heat is generated. A fire pit that operates at a maximum of 60,000 BTU will put out a lot more heat than a fire pit putting out a maximum of 15,000 BTU. Another way to consider this is by BTUs per pound. Propane gives off about 15,000 BTUs per pound, so a 35,000 BTU propane fire pit will put out 35,000 BTU an hour from all burners combined, and the firepit will use somewhat more than two pounds of propane per hour.

Other variables that determine fire pit BTU amounts/heat output are the fittings in the fire pit, including the ring, and the type, size and length of the fuel pipe or hose, the quality of the orifice that mixes air with the fuel, and the pressure in the line. So while natural gas may be less expensive, it generally has a lower firepit BTU output than propane, and you may find yourself turning up your natural gas fire pit BTU regulator to achieve the amount of heat you need, causing the fuel container to empty faster and thus costing more.