The Science of BBQ - BTU's Explained - What Are BTU's

When purchasing your first grill, maybe even your fifth grill, one of the first things you want to know is what are the BTU’s. It is a powerful number; a large number, one that may make or break your decision to purchase that particular piece of equipment. But what are BTU’s? This is BTU’s Explained – What are BTU’s and how they apply to your grill.


What are BTU’s?

By definition, the BTU is an abbreviation for British Thermal Unit. It is a common measurement used to describe how much energy it takes to raise the temperature of one pound (1 LB.) of water by one degree Fahrenheit (1°F). For those of you wondering, that is about 1055 joules. A joule, in this case, is energy dissipated as heat. The better question is What are BTU’s in relation to your grill?



BTU’s and Grills

When it comes to grills, BTU’s are used as a measurement of how much heat a grill can generate when a burner is at its maximum output. However, grills use different fuels, charcoal, natural gas, and propane; each one having a different way of achieving this maximum output, which is calculated by fuel consumed by square foot. Think of BTU’s like the miles per gallon in your car. BTU’s in a grill are measured per burner, as well as the unit overall – this is the number you usually see. The primary air shutter mixes gas and oxygen and we measure the heat generated when the mixture is burned. Logic dictates that the higher the BTU’s the hotter the unit should be. What you are looking for is about 80 to 100 BTU’s per square inch. However, there are several factors that can interfere with the heat generated. Bottom line: it all comes down to how efficiently those BTU’s are generated and utilized.

Jet Fire TQ


Misconceptions about BTU’s

People think that anything with a high BTU (grills, fireplaces, and heating equipment) will be hotter and therefore better. In actual fact, there are many factors that will actually influence how well your appliances work. In the case of a grill, the BTU’s generated by the burners are used to heat the materials that make up the grill, the air inside the grill from the drip pan to the top of the hood, and the food. It’s all about how efficiently those BTU’s are distributed and used, and that is where there are misconceptions about BTU’s. People assume that all of those BTU’s are used to cook and that is it.


Part of that misconception surrounding BTU’s is the materials that the grill and cooking grids are made from. They will utilize the BTU’s generated by burners in different ways. A grill made from aluminum will heat fast, and cool fast, the reflective materials helping to keep the heat in the base and the unit. This means that a grill will loose less potential heat. In cast iron grills thermal transfer is slow, but they hold on to that heat for a long time, absorbing the heat before the BTU’s are utilized for cooking. Once they get up to temperature, cast iron transfers heat to the food you are cooking like a champion.

Bezel TQ


The chimney effect - think of it like how your charcoal chimney starter works - uses the heat from the burners to draw in air from outside your grill, up into the grill, and out the exhaust port. This chimney effect is great for a couple of reasons. It helps with the efficient burning of the gas to create the optimum burn, creates a convection-like effect, which is great for cooking things using indirect heat and promotes even cooking. Optimum burn is important to grills. It is the ultimate clean burn and the best use of those BTU's.

This has just scratched the surface of BTU’s. Understanding misconceptions about BTU’s and learning what exactly a BTU is are the first steps in understanding not only what goes into making a quality grill, but how quality engineering can lead to a better grilling experience. Find out more about the importance of BTU's in Napoleon Grills by reading our follow-up article.