Once upon time charcoal was the only way to produce a suitable fire for a grill. Yet too many people complained about the smoke, ash, and messy cleanup. As grill technology and hydrocarbon refining evolved throughout the 20th century, it gave rise to the affordable convenience of gas grills.
Today, the marketplace is rife with propane and natural gas grill of every size with features to meet just about any imaginable occasion. While there certainly is a fair amount of marketing speak, and special features, one thing you find in common with all quality gas grills is that each has a BTU rating.
What Are BTUs?
BTU is an abbreviation for British Thermal Unit. It has come to be the standardized unit for measuring the thermal output of many heating appliances, including propane and natural gas grills
On a technical level, a single BTU is the specific amount of energy it takes to heat one pound of water by one degree Fahrenheit. Though a lot of people look past BTU ratings when they are shopping for a new grill, in place of marketing savvy terms that position the grills with more special features.
While special features, material build quality, and grill grate materials are also important, you still need to factor in the BTU rating when choosing the best gas grill to meet your needs.
How To Interpret BTU Ratings When Shopping For A Gas Grill
When it comes to gas grills, the BTU rating is telling you about the heat output of either each single burner element or the combined BTU rating of the entire gas grill. Some less reputable grill manufacturers will give you the combined BTU rating of a gas grill hoping that you don’t do the math to determine the underpowered BTU output of each individual burner element. So, anytime you see one single large BTU rating make sure to divide that number by the number of burner elements the grill has.
How Many BTUs Should A Single Burner Element Have?
This can vary by the grill size and type, as well as the type of grill grates it has. As a general rule of thumb, you want each burner element to be rated around 10,000 to 12,000 BTUs. Though for some smaller grills or grills with heat-absorbing grill grates you might still be able to get a sufficient amount of heat from a burner that only produces up to 8,500 BTUs.
On the other end of the spectrum, you might want to be wary of a grill that has burner elements producing over 15,000 BTUs per hour. While it might sound impressive on paper, these overly high BTU ratings are usually a sign that the manufacturer is trying to compensate for engineering flaws in thermal efficiency by pumping up the BTU rating. Then later you find out that all that promised heat is being lost to drafts in the primary cooking chamber or other issues.
Can Grate Materials Compensate For A Lower BTU Rating?
Grill grates can sometimes improve thermal efficiency for smaller gas grills. Porcelain-coated cast iron grill grates in particular can help improve the thermal performance of a gas grill. When properly preheated the cast iron will hold onto more thermal energy, which will be transferred to the meat. It also helps produce a powerful sear, and visually attractive grill marks. A similar thing can be said for thick gauge stainless steel grill grates of 7 mm or more.
Though thinner grill grates, like 5 mm stainless steel, chrome-plated grill grates, and expanded metal don’t hold onto as much thermal energy. They can still make some nice grill marks on the meat, but they just don’t have enough thermal mass to make up for a gas burner element with a BTU rating of less than 10,000 BTUs per hour.
How Is Infrared Different?
Infrared gas grills take advantage of new grill technology. A propane or natural gas burner element fires up under a special infrared element. This element, which is often made from some type of ceramic material, then starts to heat up. When it gets hot enough the infrared element starts to emit infrared heat energy.
This is a type of radiation that cooks the meat without causing as much damage to the natural moisture boundary. With an infrared gas grill, you tend to get meat with a richer sear on the outside and more natural juices on the inside.
Here the translation of BTUs to real-world thermal output can be a bit hard to interpret. The distance from the infrared element, the type of grate material, and other engineering factors can all play into how the grill performs when you truly lay a piece of heat over the heat.
If you do happen to find an infrared grill that you love, but you aren’t sure on how it will perform, take a moment to look for temperature ratings. Ideally, an infrared grill that claims to be able to produce up to 700 degrees Fahrenheit should be hot enough to grill pretty much anything you want. Though some of the higher-end models can get up to 1,000 degrees or more.
Other Features That Affect BTU Rating
As we mentioned earlier, an excessively high BTU rating of over 15,000 BTUs per hour, per element is usually an engineering flaw. Drafts, gaps, and exposed fireboxes can all let heat out in unpredictable ways. Not only does this make it hard to determine the true performance capabilities of the gas grill, but it can also lead to hot and cold spots across the grill grates.
The shape and layering of the grill lid can also help improve the BTU performance of a gas grill. A double-walled lid with easy to control dampers will help trap more of the heat the gas element produces. You can then adjust the dampers according to the temperature reading on the lid thermometer. You can open the dampers to let more heat out or close them to trap heat inside, which is especially handy when roasting meat.
Do Propane Or Natural Gas Burners Produce More BTUs?
Propane and natural gas burners are engineered differently. To the point that you cannot safely burn one type of gas with another type of burner. This is due to the fact that natural gas only has a third of the energy density that propane does.