Gas grills are the most popular grills sold in the United States. And it's not a wonder. Gas grilling is less of a hassle than cooking with charcoal, takes less time to prepare the grill, is less expensive (especially for those who grill often), and is a far easier cleanup after the meal. For all these benefits though, there are still some drawbacks to cooking with a gas grill.
Gas grills typically use Natural Gas (NG) or Propane (LP). The fuel is located in a container, or tank, usually mounted to a wheeled frame, or cart, and connected to the gas valve through venturi tubes, or simply 'venturis.' While these two types of gas are similar, there are many differences in the construction of NG and LP grills due to the differences in pressure between NG and LP. You should never operate a grill unless you know what type of gas it was built for. There are, however, ways to convert an NG grill to a LP one, and vice versa.
When the grill is started, burners on the bottom of the grill warm up and radiate the heat necessary to cook the food. Burners come in a variety of shapes, the most common type are 'H" burners resembling the letter 'H' turned on its side. There are also oval, 'Figure 8', 'Bowtie', and straight 'Bar' burners. The burners are designed to provide an even heat in the grill to help promote consistent cooking and preparation. These burners work to provide consistent cooking temperatures throughout the grill basin. A popular trend in gas grills has manufacturers adding an infrared radiant burner, a ceramic tile heated by the flames, to the back of the grill enclosure to ensure heat is evenly distributed throughout the cooking surface.
Gas grills warm much quicker than charcoal grills. Charcoal lumps can take 15-20 minutes to heat up and turn to embers. With a gas grill, the burners light instantly and warm much faster, making it the ideal choice for cooking in the evenings after work, or for anyone with a busy schedule. The control valves on a gas grill provide ease of temperature control. Charcoal burners are at the whim of how the charcoal briquettes are burning. And at the end of the meal, the picnic, or wherever you're grilling, cleanup is much faster. Gas grills have no messy coals or ash to dispose of, more on that below.
Gas grilling can be easier on your wallet as well. Gas grills generally cost more than electric grills or charcoal; charcoal is typically the cheapest, but charcoal is also the most expensive fuel source. One cookout with charcoal can cost $5.00USD, while NG or LP may cost as little as $ .20USD and a tank of gas can last up to 20 hours of cooking time. For someone who enjoys grilling, it may seem wiser in the short-term to purchase a less expensive grill, but in the long-run it may end up costing much, much more.
Gas grills may provide convenience in preparation and are typically more cost-effective for avid grillers, but they are more sophisticated, and thus require a greater amount of upkeep. Most gas grills are equipped with a heat shield, which may also be called burner shields, heat plates, heat tents, radiation shields, or heat angles, and are fitted above the burners. The heat shields serve a dual purpose in the grills. For one, they act as a conductor to better balance and radiate the heat in the grill, but more importantly the heat shield protects the burners from the corrosive fats and oils that drip off meats and other foods. Sometimes this runoff will vaporize and can infuse the meats with robust flavors. However, if this residue does not evaporate, it can clog the outlet ports, which would prevent the grill from lighting or create a dangerous backup to the fuel tank. Sometimes using a long, flexible object can help clear the clog, but otherwise the burner may need to be replaced. The valves sometimes will wear or become rusted and require replacement. Whereas burners are more ubiquitous and can be replaced, certain valves only fit an exact grill model. Many grills are disposed of when valves wear out, due to a lack of available replacements.
Maybe the biggest drawback to gas grill, as many grilling enthusiasts will tell you, is that gas grilling provides no additional flavoring to the foods. Charcoal and wood can add a host of flavors to meats and vegetables, but gas infuses none.
For most Americans, a gas grill is their first choice when it comes to cooking out. With the relatively short prep time, the consistent cooking temperature, and the ease of cleaning up after your meal, a gas grill makes any picnic, camping trip, or after work meal simple and fun.