If you are looking for a smoker with set-it-forget-it simplicity and good flavor, on a modest budget, go gas.
Gas fueled smokers are almost as easy to use as electric smokers and most cost less than $200! They produce a lot of clean heat, and that's why large gassers are the most popular smokers in barbecue restaurants. The smoke flavor comes from wood chips, chunks, or pellets.
Most consumer units use propane tanks. The Camp Chef units are the only ones that are natural gas friendly. You may be able to adapt another brand to run on NG, but this must be done by a professional unless your goal is to be charred on the outside and rare in the center.
The best are cabinet style, reminiscent of high school hallway lockers only smaller. There is a burner at the bottom, usually brass or cast aluminum, very durable, with numerous jets. Above the burner is a shelf for a pan for the wood, and above that is a shelf for a water pan. Above that are four or more shelves for food. The bottom vents cannot be adjusted to make sure the gas gets enough oxygen. At the top there is either a chimney or a damper or two. You should always leave the top vent open all the way to prevent soot buildup on your meat.
My favorites have two doors. A small one at the bottom so you can check the flame and add wood and water. The main door provides access to the cooking chamber. Most are thin metal and the doors are loose so they leak heat and smoke. That means you will burn more wood chips than airtight units, but there are no airtight units and frankly, the leaks really doesn't impact food quality, just fuel efficiency.
It is much easier to control the temperature of a gasser than a charcoal or wood fueled smoker. Propane smokers don't require access to electricity as do pellet and electric smokers. This makes them more portable. And they are lightweight, although the tanks are 20 pounds.
They don't come with a tank, so budget for two of them. You need to keep a spare on hand because half used tanks have a nasty habit of running out right in the middle of a five hour cooking session. If the tank is running low, you need to check up on it every 30 minutes to be sure the flame is not as dead as your dinner. This is a bit of a pain, especially when you undertake the smoking of a nine pound butt for pulled pork, a cooking session that could take 18 hours. For sure it will croak at 2 a.m. If your tank is running low, it's a good idea to remove it and hook a fresh tank when you start a long cook. Alas, this practice leaves you with several partially filled tanks in the garage.
The biggest drawback to these smokers is that most are too narrow to fit a full slab of ribs or a whole brisket on a shelf. You can cut the meat in half, or hang it. To hang it you need to be creative. I use metal shower curtain hooks and hang them from a shelf in the top position. Another option is to drill holes in the sides near the top and put in some dowels and run the curtain hooks along them. My favorite is the Camp Chef Smoke Vault 24". Although it has only one door, it is big enough to handle long slabs of ribs and whole packer briskets. It is a bit more expensive than most.
One other word of caution. I love the flavor of meat from propane smokers, but it is a tiny bit different than the taste of meat from charcoal smokers, and to my taste, much better than the flavor from electric smokers. The combustion gasses combine with the moisture and the wood smoke and produce a fragrance and flavor that is sometimes reminiscent of bacon. Purists complain about this undertone, but I ask you, just what's wrong with a little bacon?
Pimp your gas smoker
Owners complain about cheap construction, but when they look at the price tag, I don't get their complaint. If you want high quality construction, great food, and set it and forget it ease, buy a pellet smoker. You can take steps to improve these cheapo smokers by putting a gasket inside the doors, sealing leaks, and replacing the thermometer. But it really isn't necessary and it could work against you. Most of them run hot, you might make it run hotter by sealing it. Here's an article with some links that can help you tighten up your gasser.
Turn down the heat. Most of the models I have played with tend to run hot, in the 250 to 275°F range on the lowest setting. I think ideal temperature for low slow smoking is 225°F, but most meats will be just fine at the higher temp. Not ideal, but not bad. If you want to drive down the temperature a bit, try ice in the water pan or leaving the door slightly ajar. This wastes fuel, but should do the job.
Water supply. Most come with a small water pan. I jury rigged a larger pan so I don't have to keep filling it and to help stabilize temp. One reader installed a copper water pipe on the outside side with a tank to feed the pan.
Install a better thermometer. Some of the cheapest worst thermometers I've ever seen are installed in these inexpensive unites. Remove it and install a good digital thermometer probe.
Buy a cover. They don't come with a cover and the paint jobs are usually not baked on, so use a cover to prevent rust.
Buy rib racks. These smokers are small, so you will want to buy at least two rib racks in order to pack in enough to feed all the people who will come sniffin' around.
Some gas grill owners find it hard to dial the temperature down to 225°F. So they go looking for solutions. Some want to reduce the amount of gas, a method that can work, but it must be done properly and is potentially dangerous. I do not recommend this technique, but I publish it here just to give the you an idea of what is involved and with the hopes of discouraging a common mistake or two. Remember, fiddling with the gas supply system could create an explosion or fire resulting in death and destruction of your home. I strongly recommend that you use a professional if you wish to modify the factory setup. Your local LP gas company will be glad to help for a fee.
The gray saucer shaped regulator is specifically matched with your smoker, so if something is wrong with it or the hose, don't fiddle with it, just get the numbers off it and buy a new one of the exact same kind. No substitutions. It must match. The regulator is like a carburetor on a car. It is tuned for the pressure of the tank or natural gas supply, the needs of the grill, and it mixes in the correct amount of air. You can't just replace an automobile carburetor with any old carburetor. Experts tell me that the popular adjustable red regulator people buy on the internet is designed for high pressure gas sources and should not be used. If you use a high pressure regulator on a low pressure burner it can blow the seals from the valves and possibly explode. A low pressure regulator on a high pressure burner will produce a flame about the size of a kitchen match.
Bruce Swiecicki, Senior Technical Advisor of the National Propane Association says "You might be able to control the flame by turning the cylinder valve, but the flame may be unsteady. I don't know of any safety issues to look out for by doing this."
One expert says the best approach is to limit the volume of gas with a brass needle valve between the regulator and the burner like the one shown here. With a small valve after the regulator you can restrict the amount of gas going into the burner. It would still have the correct pressure but there would not be as much flow. Even though there are no marks on the valve, 1/8 turn knocks it back 15°F.
To complete the installation you will also need a high pressure gas hose. You would then take the regulator hose off the grill, attach the needle valve to hose, and attach the new hose to the valve on one end and to the smoker on the other end. Be sure to use Teflon tape or pipe dope on the pipe threads to prevent leakage and test the connection by painting soapy water over the joints and watching for bubbles when the valves are open. Installation can be a bit of a pain. One reader reports that "Channel locks and vice grips failed at the initial unscrewing and I had to use a bench mounted vice to grip the parts."
I asked Dr. Blonder about this kluge and he explained that "After installing the needle valve, the air to gas mixture is no longer the same. The amount of air depends on how quickly the gas is moving through the system because the gas pulls air in. So you will have to adjust the air mix by playing with the venturi. Looking for a nice clean blue to clear flame. Not yellow."