BBQ Water Smokers come in all shapes and sizes. Trying to understand the difference between the different styles can be confusing, but with a little information you should be able to make an educated choice.
Where will the heat come from?
The most important question to ask is what is going to be used to produce the heat in your smoker. You have three different options for heat; Charcoal, Propane/Natural Gas, or Electric. When thinking about heating options, the main question you need to ask yourself is how involved do you want to be in the cooking process.
Charcoal
Heating with charcoal is considered the "purist" way to smoke meat on a smoker. It also requires the most oversight. Hot charcoal must be added to the smoker throughout the cooking process in order to maintain the appropriate heat.
Propane/Natural Gas
A gas smoker is an ideal option if you don't want to babysit. With gas you have a lot of control over the heat. The only things you really have to monitor are the water level and wood chips. You'll need to make sure that these are replenished throughout the cooking process. One downfall of using gas is the cost associated with filling the propane tanks. You'll want to make sure you have an extra tank on hand before you start cooking.
Electric
An electric smoker offers the same convenience features as gas. As long as you monitor your water levels and wood chips, cooking on an electric water smoker is fairly low maintenance. The biggest downside to an electric water smoker is heat control. A lot of electric models do not contain thermostats.
What size smoker do you need?
Another thing to consider before purchasing a smoker is the size of the cooking surface. Think about how you are going to be using the water smoker and what you plan on smoking. Cooking surfaces are generally measured in square inches. Another thing to consider is how much weight the smoker can handle. Most small smokers have a 50 pound capacity.
Where are you going to use your water smoker?
Do you need a portable smoker or will it have a permanent location on your patio? Do you have restrictions on the type of heat you can use? There are all kinds of options, but you need to decide how much space you have available. Not only while you're using the water smoker, but also storage space that may be required.
I hope this has given you a little insight into the thought process needed before purchasing a water smoker. Personally, I have a small portable smoker because I put it in my garage for storage. I also use charcoal for heat, because I enjoy the process involved. Fortunately, there are enough options available to meet everyone's smoking needs. Best of luck in your search!