Match the capability of the dehumidifier with the interior size of your mobile home. Each dehumidifier box is labeled with the amount of square feet that it can keep dry. If the dehumidifier is too small, it will not be able to do its job; if it's too large, you'll be over-paying for what you don't need. A mobile home is generally small enough so that one unit can keep it dry.
Determine how you will drain the unit. Dehumidifiers come with a holding bucket that needs to be manually drained every few hours, depending upon the air moisture level. Many models come with an outlet for a drain hose that allows it to continually drain without having to check it. Use a small drain hose about 6 feet in length for this purpose that can be easily connected to the dehumidifier.
Place the unit so that the drain hose is on the same level as the drain. Putting it on a table in the kitchen allows it to drain into the kitchen sink when in use. If you need to use the sink, turn off the unit and move the hose to the side. Do not direct the hose out of a window as this will create a moisture problem outside due to the dripping hose, which can be a potential source of mold growth.
Locate the unit toward the middle of the mobile home to service both sides equally if there is a general problem with moisture. If one side has a greater problem, such as visible mold or mildew, then move the dehumidifier closer to the area with the greater moisture. If your bathroom has poor ventilation, it might be best to locate the unit nearby, perhaps allowing the dehumidifier to drain into the bathtub when in use.
Place the dehumidifier in the warmest part of the mobile home during colder weather. Dehumidifiers perform poorly in temperatures under 65 degrees Fahrenheit unless they have a more expensive anti-frost option built into them. If you see frost or ice forming around the unit in colder weather, then turn it off. Otherwise, damage may occur to the condenser.