This was definitely the most important “ease of use” category we considered in the review process. Water tank size has to do with the capacity of each dehumidifier’s condensate collection bucket (we use the terms “water tank” and “condensate collection bucket” interchangeably). All of the moisture that the dehumidifier removes from the ambient air is collected in a water tank nestled into the bottom half of the dehumidifier’s plastic housing. All units have a float switch attached to the top of the water tank that activates a cut-off switch when the water level reaches a certain height (when the bucket is full). Now that we’ve gotten the mechanics of things out of the way, let’s get to what really matters.
Simply put, the larger the water tank size, the better. Unless you’ve implemented gravity or pump drainage you will have to remove the water tank, empty its contents, and replace it each time it fills up. If the dehumidifier is operating continuously this means that you’ll have to go through this process at least 4 or 5 times per 24 hour period. Your dehumidifier having a larger tank means that you won’t have to go through this process as frequently as you would if it had a smaller tank.
For example, let’s compare a 70 pint dehumidifier with a smaller 12 pint tank to another 70 pint unit with a larger 16 pint tank. The dehumidifier is rated to remove up to 70 pints of moisture per day (per 24 hour period). On the unit with the 12 pint tank you’ll have to replace the bucket close to 6 times per day (divide 70 by 12). On the unit with the 16 pint tank you’ll only need to do so closer to 4 times per day (divide 70 by 16). That’s almost 2 more times per day that you’ll have to empty the unit with the smaller capacity water tank. Over the course of weeks and months of use you can easily see how much more work you’re going to have to do to empty a unit with a smaller capacity tank vs one with a larger capacity tank.
Another factor you have to consider is the time between when the dehumidifier automatically shuts off (when the bucket is full) and when you actually empty the bucket and replace it. You might be planning to use the dehumidifier you purchase in a part of your home that’s not highly trafficked such as a basement. Now you’re in a situation where you’re likely to not hear the dehumidifier when it beeps signaling that its bucket is full. The unit might be full and have automatically turned off for a few hours before you check on it and realize its full, empty the bucket, and replace it. That’s several hours over which the dehumidifier wasn’t dehumidifying. The dehumidifier having a larger water tank means that it will continue to operate for a longer period of time before the bucket fills up. This means that it will be operating for longer periods of time between bucket replacements, resulting in more effective and efficient dehumidification overall.