The first thing to know is that a dehumidifier air produces heat about 1 kWh / liter of condensed water.
If you could condense the 20 liters of water / day announced, your dehumidifier produce much more heat than the electricity it consumes.
In practice, it will condense about 10 liters / day in the best, because the announced figure assumes that it is placed in a very warm room and remains very humid. Now, as the device is effective, the humidity in the room will drop and the amount of condensed water too.
But even with 10 liters of condensed water per day, the dehumidifier will produce more heat than it consumes electricity. And as the dry walls improves insulation, you win on all fronts.
Personally, I use it in the bathroom where I also dry my laundry. Two advantages: no fog on the ice when I take my shower and my dryer consuming (winter) less than a dryer.
You can add a third advantage if you have a VMC hygro; it does happen more rarely at top speed, reducing consumption and air calls that, in winter, rarely dry.
