To ensure you’re getting your hands on a top-quality dehumidifier that will promise to be effective, you need to ensure the tank is sufficient in size. The tank refers to the amount of water the dehumidifier can extract, so the bigger the better. For example, in a room measuring 500 square feet or more, you will need a tank with at least 20 litres of capacity. Generally speaking, there are three standard sizes that dehumidifiers come in, so depending on the size of the room, you will need; a large dehumidifier (40L), a medium dehumidifier (29L) or a small dehumidifier (17L).