To answer your question. No matter what mode it is in, heating, cooling, or dehumidifying - It will cause water to build up. It doesn't need constant drainage, but it will need to have the water tank emptied. I personally do this on a daily basis when it's in use. You can keep the ports on the back plugged and then drain out into a container every so often. It doesn't tend to be more than a few hundred ml per day unless you specifically have it running in 'dry' mode. In that case continuous drainage becomes more appealing as you can potentially be taking litres of water out of the air in super humid conditions."},{"@type":"Comment","@id":"https://www.hotukdeals.com/comments/permalink/51052273","author":{"@type":"Person","name":"deleted9453"},"datePublished":"2023-09-24T15:12:43.000Z","text":"Heat mode won't create any moisture as there is nothing for water to condense as the coils will be warm/hot."}],"commentCount":3,"interactionStatistic":0,"articleSection":"Ask"}