neuraxisanswered grow question 5 years ago It depends on the space you can dedicate to it and the frequency at which you can / want to take care of it and empty the tank. Some models can be connected to an external tank or directly to a drain. It's the best options. Otherwise you have to get a model that can work for a whole day without needing to be emptied. Small models / portable can do in some restricted space in countries where the ambient humidity is lower.