Small in size unit, but output is powerful enough to cover house. Durability After having several of these units for using in the bedroom we decided to purchase the Vonado which indicated it was powerful enough that it would cover the entire house. I didn't really believe that but had faith in the brand so decided to go with this one. It takes up less space than most of the other units that we checked out and the design and colors keep it pretty neutral. While they do the job, I have never liked having them sitting there taking up space. This unit say 1.8 gallon capacity and is powerful enough that it does cover the house. Quiet to operate so it doesn't disturb anyone sleep and it smaller size/design make it not so bad to have taking up space in the home.