I bought this to replace a 12,000 BTU unit, and it does a much better job than the old one. It's also quieter and has an an air purifier built in. However, the installation manual is terrible. For example, it identifies all of the screws and nuts by code but does not use these codes in the installation steps, so you are left wondering which pieces to use where. The operations manual isn't a whole lot better. But once you get it installed and up and running, it's great.