We use these to make fans for use on a cruising sailboat. They are quiet and powerful. We have made three and plan on making more. Very happy.
These are amazingly powerful fans. I'm using two of them to push air through a modest high tunnel greenhouse (10 x 20 x 8). They're not part of a "kit" so it takes a bit of an effort to mount them properly and to fashion an armature that positions the 7" x 14" 10w solar panel. Aside from the obvious advantage of having active fans when the sun is shining... and ceasing activity when there's no sun... the panel also comes with a switch, so there are lots of options to keep the temperature balanced. The IP67 fans are not "whisper" quiet, but hardly an annoyance. They are tireless workhorses that get the job done. These two fans move about one-third of the total volume of the greenhouse every minute and thus far have been been very effective at keeping temperatures optimized. I am delighted with their performance.