I've probably seen a little big by choosing this fan. It is very large, all metal and very powerful. At the minimum speed, pulse already plenty of fresh air in my room of 30 sqm. By increasing the speed, I could take off an ultralight. It's very great professional equipment but still noisy at full power. I should select 1 or 2 sizes smaller. The size of 18 "is reserved for very large volume. We can direct the air flow more or less leaning fan manually.
