It's useful to start this analysis with an overview of what HVLS fans are supposed to be. Technically speaking, a high-volume, low-speed fan is any ceiling fan that is greater than 2.1 min diameter. This increased size is the hall mark of HVLS fans because it impacts how they operate. HVLS fans use their size to move air through out large spaces and keep your entire structure comfortable. Their long blades create a powerful flow of air that spreads through out the space like an ocean breeze. Traditional fans rely on speed to do this, which isn't usually as effective of an option nor is it as comfortable.