All air destratifiers are ceiling fans, yet not all ceiling fans are air destratifiers
Air destratifiers are ceiling fans that, using reverse mode to spin in the opposite direction, lower the hot air stuck on the highest part of the ceiling, increasing warm air at the first two meters of the house.
Air destratifying principle
Hot air is less dense than cool air, so strats of temperature are formed inside a room, like a coctel in a glass. Hot air goes up, cool air goes down. There's usually a 2º difference by linear altitude, which leads to an enormous loss of energy.
Furthermore, this applies to every form of heating, like floor heat, radiators, chimneys...
If your room is formed by a 6 meters height with a mezzanine then the difference between the highest point and the lowest can be up to 12º, then the heat must be programmed to 32º to feel 20º on the ground floor.
When this happens, there's a massive loss of energy and the top of the ceiling is being heated to 32º where there's nobody benefiting from it.
Destratifiers are a solution to this problem, aiming to keep a temperature difference of just 3º over this 6 meters, meaning 0.3º to 0,5º of difference for every linear meter.
How does it work?
Blades will spin in the opposite direction, sucking up the air. This increases the air speed that moves up, hitting the ceiling and bouncing back along the walls of the room.
while climbing, air gets cooler, increasing density and making it bounce down even faster, warming up and then repeting the process. Now this cycle has started.
So, what's the difference between a ceiling fan and an air destratifier?
To be considered an air destratifier, a ceiling fan must meet certain requirements:
1) Low power usage. Because air destratifiers never stop, first speed must be 10 watts or less.
2) Winter-summer mode accesible from the remote control. Some ceiling fans have a switch on the body itself, so some situations like tall ceilings, then it can be almost impossible to reach.
3) They must be compatible with at least 100 cm downrod extensions. Some brands can reach up to 180cm. This allows them to get closer to the ground, increasing efficiency both in summer and winter.
Finally, there are also super air destratifiers, these are products designed to primarily be destrafiers, not ceiling fans. For example, Modulo by KlassFan, BigCoolEco or Genuino by Casafan.