Systemair Revolution Vector Silenced EC FanOverview The SystemAir Revolution Vector Silenced EC Fan was designed to generate huge pressure levels, to use less energy and to offer increased control. With this product, you'll move huge masses of air silently and with low energy consumption. The unit is built to ensure high levels of efficiency and effectiveness. With no humming or vibration, even at low speeds, the product is almost indestructible. The motor doesn't overheat, and the body