There are several different systems available for heating high halls (heights exceeding 4m). With warm-air systems that feature a relatively low air-flow rate, warm air rises to the roof (convection) and accumulates there. Simply replenishing this warm layer is a very slow process for heating the lower regions of a hall. By using fans, the warm air can be forced downwards to reduce the temperature difference between the ceiling and the floor (the vertical temperature gradient). Consequently, the fan leads to more efficient use of thermal energy. Furthermore, heating times are shorter, as the fans circulate the air within the hall (higher air-change rate).
The operating principle of this fan is very similar to a radial compressor, in which air is drawn in from above and below and exits to the side. The air inflow from above is particularly crucial, as it introduces the warm air layers beneath the hall ceiling into the general air circulation. The resulting mixture of warm and cold air leads to a reduction in the vertical temperature gradient. The velocity of the air blown out laterally is very low near the floor. This prevents any noticeable draught in that area.
To improve heating in particularly large halls with a very low heat demand, FlowMotion has optimised the design to ensure an even greater air transport. The following boundary conditions were of essential importance during the optimisation process: the concept remains unchanged, and no higher electrical power for the motor is required.
Special attention was paid in this project to the aerodynamic shaping of the fan blades. As a result, 50% more effective air volume flow was achieved with only 6 blades (compared to 9 blades in the original design) for the same electrical power consumption.
