Characteristics; Large airflow rate, slow revolution speed To supply large wind volume with very low revolution rate Distinctions for other fans; Diameter 2.4m-7.3m Design and engineering; the special fan blades Strengths; To be silent, be efficient, without high speed airflow and noise Almost maintenance-free(available for examination/hour) low cost; To decrease the influence of the air when frequently door opened and closed To supply a stable and average temperature between ceiling and floor, wall to wall To the most extent, cutting the costed pipe engineering for warming and air condition Uniqueness of blades With the Whale Patent technology, in the same diameter, lager airflowrate is captured