2005 Volume 33 Issue 10 Pages 622-628
In recent years the fan heater used for industry and residence has become smaller, lighter, and more silent as the result of improvement. However there are problems that the fan heater size is very large, and the noise is very high due to air pressure loss of heat exchangers. Therefore we have been developing the centrifugal type fan with the function of heat exchanger. The features of this new type fan heater are that the fan heater size is very small and silent because the fan and the heat exchanger are in one body. This paper described the effects of number of fan blades on fan performance and noise characteristics of the centrifugal fan with the function of heat exchanger. The fan performance and noise characteristics of the fan having different number of blades (number of blades: 12,20,28) were clarified by measuring fan performance, fan noise spectrum and 3-dimensional flow velocity of fan outlet. In results, the fan static pressure decreased with the increase of number of fan blades at high flow rate region, and the noise of fan with blades number of 20 was the highest.
