low noise negative pressure exhaust fan,negative pressure ventilation fan,ventilation 1.Description of product: modelhousing materialfan blades materialmotor rotate speed(r/min)fan rotate speed(r/min)airflow(m3/h)air pressure(pa)effective area(m2)blowing distance(m)HNF-54''(6 blades beltless)FRPstainless steel/aluminum450(12-pole motor)45045000190100-12080-100rataed voltage(v)current(A)power(kw)frequency(hz)driving modeouter sizeweight(kg)noise dB(A)/3805.51.150beltless driving1480*1480*850mm7068/ 2.Product features: a)Based on the original design of n-pressure ventilating fn,Komeida triumphantly developed negative pressure horn-type ventilating fan.Low noise,even running,huge wind flow and discharge air more far distances are the strength of this products. b)Horn-type n-pressure ventilating fan use high quality home-made motor. It can work under wicked environment for long working life,suitable for all kind of indusrial environments.(matching explosion-proof motor for choice.) c)The concenric circles of the base is processed by CNC machine and setled by bearing, so it runs very low noise. d)The shutter is designed according to air pressure theory,can open or shut down without power or manual,protect against water intrusion. e)To reduce the metal resonance,the surface of whole product body are used FRP material which is acidoresistant and antlkaline,corrosion-proof and long service life.