A cooling fan air volume, air pressure and PQ curve
release date: 2016 - 05 - 16
chi car is a set research and development, production, sales in the integration of a cooling fan manufacturers, we work on a cooling fan industry more than 10 years, brand fan belongs to the first-line brand in China. Under general chi car will simply explain the cooling fan air volume and air pressure and PQ curve of related knowledge.
refers to the cooling fan air volume fan out or inhaled air volume per minute. Is CFM fan products often use air unit, is the cubic feet per minute ( 每分钟立方英尺) 。
in the case of the same cooling principle and material, air flow is the most important indicators of cooling capacity. In simple terms, the greater the volume of the fan is the higher cooling capacity. This is because the heat capacity of air is certain, larger volume, per unit time is more air can take more heat.
wind pressure of the cooling fan is known as static pressure ( 静态压力) , refers to the fan blow out on the inlet side and the pressure difference, usually use the unit for mm water column height ( mmH2O) High water (or inch inchH2O) 。
wind pressure airflow specifications and features of the cooling fan, mainly according to the Air Movement and Control Association ( AMCA) No. 210 - 85 'the Laboratory Method of Testing Fans for Rating' test specification. Characteristic curve, and its volume is generally known as PQ curve. ( As shown in the figure below)
the PQ curve, general with three physical value to describe it:
( 1) Pmax: when the air volume of 0, fixed volume in a confined space state, the maximum static pressure of the fan.
( 2) Qmax: when the fan inlet and exit the flow rate of the two ends when the pressure difference of 0 is the maximum flow of the fan.
( 3) PQ value: for the fan inlet and outlet two-terminal pressure difference and the corresponding value of the state of flow Q at that time.
the size of the cooling fan once decided, corresponding to every single voltage or speed, under different wind flow, measuring the pressure value, you can draw a pictured above PQ curve, and the curve can be used to describe the characteristics of the fan, so called the fan characteristic curve.