How to calculate the flow of a vortex fan
The selection of fans, especially vortex fans, is difficult for general customers. The main reason is that the unit of the vortex fan is complicated, and the calculation of pressure and flow parameters need to be considered. Here we will briefly explain how to calculate the flow of the fan. First, the unit of volume flow usually has ___m ^ 3 cm per second; ___ m ^ 3 cm per minute; ___ m ^ 3 cm per hour; ___ 立 L / Sec per second Or ___ cubic 呎 cfm per minute. Second, the public and English two calculation units 3. The order of air volume, wind speed and cross-sectional area of ​​the pipeline in the pipeline is calculated by the following formula: In air conditioning projects, use cfm, fpm in English, for example: In the fan catalogue, the fan nameplate is marked with cmm, and in the design calculation, cms is used. For budget or quotation, even if the metric system is used, if the number is too small, the unit of calculation per minute will be changed to the unit of calculation per hour; or if it is changed to English units, the number will change and become larger. If it is considered to be idiom, it is better to say that it is a commercial. Or (in English, it is marked by cfm).
1. Metric ___m3/sec=____cms, ____m3/min=____cmm,
____m3/hr=____cmh. (ie 1m3 / hr = 1cmh).
____cms×60=____cmm, cmm×60=____cmh.
____cmh÷60=____cmm, cmm÷60=____cms.
1mmAq=10Pa 1KPa=1000Pa=100mmAq=4′′Wg
2. Inch 1cmm = 35.32cfm; 1m = 3.28ft × 60 = 196.8fpm; fps. (ie one cubic meter per minute, equal to 35.32 cubic feet per minute, 呎 per second.)
And 1m3/Sec=1000L/Sec, 1L/Sec=2.120cfm.
Formula: Q=V×A
* According to the demand air volume: Q air volume ____cms is calculated in cubic meters per second;
Types and brands are often used ____cmm, cmh, in cubic meters per minute or hour.
* Secondly select the wind speed: v wind speed ____m/sec, how many meters per second; ____ unchanged.
* Finally calculate the cross-sectional area of ​​the duct: A suction port area m2; or tube cross-sectional area (net area) ____m2
In the calculation: using metric Q: ____cms, A: ____m2, V: ____m / S, is a metric unit.
Inch system: ____cfm, A:____ft2, V:____fpm, in English units.
According to the selection of the fan type (Manual) is the metric system is calculated in metric units: Q, V is calculated in per second,
Air volume ____cms, wind speed ____m/S, static pressure Ps____mmAq, or ____Pa, cross-sectional area ____m2; English system is used in English, Q, V is calculated per minute, air volume ____cfm, wind speed ____fpm, static pressure Ps____in, The cross-sectional area is ____ft2. The public and English systems cannot be mixed.
Otherwise the result will not end.
Air volume: 400cfm, 600cfm, 800cfm, 1000cfm, 1200cfm is an integer, which is the unit of calculation;
Wind speed: 100cfm, 200cfm, or 1000cfm, 2000cfm, 3000cfm...etc.
Especially for smaller numbers, it is easier to remember and explain in integers.
If you switch to the metric system, it will be much more fragmented. E.g:
Air volume: 400 Cfm ÷ 35.32 = 11.35 cm; 600 cfm ÷ 35.32 = 16.987 cmm.
The wind speed is calculated in seconds: 100fpm÷3.28÷60=30.48÷60=0.508m/S;
1000fpm÷3.28÷60=304.8÷60=5.08m/S.
Such as: 30cmm × 60 = 1800cmh; 60cmm × 60 = 3600cmh. 60 times the 1800's 30.
30cmm × 35.32cfm = 1059.6 small 1060cfm. 1060 is 30.32 times larger than 30.
In order to be easy to use, the introduction of the metric and imperial methods must be memorized in order to be successful.
When testing the fan, it should be done under standard conditions. Namely: 20 ° C, 760 mmHg, 75% RH, density 1.2 kg / m3, in the case of testing. Currently in China, it has not been implemented so seriously, only for general air testing. The above-mentioned specific gravity is 1.2kg/m3, which is not a serious problem for partial smoke exhaustion; however, temperature, humidity, pressure, and standard state are significantly different. If the temperature exceeds 40 °C, it should be used in this state. The ratio of the weight of the air below. In normal air, more or less air containing different qualities of gas, dust, steam or smoke is still considered uncontaminated air in the test standard. Unless otherwise required for dust-free air, it is otherwise recognized.