It is cheaper to buy from Beijing Fangshan building materials wholesale market. If you buy materials related to decoration, whether it is water supply pipes or drainage pipes, etc., it is recommended not to go to the store to buy it. It is more expensive to buy it in store. go to the wholesale market to buy it. You can say you do it yourself. After decoration, you can buy it long after using it. In this case, you can get the wholesale price from the price. .
Please provide detailed calculation methods for kitchen exhaust fans! ! ! Satisfied high scores added!
Is it possible to install an air curtain in an open kitchen?
I always had trouble knowing if the kitchen should be open. For some reasons, I finally decided that the kitchen should be open, but I was still afraid of the problem ofes oil vapors in the future. I heard a designer suggest I consider installing an open door kitchen. The air curtain machine can isolate the oil vapors, but my chief designer said it's not necessary. I would like to ask an expert if it is worth installing one. air curtain machine.
How to manage oil vapors in an open kitchen? Generally speaking, oil vapors in the kitchen are sucked in by the kitchen hood. The problem in the open kitchen is knowing what to do. do with the part of the oil vapors that the hood does not absorb and escape into the living room. At that time, it is usually installed on the suspended ceiling. Exhaust fans with air volume tend to collect on the ceiling as hot air circulates. upwards. You can install an exhaust fan with a large air volume inside the ceiling to exhaust the petrole and gas escaping from the kitchen. Next, install an air curtain in the kitchen to insulate it. the air curtain machine will form an air curtain by isolating the air on both sides. The air in this air curtain is drawn from the indoor air. It is also possible that the oil smoke generated in the kitchen is formed in the air curtain. Come on, so the key to exhausting combustion gases in the kitchen is the cooperation of a hood with sufficient exhaust air volume and an exhaust fan.
In addition, habits cooking are also very important. The method usually involves using a frying pan. Adding dishes and stir-frying will produce a relatively large amount of smoke. The current method is to heat the pan, add dishes, add oil, cover, remove from pan and add ingredients. Generally no smoke is produced. Of course it will be the same as a stir-frytraditional. There is some difference in taste, but the nutrition is not affected. Jing electromechanical technology engineers do not recommend adding air curtains to separate the kitchen. It is useless and the effect is not good
Check the table: The air exchange rate per square meter of a commercial kitchen is 60 m3 /h, it's too late, I'll do it; go into detail tomorrow...
1. Calculate the air renewal rate necessary for the kitchen (m3/h):
Q=kitchen area The smoke volume requirements are calculated strictly based on the speed of the inhaling wind from the extractor hood. The inspiration wind speed of the hood is generally not less than 0.5 m/s. The minimum exhaust volume is usually calculated using the following formula: L=2000PH
Where: L - the exhaust volume of the extractor hood, m3/h;
P - the circumference of the hood (against thewall) Sides are not counted), m; H—the distance from the mouth of the lid to the mouth of the stove, m.Use the above formula to calculate the volume of air discharged, and then calculate the air suction speed of the mask mouth based on the area of the mask mouth to ensure that the suction speed of the mask mouth is not less than 0.5 m/s. .
In actual engineering design, the estimation method is often used. In accordance with the provisions on the kitchen ventilation volume in the "Technical Measures for HVAC Design for Civil Buildings", the kitchen ventilation volume can also be determined accordingly. at the following number of air changes:
Chinese cuisine: L=40-50 (times/h);
Western cuisine: L=30-40 (times/h) ;
Staff restaurant: L=25-35 (times/hour).
The “side against the wall is not counted” mentioned here means that theside of the extractor hood against the wall forms a closed space with the wall. No air is added to the side of the extractor hood, only air is added. added vertically upwards, so the calculation does not need to calculate the length of the side against the wall.
3. Calculate the total air volume (m3/h):
Total Q = 1.1×(the volume of air required in the kitchen + the volume of air required by the stove extractor hood )
4. Calculate the pipe diameter (m):
D=√{(Q total×4)/(wind speed×3.14×3600)
5. Calculate the resistance of pipes and elbows (Pa):
H=RL
R=(λ/D)(V^2γ/2)
H-total resistance; R -pipeline friction resistance; pipe length in L m; V-wind speed m/s; γ-air density kg/m3
6. /p>
Fan air volume>Total Q
Fan pressure>H