How to design should the ventilation system of commercial buildings?

2022-11-29

How to design should the ventilation system of commercial buildings?

1. Shops and public areas

Large shops and department store areas generally use an independent all-air system, and the exhaust system is designed independently. The exhaust air volume is calculated as 80% of the fresh air volume. Select a fan.

The exhaust air of small shops and public areas is generally concentrated in the commercial atrium with exhaust vents, and fans are installed on the commercial roof, and the exhaust air volume is calculated as 80% of the total fresh air volume of the shops and public areas. If the public area air-conditioning system adopts an all-air system, the exhaust air volume in the air-conditioning season and transition season should also be calculated and selected according to the different fresh air volume or the number of fans turned on should be adjusted.

2. Dining kitchen area

The exhaust air volume in the catering kitchen area is generally calculated according to the number of air changes, and the height of the kitchen is considered as 3 meters; at the same time, the air supply and exhaust system are considered, and the air supply volume (generally 80% to 90% of the exhaust air volume) is slightly less The exhaust air volume is used to maintain a slight negative pressure in the room; the air supply system in the catering and cooking furnace area does not have pre-cooling in summer and no pre-heating in winter; considering accident ventilation, it is calculated based on the number of air changes 12 times/h.

ventilation system

3. Logistics area

Logistics areas such as garages, toilets, pantries, garbage rooms and unloading areas should be properly designed with ventilation systems.

The exhaust air volume of the toilet and garbage room is calculated according to the number of air changes 15 times/h, and the exhaust air volume of the pantry is calculated at 10 times/h. For projects with conditions in the garbage room, it is recommended to design a split air conditioner, and at the same time, the exhaust air is discharged after purification. The exhaust system of the garbage room is set up independently and adopts an independent shaft.

4. Equipment room

Equipment rooms such as pump room, refrigeration room, generator room, power distribution room and elevator machine room need to design ventilation systems according to different requirements.

The air volume of living pump room and fire pump room is calculated by the number of air changes 4-6 times/h, the air volume of waterscape pump room is calculated by the number of air changes 10 times/h, and the sewage pump room is generally calculated by the number of air changes 20 times/h (The specification requires 8 to 12 times/h) to calculate. At the same time, the air supply and exhaust system are designed. The air supply and exhaust volume of the living pump room, fire pump room and waterscape pump room are equal to the exhaust air volume. The air supply volume of the sewage pump room is calculated according to 80% to 90% of the exhaust air volume. The exhaust system of the sewage pump room needs to be set up independently and adopts an independent shaft.

Generally, the refrigeration host of large commercial buildings adopts fluorine refrigeration host, and the exhaust air volume of the refrigerating machine room is calculated according to the number of air changes per hour. In the refrigeration room using R134a refrigerant, the accident exhaust fan is controlled by the oxygen detector to exhaust the accident air; the air supply system is designed, and the air supply volume is equal to the exhaust air volume, that is, the zero-pressure design. Refrigeration rooms with open-type refrigerators require additional air conditioning cooling equipment.

The exhaust air volume of the generator room and the power transformation and distribution room is calculated according to the actual heat dissipation requirements of the equipment; when using gas to extinguish the fire, the exhaust air after the fire should be considered at the same time, generally calculated according to the number of air changes 5 times/h. The exhaust fan is selected according to the larger value of the two, and the air supply volume is calculated according to 80% to 90% of the exhaust air volume.

The exhaust air volume of the elevator machine room is calculated based on the number of air changes per hour. The exhaust fan is equipped with a temperature control device. The temperature in the machine room controls the start and stop of the exhaust fan, and the car door on each floor naturally enters the air. At the same time, a split air conditioner is designed to cool down.

hvac ventilation system