Number of views: 3584 Author: Aili Industry Release time: 2026-09-28 Source: Ai Li Industrial
Direct answer: The fan box is mainly used to provide air supply and exhaust power to the air duct or equipment, so that the air flow can overcome the resistance formed by the air duct, valves, elbows, filter sections and terminal devices. It is not a universal air treatment device, nor does it directly determine the air cleanliness level. The key to judging whether a fan chassis is suitable depends on its location in the system, the medium being transported, and how much resistance it needs to overcome.
Aili Industry is discussingWhen using a fan box , we usually ask three questions: Is this equipment installed in the air supply section or the exhaust section? Does it serve general ventilation, air conditioning systems or clean areas? What are the design air volume and external static pressure respectively? If these three issues are not clear, there will be no common basis for subsequent selection.
The fan box usually plays three roles in the ventilation and air conditioning system.
Air supply power. Provides pressure for air supply to air conditioning boxes, duct systems, clean rooms or equipment. After the air passes through the filter section, coil, muffler and air duct, it still needs sufficient pressure to be sent to the end. In this case, the working point of the fan box should be inferred based on the end demand, rather than just looking at the maximum air volume on the fan sample.
Exhaust power. Send the air in the designated area into the exhaust duct and exhaust it outdoors or for centralized treatment. The exhaust system may deliver normal indoor air, or it may deliver dusty, corrosive or high-temperature gases. Depending on the medium, the box material, motor protection and control protection requirements will all change.
Boost or circulate. Connected in series in the air duct to make up for the lack of pipeline resistance or maintain the pressure difference between areas. This type of use is common in renovation projects. When the original fan pressure is not enough and you do not want to replace the entire system, you can add a booster fan box at a suitable location. However, the boost position and air volume must be recalculated and cannot be connected in series at will.
For the same fan box, the air supply and exhaust requirements may be very different. The air supply system pays more attention to the terminal air volume, filter resistance, noise and air supply temperature; the exhaust system pays more attention to the air medium, dust content, corrosivity, explosion-proof requirements and emission paths; the clean room air supply and exhaust also pays attention to the room pressure difference, sealing level and filter replacement method.
It is a common mistake to copy the air supply plan directly to the exhaust system. The air supply fan box may be designed for ordinary indoor air, and the anti-corrosion and motor protection levels of the box and motor are not high; if used to discharge corrosive gases, the box will soon rust, and the motor may also malfunction due to poor heat dissipation or insufficient electrical protection. Conversely, the structure of the exhaust fan box is not necessarily suitable for clean air supply.
The fan box is responsible for providing power and does not directly define the air cleanliness level. If the clean project requires terminal filtration, it should be determined separately.High-efficiency air supply vents orThe location, sealing and replacement methods of HEPA/ULPA high-efficiency filters , and filter resistance should be factored into fan box selection. If the process has higher requirements for particulate matter control, it can also be evaluatedDoes the ULPA ultra-high efficiency filter meet the requirements?
When the top of the equipment needs to be partially filtered for air supply,The FFU fan filter unit is another structural solution that combines a fan and a high-efficiency filter with its own power and modular installation. When multiple FFUs need centralized management, they can be matchedThe FFU computer group control system realizes zone speed regulation and status monitoring. If the core requirement is to protect the machine microenvironment of a single process equipment,Equipment-end fan filter units (EFU) may be more suitable in terms of size and installation method.
When discussing fan box applications, at least the following information should be clear:
Supply air or exhaust air, where should it be installed in the system?
Design air volume and corresponding external static pressure
Air medium, temperature, humidity and dust content
Are there corrosive, flammable or explosion-proof requirements?
Continuous running time and control method
Air outlet direction, installation space and maintenance conditions
Whether there is a filter or other resistance component at the end of the system
Only by knowing the position of the fan box in the entire air path can the box structure, fan curve and maintenance direction be determined. Two devices with similar standard appearance may have completely different air volume and pressure requirements.
If a fan box is installed before the filter section, its task is to ensure that after the air passes through the filter section, the required air volume can still be obtained at the end. As dust accumulates on the filter, the resistance increases, and the fan operating point will move in the direction of small air volume. When selecting, the pressure difference allowed before maintenance must be calculated, otherwise the terminal air volume may be insufficient after running for a period of time.
If the same Typhoon chassis is installed on the exhaust branch, the type should be reselected according to the exhaust medium and pipeline resistance. The exhaust duct may contain dust or corrosive components, and the box material and motor protection requirements are different from those of the air supply system. The appearance of the two seems to be similar, but the air supply scheme cannot be copied to the exhaust system.
Aili Industrial can check the fan, motor, control and box structure at the same working point. CheckWhen submitting the fan box product catalog , it is recommended to provide system diagram, air volume, external static pressure and air medium description at the same time. Two devices with similar standard appearance may have completely different air volume and pressure requirements. First confirm the purpose and system resistance, and then discuss the box form and control method, so that the equipment can truly meet the usage requirements after being installed.
