How to determine the installation position of the fan box? Taking into account air path, maintenance and measurement

I have seen many projects where there was no problem with the equipment selection and the performance was up to standard, but the installation location was not chosen correctly, causing constant trouble later on. Some fan boxes are installed in the corner, and the access door cannot be opened. To change the filter, half of the air duct must be removed. Some are installed next to sensitive areas, causing constant complaints about noise and vibration. In some cases, it was discovered after installation that the pressure measuring hole was blocked by the air duct, and the data could not be measured during debugging.

The installation location is not 'put it wherever there is space'. It must meet several conditions of air path, maintenance, noise, electrical and measurement at the same time. These conditions are sometimes contradictory and need to be weighed.

The wind path should be as smooth as possible

The air inlet and outlet of the fan box have requirements for air flow conditions. If there are sharp bends, obstructions, or sudden changes in diameter near the air inlet, the incoming flow will be uneven, the fan performance will be affected, and the noise will also increase. If the air outlet is directly connected to a sharp turn, the local resistance will increase and the air volume will decrease.

When selecting the location, consider the direction of the air duct and try to have a straight section of pipe before and after the air inlet and outlet. There is no fixed standard for the length of straight pipes. It is generally recommended to leave a straight pipe section of at least one pipe diameter on the air inlet side and at least one and a half pipe diameters on the air outlet side. If the on-site conditions are really not feasible, avoid directly connecting the elbow at the most unfavorable position.

In some projects, in order to save space, the fan box is placed against the wall, and the air inlet is only a few dozen centimeters away from the wall. In this case, the air inlet resistance increases, and the actual air volume of the fan may be much lower than the sample data. If you calculate based on ideal conditions when selecting a model, the air volume will be insufficient when installed.

Inspection channels should be reserved according to actions

This is the most easily overlooked item. Just because the equipment can be placed in the computer room does not mean it can be maintained.

The maintenance space cannot be summarized by 'how many meters should be left around'. It needs to be dismantled according to specific actions: How much rotation space is needed to open the access door? How much linear space is required to extract the motor? From which direction do I need to operate the filter replacement? Where do people need to stand when wiring the drive?

Each of these actions requires different space and may be in different directions. Access doors may be side-opening, requiring side space. The motor may be axially withdrawn, requiring straight space ahead. The filter may be drawn from the top and require overhead clearance.

On the construction drawings, the opening arc of the access door, the direction in which components are drawn out, and the operating positions of personnel should be marked. Then superimpose the positions of beams, columns, bridges, water pipes, fire protection facilities and other equipment to see if there are any conflicts. Some projects look fine on the drawings, but during actual construction the bridge frame is installed first and the access door is blocked.

Changes in location can have ripple effects

Sometimes the installation location is adjusted midway through the project. For example, it was originally planned to be installed on the floor, but later changed to hoisting; or it was moved from computer room A to computer room B. This kind of adjustment is not just about changing the place to put the equipment, it will bring about a series of knock-on effects.

If the hoisting is changed to the ground, the load-bearing requirements of the foundation will change, and the vibration reduction method may also need to be changed. When moving from a large computer room to a small computer room, there may not be enough space for maintenance. Moving from non-sensitive areas next to sensitive areas, noise and vibration control requirements may increase. When moving from indoors to outdoors, the protection level and rainproof measures must be reconfirmed.

Modifications to the installation location should be reviewed by HVAC, Structural and Electrical together. The direction of the air duct, basic conditions, vibration reduction methods, power access, and control cable paths must all be adjusted accordingly. You can’t just let the movers move the equipment and leave everything else unchanged.

Measuring points must be reserved in advance

Both debugging and later troubleshooting require measurement of air volume, static pressure and pressure difference. If these measuring points are blocked by air ducts, or the installation location is inconvenient for operation, it will be very troublesome later.

Pressure measuring holes and air volume measurement sections should be reserved during the design stage. The position of the pressure measuring hole should be away from elbows, reducers and air valves, and should be selected on a straight pipe section with stable air flow. The air volume measurement section also requires sufficient straight pipe length, otherwise the reading deviation will be large.

If the project uses differential pressure control, the sensor location must be confirmed in advance. Whether the sensor is installed at the fan outlet, before or after the filter section, or at the farthest end, the control effect is completely different. Installed in the wrong location, the controller may be constantly chasing erratic readings, with the RPM fluctuating back and forth.

Noise and vibration transmission to be assessed

The fan box makes noise and vibration when running. When near offices, conference rooms, clean rooms, or precision equipment, location selection should consider the transmission paths of noise and vibration.

Noise can travel through the air or through structures. Airborne noise is dealt with by mufflers and soundproof enclosures. Structure-borne vibrations are dealt with by dampers and soft connections. However, vibration reduction and noise reduction cannot replace reasonable air path layout. If the direction of the air duct itself is unreasonable, with many bends and high wind speeds, the noise source will be there, and there will be a limit to how many mufflers you can add behind it.

When selecting the location, try to keep the fan box away from sensitive areas. If it cannot be kept away, treatment must be done on the air duct and foundation. The selection of the shock absorber and the length of the soft connection should be determined based on the weight, rotation speed and basic conditions of the equipment. You cannot just choose one and install it.

Confirm the installation conditions from the overall machine structure

The final confirmation of the installation location must go back to the structure of the equipment itself. The direction of the air inlet and outlet, the location of the access door, the orientation of the electric control box, the location of the foundation holes, and the lifting points are all on the equipment diagram. After the installation location is determined, these conditions should be checked with the site one by one.

Aili Industry has independent supporting capabilities in fans, motors, controls and sheet metal structures. It can adjust the direction of the air outlet, the position of the inspection surface and the orientation of the control box according to the installation space and inspection conditions of the project site. This kind of internal collaboration from the overall machine structure to the installation conditions can reduce on-site rework caused by incorrect orientation and mismatched interfaces after the equipment arrives at the site. The project only needs to provide machine room drawings, available space and maintenance requirements, and the equipment drawings can be confirmed before manufacturing.

System end configurationFor HEPA/ULPA high-efficiency filters , the filter replacement path should also be included in the location assessment. When the process requirements are higher, it can be evaluatedDoes the ULPA ultra-high efficiency filter meet the requirements? Clean room ceiling air supply is comparableFFU fan filter unit ; centralized management of multiple devices can be matchedThe FFU computer group control system realizes zone speed regulation and status monitoring. Protection of single process equipment can be consideredEquipment-side fan filter unit (EFU) . The final filtered air supply at the end of the air duct can beHigh-efficiency air supply outlet (HEPA BOX)。

Specific structure and configuration options can be found inIt is confirmed in the fan box product catalog that non-standard projects should provide equipment or machine room drawings, and then shape them based on the determined working points and on-site interfaces.