What preparations need to be completed before clean room acceptance?

Clean room acceptance does not end after measuring a few points on site. Whether the test results are valid depends largely on the preparation before acceptance. Construction residue, unstable air volume, uncalibrated instruments, and unclear test status will all make the data lose its representativeness.

The core of preparation before acceptance is to establish repeatable test conditions: the system is running stably, the environment is cleaned, the instrument status is confirmed, and the evaluation scope is clear. The following will start from the aspects of construction cleaning, operation and debugging, instrument preparation, and test planning.

Construction cleanliness is a prerequisite for acceptance

Cleanrooms generate large amounts of dust, debris and residue during construction and installation. If these contaminations are not cleaned, they will directly affect the particle detection results and mask the performance of the system itself.

Before acceptance, the following should be completed:

• Cleaning and removal of construction waste;

• Wiping and cleaning of walls, floors, ceilings and equipment;

• Surface cleaning of return air inlets and filters;

• Installation and sealing inspection of high efficiency filter.

When cleaning is incomplete, measured particle concentrations may reflect primarily construction residues rather than system capabilities. Specific cleaning requirements can be implemented according to project regulations, and the cleaning records should be confirmed to be complete before acceptance.

Operation debugging and air volume stability

Before acceptance, the debugging of the air supply, return air, exhaust and air conditioning systems needs to be completed to confirm that the air volume, pressure difference, temperature and humidity are in a stable state.

Things that need to be confirmed include:

• Whether the supply air volume and return air volume in each area reach the design value;

• Whether the direction and value of room pressure difference are stable;

• Whether the installation seal of the high-efficiency filter is intact;

• Whether the fan operating status and speed setting are stable;

• Whether the exhaust air and supplementary air are balanced.

When the air volume is not stable, the test results will lose repeatability due to system fluctuations. If the filter replacement or air volume adjustment has just been completed, wait until the system is stable before testing. For testing requirements after filter replacement, please refer to relevant specifications for confirmation.-5。

Instrument preparation and calibration

The status of instruments such as particle counters, anemometers, differential pressure meters, and temperature and humidity meters directly affects the reliability of measurement results.

Before acceptance, please confirm:

• The instrument is within the valid calibration period;

• The instrument range covers the target particle size and concentration range;

• The sampling flow rate and sampling time comply with the test plan;

• The instrument status is normal and there is no fault prompt.

Instrument calibration certificates and measurement records should be kept with the acceptance data. If the instrument is not calibrated or expired, the test data may not be recognized.

Clarify evaluation scope and test status

The test objects and status should be clarified before acceptance to avoid test results that do not correspond to the evaluation scope.

Things that need to be confirmed include:

• Evaluation area boundaries and area;

• Cleanliness level used and particle size measured;

• Whether the test state is empty, static or dynamic;

• Number and location of sampling points;

• Test items and sequence.

The cleanliness level must indicate the particle size and state. For specific reasons, please refer to Why must the particle size be indicated in the cleanliness grade? . The test status is different and the results cannot be directly compared.

Sampling plan and test sequence

The sampling plan and test sequence should be determined before acceptance to avoid omissions or duplications caused by temporary decisions on site.

The test sequence usually includes:

• Air volume and wind speed testing;

• Filter installation and leak detection;

• Differential pressure test;

• Particle concentration test;

• Perform airflow pattern testing and recovery testing when necessary.

If the particle test is done first and then the air volume is adjusted, the early data may be invalid. The test sequence should ensure that subsequent tests do not affect the results of completed tests.

On-site conditions and personnel coordination

The acceptance site needs to coordinate the construction party, equipment party, testing party and user party to ensure that the conditions are stable during the test.

Things that need to be confirmed include:

• Whether construction and cleaning operations are stopped during the test;

• Whether personnel access is controlled;

• Whether the equipment operating status meets the test requirements;

• Check whether there are clear procedures for test recording and exception handling.

Temporarily adjusting working conditions or temporarily turning on equipment will weaken the representativeness of the test. Test conditions should be agreed in advance in the acceptance plan.

Equipment selection and terminal matching

For the equipment and filtering configuration involved in acceptance preparation, please refer to FFU clean air supply products and EFU equipment side fan filter unit . Filter installation sealing and leak detection requirements can be learned HEPA and ULPA filters . If you are still unclear about the difference between space rating and filter efficiency, you can read What is the difference between cleanliness level and filtration efficiency?。

Project judgment example

In a certain project, a cleanliness test was conducted when the construction dust was not completely removed, and the result was that the particle concentration was high. The investigation found that the pollution mainly came from construction residues rather than insufficient system capacity. Adjustment method: Retest after completing cleaning and operation debugging, and the result returns to normal.

During the test of another project, the air volume was not yet stable and the data fluctuated greatly. Adjustment method: Wait for the system to run stably and the filter seal to be confirmed before retesting to improve data repeatability.

These two situations illustrate that the preparation work before acceptance directly affects the validity of the test results, and cleaning, debugging, instruments and planning need to be completed simultaneously.

Key points for selection and acceptance inspection

Aili industrial equipment supporting support

The quality of preparation before acceptance directly affects whether the test results are valid. Aili Industrial has collaborative capabilities in fans, motors, filters, control systems and complete machine assembly. It can cooperate to check air volume, pressure difference, filter sealing and operating status during the equipment installation and debugging stages, helping the project establish stable test conditions before acceptance and reducing repeated testing due to fluctuations in equipment status. Specific models can be viewed FFU clean air supply products , supporting equipment can be viewed EFU equipment end fan filter unit , please refer to the filter package. HEPA and ULPA filters。