Clean Room Perforated Raised Floor
01 June 2021

Clean Room Perforated Raised Floor

Perforated raised floors are often used in clean rooms, computer rooms, data centers, large high-end offices, and spaces that require good ventilation. The perforated raised floor is designed to provide excellent cooling to manage the heat load in mission-critical facilities. However, if you want to optimize the ventilation of the perforated raised floor and create the most efficient air conditioning system (UFAD - Under Floor Air Distribution) for the space, it is necessary to properly and correctly lay the perforated raised floor, which also includes selecting the right raised floor perforated tiles according to different environmental needs.

Perforated Raised Floor Installation Plan For Clean Room

How to properly install perforated raised floors in clean room to ensure an optimal UFAD air conditioning system? Regarding the layout of perforated raised floor tiles for clean room, we generally consider the following steps to install and lay access floors:

CFD (Computational Fluid Dynamics) Calculation

The owner is required to provide the relevant parameters of the production machine (such as the external dimensions, self-contained FFU, etc.) to obtain a more accurate airflow condition in the future.

Model establishment mainly includes building size, return air distribution and production equipment model. Boundary conditions mainly include FFU (Fan Filter Unit), perforated tile characteristics and obstacles.

By studying the airflow offset of each zone, the partition adjusts the floor resistance characteristics to form the vertical unidirectional flow required for the cleanroom.

Before the construction, anticipate the possible local airflow deviation, turbulence and even cross-contamination in the future, and take corresponding preventive measures.

Secondary Adjustment Plan

1. Cleanroom Large Ambient Airflow Offset

1) According to the ventilation pressure loss curve data of the raised floor manufacturer, calculate the ventilation capacity of the raised access floor with different opening ratios of the raised floor air pressure difference of about 5PA. The open floor opening rate is generally 17%, 25%, 50%, can be calculated with a 17% airflow rate as a base, then one 50% perforated panel or two 25% perforated tiles is equivalent to three perforated tiles’ ventilation with 17% airflow rate;


  • 17% airflow rate, 5PA pressure difference, floor surface wind speed 0.45m/s ventilation 583.2m3 / h
  • 25% airflow rate, 5PA pressure difference 5PA, floor surface wind speed 0.65m/s ventilation 842.4m3/h
  • 50% airflow rate, 5PA pressure difference, floor surface wind speed 1.25m/s ventilation 1,620m3/h

2) Then calculate an FFU equivalent to a few 17% of the raised floor, generally, we calculate how many 17% raised floor is needed, according to 1200 * 1200 FFU equivalent to four 17% raised floor;


  • ISO 6 level area can be interchanged with 17%, 25%, 50%
  • ISO 5 level area can use 17% or 25% + Damper
  • ISO 3 Level area can use 17%

3) According to the direction of the airflow in the lower mezzanine, the pressure gradient generated by the distance from the return air is different, and the pressure conditions in the lower mezzanine are different. The underfloor ventilation amount of each raised floor is different from the ideal condition and is selected according to the analysis and calculation. Install the perforated panels near the return air duct area - some air dampers.

2. Micro-Environment Airflow Offset

Use 25% and 50% perforated access floor tiles to supplement depending on the area of the independent abutment airflow;

In the ROBOT area, because the internal cleanliness level is as high as Class 10, it is generally recommended that the area be filled with perforated tiles to avoid turbulence.

Example: 17% for ISO level zones

For the STOCKER area, because the FFU is installed on the sidewall of the equipment, the FFU air volume in the workshop will be drawn. Therefore, the raised floor perforated panel layout should reduce the FFU air volume installed on the STOCKER side wall;

Even under the base of the Stocker equipment, even if it is full of 17% airflow plane, it cannot meet the airflow control requirements. It can be changed to 25%+Damper for forced ventilation to obtain a better vertical airflow unidirectional flow pattern.

If you are planning a raised floor solution for clean room, welcome to contact AccessFloorStore.Com, we have the high-quality Perforated Raised Floor Tiles and Anti-Static Access Floor Panels for cleanroom, computer room, data center!