The design of a cleanroom is of utmost importance. These sensitive environments need a lot of consideration when you delve into the design process. However, designing a cleanroom is possible with careful planning and a logical layout. You will need to match the stringent environmental conditions that cleanrooms require, as well as factor in human workflow and material pathways. Here are a few considerations in cleanroom design.
Consider People/Material Flow
Cleanrooms need to operate in a smooth, seamless, and logical manner for the utmost efficiency. In addition, you will need to set up checkpoints to reduce contamination in this space. In order to accomplish this flow in your workplace, you will need to evaluate how people and materials pass through the cleanroom.
In the spaces where the most critical processes take place, make sure to isolate them from personnel access doors or any pathways. You should only have a single entrance in these rooms to reduce contamination from people or objects passing through. Less critical processes may take place in the rooms that have higher traffic and multiple entrances.
Understand Your Class and Regulation Standards
In order to effectively construct your cleanroom, you need to know what regulations you must comply with in your design. Knowing your classification will provide your cleanliness and particulate standards. While you should verify your class with the Institute of Environmental Science and Technology (IEST), here are a few examples of common industry classifications:
- SMT Assembly cleanrooms are usually ISO Class 7-8
- Medical device packaging cleanrooms are also ISO Class 7-8
- Semiconductor cleanrooms are usually Class 5
- Assembly of touch screen membranes are usually ISO Class 7
Consider Your Space Supply Airflow and Pressurization
When it comes to cleanliness, determining your supply airflow and pressurization is a very important factor. You will need to maintain appropriate pressurization between different areas of your cleanroom to avoid cross-contamination. Determine the pressurization needs of each room plus your ISO classification to come up with your air pressure plan.
Different classifications have different air change rates, which apply to air filtration and cycling through your space. Your air change rate will change based on your occupancy, traffic, and particle generating processes, among other factors. You will need to evaluate your specific cleanroom application to determine your air change rate and adjust your airflow accordingly.
Lay Out Your Mechanical System
Next, you can begin placing your equipment around different areas of your cleanroom. Consider how people move through your space and where it makes the most sense to place certain equipment. You will also need to consider your cleanliness classification, process requirements, energy cost, and building codes in creating your layout.
Choose Cleanroom-Approved Furniture
Now that you’ve designed the layout and the flow of your cleanroom, you will need to consider cleanroom supplies such as furniture and apparel in the space. Purchasing stainless steel tables and cleanroom approved chairs is a must for critical environments. In addition, personnel should be protected with critical gowning apparel such as facemasks, gloves, cleanroom frocks and booties.
Consider HVAC Needs and Other Variables
You will also need to determine what your heating and cooling needs for your cleanroom are. Consider the most conservative climate conditions, filtration, and different sources of heat when performing your calculations: humidifier heat, recirculation fan heat, process load, and filtration.
You should also consider how the following factors will impact your cleanroom activities, and take steps to remedy them:
- Noise levels and vibration
- Electrostatic discharge – consider cleanroom ESD table mats.
With these steps in place, you should have the perfect design for maximum efficiency and compliance in your cleanroom.