Do You Know the Difference Between Negative Pressure vs. Positive Pressure Cleanrooms?

Do You Know the Difference Between Negative Pressure vs. Positive Pressure Cleanrooms?

In today’s fast-paced world of technology, pressurized cleanrooms are being utilized in more and more industries and applications. Two main types of cleanrooms are negative pressure rooms and positive pressure rooms. 

The level of pressure determines the way air naturally moves in a space. High and low, or positive and negative, pressure can be used as tools in cleanroom environments to help cleanrooms reach their required classifications.

Negative Pressure vs. Positive Pressure Cleanrooms

Let’s dive deeper, learn the difference between negative pressure vs. positive pressure cleanrooms, and discover how they work. 

How Does Air Pressure in Cleanrooms Work?

Air naturally flows from areas of high pressure to areas of low pressure. Examples of this are found around us every day. For example, wind and weather are formed from the uneven heating of the earth’s surface, which generates pockets of high and low pressure air. 

Have you ever witnessed the sudden closing of a door as air is sucked out of a room even though there’s no breeze? This experience is high pressure air moving to a low pressure area to achieve stasis. 

Another example of this process is when air escapes from a balloon. The air travels from a high pressure environment to the relatively low pressure of the surrounding air. 

What happens in all of these situations is that when air is moving in one direction, it’s not moving in the opposite direction. When air is moving out of the balloon, air isn’t also moving into the balloon, as long as the air inside the balloon is more pressurized. 

This concept can be applied to cleanrooms to stop airflow into a cleanroom or out of it, limiting particle transfer via the air and maintaining a cleaner environment.

To put this as simply as possible:

Higher pressure air within a cleanroom (compared to the air outside the room) blocks contaminants from entering the cleanroom, as air naturally wants to flow out. Conversely, lower pressure air within a cleanroom can trap contaminants and prevent them from leaving a cleanroom, as the natural flow of air wants to move in. 

Using Positive and Negative Pressure in Cleanroom Design

Using pressure in cleanrooms, either high pressure (positive pressure) or low pressure (negative pressure), can benefit many cleanroom applications, but how do you implement it in the cleanroom design?

Cleanroom pressure is achieved by controlling how much air is put into the cleanroom and how much is withdrawn. 

In a positive pressure cleanroom, filtered air is consistently pumped into the room through the HEPA filtration and cleanroom HVAC system. If a door or window were opened in the cleanroom, air would rush out into the outside environment. This positive pressure ensures that the products and processes within the cleanroom are protected in the event of a breach or leak. Because the cleanroom has positive pressure, the air is forced out of the cleanroom, preventing contaminated or unfiltered air from seeping in. 

To achieve negative air pressure, external exhausts pull air from the cleanroom at a faster rate than air is introduced over a span of time. The resulting negative pressure means the air will want to flow into the cleanroom to fill the low pressure area, effectively stopping contaminants from going against that natural movement to escape the cleanroom.

To maintain positive or negative pressure in cleanrooms, adjacent spaces must be maintained at a lower or higher pressure than that of the cleanroom. If you implement a pressurization system into your cleanroom design, a pressure monitoring system is vital to ensure balance and consistency. The monitoring system will check and maintain consistent pressure, which can be adjusted manually or automatically.


High pressure, or positive pressure rooms are beneficial in applications where the slightest particle interference could disrupt processes within the cleanroom. 

Semiconductor cleanrooms, microprocessor cleanrooms, and aerospace and defense cleanrooms are examples of industries that benefit from positive pressure cleanrooms, as they are highly averse to contaminating particles. Medical cleanrooms also use positive pressure to protect sensitive patients and maintain a controlled space.

Even when the stakes aren’t as high, using slightly positive pressure in cleanrooms can help reach cleanroom classifications and maintain an overall cleaner environment.


Low pressure cleanrooms, or negative pressure rooms, are ideal for applications that need to isolate substances, particles, or fumes inside the cleanroom environment to protect the space outside. They are widely used in medical cleanrooms for research, testing, and the development of treatments using sensitive substances. 

Pharmaceutical applications also use negative pressure in cleanrooms as part of a segmented layout. One room is kept at a lower pressure, while the anteroom immediately outside is maintained at a slightly higher pressure. This allows employees to transition into the negative pressure room with minimized disruption.

Need Help Choosing the Right Cleanroom Pressure? Angstrom Technology Can Help

Using the natural air movement due to pressure, we can build safer, more effective cleanrooms. Positive and negative pressure cleanrooms can protect against entering contaminants (in positive pressure cleanrooms) or contaminant leakage (in negative pressure cleanrooms). 

Which cleanroom pressure best suits your needs? At Angstrom Technology, we’re here to guide you. Our dedicated cleanroom experts are ready to precisely tailor airflow patterns and containment solutions for your unique application. Get in touch with us today for expert assistance in creating the ideal cleanroom environment for your specific requirements.



Global Cleanroom Expertise: Capabilities

Global Cleanroom Expertise: Capabilities

As you may already know, the Angstrom Technology Group of market leading cleanroom companies in the US, UK, and Europe has capabilities to provide multinational services to our global clients. But what does this mean for our customers?

The stringent control of process variables is a global requirement for pharmaceutical, electronics, and biotech industries worldwide. Our cleanrooms support top-tier multinational organizations to increase quality at sites across the world.



Through in-house expertize and collaborations with specialist industry-partners, we can deliver facilities with precise requirements, such as battery dry rooms or cell and gene therapy suites.



When it comes to global operations, maintaining consistent quality standards is crucial. Angstrom Technology understands this well and no matter where you are in the world, we can deliver compliance to the applicable regulations. This commitment to quality gives you the reassurance that partnering with Angstrom Technology will result in reliable and high-performing solutions for your business.



In a fast-paced business environment, time is of the essence. Angstrom Technology’s global network of partners enable us to reduce shipping and installation times significantly. This streamlined approach translates into improved operational efficiency for your business, giving you a competitive edge.



By having a network of support teams strategically located across different regions, Angstrom Technology ensures that you receive personalized attention and timely assistance. This localized approach strengthens our commitment to customer satisfaction and builds long-lasting partnerships.



Angstrom Technology’s global capabilities enable them to optimize their supply chain and take advantage of economies of scale. This optimized approach allows them to offer competitive pricing without compromising on quality. By partnering with Angstrom Technology, you can access cost-effective contamination control.



With a multi-disciplined, in-house team of cleanroom experts, we have expansive industry experience, with applied knowledge and skills across the globe, such as our global regulatory governance team.




Capabilities - Global cleanroom customers



If your facility needs a new cleanroom, Angstrom Technology can design, build, and install one that meets your specifications. Using proven design strategies and quality build systems, you can trust that your work and employees will always be protected.

Request a cleanroom quote today, or contact our team for more information.

What are Semiconductor Cleanrooms?

What are Semiconductor Cleanrooms?

Semiconductor chips are used in every computerized device — from household objects like your cell phone or coffee maker to complex machines like vehicles, defense technology, or spacecraft. They’re produced using highly sensitive materials to create delicate layers that must be worked on with care. That’s why tasks like semiconductor chip manufacturing, testing, and packaging must be carried out in a controlled cleanroom environment.

Below, we explore more about semiconductor cleanrooms, including their common applications, classifications, and design features.

What are Semiconductor Cleanrooms?

Before we dive into the many specialized features of semiconductor cleanrooms, let’s back up and get a better understanding of what semiconductors are and why they must be handled within a cleanroom.

What Are Semiconductors?

Semiconductors are made using a glassy, solid material of pure silicon, which is shaped in a molten state and then cut into thin wafers. Semiconductors are prized for their special conductive behavior — which behaves both like a metal and an insulator — and are a vital ingredient for manufacturing computer chips and circuitry. A wafer is a substrate that’s used for the base in an integrated circuit, or chip.

Semiconductor chips are fragile materials. Even the slightest inconsistency can compromise their safety and effectiveness — and in turn, compromise the safety and effectiveness of the machines and equipment powered by those chips. That’s why semiconductor cleanrooms are important and why they must comply with strict standards to ensure total control over the chip manufacturing environment.

Boost to the Semiconductor Industry

In August 2022, the United States government passed the CHIPS and Science Act. This act was created with the intention to boost semiconductor chip manufacturing and bring more of it back to the U.S. rather than overseas. It authorized nearly $52 billion in government subsidies for U.S. semiconductor manufacturing and research, as well as an estimated $24 billion in investment tax credits for semiconductor chip manufacturers.

Needless to say, this act has impacted the nation’s semiconductor industry tenfold. Plants that once had to stall their semiconductor projects due to lack of funding and resources can now resume. Other semiconductor chip manufacturing companies are likely to expand their operations. In order to do that, they’ll need more cleanrooms.


Sound like you? Contact Angstrom Technology to get started on your semiconductor cleanroom project today. 


Semiconductor Cleanroom Applications

Semiconductors are used in many industries and applications. Whenever maintaining quality and purity in semiconductor chip manufacturing is crucial (which is all the time), a cleanroom is required. Some of the most common industries and applications that require semiconductor cleanrooms include:

Semiconductor Cleanroom Classifications

Semiconductor cleanrooms often run 24 hours per day due to our technologically inclined society’s demand for valuable circuitry components. Some of the most stringent cleanroom classifications must be maintained consistently throughout the chip manufacturing process.

In most cases, semiconductor cleanrooms must comply with ISO 14644-1 Class 4-6 requirements. This stipulates a maximum allowed particle count between 352-35,200 particles 0.5μm or smaller. They must also meet the requirements of ISO 14644-2, which imposes a quality control system in order to maintain these standards. However, not all processes require such stringent control. The packaging, assembly, and testing of manufactured wafers could be performed in ISO class 7 or ISO class 8 cleanrooms.

Depending on their unique application, semiconductor cleanrooms will also likely have to meet some industry-specific requirements, for example, ASTM standards for automotive applications and NASA standards for aerospace applications. These are usually complied with in addition to ISO standards to ensure that semiconductor cleanrooms are always controlled and that the chips that come out of them are of consistent quality.

Any drop below these stringent standards could lead to defects.



Semiconductor Cleanroom Design

Semiconductor cleanrooms require a robust cleanroom design that helps them reach and maintain strict cleanliness standards while also allowing for easy movement and workflow. Here are a few especially important semiconductor cleanroom design aspects to consider.

Operators & Operator Processes

Just like with any other type of cleanroom, the biggest threat to cleanliness and control in semiconductor cleanrooms is the people working within them. That’s why semiconductor cleanroom operators must be specially trained and outfitted to prevent contamination.

But this semiconductor-operator relationship goes both ways. Semiconductors and the processes that are needed to manufacture circuitry from them can be harmful to human health. Therefore, it’s important to design semiconductor cleanrooms in way that allows operators to complete tasks safely. Some semiconductor cleanrooms even have robotic equipment or special safety protocols in place to protect workers from radioactive processes, toxic chemical exposure, lasers, and magnetic fields.

Air Quality & Filtration

As mentioned above, semiconductor cleanrooms must have a high level of air quality — some of the cleanest air required for any cleanroom application. This starts with powerful cleanroom HVAC and filtration systems, like HEPA or ULPA filters, which are used to process the air to remove particles up to allowed limits.

Machines within the cleanroom may also have their own exhaust system that removes unclear air and particulate matter.

Other Environmental Threats

Aside from airborne particle filtering, semiconductor cleanrooms must also be protected against other environmental threats. Control is especially important over factors like:

  • StaticElectro-static discharge damages the conductive properties of semiconductors. Static dissipative materials for flooring, wall panels, furniture, and more must be used.
  • Humidity – Uncontrolled humidity in semiconductor cleanrooms can result in inconsistent bake-out times, surface swelling and corrosion, and evaporation of solvents. A consistent relative humidity between 35-65% is necessary.
  • Out-gassing – Semiconductor cleanroom equipment can produce outgassing and introduce airborne contaminants into the space. This must be controlled with proper equipment cleaning and maintenance, as well as consistent air filtration.

Do You Have a Semiconductor Cleanroom Project in Mind? Let’s Talk!

If your facility needs a new semiconductor cleanroom, Angstrom Technology can design, build, and install one that meets your specifications. Using proven design strategies and static dissipative materials, you can trust that your work and employees will always be protected.

Request a semiconductor cleanroom quote today, or contact our team for more information.

Whitepaper: Dry room design guide for lithium battery manufacturing




dry room design guide
How to Decide on the Right Wall Material for Your Cleanroom

How to Decide on the Right Wall Material for Your Cleanroom

If you’re working on a technical specification for your new cleanroom design, you’ve likely noticed different types of cleanroom wall materials in the market. Unless you have experience with all the different types of cleanrooms, you might not yet know which cleanroom envelope system is suitable for your project.

Well, we’re here to help you out as best we can. We know it can be tough to find the info you’re looking for when it comes to cleanroom components, so we put together this blog to help you figure out your options for cleanroom walls. First, what essential elements do you need for a successful cleanroom wall that upholds your application’s standards?

When it comes to cleanroom walls, you’re looking for two things: smooth, dust-free surfaces. But finding the perfect surface type for your operation is easier said than done. Here are some considerations to determine what wall material type is best for you:



One of the biggest concerns for any new cleanroom is deciding how flexible your cleanroom should be. If you plan on housing it in the same building for a decade or more, you can probably get by with cheaper wall options.

Drywall coated with epoxy paint was a popular way to create cleanroom walls. You would take your building’s existing walls and paint them with an epoxy coating rated for cleanrooms. But one of the main problems with painted drywall is that those will be the walls you’re stuck with now and forever. When it comes to stick-built cleanrooms, there’s minimal scope for rearranging or expanding the space you started with, and providing the required extraction levels is challenging.

If you think your cleanroom is likely to expand once operations get underway, then a modular cleanroom with moveable wall panels would be a much better option. The materials might cost a bit more upfront, but you’ll also want to consider what you’d be getting for that additional fee.

Modular cleanroom wall panels are typically manufactured out of scratch and damage-resistant materials. This is helpful because if something runs into one of your modular wall panels, you don’t have to worry about drywall particulate below an epoxy coating seeping out and contaminating your cleanroom. If a modular wall panel gets a scratch, there’s very little cause for concern, and in most cases, you can return to business as usual. Worst case scenario: if the damage is substantial, you can arrange for a replacement panel to be easily fit into your existing system in no time.



SoftWall cleanroom walls are the most economical type of modular cleanroom wall construction. Clear and flexible panels are mounted onto a robust steel frame, enclosing the clean area. As the panels overlap, the walls remain an effective barrier to create an ISO class 7-8 cleanroom, but with a higher volume of air required to achieve a higher level of cleanliness, you may need a solid wall panel.

RigidWall cleanroom construction can withstand the high airflow required for ultra-clean environments such as ISO class 5-6 clean zones. But the bright and durable finish makes them an attractive option for ISO class 7-8 cleanrooms.

HardWall cleanroom panels create a flush finish to a cleanroom wall. They are perfect for high-performance cleanroom applications with a range of proprietary features, such as raceway trunking to supply services, flush glazing, doors, and wall and ceiling panels.



Once you’ve decided on modular cleanroom walls, it’s time to consider the cleaning agents you’ll be using on those walls. Every cleanroom classification is different and requires different levels of cleaning and disinfection. Pharmaceutical cleanrooms, for example, must be disinfected regularly with very harsh chemicals to prevent microbial buildup. In this situation, you need a HardWall cleanroom wall finish that can hold up to those chemicals without warping, corroding, or melting. Walls made from stainless steel with a cleanroom-specific coating are typically suitable for applications that use super-strong cleaning materials.

On the other side of the coin, if you plan on cleaning your cleanroom regularly but don’t need to use the highest-grade disinfectants, RigidWall cleanrooms wall options like acrylic, static dissipative PVC, or polycarbonate wall panels are a more cost-effective choice. When using lower-grade cleaning materials, you need a wall panel that prevents bacteria and particulate from sticking to it. You won’t have to worry about harsh chemicals eating through coatings and materials, causing a lot of particulate buildup within your cleanroom.



As mentioned before, durability can play a significant role in choosing cleanroom wall material. Depending on your application, you’ll need varying levels of material durability. Some materials, like lightweight vinyl modular wall panels, or epoxy-coated drywall, can easily scratch. When the protective coating is breached, the material underneath is exposed and can give off dangerous particulate that can interfere with your processes. Moreover, some wall materials not certified for cleanroom use could outgas or start to give off particulate as they age.

Cleanrooms with more intensive standards are typically best served by walls made primarily of aluminum structure. Aluminum is lightweight, durable, and, best of all, doesn’t give off particulate as it ages. That said, it is a more costly option. So if your cleanroom doesn’t need quite that level of cleanliness, you might choose a less expensive option.



Perhaps the most significant consideration for your cleanroom wall material decision is that you have to stick to a specific budget. With cleanrooms, particulate control is the most critical factor, so it stands to reason that a large part of the investment goes into the airflow, the expensive filtration systems, and the energy you use to keep your cleanroom functioning correctly. Because of this, many cleanrooms don’t look as expensive as they are.

Your cleanroom walls can be one of the least costly aspects of your cleanroom as they are relatively low-tech. So, if you’re looking for an area of the project where you can save money, this could be it.

That said, a few companies want their cleanrooms to reflect the expense put into them, so they spend more on their walls. A high cosmetic finish can be achieved if you have extra room in the budget and want to build a cleanroom that looks like a high-tech, cutting-edge facility. But know that you don’t have to have the highest specification of walls to meet your cleanroom standards.


When designing a new cleanroom, deciding which cleanroom wall material will work best for your application and convey the image you’re looking for can be difficult. If you have more questions about choosing a suitable wall material for your cleanroom, call the experts at Angstrom! We’re here to help you, and we’d love to provide you with any cleanroom information you want to make the best, informed choice for your company. Call our office at 888-768-6900, or request a quote online today!



Building a battery dry room

Building a battery dry room

Many materials and processes used in battery production are susceptible to moisture damage. For that reason, humidity control is critical in a battery dry room. The experts at Angstrom Technology can create a stable low dewpoint production environment to meet your requirements. In this blog post, we explain how.


Battery dry room construction

Battery dry rooms require a constant supply of ultra-dry air to create and maintain low-humidity conditions for the R&D and production of solid-state and lithium-ion batteries.

We can develop an energy-efficient dry room to protect your critical process in any of the following applications. We do this by combining airtight envelope systems, dehumidification systems, and HVAC design.

Small-scale battery research

Pilot plants

Mega / Giga-factory

Single-zone facilities for testing the chemicals and processes during battery R&D.Multi-zoned facilities for scaling up production to manufacture at volume.Large-scale battery production facilities for high-volume battery production.


Battery dry room manufacturers

As battery dry room facility manufacturers, we deliver complete dry room systems. Working with specialist humidity control partners, we provide bespoke solutions that include industry-leading energy-efficient HVAC systems.

A typical clean room environment operates at 20.0°Cdb, 50% Relative Humidity — which is a dewpoint of 9.3°Cdp. Due to the materials’ sensitivity in the process, solid-state battery dry rooms can require control to minus 40.0°Cdp at the room’s exit point. A lower dewpoint of minus 50.0°Cdp is required for Lithium-ion battery dry rooms, and the next generation may have even tighter requirements. The battery chemistry may need the environment to reach minus 80.0°Cdp at the point of supply into critical areas, such as Electrolyte Fill.

Look at how we can custom-build your perfect battery dry room.


Footprint & zones

Establish a suitable layout for your process, featuring multiple zones, each with the optimum dew point temperature and ISO class.


Dehumidification systems

Single or multi-rotor low dewpoint AHU options to suit your budget, space, and specification needs.


Internal airflow distribution methods

Horizontal unidirectional airflow with a supply and return air plenum or a high-level distribution system with uni or non-unidirectional airflow.


Airflow modelling

Using Computational fluid dynamics (CFD) studies to verify HVAC design with equipment and furniture layouts.


Scalable HVAC designs

With specialist AHUs designed for deployment in battery facilities, airflows range from 2,000 m³h to 50,000 m³


Energy-efficient design

Airtight envelope systems and recirculated air manage energy efficiency.


Battery dry room design & build projects with Angstrom Technology

As Angstrom Technology are cleanroom specialists, our dry rooms can also achieve ISO classification. Not only that, but they can also meet any applicable international engineering and building standards and regulations.

We’ve developed proven envelope solutions and reliable cleanroom HVAC designs for many applications. The Angstrom Technology group pride ourselves on our in-house expertise and capability to deliver over 100 cleanrooms annually across America, the UK, and Europe.

Tell us about your new dry room project!

Whitepaper: Dry room design guide for lithium battery manufacturing




dry room design guide
5 reasons you need a modular cleanroom

5 reasons you need a modular cleanroom

At Angstrom Technology, our modular cleanrooms are a popular choice for organizations looking to create cleanroom space quickly. Here are just 5 reasons you need one.


1.     Flexibility to extend or relocate

If you need some cleanroom space right now but know you may soon need a larger area — don’t be held back by your future plans! Our modular cleanrooms can be extended or relocated. So your investment is futureproofed against any changes to your requirements — planned or unplanned!


2.     Self-installation option for modular cleanrooms

If your team is particularly hands-on, you can choose the self-assembly option. Since our modular cleanrooms are prefabricated at the factory, it will only take you about 2-3 days to install it. Or, you can hire the technicians at Angstrom Technology to put it together for you. Our team will manage the project from delivery to validation, with minimal distraction, so your team can get on with their workload.


3.     Protect your injection molding machines

Are you an injection molder? Are you looking to protect the tool face of your molding machine without enclosing the hopper? Look no further! Our modular SoftWall cleanrooms are the solution to your challenges. Many molders have used them to protect the critical zone, as the SoftWall curtains can be profiled around a machine to give part coverage and create an ultra clean zone where it counts.


4.   Use a modular cleanroom for R&D

Our modular RigidWall cleanrooms can quickly upgrade your R&D zone to create a classified environment. Many sectors, like medical device, space, and manufacturing, have taken advantage of this ultra-quick solution to protect their intricate and sensitive products.


5.     Medical device production

Our RigidWall modular cleanrooms can achieve particle counts according to ISO Class 5-8 requirements. What does this mean for medical device manufacturers? If your quality risk-based assessment deems this suitable, you can manufacture your medical devices in them!


Build an ISO Modular Cleanroom With Angstrom Technology

At Angstrom Technology, we’re proud to have delivered high-quality, high-performance cleanrooms across North America for over 30 years.

If you’re interested in building an ISO cleanroom in your facility, contact us online for information on how to get started.