What’s the Difference Between a Positive and Negative Air Pressure Cleanroom?

What’s the Difference Between a Positive and Negative Air Pressure Cleanroom?

by | Mar 30, 2023 | Air Circulation, Cleanrooms

If you’re considering a cleanroom, you’re probably trying to gather as much information as possible. What type of cleanroom is right for you? What industry standards do you have to meet? Where will your cleanroom go? You get the picture. Well, it might be helpful for you to understand the difference between a positive and negative air pressure cleanroom. As you probably already know, airflow plays a leading role in keeping your cleanroom to standard, but you may not have known that air pressure can also have a big effect on that. So here’s a broken-down explanation of each positive and negative air pressure.

POSITIVE AIR PRESSURE CLEANROOM

Positive pressure means the air pressure inside your cleanroom is greater than outside. You achieve positive pressure by pumping clean, filtered air into the cleanroom — generally through the ceiling. In the event of a leak, or a door opening, clean air would flow out of the cleanroom, preventing unfiltered air from flowing into the cleanroom.

A balloon popping is a perfect illustration of positive pressure. When you pop a balloon, air rushes out because the air pressure in the balloon is higher than the ambient air pressure.

Positive pressure cleanrooms are used primarily for industries where the primary goal of the cleanroom is to keep the product clean and safe from particulates, like in the semiconductor industry, where even the tiniest particle can damage the integrity of the microchips or wafers.

NEGATIVE AIR PRESSURE CLEANROOM

In a negative air pressure cleanroom, the air pressure in the room is lower than outside pressure. If the goal for your environment is to keep contamination from escaping the cleanroom, you likely need a negative-pressure cleanroom.

Negative pressure is created by filtering air out of the room at a higher rate than the supply air. In most situations, air enters through filters near the floor, then removed through filters in the room ceiling.

Windows and doors need an airtight seal to prevent air outside the cleanroom from flowing into it rather than out of it.

Negative air pressure cleanrooms are needed for industries that manufacture pharmaceutical products, do biochemical and chemical testing, and also in hospitals to quarantine seriously contagious patients. Any air that is removed from the room must first flow out of a filter, ensuring no contaminants can escape.

CONTACT THE CLEANROOM EXPERTS AT ANGSTROM TECHNOLOGY

If you have any more questions regarding negative and positive air pressure cleanrooms, call the experts at Angstrom today! We custom design all of our cleanrooms to meet your exact specifications and standards. Call us at 888-768-6900, or contact us online.

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Should You Install Your Cleanroom Yourself or Hire A Pro?

Should You Install Your Cleanroom Yourself or Hire A Pro?

by | Oct 16, 2019 | Cleanroom Installation

Once you’ve designed and ordered a cleanroom, then comes the good part: installing it and putting it to use. Unlike traditional construction, with modular cleanrooms, you have the option of installing it yourself or having a professional handle the installation. How do you know which cleanroom installation option is right for your organization? That depends on a variety of factors, including timeline, personnel, and complexity.

How much time do you have?

Modular cleanroom design means that cleanrooms can be assembled and installed quickly to meet business needs. But, this depends on your timeline. If your cleanroom installation isn’t an urgent priority, having your own employees handle the installation might work. If you’re on a tight deadline (and you probably are) having a professional installation crew install your cleanroom can get the job done faster and more efficiently.

How confident are you in your personnel?

Your employees are great—if they weren’t, you wouldn’t have hired them. And though they may have lots of experience in facilities maintenance and other operations, cleanrooms can be complicated and complex assembly projects, even with the best of instructions. If you want to ensure that the job is done right and that your employees aren’t overburdened, consider hiring an installation crew for your new cleanroom. 

How complex is your cleanroom design?

It follows that the more complex your cleanroom design, the more time, effort, and difficulty there will be in installing it. This is especially true if your design includes any delicate or specialized equipment. In the case of a complex design, it’s best to leave it to the professionals. 

A simple storage cleanroom, on the other hand, can be simple enough to be installed easily, without a professional installation crew.

Whether you want to install your own cleanroom or have it installed professionally, Angstrom Technology can help. We provide detailed instructions for installation with all of our cleanrooms in case you chose to DIY, but also offer installation services.

 

Cleanroom Terminology: BioSafety Hoods & Cabinets

Cleanroom Terminology: BioSafety Hoods & Cabinets

by | Oct 2, 2019 | Cleanroom Terminology

Anyone in quality assurance or testing who works in or has to design a cleanroom knows how confusing the terminology around cleanrooms can be. To demystify some of the cleanroom design processes, here is an explanation of two potentially confusing terms: biosafety hoods and biosafety cabinets.

What is a biosafety hood?

A biosafety hood is generally known as a fume hood. The purpose of a fume hood is to isolate fumes from materials that may be hazardous and filter those fumes out of your cleanroom space. An exhaust fan at the top of the cleanroom building pulls air, fumes, and airborne contaminants out of the fume hood and exhausts outside of the building.

What is biosafety cabinetry?

Biosafety cabinetry works very similarly to biosafety fume hoods. Biosafety cabinetry uses laminar airflow to filter airborne fumes and contaminants away from the cabinet area, which like a fume hood can be used as a work surface or storage area.

What are the classifications?

There are three classes of biological safety cabinets, Class I, Class II, and Class III. The classification determines the level of protection. Class I protects the user and the surrounding environment, but does not protect the sample. Class II and Class III protect the user, sample, and surrounding environment. Class II is divided into four subcategories, A1, A2, B1, and B2, based on exhaust system and minimum airflow. Class III is the highest level of protection and control. Class III cabinets are also known as “glove boxes” and are completely gas-tight with a double-door autoclave or dunk tank. 

 

Protection

User

Environment

Sample

Class I

Yes

Yes

No

Class II

Yes

Yes

Yes

Class III

Yes—highest 

Yes—highest 

Yes—highest 

 

Special considerations

If your cleanroom requires work with dangerous, hazardous, or toxic substances with airborne contaminants or fumes, your cleanroom likely requires some kind of biosafety cabinetry or hood. The level of protection necessary for your specific application, whether your application requires Class I, Class II, or Class III cabinetry, will depend on the specific operations and substances used in your cleanroom. 

 

Looking for a cleanroom that incorporates biosafety cabinetry? Angstrom Technology can design a cleanroom to accommodate any kind of cabinetry or other equipment necessary for your application.

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Do You Need A Soundproof Cleanroom?

Do You Need A Soundproof Cleanroom?

by | Sep 17, 2019 | Cleanroom Design, Manufacturing Cleanrooms

A cleanroom can be designed to meet the needs of almost any application with any requirements, from controlling static and humidity to even controlling sound. You probably know whether your application requires control for things like humidity and static, but what about sound. Do you need a soundproof cleanroom? Here are some conditions where you might.

Loud Manufacturing Environments

If your facility is a manufacturing environment that requires protective hearing equipment like earplugs ear, soundproofing your cleanroom is a good idea, especially if hearing protection isn’t necessary for your cleanroom processes. Hearing protection might even hinder those processes, as foam from earplugs and earmuffs can hold and shed particles.

If your cleanroom contains the loud equipment and the rest of your processes outside the cleanroom don’t require hearing protection, it can be worthwhile to soundproof your cleanroom so that hearing protection is only required inside. This can greatly reduce hearing-related injuries to your personnel and reduce the cost of hearing protection for your company.

Loud Equipment Containment

If you have a piece of equipment or pieces of equipment that are particularly loud, rather than creating a soundproof cleanroom, a more efficient solution might be creating a soundproof containment room for that equipment. A modular soundproof room can be created around a loud piece of equipment. The benefit to this is reduced noise and need for ear protection in your facility. Additionally, modular containment rooms can be freestanding or can incorporate your existing structure, so no matter where a piece of equipment is housed, it can be soundproofed.

Sensitive Processes

If your cleanroom operation is a particularly sensitive process, a soundproof cleanroom may also be beneficial. Sound is vibration, and delicate operations may be affected by loud noises and strong vibrations, which a soundproof cleanroom can reduce.

Proprietary Information

If your cleanroom operations are top secret or deal with proprietary information which should not leave the walls of the cleanroom, a soundproof cleanroom can also prevent the unplanned and unwanted spread of information by containing sound within the cleanroom.

 

Angstrom Technology’s modular cleanrooms and in-plantinplant buildings can be customized to control sound, if your application requires. Get in touch with one of our design engineers to discuss your project.

 

Cleanroom Terminology: Air Showers

Cleanroom Terminology: Air Showers

by | Sep 3, 2019 | Air Showers

Early in the cleanroom design process, all of the cleanroom terminology and jargon can be confusing, especially when designing a controlled environment is a complex process with many factors to take into account. Here’s an explainer on one of those terms, air showers, that may help you determine whether your cleanroom requires an air shower.

What are air showers?

Air showers are enclosed spaces that use high-velocity air jets to remove contaminants from people and items entering the controlled environment. They are placed at all entrances to the cleanroom and are connected to a HEPA or ULPA filtration system. Air showers can be used to prevent contaminants from entering the cleanroom, but they can also be used to remove contaminants from people and objects exiting a quarantine or other controlled environment to prevent cross contamination.

Air showers are particularly useful for cleanrooms requiring a high level of control, such as ISO Classes 1-5. Industries that commonly use air showers include pharmaceuticals, biotech, hospitals, aerospace, and semiconductor manufacturing.

Air Shower Specifics

All air showers function in the same way—air blows onto the person or object in the air shower, blowing loose contaminants off before the person or object enters the cleanroom space. The differences are really in size, materials, and filtration system.

Size

The size of your air shower will depend on what needs to pass through it. If only people will be passing through your air shower, then you won’t need a large one (depending on the number of people). However, if carts with product need to enter your cleanroom, your air shower will need to accommodate the person pushing the cart as well as the cart.

Materials

Air showers are generally constructed from either steel, aluminum, stainless steel, or plastics. The material used may depend on your budget as well as the application and requirements of the air shower.

Filtration system

Air showers can use HEPA (high-efficiency particulate air) filters or ULPA (ultra-low particulate air) filters, depending on your needs. HEPA filters remove particles greater than or equal to 0.3 µm with 99.99 percent efficiency; ULPA filters remove particles greater than or equal to 0.12 µm with 99.9995 percent efficiency.

Angstrom Technology designs cleanrooms that can incorporate a variety of design features, including air showers. Talk to an engineer today to get started designing your cleanroom.