Understanding Cleanroom HVAC Requirements

Understanding Cleanroom HVAC Requirements

Just as different cleanrooms have different requirements for class specifications, HVAC systems are not one-size-fits-all. Your cleanroom HVAC system might even have to be reconfigured to best suit the needs of your facility. 

If your cleanroom is the body that enables you to manufacture, test or create your products, the HVAC system is its lungs. When functioning efficiently, a cleanroom can control down to a minute detail the temperature, pressure, humidity, particles, and levels of contamination of its contents. To do this, the cleanroom must be able to change its air and filter particulates. If the cleanroom is unable to do this, it is essentially left breathless.

The process of changing air can happen from 10 to more than 600 times per hour. The less “clean” the room has to be, the less often the air will change. Conversely, the more stringent the cleanroom’s standards, the more often the air will have to be changed per hour. This is referred to as air-change rate or ACR.

 

Understanding Cleanroom HVAC Power Levels and Capabilities

HVAC systems differ in their power levels and capabilities. If your cleanroom has lower standards, it may not need a system with a high BTU (British thermal unit of heat required to raise temperature in a pound of water by one degree), and strictness in temperature regulation or relative humidity (rh) may not be necessary. Cleanrooms that require exactness in these levels and extremely fine particulate filtration, however, may need the investment of a powerful HVAC system, one that is capable of maintaining a consistent and controlled environment for employees and their work.

Different industries have different requirements, and therefore different cleanroom HVAC needs. To help break this down, we’ve divided cleanroom users into three broad categories: Manufacturing, Pharmaceutical, and Laboratory. Of course, many exceptions exist. For a more specific consultation, reach out to our cleanroom design team.

 

Manufacturing Cleanroom HVAC Requirements

 

 

Cleanrooms used in manufacturing facilities are designed to meet a variety of standards, depending on the specific products they involve and the size of the particulates that need to be filtered. Most manufacturing cleanrooms meet ISO Classes 7 or 8, which translates to a maximum number of particles of .05μ or greater in the air ranging from 352,000 to 3,520,000. Since this type of facility does not typically depend on extreme control of temperature or a high ACR, they can be adequately maintained with the use of an HVAC system with an average to low BTU level. 

 

Pharmaceutical Cleanroom HVAC Requirements

 

 

Pharmaceutical cleanrooms will need much higher control over environmental variables and so will need a powerful HVAC system to help them achieve this. They will need to maintain a strict temperature range as set forth in all USP regulations in order to stabilize materials, meaning precise heating and cooling — especially if the cleanroom is located in a climate that experiences many temperature variations such as the Midwest. Pharmaceutical cleanrooms, on average, must comply with a minimum ISO 7 standard — Federal Standard 209 Class 10,000.

 

Laboratory and Medical Device Cleanroom HVAC Requirements

Laboratory work, especially the development and production of medical devices, requires an extremely controlled cleanroom environment that must comply with intensive standards. The majority of these types of cleanrooms comply with ISO 14644 standards. A powerful HVAC system with the necessary filters will restrict particulates in the environment to the acceptable level, maintaining the quality of the cleanroom’s air. In this environment, the air will need to be changed with high consistency, removing any contaminants before they interfere with the integrity of the work.

Depending on the size of the particles that need to be filtered, the importance of temperature or humidity to your products and the ACR rate needed to keep your environment clean, your system capabilities will need to reflect the type of work conducted in your facility. With the proper cleanroom HVAC system working in tandem with your perfectly equipped cleanroom, you will have complete control over your space and the products developed within it. It’s important to make sure your HVAC is able to filter and properly change the air of your cleanroom so it can breathe and function efficiently.

 

It’s possible that your current HVAC system may not be up to the task of supporting your new cleanroom. That’s where Angstrom Technology comes in. As expert cleanroom designers, we can help you determine what type of HVAC system you need, and help you make it happen, too. For help designing, installing, or servicing your cleanroom’s HVAC system, give our team of experts a call at 888-768-6900 or contact us online today.

Understanding Cleanroom HVAC Requirements

Cleanroom HVAC Systems Explained

In cleanrooms, air is crucial – how it’s filtered, how it’s heated and cooled, and how it’s circulated. Because of this, knowing how HVAC and filters work together is crucial to maintaining cleanroom air decontamination and meeting cleanroom standards. Before you install a new cleanroom, here’s what you need to know about your cleanroom’s HVAC system:

Dedicated vs. Integrated HVAC

When it comes to cleanroom HVAC systems, the first decision is whether to have a dedicated HVAC system or to incorporate your building’s existing HVAC. This depends on the necessary level of environmental control, the size of your cleanroom, and the other energy requirements of your facilities. Using an existing HVAC system can help you save money at the outset, but for very large cleanrooms or factories, a dedicated system might be more efficient and keep a reasonable load on each system so that they can run efficiently. Additionally, while you can combine a filtration system with an existing HVAC system very efficiently, for extremely stringent cleanroom standards, dedicated HVAC may be your best bet.

Filtration systems

Filtration is also an important consideration here. There are three basic types of filters used in cleanrooms: prefilters, HEPA filters, and ULPA filters. Prefilters are used with both HEPA and ULPA filters as a first step in the filtration process, removing large particles.

HEPA filters are High-Efficiency Particulate Air filters, and they filter out 99.99 percent of particles 0.3µm or larger.

ULPA filters are Ultra Low Particulate Air filters, and filter out 99.999 percent of particles larger than 0.12µm.

Purity Testing

Once your HVAC and filtration systems are in place, you must regularly test the air purity of your system. Testing should occur initially in three phases: as-built testing (when all services are connected and working), at rest (when all equipment is installed and in place), and performance qualification (occurring regularly while the cleanroom is in operation).  

Are you designing a new cleanroom or updating an existing one? Angstrom Technology has the products and expertise you need.

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

What’s the Difference Between Positive and Negative Air Pressure 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, one piece of information that might be useful to you is understanding the difference between positive and negative air pressure cleanrooms. As you probably already know, airflow plays a leading role in keeping your cleanroom to standard, but what you may not have known is that air pressure can have a big effect on that as well. So here’s a broken down explanation of each positive and negative air pressure.

 

Positive Air Pressure Cleanrooms

 

This means that the air pressure inside your cleanroom is greater than the pressure outside of it. This is achieved by pumping clean, filtered air into the cleanroom, generally through the ceiling.

Positive pressure is used in cleanrooms where the priority is keeping any possible germs or contaminants out of the cleanroom. In the event that there was a leak, or a door opened, clean air would be forced out of the cleanroom, rather than unfiltered air being allowed into the cleanroom. This works somewhat similarly to deflating a balloon; when you untie a balloon, or pop it, air rushes out because the air pressure in the balloon is higher than the pressure of the ambient air.

Positive pressure cleanrooms are used primarily for industries where the cleanroom functions to keep the product clean and safe from particulates, like in the microelectronic industry where even the tiniest particle can damage the integrity of the microchips being manufactured.

 

Negative Air Pressure Cleanrooms

 

In a negative air pressure cleanroom, the air pressure in the room is lower than the pressure outside of the room. Generally this is achieved by filtering air out of the room. In most situations, air enters through filters near the floor, and then is sucked out through filters in the room ceiling.

Negative air pressure is used in cleanrooms where the goal is to keep any possible contamination from escaping the cleanroom. Windows and doors have to be completely sealed, and by having a lower pressure, air outside the cleanroom is likely to flow into it, rather than out of it. Think of it like an empty cup that you set in a bucket of water. If you push the cup into the water rightside up, water flows into the cup, because it has lower pressure than the water. The negative pressure cleanroom is like the empty cup here.

Negative air pressure cleanrooms are used in industries that manufacture pharmaceutical products, do biochemical testing, and also in hospitals to quarantine seriously contagious patients. Any air that flows out of the room has to first flow out of a filter, ensuring that no contaminants can escape.

 

 

If you have any more questions regarding negative and positive air pressure cleanrooms, take a look at our Dwyer Digital Differential Pressure Gauge or if you’re looking to purchase a cleanroom for your business, give the experts at Angstrom a call today! We custom design all of our cleanrooms, so that they meet your exact specifications and standards. Call us at 888-768-6900, or contact us online.

 

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