Air Showers

The Importance of Airlock Design

Airlocks are vital in safeguarding cleanrooms from contamination and ensuring compliance with ISO standards. By maintaining pressure differentials between adjoining spaces, airlocks act as barriers preventing cross-contamination while transferring personnel, materials, or samples. The pressure cascade, from the gowning area through the airlock and into the cleanroom, creates a protective shield that minimizes the infiltration of particles, dust, and microbes.

How Do Airlocks Function?

Airlocks facilitate a controlled airflow, moving from high-pressure to low-pressure zones, ensuring contaminants don’t infiltrate adjacent areas. By sustaining precise pressure differences, they help to isolate clean environments effectively. Additionally, most airlocks are equipped with interlocking systems that prevent both doors from being open simultaneously, further reducing contamination risks. For enhanced protection, airlocks can integrate other technologies, like air showers, to minimize the transfer of particles.

There are three main types of airlocks, each tailored for specific applications: Cascade, Bubble, and Sink:

Cascade Airlock

Cascade airlocks balance the pressure between a high-pressure environment, such as a Class A or B cleanroom, and a lower-pressure area, like a corridor or storage room. This design is ideal for processes like tablet manufacturing, where only one adjoining space requires strict environmental controls.

Bubble Airlock

Bubble airlocks maintain higher pressure within the airlock than in the adjacent spaces. The air flows outward into the adjoining rooms, ensuring contaminants from less controlled areas cannot enter the airlock. This system is often used in sterile injectable production or drug discovery applications.

Sink Airlock

Sink airlocks operate inversely to bubble airlocks, maintaining lower pressure inside the airlock than in adjoining rooms. Air is drawn into the airlock from the surrounding spaces and then vented out through the facility’s exhaust system. This approach benefits industries such as food and beverage production or industrial packaging.

Airlock Standards and Compliance

The standards governing airlocks depend on the ISO classification of the connected cleanroom. For instance, the FDA requires ISO 7 cleanrooms with ISO 8-rated personnel airlocks to maintain at least 20 air changes per hour. Similarly, EU guidelines specify a pressure differential of 10–15 Pascals between the cleanroom and the airlock. While these figures provide a solid foundation, it’s essential to customize your airlock design to meet the specific needs of your application. In many scenarios, exceeding these baseline requirements can further mitigate contamination risks.

Optional Features

Although most air shower applications just require the basics: enter, cleaning cycle and exit, there are a large number of customizations available to suit any application. Examples include stainless steel shells for pharmaceutical applications, explosion-proof blower cabinets, key card access, fire alarm integrations, and motion sensor starts.

Important Installation Considerations

Most common air showers have a blower cabinet that must be suspended at 8' while the side wall air chases are attached. That means there will have to be some lifting mechanism to hold it in place, most often a forklift. You must account for not only installing the air shower in its final location, but also having a device capable of accessing that area.

How are Air Showers Shipped & Installed?

Air shower can be shipped fully assembled (on its side on the skid) or knocked down with the wall panels off from the upper blower cabinet, allowing the components of the air shower to fit through a standard 3' x 7' door opening when removed from the shipping skid. If the components are required to fit through a different size door, please indicate so in the quote request.

Air showers can be installed so the entire air shower sticks through the wall, with space around the air shower. This space is filled with an optional trim angle. The shower can also butt up against a wall with an opening large enough for the door and related end-mounted hardware (approximately 48" x 90"). Please request a quote before planning cut-outs, as different configurations and sizes may require different cut-out sizes. When the unit is butting against the wall, the contact point between the air shower and the framed opening is typically caulked or a small trim molding is applied. The exterior of the air shower would also have a trim angle.

What is the Typical Installation Process?

When shipped fully assembled on its side, the weight for an air shower is approximately 1,300 lb. Two eye bolts located on the top of the air shower can be used to assist in lifting. After standing up the unit, it is then moved into position and leveled using shim stock and is anchored to the floor (anchors to be provided by the installer).

When the unit is shipping knocked-down, the air shower upper blower cabinet is 650 lbs. The wall panels are 250 lbs. The knocked-down air shower needs room on the sides of the unit during the assembly process to install the 3/8" mounting bolts. To assemble the unit, the blower section is taken off the skid and raised into position. The two wall sections are then bolted from the outside onto the upper blower housing. At this point, the assembly is self-supported. The doors are attached, power is connected, and the unit is ready to run. Assembly is fast and uncomplicated. Each unit is shipped with a detailed manual. We do recommend using mechanical lifts to assist in the assembly process. Once the unit is assembled, no space is required on the sides of the unit. After the unit is assembled, moved into place, and the mounting is complete:

1. An electrician needs to connect power to the air shower, start the unit, and check blower rotation.
2. A sprinkler contractor needs to install the sprinkler.
3. The installer touches up the paint (if needed).
4. The installer adjusts the doors and door closers (if needed).
5. The installer adjusts the magnetic door interlocks (if needed).
6. The installer confirms that high-velocity air is flowing out the nozzles at approximately 90 MPH. If the blower is running backwards, air will still come out of the nozzles, but only at about 15 MPH. Blower rotation can also be confirmed by looking at the blower itself.
7. The installer cleans the inside of the air shower and the interior floor space.
8. The installer seals any seams with caulk (provided by the installer) as required.