How to Choose a Fan Filter Unit for your Cleanroom

In order to ensure your facility is meeting required cleanliness standards, fan filter units (FFU) are a critical component of your cleanroom design. Let’s explore more about fan filter units: how they work, what types there are, and how to choose the right one for your cleanroom.

What Is a Fan Filter Unit?

A fan filter unit is an independent filtration system mounted in a modular cleanroom ceiling grid that is used in conjunction with an air handling unit or HVAC system. It contains a fan, a pre-filter, and a filter (either HEPA or ULPA). In most cleanrooms, multiple fan filter units are installed in the cleanroom ceiling grid and are designed to provide a consistently treated workspace, minimizing dead zones.

Individual fan filter units can be added and subtracted according to the size and necessary ISO Class regulations. In general, the bigger your cleanroom, and the more stringent your ISO Class, the more fan filter units your cleanroom will likely need.

How Does a Fan Filter Unit Work?

Fan filter units work by continuously pushing clean, filtered air into your cleanroom. Air travels through a pre-filter, through the fan, and then through the HEPA or ULPA filter that treats and filters out airborne particles prior to entering your cleanroom.

When Do You Use a Fan Filter Unit for a Cleanroom?

Fan filter units provide a number of advantages over traditional air handling units. Here are a few reasons you may consider using fan filter units for your cleanroom:

• Easy to install – Because they are mounted in the cleanroom ceiling grid, fan filter units are easy to install and are easily accessible from within the cleanroom.2
• Easy to modify – As your facility grows and changes, your filtration system can too. Fan filter units can easily be added into the ceiling grid if you have to meet increased cleanliness requirements in the future.
• Cost-effective – Fan filter units are generally less expensive than a completely new air system, both in terms of production cost and installation cost.

Types of Fan Filter Units: PSC vs. ECM

While all fan filter units function in generally the same way, there are two types of motors that commonly power a cleanroom FFU: permanent split capacitors (PSC) and electronically commutated motors (ECM). Each motor functions a little differently, providing distinct advantages depending on which option you choose. PSC motors operate at one consistent speed, while ECM motors have a variable speed drive and can adjust speed based on application requirements.

PSC vs. ECM: Which Fan Filter Unit is Right for Your Cleanroom?

Both of these are reliable options, guaranteed to provide the filtration your cleanroom needs. However, ECM units are often the best choice to help you meet your cleanroom goals and maximize treated space.

The Benefits of an ECM Fan Filter Unit

ECM fan filter units are known to be air-treating powerhouses for a range of applications — especially if those applications require varying filtration speeds. Its variable speed drive includes numerous benefits, including:

• Smooth operation in inconsistent conditions
• Great durability for big, long-haul projects
• Energy-saving technology to help you reduce utility costs

Looking for a cleanroom that incorporates high performance filter fan units? Angstrom Technology can design a cleanroom to accommodate any equipment for your application. Contact us today to get started.