Unidirectional or laminar airflow refers to air that flows in a straight, unimpeded path. It is defined as the controlled airflow through the entire cross-section of a clean zone with a steady velocity and approximately parallel streamlines. Unidirectional flow is maintained in cleanrooms through the use of laminar airflow hoods that direct air jets downward in a straight path, as well as cleanroom architecture that ensures turbulence is reduced.
Unidirectional airflow is a way of ensuring air flows in only one direction, lessening the possibility of particles being kicked around and landing in your cleanroom. In most cleanrooms, air is directed from the top of the room to the bottom, ensuring any contaminating particles are pushed out and don’t land where they’re not supposed to.
Laminar airflow pushes air through the filters that remove any particles. As air goes through the filters, particles get stuck to the tiny, randomly placed fibres within the filter and are subsequently removed from the air entering the cleanroom. Those cleanrooms employing laminar airflow are typically referred to as ‘Unidirectional Airflow Cleanrooms’.
Total Clean Air are the leaders in cleanroom construction services. We offer an integrated approach from planning through to implementation, providing all the services and products necessary to deliver controlled environment solutions. We have a reputation for quality workmanship and can install unidirectional airflow technologies in cleanrooms anywhere in the UK.
Modular Cleanroom Benefits
- Modular Construction
- Quick Assembly Time
- Airflow Control
- Inexpensive Modifications
Understanding How Unidirectional Airflow Works
Unidirectional airflow generally involves parallel stream lines, operating in a single direction with uniform velocity over its cross section. This means non-turbulent streams of air flow in one direction, parallel to one another. It is the most efficient option for removing particulate contamination from a controlled area, because the airflow uniformity and lack of turbulence keep clean airstreams from mixing with contaminated airstreams.
In the unidirectional airflow type of cleanroom, the design intent is that air should make a single pass through the room with a piston-like effect. Meanwhile, in vertical laminar flow rooms, cleaned air enters the room through the ceiling and exits through floor grilles or continuous outlets in the walls at floor level.
Cleanroom Design, Build & Validation
- Budgeting and planning
- Engineering, design & layout
- Airflow and filtration design
- Construction and Installation
- Full Certification of our product
- Industry-specific equipment installation
There are some restrictions as to how wide the room can be to still maintain unidirectional flow. Air can also enter through one wall and exit through the opposite wall. This is sometimes referred to as ‘horizontal laminar flow’.
With unidirectional airflow systems, the filtered air is directed downwards in a constant stream, passing through raised floor panels that are perforated in order to be recirculated. Working in conjunction with laminar airflow, multiple filters remove the necessary number of particles in order to meet your cleanroom standards.
Modular Cleanroom Services
- Design & Build
- Free Site Survey
- Free Design Service
- Cleanroom Planning
- Construction and Installation
- CNC Engineered
- Training & Support
- Discounted Service Contracts
- Remedial Works
- Panel Repairs
- BMS Management
- Cleanroom Certification
- Differential Pressure Qualification
- Servicing Testing Validation
- Smoke Testing
- DOP Testing
How Unidirectional Airflow Aids Contamination Control
Unidirectional airflow systems direct filtered air downward or in a horizontal direction in a constant stream towards filters located on walls near the cleanroom floor or through raised perforated floor panels to be recirculated. This system is employed across 80% of a cleanroom’s ceiling to maintain constant air processing.
In a laminar flow cleanroom, the HEPA filters are located in the wall or ceiling of the room, so that once the air passes through the filter, it can reach the cleanroom. This way, intermediate sources of contamination are eliminated. HEPA filters are sealed into the framing system, so that there can be no by-pass of dirty air around them or in the cleanroom itself.
- ISO 4-9
- ISO 14644
- Low Power Consumption
- Environmentally Friendly
- HEPA Filters
- Air Filtration
- Fan Filter Units
- Cleanroom Ceiling System
- Temperature Control
- Access Control
- Inter Lock Door Systems
- Air Showers
- Unidirectional Airflow
- Desiccator Cabinets
- Horizontal Flow Wall Modules
- Horizontal Laminar Flow Clean Benches
- Laminar flow cabinets
- Laminar Flow Canopy
An object being bathed with clean, turbulence-free, laminar airflow will remain clean and protected from nearby contamination. Clean benches with either vertical or horizontal laminar airflow provide the cleanest working environments, because HEPA-filtered air within these benches is unidirectional and turbulence-free.
Unidirectional airflow utilises HEPA filters to filter and clean all air entering the environment. Laminar filters are often composed of stainless steel or other non-shed materials to ensure the number of particles that enter the facility remains low. The filters themselves must also be leak-free.
Total Clean Air for a Guaranteed Secure Environment for your Critical Processes
At Total Clean Air, we are committed to constructing and delivering top of the line cleanrooms for diverse industries. We make use of our ample years of experience and skilled engineers to deliver state-of-the-art cleanroom technology on budget and at very competitive prices.
We offer first class cleanroom services – especially airflow and filtration design. Our services are ISO 14001, ISO 9001 and OHSAS 18001 accredited. Our experienced CTCB certified engineers can provide ISO-classified controlled environments for your UK-based facility, regardless of industry.