Clean Room Windows for Modular FFU Cleanroom Projects in Hospitals

Modular FFUs (Fan Filter Units) are used more and more in hospital cleanroom renovations. They are flexible, can be installed in a shorter period and can provide a more accurate control of contamination than traditional ducted HVAC. But, for a modular FFU cleanroom to be successful, all components of the enclosure (including clean room windows) need to be successful. Airflow disruption, pressure loss and contamination pathways can result from windows not designed for FFU systems. Choosing the appropriate clean room windows is therefore crucial. Here are four key points to think about for a hospital modular FFU project.

1. Flush-Mount Profiles Maintain Laminar Airflow

In modular FFU cleanrooms, the unidirectional (laminar) airflow is generated by the ceiling mounted cleanroom return airflow (FFU) that is blown into a low wall return grille. Anything that protrudes off the wall surface - such as window frames or sills, will create turbulence and reduce the sweeping effect of airflow, trapping particles.

Huaao's clean room windows come with flush mounted profiles which lie flat with the surrounding clean room sandwich panels. No ledges, no recess and no protruding handles. This transition with the FFU supplied air will result in a smooth flow of air down the wall without separation or formation of eddies. For hospital operating rooms where ISO Class 5 or Class 6 conditions are required, flush-mount windows cannot be considered a choice – they are a necessity to assist in the unidirectional air flow to keep the surgical area protected.

2. Airtight Seals for Pressure Cascade Integrity

The pressure cascades used in hospital cleanrooms are: Hospital operating rooms are positively pressurized when compared to the surrounding corridors; The isolation rooms are negatively pressurized when compared to the surrounding corridors. Modular FFU systems are designed to maintain these pressure differentials (typically 10–50 Pa). However, a leaky window may break this cycle by allowing conditioned air to leak out or unconditioned air to enter.

Huaao's windows use gaskets that are compressed to establish a continuous seal between the window and the frame; the gaskets are either EPDM (ethylene-propylene-diene-monomer) or silicone. It can withstand differential pressures up to 250 Pa according to the Air leakage test standard of GB/T 7106. Air tight windows with proven pressure integrity and employed for projects with containment concerns such as hospital projects that include TB isolation rooms, Burn units etc.

3. Chemical-Resistant Finishes for Hospital Sanitization

Quaternary ammonium compounds, chlorines and hydrogen peroxide vapor and alcohol wipes are the most aggressive disinfectants employed in hospital cleanrooms many times each day. This will cause typical window coverings to fail, pit and discolor.

Huaao clean room windows are manufactured with aluminium frame, and the electrostatic powder coating (epoxy powder coating / polyester powder coating) is chemical resistant. This coating is subjected to adhesion, hardness and common hospital disinfectant resistance tests. Options for glass include anti-microbial coatings which won't be impacted by UV or chemicals, along with safety glass tempered for safety. Chemically resistant finishes are employed in operating theatres, pharmacies and central sterile supply rooms to ensure that the high level of cleanliness is maintained while giving the project long-lasting durability.

4. Custom Sizing for Existing Hospital Openings

Typical hospital renovation projects don't always have standard, square openings. Walls may not be straight, openings may not be rectangular, and some walls may not be able to be modified due to structural considerations. Standard window sizes do not usually fit and this reframing or the use of temporary seals are often very expensive, as they can leak and trap contaminants.

Huaao produces custom size clean room windows based on the size/location in the field. Our engineering team designs windows to fit a window opening exactly, either by using laser measurement instruments or by referring to the customer's drawings. There are various customisations available such as different glass thickness (from 4 mm to 12 mm), frame colour (RAL or custom), seal material (silicone, EPDM or Viton) and glazing clear, frosted or anti-static. The size option is ideal for projects in a hospital environment, where the timing of the renovations is the key – there are no delays to be expected and no need to modify the size in any way, from the beginning.

Summary

For modular FFU clean room projects, there are four requirements that the windows must meet: They should be custom sized to fit existing windows; They should be chemical resistant to be capable of being sanitized daily in a hospital setting; They should be airtight to assure the integrity of the pressure cascade in the cleanroom; They should be flush-mount to ensure the laminar airflow in the clean room. These windows are part of the complete modular cleanroom one-stop system offered by Huaao Clean Technology Group, a national high tech enterprise, which has 250,000 m² of factory, 800 highly experienced employees and annual revenue of 1 billion RMB. We can provide cleanroom windows and doors, aluminum profiles, PVC cleanroom floor, purification equipment, cleanroom ventilation valves, shadowless lamps and cleanroom sandwich panels. Contact Huaao today to design windows for your next hospital modular FFU project.