Difference between Hygienic and Non-Hygienic AHUs

The Main Difference 

The main difference between hygienic and non-hygienic air handling units (AHUs) is their intended use and the types of applications they are designed for. Here are some key differences:

1. Intended use: Hygienic AHUs are specifically designed for applications where maintaining clean air quality is critical, such as in hospitals, laboratories, and pharmaceutical manufacturing facilities. Non-hygienic AHUs, on the other hand, are typically used in commercial or industrial settings where air quality standards are not as strict.

2. Construction materials: Hygienic AHUs are constructed with materials that are resistant to bacteria growth and easy to clean, such as stainless steel or aluminum. Non-hygienic AHUs may be constructed with a wider variety of materials, such as galvanized steel or sheet metal.

3. Air filtration: Hygienic AHUs often have higher-efficiency air filters to remove particles and contaminants from the air supply, such as HEPA filters or ULPA filters. Non-hygienic AHUs may have lower-efficiency filters or no filters at all.

4. Airflow design: Hygienic AHUs are designed to minimize turbulence and promote laminar airflow, which can help reduce the spread of airborne contaminants. Non-hygienic AHUs may have less strict airflow requirements.

5. Maintenance requirements: Hygienic AHUs require more frequent maintenance and cleaning to ensure compliance with air quality standards. Non-hygienic AHUs may have less stringent maintenance requirements.

Overall, hygienic AHUs are designed to meet more stringent air quality requirements and are typically used in applications where maintaining clean air is critical to human health or product quality. Non-hygienic AHUs are suitable for a wider range of applications where air quality standards are less strict.

Suitability of Non-Hygienic AHUs for Supplying Cooled Air to Class C & D Rooms in Pharma Industrial Projects

Non-hygienic AHUs are not specifically designed to meet the stringent air quality requirements of pharmaceutical manufacturing facilities, which require a high level of cleanliness to prevent contamination. These rooms typically require HEPA or ULPA filters with a minimum efficiency of 99.97% for particles as small as 0.3 microns, and the air handling units serving these rooms must be designed to minimize turbulence and promote laminar airflow. Therefore, it is recommended to use hygienic AHUs that are specifically designed to meet these standards.

Using Non-Hygienic AHUs with HEPA Filters for Supplying Class C & D Rooms: Is it Acceptable?

Yes, it is possible to use non-hygienic AHUs with HEPA filters on the main supply duct for supplying Class C and D rooms in pharmaceutical manufacturing facilities. However, it is important to ensure that the AHUs are properly designed to maintain laminar airflow and minimize turbulence, and that the HEPA filters are installed and maintained correctly to meet the required air quality standards. Additionally, it may be necessary to periodically test the air quality within the rooms to ensure that the AHUs and filters are functioning as intended.