English
HVAC Selection for Food Cleanrooms
Created on 12.24
The HVAC system in a food cleanroom not only provides cooling, dehumidification, and air circulation but also plays a key role in ensuring food safety, maintaining cleanliness, and complying with regulatory standards. The selection should focus on temperature and humidity control, cleanliness class, airflow requirements, and system type (AHU or MAU).
1. Temperature and Humidity Requirements
Different processes have different requirements, but general guidelines are as follows:
Temperature:
General food processing areas: 18–26°C
Fine processing or cold processing areas (e.g., chocolate, bakery pre-processing): 18–22°C
High-heat processing zones (steaming, frying) require separate exhaust to avoid impacting clean areas
Relative Humidity (RH):
General areas: 45–65% RH
Moisture-sensitive powders or sugar: ≤60% RH
Low-humidity zones may require independent dehumidification or reheating control
Stable temperature and humidity are essential for preventing microbial growth, mold, or condensation.
2. Cleanliness Class Requirements
Food cleanrooms typically have lower cleanroom standards than pharmaceutical labs but still require strict particle control:
Area Type | Common Cleanliness Class |
Raw material handling | ISO Class 8 (100,000-level) |
Fine processing / inner packaging | ISO Class 7 (10,000-level) |
High-risk exposure zones (ready-to-eat, sterile packaging) | ISO Class 6–7 (1,000–10,000-level) |
Cleanliness class determines:
Air change rate (ACH)
HVAC airflow volume
Filter configuration (Pre-filter + Medium filter + HEPA)
3. Airflow Requirements
Typical Air Change Rates (ACH):
Cleanliness Class | ACH (times/hour) |
ISO Class 8 | 10–20 |
ISO Class 7 | 20–40 |
ISO Class 6 | 40–60 |
Design Considerations:
Supply airflow ≥ exhaust + leakage to maintain positive pressure
High humidity or high-heat zones require separate airflow calculations
Typically 10–15% airflow redundancy is reserved
4. AHU vs. MAU for Food Cleanrooms
4.1 Packaged Air Handling Unit (AHU)
Use Cases:
Medium to high cleanliness zones (ISO 7–8)
Stable temperature and humidity requirements
Controlled return air conditions
Features:
Mixed air (return + fresh) operation
Lower energy consumption
Can include cooling coil, heating coil, humidifier, and reheat section
Serves as the main cleanroom HVAC system
Most commonly used solution for food cleanrooms
4.2 Make-Up Air Unit (MAU / 100% Fresh Air)
Use Cases:
Areas with strong odors or high contamination risk
Zones where return air is not permitted
Often used in conjunction with AHU
Features:
100% fresh air
Quickly removes odors and contaminants
Higher energy consumption
Usually combined with AHU or FFU systems
Not recommended as the sole HVAC solution for the entire cleanroom
5. Recommended Configuration
ISO 8–7 food cleanrooms:
High-risk ready-to-eat zones:
Key Points:
Stable temperature and humidity control
Adequate air change rate and airflow
Positive pressure gradient design
Multi-stage filtration
Conclusion
Food cleanroom HVAC selection should prioritize temperature and humidity stability, appropriate cleanliness class, and proper airflow. Typically, a packaged AHU serves as the main system, optionally supplemented by MAU 100% fresh air units. Proper system selection ensures food safety, energy efficiency, and regulatory compliance.
Contact
Leave your information and we will contact you.
WhatsApp