انظمة التدفئة – التهوية – تكييف الهواء HVAC systems

Technical Specifications – HVAC for Laboratories

1. General Requirements

• The HVAC system shall provide ventilation, air conditioning, and air quality control according to laboratory standards.
• System design shall comply with ISO 14644-1 (Cleanroom Standards), ASHRAE 170 (Laboratory Ventilation), and local safety regulations.
• The system must maintain constant temperature, humidity, and air pressure differentials to avoid contamination between areas.
• The system must be energy-efficient with variable frequency drives (VFDs) for fans and pumps.

2. Air Handling Units (AHU)

• AHUs shall be modular and corrosion-resistant, suitable for chemical-lab environments.
• Filters:
  • Pre-filter: G4/G3 (removable, washable).
  • HEPA filter: H13/H14 for cleanrooms and critical areas.
• Cooling & Heating Coils: Copper/aluminum or stainless steel, designed for chilled water or DX systems.
• Fans: Forward-curved or plug fans with low noise and vibration.
• AHUs shall be equipped with humidity control and sensors.
• AHUs must allow easy access for maintenance and filter replacement.

3. Ducting

• Ducts constructed of galvanized steel with airtight joints, internally lined with sound-absorbing material if required.
• All ducting in critical areas shall be smooth, sealed, and leak-proof.
• Branch ducts to laboratories must have adjustable volume dampers.

4. Air Distribution

• Diffusers and grilles: Stainless steel or powder-coated steel, easy to clean.
• Laminar airflow diffusers for cleanrooms if required.
• Return air: Separate ducts for exhaust air to maintain negative pressure in hazardous labs or positive pressure in cleanrooms.

5. Pressure Control

• The system shall maintain pressure differentials between zones:
  • Negative pressure for chemical/fume labs.
  • Positive pressure for cleanrooms or storage of sensitive chemicals.
• Pressure monitoring devices installed with local display and remote monitoring capability.

6. Temperature and Humidity Control

• Temperature control: ±1 °C stability.
• Relative Humidity (RH) control: ±5% stability.
• Control panels with PLC or BMS integration.
• Adjustable setpoints for each laboratory or zone.

7. Exhaust System

• Dedicated exhaust for fume hoods, wet labs, and chemical areas.
• Exhaust fans must be corrosion-resistant, chemical-resistant, and vibration-isolated.
• Air must be discharged safely according to local environmental regulations.