The below Specification of Air Handling Unit (AHU) helps you to guide for new pharmaceutical facility projects. This help you to generate your own specification for buying new air handling units. The Air Handling Unit (AHU) shall be constructed with double-skin panels and designed to meet the airflow, cooling, and heating capacities as specified in the Basis of Design. It will comprise multiple sections arranged sequentially in the airflow direction. The design and construction must ensure low energy consumption, ease of maintenance, and compliance with performance standards.
AHU Sections
The AHU will include the following sections:
A. Mixing Section
- Equipped with manually operated extruded aluminum low-leakage, airfoil-type dampers for return air and fresh air.
- Dampers must provide effective control over airflow and prevent leakage, even under varying pressure conditions.
B. Pre-Filter Section
- Designed to house flanged filters as specified in the Basis of Design.
- Inspection door with a minimum width of 500 mm and a view window for visual inspection without opening the section.
- Filters must ensure efficient particle removal and meet the required filtration efficiency.
C. Coil Section
- Insulated condensate tray constructed from SS 304, with a minimum thickness of 18 gauge.
- Tray must have a slope for efficient drainage and be connected to a condensate drain.
- Chilled water cooling coils and hot water heating coils designed to provide uniform heat exchange.
D. Fan Section
- Equipped with either:
- Plug fans with backward-curved aerofoil blades, direct-coupled with integrated inlet rings and pressure ports.
- Belt-driven centrifugal DIDW backward-curved aerofoil blade fans.
- Includes motor base frames, side rails, diffuser plates, and anti-vibration mounts for noise and vibration control.
E. Purge Section
- Designed for air diffusion and equipped with manually operated, extruded aluminum airfoil blade dampers for exhaust air control.
F. Fine Filter Section
- Houses flanged filters designed to provide secondary filtration as per design specifications.
G. Discharge Plenum
- Fitted with manually operated, extruded aluminum airfoil blade dampers at the supply air outlet to control discharge flow.
H. Dampers
- All dampers must be motorization-ready, with provisions for mounting modulating motors in the future.
- Dampers to have low-leakage blades with opposed operation for effective control.
I. Fixing Mechanism
- Filters must be securely fixed using wing nuts to allow for easy removal and replacement during maintenance.
Capacity and Performance
- Air Handling Capacity: As indicated in the Basis of Design.
- Static Pressure: Designed to accommodate system resistance while maintaining efficiency.
- Cooling/Heating Capacity: Verified through Factory Acceptance Tests (FAT).
Housing / Casing Construction
- Framework: Anodized extruded aluminum hollow sections with thermal break profiles. Joints assembled using die-cast aluminum for structural integrity.
- Panels:
- Double skin, 43 mm thick.
- Outer layer: Pre-plasticized 0.8 mm galvanized sheet steel (125–275 GSM).
- Inner layer: Plain 0.8 mm galvanized or SS 304 sheet.
- Insulation: CFC-free PUF or PIR, density ≥ 40 kg/m³, sandwiched between sheets.
- Sealing: Panels to be sealed with heavy-duty ‘O’ ring gaskets to ensure low air leakage (Class A of EN 1886).
- Doors: Hinged, quick-opening access doors with double-skin construction for fan and filter sections.
Drainage System
- Condensate Tray: Fabricated from 18-gauge SS 304 with a slope for complete drainage.
- Insulation: External insulation to prevent condensation, with a 40 mm male connector outlet nipple in SS 304.
Motor and Drive System
- Motors:
- Energy-efficient, as per IEEMA Std. 19-2000, efficiency norm 1.
- Voltage: 415 ±10%, 50 Hz, 3-phase squirrel cage.
- Enclosure: Totally enclosed fan-cooled, IP 55 protection, Class F insulation.
- Drive System:
- Plug fan or belt-driven arrangement.
- Belts: Heavy-duty, oil-resistant, flat belts with 120% motor power capacity.
- Pulleys: Precision-balanced, dynamically tested, taper-lock type.
Fans
- Type: Backward-curved, double inlet, double width (DIDW) or direct-mounted plug fans.
- Material: Fabricated from heavy-gauge galvanized steel.
- Performance:
- Fan outlet velocity: ≤ 1800 ft/min.
- Impellers dynamically balanced, operating at ≤ 90% of rated motor RPM.
- Mounting: Anti-vibration springs or cushy foot mounts to isolate vibration.
Coils
- Construction:
- Copper tubes (12.5–15 mm dia, 26G thickness) with aluminum fins.
- Hydrophilic coating for enhanced efficiency.
- Mounted in zinc-coated steel frames.
- Performance: Factory-tested at 21 kg/sq.m under water pressure.
- Air Velocity: ≤ 500 ft/min.
Note: Coil should be minimum 6 row or to meet the design requirements.
ARI certified computerized cooling coil selection output shall be submitted.
Filters
- Pre-Filters: 75 mm thick, cleanable and washable, with a filtration efficiency as specified.
- Secondary Filters: Fine or HEPA filters with efficiency tested as per BS 6540.
- Housing: Rigid construction of GI or aluminum sheets.
Accessories
- Inspection Doors: Die-cast aluminum hinges, view windows with double panes to prevent condensation.
- Lighting: Interior lighting in all sections with an external on-off switch.
- Monitoring Ports: Provision for temperature, humidity, and pressure sensor insertion.
- Bypass Dampers: Opposed-acting, airfoil-shaped aluminum blades with EPDM seals.
- Isolators: Cushy foot vibration isolators for AHU and spring mounts for fan/motor.
Safety Features
- Micro-switch interlocked fan access doors to switch off motor when opened.
- Earth grounding for fan and motor.
- Guards for fans and heater sections.
Testing and Validation
- Performance Testing: Conducted on-site and factory, covering airflow, cooling/heating capacities, and noise levels (<80 dBA at 1 m).
- Filter Testing: Random sampling for pre-filters and microvee filters at site.
- Certification: HEPA filters to be certified for efficiency using POA particles.
Installation
- Skid-mounted assembly with neoprene pads or vibro mounts.
- Continuous gaskets for air-tightness.
- All nuts, bolts, and fasteners zinc/nickel-plated.
Nameplate Details
The AHU shall have a nameplate with:
- Fan model:
- Motor HP:
- Frame size.
- Belt size,
- CFM details,
- filter sizes.
- Connected areas and terminal heater details.
Documentation
- Factory Acceptance Test (FAT) report.
- Filter efficiency and testing certificates.
- Detailed drawings for client approval.
Certifications and International Standards for Air Handling Units (AHUs)
Air Handling Units (AHUs) are critical components in Heating, Ventilation, and Air Conditioning (HVAC) systems, and their design, performance, and safety must comply with international standards and certifications. Below is a detailed overview of the key certifications, their governing bodies, and the associated parameters for AHUs.
1. AHRI (Air-Conditioning, Heating, and Refrigeration Institute) Certification
Scope:
AHRI certification ensures that AHUs meet specific performance standards for heating, cooling, and airflow. This certification is widely recognized in North America.
Standards Covered:
- AHRI 430: Performance rating of central station air-handling units.
- AHRI 410: Standard for forced-circulation air-cooling and air-heating coils.
- AHRI 440: Standard for indoor central-station air-handling units.
Key Parameters Tested:
- Thermal Performance: Ensures cooling and heating coils deliver the required thermal performance.
- Airflow Accuracy: Verifies the unit delivers the rated airflow at specified conditions.
- Static Pressure Drop: Measures fan and system resistance to ensure energy efficiency.
- Sound Levels: Confirms noise levels are within acceptable limits.
Certification Process:
Manufacturers submit AHUs for independent laboratory testing to validate performance claims. Once certified, units are listed in the AHRI Certified Product Directory.
2. EUROVENT Certification
Scope:
EUROVENT Certification is primarily recognized in Europe and ensures compliance with European standards for energy efficiency and performance.
Standards Covered:
- EN 1886: Mechanical performance of air handling units.
- EN 13053: Performance of air handling units, including thermal and airflow parameters.
Key Parameters Tested:
- Thermal Insulation: Thermal transmittance (U-value) and thermal bridging factor (TB).
- Leakage Class: Internal and external air leakage rates under specified pressure conditions.
- Casing Strength: Mechanical strength of the AHU casing under pressure.
- Filter Bypass Leakage: Efficiency of the filter housing in preventing unfiltered air bypass.
- Acoustics: Measurement of noise emission levels.
- Energy Efficiency: Evaluation of the unit’s energy consumption against EU standards.
Certification Process:
Independent testing and regular audits ensure compliance with EUROVENT standards. Certified units are listed in the EUROVENT Certification Directory.
3. CE (Conformité Européenne) Marking
Scope:
CE marking is mandatory for AHUs sold in the European Economic Area (EEA) and ensures compliance with health, safety, and environmental protection standards.
Key Directives Covered:
- Machinery Directive (2006/42/EC): Safety of mechanical parts such as fans, dampers, and casing.
- Low Voltage Directive (2014/35/EU): Electrical safety of motors and controls.
- Electromagnetic Compatibility Directive (2014/30/EU): Prevention of electromagnetic interference.
- Eco-Design Directive (2009/125/EC): Energy-related performance requirements for fans and motors.
Key Parameters Tested:
- Safety Features: Verifies mechanical and electrical safety measures.
- Energy Efficiency: Ensures compliance with the EU’s Minimum Energy Performance Standards (MEPS).
- Environmental Impact: Confirms adherence to RoHS (Restriction of Hazardous Substances) and WEEE (Waste Electrical and Electronic Equipment) regulations.
Certification Process:
Manufacturers must perform a conformity assessment and issue a Declaration of Conformity (DoC) to affix the CE mark.
4. ISO (International Organization for Standardization) Certification
Scope:
ISO certifications are globally recognized standards for quality management, environmental impact, and energy performance.
Key Standards Covered:
- ISO 9001: Quality management systems for manufacturing processes.
- ISO 14001: Environmental management systems to ensure sustainable production practices.
- ISO 16890: Air filter performance evaluation, replacing the EN 779 standard.
- ISO 50001: Energy management systems for improving energy efficiency.
Key Parameters Tested:
- Manufacturing Quality: Ensures consistent production quality and product reliability.
- Energy Efficiency: Measures compliance with global energy conservation goals.
- Environmental Impact: Evaluates waste reduction, emissions, and material use.
Certification Process:
Independent auditing bodies assess compliance with ISO standards, and certified products are issued an ISO certificate.
5. Other Notable Certifications
ETL (Electrical Testing Laboratories) / UL (Underwriters Laboratories):
- Ensures compliance with North American safety standards for electrical components.
- Relevant UL standards include UL 1995 (Heating and Cooling Equipment) and UL 94 (Flammability of Plastic Materials).
AMCA (Air Movement and Control Association) Certification:
- Focuses on fan performance, efficiency, and sound levels.
- Standards include AMCA 210 (Laboratory Methods of Testing Fans) and AMCA 300 (Reverberant Room Method for Sound Testing).
HEPA Filter Certification:
- Tested under BS EN 1822 for filtration efficiency.
- Parameters include penetration rates for particles ranging from 0.1 to 0.3 microns.
Importance of Certifications
- Performance Assurance: Verifies that the AHU meets advertised thermal, airflow, and filtration performance.
- Energy Efficiency: Ensures compliance with stringent energy standards, reducing operational costs.
- Safety Compliance: Guarantees safe operation of mechanical and electrical components.
- Global Market Access: Certified AHUs meet the regulatory requirements for various regions, enabling international sales.
- Environmental Responsibility: Demonstrates adherence to eco-friendly and sustainable practices.
By adhering to these certifications and standards, AHUs achieve a balance of efficiency, safety, and performance, ensuring reliability in diverse applications.
Frequently Asked Questions
What is AHU in the pharmaceutical industry?
An Air Handling Unit (AHU) is a key component in the HVAC system, designed to control temperature, humidity, air filtration, and cleanliness in pharmaceutical environments to maintain compliance with Good Manufacturing Practices (GMP).
What is HVAC in the pharmaceutical industry?
Heating, Ventilation, and Air Conditioning (HVAC) systems in the pharmaceutical industry regulate environmental conditions such as temperature, humidity, airflow, and particulate levels to ensure product safety and process efficiency.
What is CFM for AHU?
CFM (Cubic Feet per Minute) refers to the volumetric airflow delivered by the AHU. It is a standard measure to indicate how much air is supplied or exhausted.
How many CFM is equal to 1 TR?
1 TR (ton of refrigeration) is approximately equal to 400 CFM for air conditioning purposes.
What are the requirements for AHU?
Key requirements for pharmaceutical AHUs include:
- HEPA filtration for air purity.
- Temperature and humidity control.
- Compliance with GMP and ISO standards.
- Energy-efficient operation and minimal air leakage.
What is the full form of CFM?
CFM stands for Cubic Feet per Minute.
What is AHU principle?
The principle of an AHU is to condition and circulate air by cooling, heating, humidifying, dehumidifying, or filtering it, ensuring the desired indoor air quality.
What is the micron size of bag filter in AHU?
Bag filters in AHUs typically have a filtration efficiency for particles as small as 5–10 microns, depending on the application.
What is the logic of AHU?
The AHU logic includes controlling air temperature, humidity, and pressure differentials while maintaining air quality and energy efficiency to meet specific environmental conditions.
What is HVAC qualification as per ISO?
HVAC qualification as per ISO involves validating the system’s ability to consistently meet specified performance criteria, including parameters like temperature, humidity, airflow, and filtration efficiency.
How many types of HVAC are there?
There are four main types of HVAC systems:
- Split systems
- Hybrid systems
- Duct-free systems
- Packaged systems
What are the relative humidity limits in the pharmaceutical industry?
Typically, relative humidity (RH) limits range between 40% and 60%, depending on the product and process requirements.
What is AHU in pharma?
An AHU in pharma refers to a unit used for controlling air purity, temperature, and humidity to maintain a contamination-free environment.
What is GMP HVAC?
GMP HVAC refers to HVAC systems designed and validated to comply with Good Manufacturing Practices, ensuring controlled environments for pharmaceutical production.
What is area qualification?
Area qualification involves verifying that a specific room or zone meets the required cleanliness, temperature, and humidity standards for pharmaceutical operations.
What is HVAC validation?
HVAC validation ensures the HVAC system consistently performs as intended, meeting specified regulatory and environmental criteria.
WHO guidelines for compressed air?
WHO guidelines for compressed air include specifications for purity levels, particulate contamination, humidity, and oil content, ensuring its suitability for pharmaceutical use.
What is the full form of API in pharma?
API stands for Active Pharmaceutical Ingredient.
What is AHU in HVAC?
An AHU in HVAC is a component that conditions and distributes air as part of the overall heating, ventilation, and air conditioning system.
What is the pressure differential limit in pharmaceuticals?
Pressure differential limits typically range from 10–15 Pascals (Pa) between adjacent classified areas to prevent cross-contamination.
What is HVAC details?
HVAC details include components (AHU, chillers, ducts, filters), parameters (temperature, humidity, airflow), and system types (centralized, decentralized).
What is the working principle of HVAC system?
HVAC systems work by transferring heat, managing airflow, and filtering air to maintain desired environmental conditions.
What is pharmaceutical air?
Pharmaceutical air refers to air that is filtered, controlled, and treated for use in production processes, ensuring compliance with quality standards.
What is in thermostats?
Thermostats contain sensors and controls to regulate temperature by turning heating or cooling devices on or off.
How does AHU work in the pharmaceutical industry?
AHUs in pharma filter, condition, and circulate air to maintain strict cleanliness, temperature, and humidity standards required for product safety and efficacy.
What is HVAC in design?
HVAC design involves planning and engineering systems to control environmental conditions like air quality, temperature, and humidity efficiently.
What is HVAC treatment?
HVAC treatment includes air filtration, cooling, heating, and humidification/dehumidification to create a controlled environment.
What is the role of HVAC?
HVAC systems ensure comfort, energy efficiency, and controlled environments for industrial and pharmaceutical processes.
What is area qualification in pharma?
It verifies that production or cleanroom areas meet predefined environmental conditions for air quality, temperature, and humidity.
What is a condenser in the pharma industry?
A condenser in pharma removes heat from vapors, converting them into liquid for processes like solvent recovery or air conditioning.
What is an example of HVAC?
An example of HVAC is a centralized air conditioning system used in a pharmaceutical cleanroom.
What is the full form of AHU?
AHU stands for Air Handling Unit.
Is HVAC a direct impact system?
Yes, HVAC is a direct impact system in pharmaceuticals as it directly affects product quality, cleanroom conditions, and regulatory compliance.