Heating, ventilation and air conditioning (HVAC) system is the technology of indoor and vehicular environmental comfort. It is one of the most important factor for maintaining acceptable indoor air quality in buildings. A clean and well-maintained HVAC system is more environmentally friendly. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer.
- Air Conditioner – Connected to the inside cooling coil, the compressor pumps refrigerant back and forth, extracting heat and moisture from the indoors. It transfers the heat to the outdoors. Warm indoor air is blown over the indoor cooling coil, then is cooled and distributed throughout your home.
- Air Handler – Matched in capacity and efficiency rating with the air conditioner, air handlers circulate conditioned air throughout your home. An air handler contains an inside coil and a blower fan, with the additional possibility of an auxiliary electric strip heater. Trane air handlers are available with single- or variable-speed motors. Variable-speed models are known for soft starts, high humidity control features and 12 selectable levels of airflow capacity, as well as the enhanced comfort mode, the Comfort-R™ airflow system.
- Air Cleaner – An integral part of a home comfort system, filtering dust and pollutants out of the air you breathe, and keeping your rugs and home furnishings cleaner as well. Reduced pollen, dust, pet dander, smoke, etc., could help reduce allergy and asthma discomfort. HEPA "(high efficiency particulate air [filter])" is a type of air filter can theoretically remove at least 99.97% of dust, pollen, mold, bacteria, and any airborne particles with a size of 0.3 microns (µm).
A humidifier is a machine that can be added to any central heating and cooling system to monitor the humidity levels in a home and increase humidity when needed.
- The humidifier unit uses a humidity-sensing control that cycles the humidifier on and off and a water panel that adds water vapor to the circulated air when needed. Relative humidity is the amount of moisture in the air expressed as a percentage of the maximum amount that the air is capable of holding at a specific temperature. In dry air conditions, the sensor tracks that percentage and adjusts the amount of added water vapor, giving your skin the moisture it needs and helping to keep any personal belongings, such as wood floors, furnishings, and keepsakes, from drying out. In essence, it’s one more way Trane makes your home more comfortable all year long.
- The cooling coil with incoming temperature is range to 5-7 degree Celcius and travel back to chiller around 11-14 degree Celcius. The temperature range is fully depend on the temperature requirement in each room respectively.
- The chiller capacity is depend on the total cooling load for the whole AHU systems. the type of chiller depends on the Cooling capacity . For Example, if the cooling capacity range to 700-2800 kW, we normally choose Screw / Centrifugal type of Compressor Water cooled Chiller.
- The air is then transfer to each room and filtered again through HEPA filter with 99.995% efficency.
- Volume of air transfer to each room control by VAV which is known as variable air volume located at the returned duct.
- Cooling Tower for a water cooled condenser are the effecitve removal of total heat rejected at the condenser and the minimization of the sum of power consumption in compressor , condenser fans and condenser water pumps.
The design, installation, commissioning and qualification of clean rooms heating, ventilation and air conditioning (HVAC) systems is often one of the largest considerations in the design of a new pharmaceutical or biotechnology manufacturing facility. With high running costs (energy associated with the movement, cooling and heating of air) and the potential to impact upon safety and product quality, getting them right is important for business, safety and good manufacturing practice (GMP) criticality.
- The design of the HVAC system will be based upon the clean room suite that it serves, and will be affected by factors such as the number of rooms served, the layout of the rooms, the equipment within the rooms and, most critically from a qualification perspective, the environmental conditions that the rooms must achieve.
- The air handling unit helps maintain each room's clean environment by providing an appropriate volume of clean air to each room at the correct temperature and humidity.
- The air is filtered by pleated paper filters called high efficiency particulate air (HEPA) filters which, depending upon the classification of the rooms, are located either within the air handling unit or where the air enters each room. Cooling and heating coils are also located within the air handling unit, increasing or decreasing the air temperature to ensure that the room temperatures remain within specification.
Importance of HVAC system in Pharmaceutical Industry
HVAC system is an important part of pharmaceutical manufacturing facility to maintain the indoor environment with desired temperature, humidity and air class.
Reliable operation of the air handling unit within established limits is critical, not only to prevent product quality from being compromised by poor air conditioning, but also for the following reasons:
- to prevent cross contamination of products.
- to maintain operator safety, where the HVAC is being used for this purpose.
- to maintain product safety, where the HVAC is being used for this purpose.
Validation of HVAC System
The objective of HVAC system is to requalify the HVAC system of all area including air handling units, ventilation units, exhaust units, laminar air flow and reverse laminar air flow are qualified to perform well within the predetermined acceptance limit.
Qualification of HVAC Systems
As per PICS guideline qualification of HVAC systems include -
- DQ, IQ, OQ and PQ
- Average speed and uniformity of airflow
- Pressure differentials
- Air changes
- Integrity and tightness of terminal installed final filters
- Number of particles
- Recovery tests
- Air temperature
- Smoke tests
- Requalification (parameters for requalification)
- Change control
DESIGN MANAGER AIR HANDLING UNIT
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