Air Handling Unit (AHU) Requalification Protocol

Protocol For Qualification / Requalification of Air Handling Unit / System (AHU). This protocol describes the procedure for different tests methods, acceptance criteria, requalification criteria and documentation to be used for requalification of Air handling unit (AHU) serving to manufacturing area of Drug Product.

Qualification of Air handling unit (AHU)

Sr No.	Item Description	Page No.
1.0	Protocol Approval
2.0	Objective
3.0	Scope
4.0	Responsibility
5.0	Requalification check list
6.0	Requalification test Procedure
6.1	Air Velocity and Air Changes
6.2	Filter Integrity test
6.3	Differential pressure test
6.4	Airflow Pattern test
6.5	Temperature and Relative humidity test
6.6	Non- Viable Particle count test
6.7	Decontamination study
6.8	Microbial monitoring
6.9	Sound level test
7.0	Requalification Criteria
8.0	Documentation

1.0 PROTOCOL APPROVAL – QUALIFICATION OF AIR HANDLING UNIT (AHU):

Signing of this Approval page of Requalification Protocol No.________________ indicates agreement with the Requalification approach described in this protocol for Air Handling Unit (AHU).
Preparation of this Requalification protocol is the responsibility of Validation Coordinator.

Prepared By	Department	Designation	Sign & Date
	Quality Assurance

Review of this Requalification protocol is the responsibility of Validation Coordinator.

Reviewed By	Department	Designation	Sign & Date
	Engineering
	Production
	Quality Control
	Quality Assurance

Approval of this Requalification protocol is the responsibility of the Head of department.

Approved By	Department	Designation	Sign & Date
	Engineering
	Production
	Quality Control
	Quality Assurance

2.0 OBJECTIVE :

- The objective of requalification of Air handling unit (AHU) is to verify previously established parameters and to have a documented evidence to assure that the set parameters are achieved.

3.0 SCOPE :

- This protocol describes the procedure for different tests methods, acceptance criteria, requalification criteria and documentation to be used for requalification of Air handling unit (AHU).

4.0 RESPONSIBILITY :

DEPARTMENT	RESPONSIBILITY
Quality Assurance Officer / Executive	Preparation and Review of Protocol, Monitoring the requalification activities.
Production Officer / Executive	Execution support during Requalification.
Quality control Officer/Executive	Execution support during Requalification.
Engineering Officer / Executive	Provide necessary execution support for the proper operation of the system.
Engineering Head	Protocol review and approval.
Production Head	Protocol review and approval.
Quality control Head	Protocol review and approval.
Quality assurance Head	Protocol review and approval.

5.0 REQUALIFICATION CHECKLIST – AIR HANDLING UNIT (AHU):

- Verify the fresh air, Supply air and Return air damper is properly marked.

- Verify the insulation of duct for any physical damages.

- The system is properly earthed.

- Verify that there is no observable physical damage.

- Equipment /system identification number visible.

- Verify that all the access door is properly closed and there is no any air leakage across it.

- Verify the functional parameter for AHU.

- Calibration of all critical gauges installed in the system.

6.0 REQUALIFICATION TEST PROCEDURE:

- Air Velocity and No. of Air Changes per hour (ACPH)

- Filter Integrity test

- Differential pressure test

- Airflow Pattern test

- Temperature and Relative humidity test

- Non- Viable Particle count test

- Decontamination time study

- Viable counts (Active and Passive).

- Sound level test.

6.1.0 AIR VELOCITY MEASUREMENT AND CALCULATION OF AIR CHANGES:

6.1.1 Objective:

- To demonstrate that the air system is balanced and capable of delivering required air volume and providing number of air changes per hour as per design.

6.1.2 Instrument Used:

- Anemometer.

6.1.3 Method Applied:

- Ensure that the Air handling unit (AHU) is switched “ON” prior to the start of requalification.

- Ensure the Calibration status of the Anemometer.

- Open the grill and measure the air velocity Approx. 2 inches below the filter, at 5 different locations (Four Corners and center) with the Anemometer and record.

- Calculate the average velocity of the air coming from Supply filter.

- Calculate the air volume by multiplying the average velocity with the effective filter area.

- Air flow volume (CFM) = Average Velocity x Face Area of the supply filter

= Ft / Min. X Ft ²

= Ft ³/ Min. or CFM

- Calculate the airflow for all the Supply Grill in the room and add values to get the total airflow in the room (CFM).

- Calculate the number of air changes per hour in the room using the formula:

Air Changes / hour = Total air flow in the room (CFM) x 60

Room Volume (Ft ³⁾

6.1.4 Acceptance Criteria:

- Minimum and maximum velocity and subsequent airflow across the HEPA filter should be within the design specification range to achieve the specified Air changes.

- A variation in air volume should not be more than 20% from the design CFM.

6.1.4 Result Recording:

- Raw data shall be collected in the data sheet.

- Measure and Record the air velocity at five points of each Supply filter.

- Recording shall be done in data sheet No.2 for respective rooms.

- Calculate the average velocity and no. of air changes per hour then record the same in data sheet No.2.

6.1.6 Evaluation of result:

- The air volume (CFM) across the HEPA filter should comply with the design specifications.

- The no. of air changes per hour should not be less than design datasheet.

- If velocity is not within the specified limit, damper should be regulated and if the minimum velocity is not achievable, filter should be changed as per defined procedure, irrespective to other test complying with the acceptance criteria.

6.2.0 INTEGRITY TEST OF HEPA FILTERS:

6.2.1 Objective:

- To check the integrity of installed HEPA filters.

6.2.2 Instrument Used:

- Cold DOP smoke generator Aerosol photometer, duly calibrated with national / international traceability certificate.

6.2.3 Method Applied:

- Position the smoke generator near fresh air damper and introduce DOP aerosol into the mixing chamber by opening both port 1 and 2.

- First check the upstream for DOP aerosol and Set the instrument at 100% concentration against upstream.

- Scan the downstream side of the filter with an appropriate photometer probe at a sampling rate of 1 CFM.

- The probe should scan the entire filter face and frame at a position about 1 to 2 inches from the face of the filter.

- Scanning shall be done at a maximum rate of 2 feet per minute.

6.2.4 Acceptance Criteria:

- During scanning percentage of the DOP penetration shown by photometer should be less than 0.01% through the filter media and should be ‘zero’ through mounting joints.

6.2.5 Result Recording:

- Record the results in the data sheet No.3.

- Record the details of the instruments used including its calibration status, filter identification number, upstream and downstream concentration of DOP.

- Attach the calibration certificate of the photometer with the report.

6.2.5 Evaluation of result:

- Results, complying with the acceptance criteria, shall establish the integrity of the HEPA filter suitable for respective area.

- If any leakage is observed from the mounting, it should be rectified through adjustment and application of food grade silicone sealant.

- If leakage is observed from the Filter media more than the acceptable limit, filter shall be replaced with new one as per defined procedure and qualified.

6.3.0 AIR PRESSURE DIFFERENTIAL TEST – AIR HANDLING UNIT (AHU):

6.3.1 Objective:

- To verify differential pressure with respect to the adjacent area.

6.3.2 Instrument Used:

- Magnehelic gauges

6.3.3 Method Applied:

- The Air handling unit (AHU) and respective dust collection system shall be in operation during this study.

- To avoid unexpected changes in air pressure and to establish a baseline, all doors in the facility must be closed and no personal movement should be allowed during the test.

- Observe the differential pressure through Magnehelic gauge.

- Differential pressure of the room shall be recorded once in two hours and it shall be continued for 72 hours.

6.3.4 Acceptance Criteria:

- Pressure differentials between the rooms shall be maintained as per the table mentioned below.

Room name	Pressure Gradient (In MM WC)	Acceptance limit
Solution Preparation w.r.t Corridor	NLT 1.5 mm WC	1.5 to 2.5mm WC

- Pressure differentials should be maintained as indicated in the design conditions under standard operating condition.

6.3.5 Result Recording:

- Measure and record differential Pressure in the data sheet No.4.

6.3.6 Evaluation of Results:

- Results, complying with the acceptance criteria and design requirement shall indicate the correct air pressure balancing of Air handling unit (AHU).

- Transient drop in differential shall be recorded and investigation shall be done to find out the reason. Corrective action shall be taken if required.

6.4.0 AIRFLOW PATTERN TEST -AIR HANDLING UNIT (AHU) :

6.4.1 Objective:

- To verify that the air flow is maintained throughout the operation.

- The air contaminants should be flushed from the supply filter and it should sweep towards the return riser installed in the area.

6.4.2 Procedure:

- Take a glass rod with cotton or sponge tied to it.

- Dip it in Titanium Tetrachloride solution (TiCl₄) and check for airflow direction in the rooms, under terminal grill, return filter or grill and corridor to process area with the doors of the room both in open and closed condition.

- Carry out the videography/photography for the same test.

6.4.3 Acceptance Criteria:

- Air should flow from the higher-pressure zone to lower pressure zone.

- The air should flow towards the return air filter or grill.

- Videography/Photography shall be carried out to demonstrate the air flow.

6.4.4 Observations and Result Recording:

- Observe the air flow pattern as per the procedure mentioned above and record in the data sheet No.5

6.4.5 Evaluation of Result:

- Analyzing the airflow pattern, recorded in the test report, it can be concluded that the airflow pattern, follows the acceptance criteria.

6.5.0 TEMPERATURES AND RELATIVE HUMIDITY CONTROL TEST

6.5.1 Objective :

- To verify the ability of the Air handling unit (AHU) to maintain temperature and Relative Humidity within the specified range throughout the operation.

6.5.2 Instrument Used:

- Thermometer & RH sensor (Sling psychrometer)

6.5.3 Method Applied:

- Air handling unit (AHU) shall be in operation for at least 20 minutes prior to performing these tests.

- All lights in the critical and controlled areas should be ON during the testing.

6.5.4 Acceptance Criteria:

- The temperature of the area should be 23 ± 4^oC and the Humidity should be 50% ± 5.

- The monitoring shall be carried out at an interval of 2 hours and record for 72 hours.

6.5.5 Results:

- Measure and record temperature and RH using sling psycychrometer.

- Record the observations for critical processing area or where processed material is stored in the data sheet No.6.

6.5.6 Evaluation of Result :

- On the basis of observations recorded in the test reports, it can be concluded that the Air handling unit (AHU) is capable of consistently maintaining the required temperature and relative humidity in the controlled areas.

6.6.0 NON –VIABLE AIR BORNE PARTICLE COUNT TEST

6.6.1 Objective:

- To establish all classified areas meet the requirement for cleanliness class as per ISO 14644 1standard.

- Air sample should be taken near the equipment at working height.

6.6.2 Equipment Used:

- Air borne particulate counter, duly calibrated with national / international tractability.

6.6.3 Method Applied:

- Air conditioning system shall be in continuous operation for at least 20 minutes prior to performing these tests.

- Particulate count for all pre decided location (layout attached) in each location takes 1 reading at the working height, shall be taken.

- Number of sampling location will be decided as per the ISO 14644-1.

N_L = √A

- Where N_L is the minimum number of sampling locations (Rounded up to a whole number)

- Where A is area of the cleanroom or clean zone in square meters.

- UCL factor for 95% upper confidence limit for different number of locations is indicated in the Following table.

- UCL Factor for 95% upper confidence limit

No. of locations (L)

* When the number of locations is greater than 9 and less than 2, the calculation of a UCL is not required.

	UCL Factor for 95% upper confidence limit
No. of locations (L)	2	3	4	5-6	7-9	>9*
95% UCL Factor	6.3	2.9	2.4	2.1	1.9	NA
* When the number of locations is greater than 9, the calculation of a UCL is not required.

Area Name	Grade	Area (m²)	No. of Locations	Location No.

6.6.3 Acceptance Criteria :

- The clean room or clean zone shall meet the acceptance criteria for an air borne particulate cleanliness if

- - The average of the particulate count measured at each location falls at or below the class limit

- - The mean of these averages falls at or below class limit with a 95% confidence limit (as referred in standard ISO 14644-1).

- The particle count of the area should not be more than 3520000 (³ 0.5 m size) and 29300 (³ 5.0m size) per cubic meter “at rest condition”.

6.6.3 Result Recording :

- Data shall be collected in the data sheet.

- Measure and Record the particulate count at various locations as per attached sheet.

- Recording shall be done in data sheet No.7

- Calculate the average count for each location / zone and record.

- Average count at each location / zone shall be used to calculate 95% upper confidence limit (UCL) for each area.

- Calculation is given in the data sheet with reference to standard ISO 14644-1.

- Attach the calibration certificate of Particle Counter.

6.6.5 Evaluation of result:

- The calculated UCL count should be as per the specified class range for individual areas.

6.7.0 DECONTAMINATION STUDY – AIR HANDLING UNIT (AHU) :

6.7.1 Purpose:

- To verify the decontamination time study against the established recovery period.

6.7.2 Instrument Used :

- Air borne particulate counter, duly calibrated with national / international traceability.

6.7.3 Method Applied :

- Start the Air handling unit (AHU), wait for 20 minutes and take the samples (near return riser and at working height) for enumeration of particles of >0.5m and > 5.0m particles and take the reading for temp. and RH.

- Switched off the Air handling unit (AHU), start the particle count monitoring at an interval of 1 minute until the particles shall reach more than the specified class.

- Record the temp. and RH when area shall reach more than the specified class.

- Again start the Air handling unit (AHU) and take the sample for enumeration of particles of >0.5m and > 5.0m particles.

- Take the samples at an interval of 1 minute and it shall be continued till the desired level of cleanliness (approx. initial particle count reading) is achieved and take the reading for temp. and RH when desired level of temp. and RH (approx. initial reading) is achieved.

6.7.4 Acceptance Criteria

- The recovery period should not be more than 20 minutes.

6.7.5 Result Recording

- Record the observations in data sheet no. 8.

6.7.6 Evaluation of result:

- Record the recovery time of the AHU in the data sheet No.8

6.8.0 MICROBIAL MONITORING – AIR HANDLING UNIT (AHU):

(A) PASSIVE AIR SAMPLING

6.8.1 Objective:

- To determine the viable air borne microbial contamination level by exposing settle plate in the defined areas.

6.8.2 Procedure

- SCDA plates shall be exposed on plate exposing stand in the area.

- Plate exposure shall be done under dynamic condition.

- Plate shall be exposed for 4 hours.

- Exposed plate shall be incubated at 30 to 35°C for 48 Hrs followed by 20 to 25°C for 72 Hrs.

- Plates shall be observed for any microbial growth after 5 days.

- In dynamic condition, mock machine operation with normal man movement shall be there.

- The Sampling shall be done for seven consecutive working days.

6.8.3 Acceptance Criteria:

S.No	Classification	CFU/90 mm Plate (exposed for4 hrs.)
01	ISO 6	<3
02	ISO 7	<5
03	ISO 8	<50

(B) ACTIVE AIR SAMPLING:

6.8.4 Procedure:

- Operate the Air sampler as per the SOP and collect air samples of 1000 L volume at the designated locations as per the sampling plan attached.

- Sampling shall be carried out in dynamic condition.

- After sampling remove the plate from the sampler aseptically.

- Exposed plates shall be incubated at 30 to 35°C for 48 Hrs followed by 20 to 25°C for further 72 Hrs.

- In dynamic condition, mock machine operation with normal man movement shall be there.

- The Sampling shall be done for seven consecutive working days.

6.8.5 Acceptance Criteria

S.No	Classification	CFU/ 90 mm plate
01	ISO 6	<7
02	ISO 7	<10
03	ISO 8	<100

6.8.6 Evaluation of Result

- All microbial result complying with the acceptance criteria will establish the microbial environment suitable for operation.

6.9 SOUND LEVEL TEST – QUALIFICATION OF AIR HANDLING UNIT (AHU) :

6.9.1 Objective :

- To verify the air borne sound generated due to operation of Air handling unit (AHU).

6.9.2 Instruments used for testing:

- Sound level meter

6.9.3 Method Applied

- All the noise/sound making system in the proximity of the area shall be switched off.

- Start the AHU and take the sound level reading for supplied areas.

- ON the sound level meter, set it at fast response mode and take the reading in area.

6.9.3 Acceptance criteria

- The sound level should be less than 65 db in the working area.

6.9.4 Result Recording

- Data shall be collected in the data sheet.

- Measure and record the sound level at the working height and recording shall be done in data sheet.

6.9.5 Evaluation of result

- Record the sound level in the data sheet.

7.0 REREQUALIFICATION CRITERIA OF AIR HANDLING UNIT (AHU) :

- System should be revalidated under following conditions.

7.1.0 Major changes:

- If any major changes or modification in the system is done.

- When any Major changes have been done in the respective room or module, which is affecting the environmental condition.

- If any major maintenance has taken place in the system which can affect the performance of Air handling unit (AHU).

7.2.0 Periodic Requalification of Air handling unit (AHU):

Sr. No.	Test	Frequency
1	Particle Count	Twice in a year
2	Air Velocity	Once in a year
3	Room pressurization	Once in a year
4	Filter Integrity	Once in a year
5	Airflow Pattern	Once in a year
6	Temperature and RH	Once in a year
7	Recovery and power failure	Once in a year
8	Air velocity of dust extraction system	Once in a year
9	Sound level test	Once in a year

Note: For recording the results/observations during requalification of Air handling unit (AHU), only annexures of the parent protocol shall be used.

8.0 Documentation of Qualification of Air Handling Unit (AHU) :

- Results and reports shall be compiled in a binder. Binder shall contain the following sequentially

- - Requalification Protocol

- - Requalification Reports

- Conclusion should be the last paragraph of the report, which should clearly state the compliance or failure to meet the objective of the protocol.

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