Operation & Maintenance of AHUS of Sterile Block

Operation & Maintenance of AHUS , Purpose Operation & Maintenance of AHUS , The purpose of this SOP is to define the operation and maintenance procedure of Air Handling Units of Sterile Block of XX Pharmaceuticals Ltd. Operation & Maintenance of AHUS , Scope This SOP applies to all the AHUs which are located in […]

Operation & Maintenance of AHUS , Purpose

Operation & Maintenance of AHUS , The purpose of this SOP is to define the operation and maintenance procedure of Air Handling Units of Sterile Block of XX Pharmaceuticals Ltd.

Operation & Maintenance of AHUS , Scope

This SOP applies to all the AHUs which are located in the Sterile Block of XX Pharmaceuticals Ltd.

Definitions / Abbreviation:

[][]AHU: Air Handling Unit (AHU)
[][]EHS: Environment, Health and Safety.
[][]PPE: Personal Protective Equipment.
[][]SOP: Standard Operating Procedure.


[][]The roles and responsibilities are as follows

Engineering (Validation) Department

[][]To prepare the SOP & revise it when necessary.

Engineering (Maintenance) Department

[][]To provide necessary support for smooth operation & maintenance of AHUs.
[][]To check the log books.


[][]To operate the AHUs according to the SOP.
[][]To do the maintenance job according to the schedule.
[][]To fill up the operation and maintenance log book.

Head of Engineering

[][]To approve any maintenance/plans activities related to the AHUs.

Head of Quality Assurance

[][]To approve this SOP.



[][]All maintenance work must be carried out safely in accordance with the requirements of the Plant Safety Requirements and the EHS safety notices must be displayed around the plant. [][]Specific attention must be paid to the following:
[][]Personal protective equipment (PPE) such as masks, safety glass, boots etc. appropriate to the job must be worn.
[][]Equipment must be electrically isolated and locked out where possible.
[][]Ensure the control panel is switched off before carrying out any check.
[][]Maintenance activity must be carried out by trained technician/operators.


[][]Filtration is ordinarily positioned first in the AHU to keep every one of the downstream parts clean. Contingent on the grade of filtration required, regularly channels will be organized in (at least two) progressive manages an account with a coarse-grade channel gave before a fine-grade channel, or other “last” filtration medium.

[][] The coarse-grade channel is less expensive to supplant and keep up with, and in this manner safeguards the more costly channels.

Heating and/or cooling coil:

[][]Air taking care of Unit needs to give warming, cooling, or both to change the stockpile air temperature, and dampness level contingent upon the area and the application.

[][] Chilled water from the chiller is gone through a twisting container of the cooling curl, heat trade among water and air. Blades are appended to the cylinders effectively increment the surface for heat move to water from air.

[][]Boiling water from the high temp water age framework is gone through a twisting container of the warming loop, heat trade between boiling water and air.

[][]Blades are appended to the cylinders increment surface for heat move to air.


[][]In the air handling unit fan/motor is used for supplying or extracts air from room. Depending on the size of AHU more than one fan/motor is installed.


[][]In AHU dampers are provided to control the flow of conditioned air to the room.

Pre-Start Check

[][]Check that the electrical connection is supplied.
Ensure that the chilled water is supplied to the cooling coil.
[][]Ensure that the hot water is supplied to the heating coil.
[][]All maintenance panels are to be closed and check all maintenance panels and locks for perfect position.
[][]Make sure that filters have been installed properly in their places.
[][]Make sure all filters media are installed in correct airflow direction.
[][]Starting Procedure
[][]Power ON for VSD.
[][]Press “Hand” Button.
[][]Press Start Button.

During Operation

[][]Check that there is no unusual noise or vibration. Stop and investigate if found.
[][]The Operational Log Sheet (Annexure – I) of AHUs will be filled up once a week by the operator. The reading of magnehelic gauges will be used to monitor whether the filter is blocked.

[][] If the pressure reaches the maximum limit as stated in the filters will be changed or cleaned according to the described procedure in that SOP.

[][] Photocopy of all the approved forms will be used where easily applicable. For the cases where computer generated copies are relatively easy to handle, the exact format of the approved form can be used(except the approval sign) with the following notes as footer:
“This is a computer generated report. The format is as per the original approved form.”

Stopping Procedure

[][]Press the Stop (Red) button.(See Figure-I)
[][]Power off for VSD.

Preventive Maintenance

[][]At first switch off power supply /isolate the AHU from power supply. The maintenance job is performed by trained personnel. “Under Maintenance” be displayed in a prominent position on a machine
[][]undergoing maintenance work.


[][]Check for soiling, corrosion, damage and tendency of excessive vibration.
[][]Check the electrical connection.
[][]Check that all bolts, nuts and flexible connection are securely fixed.
[][]Check that vibration isolator mounts is functioning well.
[][]Inspect for any obstructions or blockages at air intakes and discharges.
[][]Check fan bearing are secured and no undue noise by observe/listen using metal bar as a conductor.
[][]Check noise or knocking from bearing, replace both bearings.
[][]Check fan bearing and lubricate with grease.
[][]Check whether the fan impeller rotates freely.

Drive Belt

[][]Belts that are split or have frayed edges or any other sign of damage must be replaced in full set.
[][]Check the belt tension and alignment, retention and realign if necessary.
[][]Check drive belt, if damage replace belt.

Coil Section

[][]Ensure that coils are cleaned.
[][]Check for any leakage in coil.
[][]Ensure coil fins are not damage when performing dry/wet cleaning.

[][]Check that drain pan and drain trap are free from blockage and water accumulation at pan.

Filter Section:

[][]Disposable filters must be replaced each time when pressure drop reaches the indicated by dirty condition by magnehelic gauges. Washable filters must be cleaned periodically. For filters changing and cleaning procedure follow the SOP..


[][]Check for dirt accumulation, damage, and sign of corrosion.
[][]Clean with cloth or high pressure air.
[][]Check damper blade by turning manually or central control for smooth operation.

Preventive Maintenance Schedule

[][]During maintenance work the equipment must be electrically isolated. After performing maintenance works maintenance log book (as same as Annexure – II) has to be filled up by the operator.

Weekly Maintenance

[][]Check and clean fan
[][]Check Fan for excessive vibration.
[][]Check Fan belt.
[][]Check fan motor bearing.
[][]Check the functioning of auto actuator valves of chilled and hot water line.

Monthly Maintenance

[][]Check and Clean Motor.
[][]Check the belt drive tension.
[][]Check or replace V-belt condition.
[][]Check filter.
[][]Check nuts and bolts and tighten it if necessary.
[][]Grease the motor if necessary.

Quarter yearly Maintenance

[][]Check Vibrator Isolator.
[][]Check the electrical connection.
[][]Check the bearing for motor.
[][]Check drain trap clog.

Half Yearly Maintenance

[][]Check fan bearing.
[][]Check motor bearing.
[][]Check bolt and nut tighten.
[][]Check fin block.
[][]Check coil leakage.
[][]Check dirt accumulation of damper & Heater.
[][]Check sign of damage.
[][]Check position of damper.

Yearly Maintenance

[][]Servicing cooling coil and heating coil.
[][]Check/treat/repair corrosion of coil.
[][]Check/repair Electrical control box.
[][]Check/Replace Circuit Breaker.
[][]Check/replace internal lighting.


Annexure-I: Differential Pressure Monitoring Log sheet of AHUs
Annexure-II: Maintenance Log Book of AHUs

Leave a Comment

Your email address will not be published. Required fields are marked *

error: Content is protected by www.pharmaguideline.co.uk !!