Service 25 / 27 · Cleanroom Classification & Pressure Cascade
Air Should Always Know Which Way to Go.
A pressure cascade that exists only in the HVAC model is difficult to operate and harder to demonstrate. ALVEDA defines the classification of each room, its neighbors and the intended direction of air movement between them, then resolves where airlocks and pass boxes are needed and where containment requires negative pressure instead of product protection. The cascade is documented on a single diagram that architecture, HVAC, controls and the client quality team can all work from, together with a monitoring strategy that shows it is being maintained.
Engineering phases
Where this service fits
05 / 09 phases in scope
- 01Feasibilitynot in scope
- 02ConceptIn scope
- 03Basic EngineeringIn scope
- 04Detailed EngineeringIn scope
- 05Procurementnot in scope
- 06Constructionnot in scope
- 07CommissioningIn scope
- 08ValidationIn scope
- 09Operationnot in scope
Scope
What the service covers
- 01Cleanroom zoning and room classification
- 02Room adjacency and relative pressure relationships
- 03Airlock and pass-box concepts
- 04Positive and negative pressure containment strategy
- 05Door, envelope and transfer-air considerations
- 06Pressure monitoring and alarm strategy
Method
From inputs to deliverables
INInputs
05 items- I01Zoning and flow study or concept layout
- I02Room functions and required classifications
- I03Hazard classification of materials handled, as defined by the client
- I04Process equipment and primary containment devices
- I05Quality requirements defined by the client
WORKActivities
06 items- W01Room classification and adjacency review
- W02Risk-based definition of pressure relationships
- W03Airlock regime selection: cascade, bubble or sink
- W04Containment versus product-protection decisions
- W05Coordination of the cascade with HVAC airflows and door arrangements
- W06Definition of monitoring points and alarm logic
OUTDeliverables
05 items- D-25.01Classification zoning layout
- D-25.02Pressure cascade diagram
- D-25.03Room adjacency and pressure relationship schedule
- D-25.04Airlock and pass-box concept
- D-25.05Pressure monitoring and alarm philosophy
Technical detail
How the cascade is defined
Contents · 05
01 / 05
Classification & room adjacency
The cascade starts from which rooms touch which, and what each one must protect.
- Classification assigned per room
- Adjacency matrix between rooms and corridors
- Boundaries between classified and unclassified areas
- Critical zones and their surrounding background rooms
02 / 05
Relative pressure relationships
Positive pressure protects the product from its surroundings; negative pressure protects the surroundings from what is handled inside. Some rooms need both, which is where airlocks do their work.
- Direction of air movement at every door
- Positive-pressure product protection
- Negative-pressure containment for hazardous handling
- Differentials set per project from risk and adjacency
03 / 05
Airlocks & pass boxes
- Personnel and material airlocks
- Cascade, bubble and sink airlock regimes
- Pass boxes for material transfer between classifications
- Interlocking and door-opening logic
04 / 05
Containment strategy
Where hazardous materials are handled, room pressure works together with primary containment equipment and exhaust, never on its own.
- Negative-pressure rooms and their buffer spaces
- Interfaces with isolators, BSCs and other primary containment
- Exhaust routing for contained areas
- Door leakage and envelope integrity
05 / 05
Pressure monitoring
The cascade has to be visible during operation, not only at handover.
- Local pressure indication at critical doors
- Monitored points and alarm delays
- BMS and EMS integration
- Data recording and trending for review
Illustrative Engineering Model
ALVEDA Facility Intelligence
One compact, generic facility read nine ways — classification, pressure, air handling, the flows of people, materials and waste, utilities, laboratories and containment. Choose a layer, then a room, to see the engineering intent behind it.
Swipe to see the whole plan · tap a room for details
01 / 09 — Z-CLAS
Classification
Cleanliness classes step up toward the point of exposure. The critical ISO 5 zones exist only inside the PEC and C-PEC, not across whole rooms.
- ISO 5 — inside PEC / C-PEC
- ISO 7 — buffer and HD rooms
- ISO 8 — ante, airlock, production
- CNC — controlled, not classified
- Unclassified
Showing layer: Classification
Interactive engineering model
Explore how the engineering fits together.
PC-S
Sterile compounding cascade
Pressure rises toward the critical zone, so air always moves from clean to less clean.
++Ante room
- Room function
- Hand hygiene, garbing and staging — the buffer between uncontrolled and critical air.
- Classification
- ISO 8
- Relative pressure relationship
- Positive to the corridor, negative to the buffer room.
- Airflow direction
- Air enters from the buffer room and leaves toward the corridor.
- Adjacent spaces
- Corridor, Buffer room
- Design consideration
- Mark a line of demarcation between the dirty and clean sides; size the room for peak shift change.
Selected zone: Ante room
Relative relationships only — differential values are set per project.
PC-H
Hazardous drug containment cascade
A positive ante room shields the corridor, while the preparation room is held negative so hazardous particles stay in.
–HD buffer room
- Room function
- Houses the containment primary engineering control (C-PEC) used to prepare hazardous drugs.
- Classification
- ISO 7
- Relative pressure relationship
- Negative to the HD ante room — the lowest room pressure in the chain.
- Airflow direction
- Air enters from the ante room and is exhausted to outside, not recirculated to other areas.
- Adjacent spaces
- HD ante room, C-PEC
- Design consideration
- Externally vented, sealed room envelope; monitor the negative step continuously with a local display and alarm.
Selected zone: HD buffer room
Relative relationships only — differential values are set per project.
Deliverables
Typical documents and outputs
- D-25.01Classification zoning layout
- D-25.02Pressure cascade diagram
- D-25.03Room adjacency and pressure relationship schedule
- D-25.04Airlock and pass-box concept
- D-25.05Pressure monitoring and alarm philosophy
Services
Related services
- 21
Hazardous Drug Facility Engineering
Receiving, storage, compounding, decontamination and waste routes engineered for containment.
Next step
Planning a pharmaceutical project?
Share the product type, the current stage and the main constraints. We will respond with a proposed scope and next steps.
+20 101 171 1700