Critical airflow control and venturi air valves
Labs, isolation rooms and cleanrooms depend on airflow that holds steady while fume hood sashes move and doors open. We design, verify and retrofit venturi air valve systems, the pressure-independent valves made by manufacturers such as Antec Controls, Phoenix Controls and Accutrol, so rooms keep their pressure and hoods keep their face velocity.
When you need it
- You’re designing a new lab, isolation room or vivarium.
- Rooms are losing pressurization when hoods open or doors are used.
- Fume hoods fail face velocity tests or alarms are frequent.
- Legacy air valves or controls are obsolete and need replacing.
- You want to cut lab energy with lower minimum air change rates or sash management.
What we do
Review the room
We document every hood, valve, offset and air change requirement, and how the lab is actually used.
Size and select valves
We size supply, exhaust and hood valves for the full flow range, with the turndown, materials and response the application needs.
Write the sequences
We define how supply tracks exhaust, how offsets are held, and how the system responds to sash movement, occupancy and alarms.
Verify
We measure valve flows across their range, confirm room offsets and pressure direction, and test hood face velocity and response.
Document
You receive a report showing each valve, hood and room against its design.
What you receive
- Valve schedules with design minimum and maximum flows
- Control sequences and BAS integration points
- Measured valve flows, room offsets and pressure direction for every room
- Fume hood face velocity results and a deficiency list
Questions
What is a venturi air valve?
It’s an airflow control valve with a spring-loaded cone inside a venturi-shaped body. The cone moves to compensate for changes in duct pressure, so the valve holds its set flow without needing a flow sensor, and it can change setpoint in about a second.
Do you only work with one brand?
No. We design to performance requirements and work with the major air valve manufacturers, and we can verify or retrofit systems from any of them.
How is room pressure controlled?
Most labs use flow tracking: supply is set a fixed amount below exhaust so air always flows into the room. A room pressure monitor confirms the direction and alarms if it reverses.
Further reading
- Cleanroom pressurization cascades
Learn how pressure differentials keep contamination flowing in the right direction, how to choose airlock types, and how to calculate and control the airflow offsets that create the cascade.
- Containment labs: BSL-2 and BSL-3 HVAC
Learn how HVAC requirements change from containment level 2 to level 3 under the Canadian Biosafety Standard, and how to design, control and verify inward airflow and HEPA exhaust.
- GMP cleanroom grades A to D
Learn how GMP grades A to D are defined for sterile manufacturing, how they relate to ISO classes, and what each grade means for HVAC design and monitoring.
- Hospital pharmacy compounding rooms (USP 797 and 800)
Learn how USP 797 and 800 and the NAPRA model standards shape HVAC design for hospital and community pharmacy compounding rooms, and what certification involves.
- Pharmaceutical cleanroom HVAC
Learn how GMP requirements shape HVAC design for sterile and non-sterile pharmaceutical facilities, from contamination control strategy to qualification and ongoing monitoring.
- Unidirectional vs non-unidirectional airflow
Learn the difference between unidirectional and non-unidirectional cleanroom airflow, the design rules that make each work, and how to choose the right pattern for each zone.
Related services
Also in HVAC design and design-build: New HVAC design, HVAC design-build, High-efficiency HVAC upgrades, Building automation and BACnet integration, Healthcare HVAC, Restaurant and commercial kitchen HVAC, Data center cooling design, Cleanroom HVAC design.
Get a quote for critical airflow control and air valves
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