Sector
Science and laboratories
MEP design for laboratory and research buildings — containment, fume cupboard ventilation, pressure regimes, resilience and the energy cost of once-through air.
OVERVIEW
A laboratory is a ventilation problem with a building around it. Air change rates are high, much of the air cannot be recirculated, and the ventilation system is a safety system rather than a comfort one — which changes the design standard, the resilience requirement and the commissioning regime.
It is also where the energy strategy is hardest. Once-through air at laboratory air change rates dominates the building's energy use, and the usual answer to that — recirculation — is unavailable. What is left is heat recovery that cannot cross-contaminate, demand-based control that can be justified safely, and reducing the volume of air that has to be once-through in the first place by zoning the building properly.
DESIGN
What drives the design
Containment sets the pressure regime, and the pressure regime sets everything else
The containment level determines whether a space is held at negative or positive pressure relative to its neighbours, how the cascade is maintained under fault conditions, and what happens when a door is opened. That cascade has to survive fan failure, filter loading and the building's own stack effect, which is a control and commissioning problem as much as a sizing one.
Fume cupboards drive the extract, and diversity is a safety decision
Fume cupboard face velocity requirements set the extract volume. Applying diversity across a group of cupboards reduces plant size significantly and is common practice — but it is a decision with a safety consequence, and it has to be agreed with the users and recorded rather than assumed by the designer.
Discharge location is a dispersion calculation
Where laboratory extract discharges, at what velocity and how far from any intake, is a dispersion question, not a convenience one. It constrains plant location on the roof and the position of every air intake on the building.
Resilience is specified, not implied
Which systems must continue on loss of a supply, for how long, and on what changeover time — cold rooms, freezers, containment ventilation, critical extract — needs to be stated by the client and designed to, rather than inferred from the word "laboratory".
REGULATION
Statutory and guidance documents
Scotland and England take different statutory routes. Where a document applies to one and not the other, it says so.
- BS EN 14175Fume cupboardsUK-wide
- COSHH 2002Control of Substances Hazardous to Health RegulationsUK-wide
- HSE Control of laboratory ventilationGuidanceUK-wide
- BS EN ISO 14644Cleanrooms and associated controlled environmentsUK-wide
- CIBSE Guide B2Ventilation and ductworkUK-wide
- BS 7671:2018+A4:2026Requirements for Electrical InstallationsUK-wide
SCOPE
Typical scope in this sector
- Containment ventilation and pressure cascade design
- Fume cupboard extract, diversity and discharge strategy
- Laboratory gases and specialist services
- Resilience and standby strategy for critical equipment
- Heat recovery without cross-contamination
- Vibration and acoustic criteria for sensitive equipment
QUESTIONS
Common questions
Why do laboratories use so much energy?
Because much of the supply air cannot be recirculated. High air change rates delivered as once-through air have to be heated or cooled from outside conditions every time, which typically makes ventilation the dominant energy use in the building. The available reductions are heat recovery that cannot cross-contaminate, safely justified demand-based control, and zoning the building so that only the spaces that genuinely need once-through air receive it.
Can diversity be applied to fume cupboard extract?
Yes, and it materially reduces plant size and running cost, but it is a safety decision rather than an engineering shortcut. It requires agreement with the users on how many cupboards can be in simultaneous use, a control system that enforces it, and a record of the assumption in the operating documentation. Applying diversity silently is how a laboratory ends up unable to run the experiments it was built for.
What determines the pressure regime in a laboratory?
The containment level of the work being carried out. Spaces handling hazardous material are generally held negative relative to adjacent areas so that leakage is inward; cleanrooms and some pharmaceutical spaces are held positive so that leakage is outward. The design has to maintain that cascade under normal operation, during door openings and under fault conditions, which is a control and commissioning requirement as much as a sizing one.
SERVICES