Ventilation Systems in PEB Buildings: Types & Design

Ventilation Systems Used in PEB Buildings

Proper ventilation in Pre-Engineered Buildings (PEB) ensures indoor air quality, temperature control, and removal of moisture, fumes, and contaminants. The lightweight steel structure and large clear spans of PEBs require tailored ventilation solutions to maintain comfort and meet building codes.

1. Natural Ventilation

Natural ventilation relies on wind and thermal buoyancy to move air through the building without mechanical assistance.

• Ridge Vents: Continuous ridge openings along the roof peak allow warm air to exhaust naturally.
• Soffit and Eave Vents: Intake vents at the eaves introduce fresh air to create a flow through the roof space.
• Operable Louvers: Wall-mounted adjustable louvres permit cross-ventilation and daylight entry.
• Ventilators and Whirlybirds: Roof-mounted turbine vents that spin with wind to draw air out.
• Stack Effect Openings: High-level vents paired with low-level intakes encourage vertical airflow.

2. Mechanical Ventilation

Mechanical systems force air movement with fans and ducts for precise control of airflow rates and distribution.

• Exhaust Fans: Wall or roof-mounted centrifugal fans remove stale air, fumes, and moisture.
• Supply Fans: Fans with ductwork push fresh air into occupied zones or production areas.
• Air Handling Units (AHUs): Condition, filter, and distribute large volumes of air, often integrated with heating or cooling coils.
• Roof-Mounted Ventilator Units: Packaged rooftop units combining fans, filters, and coils for make-up air.
• Jet Fans: Installed in large clear-span workshops to induce airflow across long distances.

3. Hybrid Ventilation

Hybrid (or mixed-mode) systems combine natural and mechanical ventilation to optimize energy use and indoor comfort.

• Use ridge vents and louvers for free cooling when conditions permit.
• Activate mechanical fans during peak heat or high humidity periods.
• Integrate sensors and control systems to switch modes based on temperature, CO₂, or humidity.

4. HVAC Integration

In climate-controlled PEBs such as office areas, showrooms, or cold storage, full HVAC systems may be necessary.

• Central HVAC: Chilled water or DX systems serving AHUs distribute conditioned air through duct networks.
• Roof-Top Units (RTUs): Self-contained units mounted on the roof provide heating, cooling, and ventilation.
• Variable Air Volume (VAV): Boxes modulate airflow to maintain zone temperatures efficiently.
• Air Curtains: Installed at dock doors to minimize infiltration of unconditioned air while facilitating material handling.

5. Design Considerations for PEB Ventilation

• Building Orientation: Align ridge vents and louvers to prevailing winds for maximum natural ventilation.
• Insulation and Air Sealing: Prevent unwanted infiltration and optimize performance of mechanical systems.
• Internal Layout: Plan zoning and partitioning to ensure even air distribution and avoid stagnant areas.
• Thermal Stratification: Use destratification fans or high-volume low-speed (HVLS) fans to mix warm and cool air.
• Industrial Fume Extraction: Provide localized exhaust hoods and ducting in welding bays or chemical handling zones.
• Maintenance Access: Design platforms and clearances for fan and duct servicing.
• Noise Control: Use silencers, vibration isolation mounts, and low-noise fan selections.

6. Energy Efficiency Strategies

• Incorporate demand-controlled ventilation using CO₂ or occupancy sensors.
• Employ heat recovery ventilators (HRVs) to reclaim energy from exhaust air.
• Optimize fan selection for high efficiency and variable-speed drives.
• Use reflective roof coatings and insulation to reduce cooling loads.
• Implement building management systems (BMS) for centralized control and monitoring.

7. Examples of Ventilation Configurations

• Warehouse: Continuous ridge vents, wall louvers, HVLS fans, and dock door air curtains.
• Manufacturing Plant: Roof turbine vents, jet fans, localized fume extraction, and AHU integration.
• Office Block within PEB: RTUs, VAV terminals, fresh-air intake through louvers, and ducted supply.
• Cold Storage: Dedicated mechanical refrigeration, positive-pressure ventilation, and humidity-controlled intake.

Conclusion

Effective ventilation in PEB buildings balances natural and mechanical strategies to ensure occupant comfort, process requirements, and compliance with health and safety standards. By leveraging ridge vents, louvers, fans, and HVAC integration—and applying energy-saving measures—designers can optimize indoor air quality and thermal comfort in these versatile steel structures.