Pressure relief vents operate by responding to differences in pressure between two spaces. Many designs use mechanically balanced or counterweighted blades that remain closed under normal conditions.
When pressure reaches a predetermined threshold, the blades open, allowing excess air to escape. As the pressure decreases, the blades return towards their closed position.
This mechanism can operate without an electrical supply, making passive pressure relief vents particularly suitable for critical safety applications.
Apreco’s Pressure Relief Vents include products developed for gaseous fire suppression systems, pressurised stairwells and data centre installations.
Why Data Centres Require Pressure Relief
Data centres house valuable electronic infrastructure that must remain protected against fire, temperature fluctuations and environmental disruption.
Many facilities use gaseous fire suppression systems to protect servers and networking equipment. These systems release extinguishing agents into an enclosed space when a fire is detected.
Although effective for fire protection, the rapid discharge of gas can cause substantial pressure changes.
Inert gas systems typically create positive pressure as additional gas enters the enclosure. Certain synthetic gas systems can generate both negative and positive pressure conditions.
Without appropriately sized pressure relief equipment, these changes may place excessive stress on walls, doors, ceilings and other structural components.
Pressure relief vents help prevent this by allowing controlled airflow during the discharge process.
Apreco’s Inert Gas Pressure Relief Solutions
Apreco’s IGV Inert Gas Vent range is designed specifically for high-pressure inert gas fire suppression systems.
These vents use a counterweighted blade arrangement that opens when pressure reaches the required operating level.
According to Apreco’s published specifications, the IGV range offers:
- Single-direction pressure relief.
- Full opening at 100 pascals.
- Fire-resistance options of up to four hours.
- BSRIA-validated free vent area.
- Eight standard sizes.
- Reversible flange arrangements.
- A standard 10-year warranty.
The reversible flange configuration allows installers to adjust the direction of airflow according to the application.
This flexibility is useful where pressure relief equipment must be integrated into existing building layouts.
Ceiling-Mounted Pressure Relief Vents in Data Centres
Data centres often have limited wall space because of equipment racks, electrical infrastructure and cooling systems.
Ceiling-mounted pressure relief vents can provide an alternative installation arrangement.
Apreco’s PRV-F2-C-0510 is specifically designed for over-pressure relief associated with data centre ceilings.
The product remains closed below 35 pascals, begins opening at approximately 40 pascals and is fully open at 50 pascals.
Its published performance data includes an airflow capacity of 1,548 litres per second at 45 pascals and 2,600 litres per second at 50 pascals.
The standard model has nominal dimensions of 500 × 1,000 mm, while alternative sizes and pressure settings are available on request.
These characteristics make it possible to incorporate a defined pressure-relief response into a data centre’s fire protection design.
Managing Positive and Negative Pressure
Different fire suppression agents create different pressure conditions.
Inert gas systems generally require positive-pressure relief, allowing air to escape as the extinguishing agent enters the room.
Synthetic gas systems may require bidirectional pressure relief because their discharge characteristics can produce both negative and positive pressure.
Apreco’s SGV Dual Flo® Halocarbon Pressure Relief Vent is designed for synthetic gas fire suppression applications.
Unlike single-direction vents, this product provides two-way venting.
Selecting the correct airflow direction is essential because a vent designed for positive-pressure relief alone may not adequately protect an enclosure against negative pressure.
Supporting Fire Suppression Agent Retention
Effective pressure relief involves more than allowing air to escape.
After a gaseous fire suppression system activates, the extinguishing agent must remain within the protected enclosure for the required retention period.
If excessive ventilation occurs after discharge, the concentration of extinguishing agent may decrease.
This could compromise the system’s ability to prevent re-ignition.
Pressure relief vents must therefore provide sufficient airflow during discharge while
