Vault Coordination 101: Electrical, HVAC, and Penetrations Done Right

In vault construction, the most critical failures rarely occur at the walls or doors. Instead, they happen at the interfaces—electrical systems, HVAC integration, and penetrations that pass through the vault envelope.

These elements may seem secondary, but in reality, they are often the deciding factor in whether a vault maintains its security rating, passes inspection, and performs as intended over its service life. Poor coordination doesn’t just create construction delays—it can compromise the very security the vault was designed to provide.

Why Vault Coordination Matters

A vault is only as secure as its weakest point. Every penetration through a vault wall or ceiling, whether for electrical conduit, HVAC ductwork, fire protection, or data cabling, introduces potential risk.

When penetrations are not properly engineered, coordinated, and sealed:

• Security ratings can be compromised

• Third-party certifications may be jeopardized

• Costly rework and delays become unavoidable

For facilities governed by UL, Intertek, or agency-specific security standards, even a single unapproved penetration can trigger corrective action, reinspection, or loss of compliance.

Electrical Systems: Delivering Power Without Compromising Security

Start With Accurate Load Planning

Before any conduit routing is considered, electrical loads must be clearly defined. This includes:

• Vault lighting

• Intrusion detection and access control systems

• Environmental monitoring

• Specialized equipment operating within the vault

Underestimating electrical demand often leads to late-stage additions—exactly the scenario most likely to result in non-compliant penetrations.

Conduit Penetrations: Precision Matters

Every electrical penetration must be engineered with intent.

Location
Approved penetration locations should be coordinated with the vault manufacturer early in design. Vault panels are structural and security-rated assemblies—not generic walls—and penetration locations must preserve both load capacity and resistance characteristics.

Size
Penetrations should be sized precisely. Oversized openings increase security risk and complicate sealing. While future capacity should be considered, “oversizing for convenience” is a common and costly mistake.

Materials
Conduits, boxes, and fittings passing through the vault envelope must meet or exceed applicable fire and security ratings. This is not an area for substitution or value engineering.

Sealing and Fire-Stopping

Electrical penetrations typically require layered sealing systems that address both physical security and fire resistance, including:

• High-density grout or cementitious fill rated for vault applications

• Intumescent fire-stopping materials where required

• Proper curing and inspection prior to energization

Documentation of materials, installation methods, and inspection approvals is essential to maintain certification.

HVAC Integration: Environmental Control Without Vulnerabilities

Balancing Security and Environmental Performance

Vaults often require tight environmental control to protect contents from humidity, temperature fluctuations, and condensation. HVAC systems must be designed to meet these needs without introducing security weaknesses.

Because ductwork represents a larger opening than most penetrations, HVAC coordination is especially critical.

Duct Penetrations and Security Measures

Depending on security classification, HVAC penetrations may require:

• Security-rated grilles or screens

• Labyrinth or offset duct configurations

• Integration with intrusion detection systems

These measures maintain airflow while preventing access, line-of-sight intrusion, or tool-based attacks through the duct system.

Proper Sizing and Airflow Design

Vault environments behave differently from standard rooms:

• High insulation and low air infiltration affect load calculations

• Dense contents (metals, records, equipment) add thermal mass

• Poorly sized systems can create humidity instability

HVAC engineers with vault experience are essential. Oversized systems short-cycle and underperform; undersized systems fail to maintain conditions.

Penetrations Done Right: A Systematic Approach

Pre-Construction Coordination

Successful penetration coordination begins early:

• Develop a penetration schedule documenting location, size, purpose, and rating requirements

• Conduct coordination meetings with the vault manufacturer, GC, MEP trades, and security integrator

• Require mock-ups for complex or high-risk penetrations when appropriate

Installation Best Practices

• Sequence installations logically—larger penetrations first

• Complete internal work and inspections before final sealing

• Document each penetration with photographs, materials used, and approvals

Reopening sealed penetrations introduces unnecessary risk and cost.

Common Pitfalls to Avoid

• Field changes without engineering approval

• Mixing sealing materials from different manufacturers

• Treating fire-stopping and security sealing as interchangeable

• Relying on penetrations for conduit support

• Assuming vault walls can be modified like conventional construction

Each of these mistakes can compromise compliance.

Technology and Data Penetrations

Modern vaults frequently house sensitive electronics and communications systems. Coordination must address:

• Cable density and future growth

• Separation of power and data to minimize EMI

• Integration of IDS, access control, and monitoring systems

Reducing the total number of penetrations is always preferable to adding more later.

Inspection, Certification, and Documentation

Penetrations are not complete until:

• Inspected by qualified personnel

• Approved by applicable third-party agencies (when required)

• Fully documented for certification and future reference

Any future modification typically requires re-inspection and potential re-certification.

The Bottom Line

Vault coordination may not be visible when the project is complete—but its impact lasts for decades.

Early planning, disciplined coordination, and refusal to cut corners ensure that electrical systems, HVAC integration, and penetrations support—not undermine—the vault’s security and performance.

When done right, penetrations disappear into the system.
When done wrong, they become the weakest link.