Is Your Machine Room Door Compliant?

Machine Room Door Requirements (IIAR 2-2021, Section 6.10.2)

Each Machine Room door must meet the following requirements:

• Self-closing and tight-fitting
• Equipped with panic hardware (crash bar)
• Restricted to authorized personnel only
• Outward-opening in the direction of egress

Many doors appear compliant at a glance but fail upon closer inspection. A common issue is light visible under or around the door, indicating that it is not tight-fitting. In these cases, installing a door sweep may be a simple fix. Larger gaps or poor construction may require more extensive adjustments or a full replacement.

How to Spot and Fix Non-Compliant Doors

Many Machine Room doors have visible light beneath them or gaps in the frame—making them non-compliant and unsafe. Solutions include:

• Door sweeps to seal the base
• Adjustments or full replacements for poorly fitted doors
• Routine inspection to check seals and closing hardware

A tight-fitting door isn’t just a compliance box to check—it preserves temperature, protects pressure integrity, and most importantly, provides a first line of defense in the event of an ammonia release.

Keep Doors Shut and Access Controlled

Even a compliant door can be rendered ineffective if left open, propped, or unlocked. Best practices include:

• Assigning key fobs, swipe cards, or keys to authorized personnel
• Ensuring doors remain shut at all times
• Addressing ventilation issues that tempt personnel to prop doors open

Quick Compliance Checklist:

1. Doors closed and locked
2. No visible cracks or light at the base or sides

Signage Requirements: What Must Be Posted?

IIAR 2-2021 requires signage to fall into three major categories:

1. System Installation Signage

Located where trained personnel and emergency responders can view it, this includes:

• Emergency shutdown instructions
• Emergency contact info
• Ammonia inventory & refrigerant details
• System pressures
• Equipment and pipe labels

2. Alarm Signage

Placed near visual and audible ammonia alarms. Required color-specific signs indicate different alarm states.

3. Door Signage

Two door types, two sets of sign requirements:

Principal Door

Includes emergency shut-off, ventilation switch, and alarm override:

• “Refrigeration Machinery Room – Authorized Personnel Only”
• “Caution – Ammonia R-717”
• “Eye and Ear Protection Must Be Worn”
• “Warning – Ammonia Detected When Alarms Are Activated”
• Emergency-only operation and ventilation switch signage
• NFPA 704 Fire Diamond (3-3-0 indoor / 3-1-0 outdoor)

Auxiliary Doors

No shut-off or switches; only warning signs and NFPA 704 Fire Diamond required.