Complete RTU Removal Checklist: Essential Pre-Demolition Steps for HVAC Professionals

1. Why Pre-Removal Planning Matters

A successful rooftop unit replacement doesn't begin when the crane arrives—it starts with thorough pre-inspection. Rooftop AC units are positioned in challenging locations, serving large commercial spaces with complex electrical and mechanical systems. Any gap in preparation can cascade into budget overruns, schedule delays, or worse—roof damage and safety incidents.

Key pre-inspection activities include verifying the unit's electrical parameters, documenting original system wiring, and confirming the replacement model matches the building's electrical infrastructure. These seemingly routine steps form the foundation for a smooth removal operation.

2. Electrical Verification and Equipment Inspection

One of the most overlooked—yet critical—steps in rooftop unit demolition is confirming electrical compatibility between the old and new units. Voltage discrepancy is the most common issue in replacement projects, and also the most likely to cause significant losses if not caught early.

Documentation Before Disconnection

Before disconnecting any lines, technicians should photograph both high-voltage and control-side wiring. This documentation ensures accurate reconnection and serves as a reference if troubleshooting is needed later.

Pre-Lift Damage Assessment

Transport damage inspections must be completed before the new unit is lifted into position. Check for:

• Visible dents or panel damage
• Bent coil fins that may restrict airflow
• Smooth fan blade rotation
• Intact electrical connections and control boxes

These inspections demonstrate professionalism and prevent liability disputes after installation is complete.

3. Creating a Safe Work Environment

Rooftop AC unit removal involves multiple high-risk operations: height work, electrical power interruption, refrigerant recovery, and heavy lifting equipment coordination. Safety and on-site organization capabilities are absolutely critical.

When dealing with large commercial rooftop units, a well-organized construction environment isn't an optional extra—it's a fundamental requirement for project success.

4. Precision Crane Planning for Efficient Operations

Hoisting is typically the most expensive, highest-risk, and most time-sensitive phase of any rooftop unit replacement project. Detailed pre-planning of lifting operations is essential.

Critical Crane Specifications

Crane type, boom length, and lifting capacity must be calculated based on:

• Horizontal distance from ground-level crane position to roof edge
• Vertical height to the installation point
• Weight of the unit being removed (and the replacement)
• Available ground clearance and swing radius

Day-of Coordination

The construction team should arrive before the crane to communicate lifting routes and action sequences with the operator. After the old unit is removed, immediately inspect the roof curb structure, sealing materials, and waterproof membrane condition before positioning the new unit.

5. Post-Removal Connection Preparation

When the old rooftop unit is lifted off the base, attention should immediately shift to preparing for new unit installation. Many details at this stage are often overlooked, yet they directly affect installation quality and system performance.

Pre-Installation Verification

• Check if ductwork interfaces need adjustment
• Verify electrical cable lengths are sufficient
• Inspect control wiring for damage or wear
• Assess roof penetrations and seals for potential re-treatment

Any issues should be resolved before the new unit is lifted into position. This prevents costly rework and ensures the system starts up smoothly during commissioning.

Making Every Replacement Project a Success

Removing a rooftop AC unit is never a simple "out with the old, in with the new" operation. It's an engineering project requiring strict process management across electrical verification, refrigerant recovery, safety planning, crane coordination, and structural inspection.

For professional HVAC teams, thorough preparation not only reduces errors and improves efficiency—it builds client trust. Solid pre-planning is the key to successful rooftop unit replacement and the core value that distinguishes experienced contractors from the rest.