Finding the right size crane for a commercial rooftop unit (RTU) replacement depends on three numbers: the physical weight of the unit, the height of the building, and the distance from the roof edge to the installation spot. Most single-story retail or office replacements require a 15-ton to 30-ton boom truck. Larger facilities or units set far back from the roof edge often need a 40-ton to 100-ton hydraulic crane.
Understanding HVAC “Tons” vs. Physical Weight
In the heating and cooling world, a “ton” measures cooling capacity, not physical weight. A 5-ton air conditioning unit does not weigh 10,000 pounds.
To order lifting equipment, you need the physical weight. This is listed on the manufacturer’s submittal sheet or the unit’s data plate as “shipping weight” or “operating weight.”
Typical physical weights for standard commercial rooftop units include:
- 3 to 5-Ton Cooling Capacity: 600 to 1,000 pounds. (Small retail, single-story offices).
- 7.5 to 12.5-Ton Cooling Capacity: 1,200 to 2,500 pounds. (Medium retail, restaurants).
- 15 to 25-Ton Cooling Capacity: 2,500 to 4,500 pounds. (Large offices, grocery stores).
- 30 to 50-Ton Cooling Capacity: 5,000 to 8,500 pounds. (Big-box stores, manufacturing).
- 75 to 100+ Ton Cooling Capacity: 12,000 to over 20,000 pounds. (Heavy industrial).
Added Weight from Accessories and Hardware
The base weight of the unit is just the starting point. High-efficiency RTUs are customized, and additions increase the weight. Energy recovery ventilators (ERVs), economizers, gas heat exchangers, and hail guards can add hundreds of pounds.
When calculating total weight, include the curb adapter. If switching brands, a metal adapter on the existing roof curb ensures the new unit fits. Adapters add 200 to 500 pounds. The commercial HVAC crane rigging crew will also use spreader bars and rigging gear that add another 100 to 300 pounds.
The Load Radius: Why Distance Matters More Than Weight
A common mistake is assuming a 40-ton crane lifts 40 tons anywhere on the job site. A crane’s advertised capacity is its maximum lifting ability, only achievable when the load is directly next to the crane.
As the boom extends horizontally to reach the roof, lifting capacity drops. This horizontal distance from the crane’s center to the HVAC unit is the “load radius.”
For example, a 17-ton boom truck might lift 34,000 pounds next to its bumper. If it extends 80 feet across a warehouse roof, its capacity might drop to 650 pounds. To place a 2,000-pound RTU at that distance, you need a 40-ton or 60-ton crane just for the reach.
Building height also matters. Taller buildings require extending the boom higher. The boom is heavy, so holding it in the air reduces the capacity available for the HVAC unit.
Common Rooftop Scenarios and Crane Sizes
Scenario 1: Small Office Building (Edge Lift)
Replacing a 5-ton cooling unit (850 pounds physically) on a 3-story building. The crane parks next to the building, and the unit is 10 feet from the roof edge.
- Estimated Crane Size: 15 to 25-Ton Boom Truck.
- Why: Low weight and short reach allow a standard boom truck to handle the job.
Scenario 2: Single-Story Warehouse (Deep Setback)
Replacing a 15-ton packaged unit (3,200 pounds physically) on a wide distribution center. The unit is 60 feet from the roof edge.
- Estimated Crane Size: 40 to 90-Ton Hydraulic Crane.
- Why: Pushing 3,200 pounds 60 feet horizontally requires a large counterweight and reinforced boom. This load radius pushes the job into commercial HVAC heavy lifting.
Scenario 3: Urban High-Rise or Tight Alley
Replacing a 20-ton cooling RTU (4,000 pounds physically) on a 5-story building. The crane parks across the street, reaching over power lines and up 5 stories.
- Estimated Crane Size: 100+ Ton All-Terrain Crane.
- Why: Reaching high and far while avoiding obstructions demands long boom length and a “jib” extension to angle over the roof.
Scenario 4: Heavy Industrial Plant
Installing an 80-ton cooling system (16,000 pounds physically). The crane parks 40 feet away to avoid underground tanks.
- Estimated Crane Size: 150 to 200+ Ton Mobile Crane.
- Why: High weight and moderate reach require a large crane that needs support trucks to deliver its counterweights.
What Does It Cost to Rent a Crane for an RTU?
Most crane companies bill hourly from the moment the crane leaves their yard until it returns (portal-to-portal pricing).
Hourly Rates and Minimums
Expect to pay between $150 and $600 per hour depending on the crane size. A 20-ton boom truck sits at the lower end, while a 150-ton hydraulic crane sits at the top.
Crane companies usually enforce a three- or four-hour minimum charge. Even if the lift takes 45 minutes, you pay the minimum. For a 30-ton crane, expect a base invoice of $600 to $1,400 for a simple swap. Some companies offer a flat “pick” rate for quick, simple swaps.
Weekend and Overtime Costs
HVAC replacements often happen on weekends to avoid disrupting businesses. Weekend work usually carries an overtime premium of $50 to $150 per hour on top of the base rate. The minimum time requirement may also jump to an eight-hour daily minimum. A simple job that costs $800 on a Tuesday might cost $1,500 to $2,000 on a Saturday.
Permits and Additional Fees
If the crane must park on a public road or block a sidewalk, you need a street closure permit. These range from $150 in small towns to over $1,300 in major cities. You may also need to pay for a police detail to manage traffic.
Other line items on your quote may include:
- Mobilization Fees: Sometimes billed as a flat rate ($250 to $500) instead of hourly travel time.
- Fuel Surcharges: Often a percentage of the total bill.
- Rigging Equipment: Extra riggers or specialized gear may add $200 to $300.
How to Assess Your Job Site Before Calling
Having answers ready when you call for pricing ensures you get the right machine and prevents the crane from being turned away on lift day.
Measure Distances
Measure the distance from the closest parking spot to the building wall. Then, measure from that wall to the center of the HVAC unit on the roof. Add these together for your rough load radius. Never guess. A 5-foot discrepancy can cause the operator to refuse the lift for safety reasons.
Identify Overhead Obstructions
Note any trees or power lines above the parking area. OSHA rules prohibit cranes from operating within 10 to 20 feet of active power lines, depending on the voltage. If lines are present, the crane must park further away or the utility company must drop the lines.
Check Ground Conditions
A 60-ton crane weighs about 80,000 pounds. When it sets its outriggers, it applies significant pressure. Verify what is under the surface. Underground parking garages, septic tanks, storm water vaults, and uncompacted dirt are hazards. On hot summer days, ask the crane company to bring timber mats to prevent outriggers from sinking into soft asphalt.
Weather, Wind, and Scheduling Restrictions
Rooftop units have large surface areas and act like sails in the air. Operators usually halt operations if sustained winds exceed 20 to 25 miles per hour. This limit is lower for exceptionally bulky loads. If the crane company cancels due to wind, respect the call to protect your building and the crew.
What to Expect on the Day of the Lift
Your preparation dictates how much you pay in hourly overages.
Before the crane arrives, ensure the old unit is fully disconnected. Electrical whips, gas lines, and duct connections must be severed. Secure all panel doors and clear loose debris. If the operator waits while your team finishes removing screws, you pay hourly rates for a spectator.
Upon arrival, the operator spends 30 to 60 minutes positioning the truck, extending outriggers, leveling the machine, and preparing the rigging gear. The crane lifts the old unit onto a truck for disposal, hoists any curb adapters, and finally sets the new RTU.
Communicating with the Crane Dispatcher
Tell the crane company exactly what you are lifting. Provide the make, model, and physical shipping weight of the new unit. Provide the building height in feet, not stories, and the setback distance on the roof.
Send photos of the parking lot, the side of the building (showing any power lines or trees), and the path from the unit to the roof edge. If the lift is complex, ask the company to perform a site visit and create a formal lift plan. You can learn more about this in our guide on how to plan a critical lift. Clear information ensures the job stays within your budget.