HVAC Contractors: What You Need When Replacing a Rooftop HVAC System

If you are a new HVAC contractor, there's no doubt that, at some point, you'll be tasked with the installation of a replacement HVAC system on a rooftop—especially when a commercial facility calls for your services. It's important to understand the logistical nightmare that could occur with the delivery of large HVAC systems that need to be installed on the top of roofs via a crane service so you can sub-contract with other professionals to get the job done. Here's what you'll need help with.

Curb Adaptor

Unless you fit the exact same model and size unit in the exact same location as the old one, you'll need to have curb adaptors installed before the crane delivers the replacement HVAC system to the roof. Curb adaptors protect the roofing from being damaged by HVAC systems.

Curb adaptors are designed by structural engineers. The engineer will need the measurements of the bottom of the current HVAC system as well as the replacement system to draw up a plan to compensate for the differences in the footings of the systems. Depending on the size of the final product, a curb adaptor may need to be delivered to a rooftop by a crane service.

Metal Fabrication

A metal fabrication company can build the curb adaptor to the specifications and dimensions called for by the structural engineer. The same metal fabrication service can also fabricate the various ducts and other pieces that need special measurements for the project so you can adapt the existing ductwork to the new HVAC system.

All the components made by the metal fabrication company can be secured to a rigged pallet so the crane service can lift it directly on the roof in one neat bundle, or several bundles for larger projects.  


You'll need to dispose of the old systems through either a waste management company or a scrap metal recycling facility. It's a good idea to consider recycling old systems for the scrap metal that is contained in them, especially the copper tubing. That way, you can make some money from the old systems and protect the environment.

You'll need a large flatbed trailer for the crane service to place the old systems onto. Therefore, rent a flatbed trailer for the same day. That way, the crane can lift off the old system and place it onto the trailer before it lifts the new system onto the roof.


The crane will need to be delivered, as well as the new system. And remember, you also need the flatbed available to place the old system on. Therefore, the number of heavy equipment trucks and equipment can be problematic if there is no room for them all, especially if there is no parking lot and/or the streets are narrow.

Not only can these types of situations create a logistical problem, they can cause traffic accidents to occur if traffic is not controlled. For this reason, it's important to hire a traffic control service to direct public traffic and the placement of the trucks and equipment for your HVAC replacement projects.


If there's no room for everything to be on-site all at once, you'll need to scout out the area and neighborhood beforehand to find places off-site to park one or several of the trucks and trailers while you complete the replacement. For example, you may need to ask the facility manager of a nearby shopping center if you can temporarily park there.

It's a good idea to have a CB radio to communicate with the vehicles as they wait off-site for their turn to deliver or pick up equipment. If the distance is outside of the CB radio range, be sure to have everyone's cell phone numbers so you can reach them. 

For more information on how to get this done, visit resources like http://winslowcrane.com.