For commercial and industrial HVAC retrofit projects, a custom rooftop curb adapter bridges the gap between the curb you already have and the equipment you need next. At Macy Industries, we fabricate custom curb adapters around each project’s actual dimensions, equipment specifications, and field requirements. The result is a better fit, fewer installation headaches, and improved airflow alignment, all from one reliable fabrication partner.
After all, when that adapter is sitting between a new unit and an open roof penetration, “close enough” isn’t what you want.
What Are Rooftop Curb Adapters?
A rooftop curb adapter is a custom transition that allows a new rooftop HVAC unit to fit an existing roof curb. These adapters are commonly used on commercial and industrial buildings such as schools, manufacturing facilities, warehouses, and office buildings.
The curb itself is the raised metal frame on the roof that supports the building’s HVAC unit. Before the original unit was installed, an opening was cut into the roof and the unit was elevated on a curb, often about 12 inches, to help keep rain and snow out of the space below.
When that unit needs to be replaced, the existing curb may still be in good shape. But rooftop HVAC units can last around 20 years, and designs change enough over that time that the new equipment rarely matches the curb it’s going on. A curb adapter creates the transition between the two, so the project team doesn’t have to start over at the roof opening.
If you’re preparing to replace a rooftop HVAC unit, there’s a good chance a curb adapter will be part of the project.
Why Off-the-Shelf Isn’t Always Enough
Off-the-shelf adapters can work in some standard situations, but when was the last time you worked on a project that was considered “standard”? Existing curbs may have unique dimensions that don’t match the replacement unit, roof conditions vary from building to building, and the supply and return openings may need to transition in a very specific way to maintain airflow.
A custom curb adapter gives the project team more control over the details that matter most, including:
- Fit on the existing curb
- Airflow alignment between the supply and return openings
- Weather sealing against rain and snow
- Structural support for the new unit
By accounting for measurements and field conditions up front, a custom adapter can help prevent installation problems, reduced performance, and expensive rework on the roof. In many cases, a stock part simply can’t account for the realities of the project. A custom adapter, however, is built around them.
A Smoother Process From Start to Finish
For over 50 years, Macy Industries has served New England with custom fabrication work, curb adapters included. For your project, that means one local team supporting the entire process, so you’re not handing the work between vendors or trying to turn field measurements into a finished adapter on your own.
Design
We start with your existing curb dimensions, the new unit’s specifications, submittal drawings, and any available site information. As a local fabricator, we can also take field measurements, walk the project with you, and coordinate early, which is how we head off surprises on install day and support a cleaner fit from the start.
Fabricate
From there, we build the adapter in our Hooksett, NH shop, as part of the broader fabrication work we do every day. We usually fabricate from galvanized steel, and we can add welded or custom-finished construction depending on the project. For smaller adapters, like those on kitchen exhaust fans, aluminum may be the better option.
Installation Support
When fabrication is done, we coordinate directly with the contractor and facility team through installation. On install day, the old unit comes off, the adapter is craned onto the existing curb, and the new unit is set on top before the HVAC crew handles the wiring and startup. Our job is to make sure the adapter is ready and fits right when the crane and crew are on site, so the replacement keeps moving.
That single point of contact means fewer handoffs between vendors, fewer avoidable miscommunications, cleaner accountability, and tighter quality control end to end.
Start Your Next Rooftop Retrofit
A rooftop replacement runs on a tight schedule, and the curb adapter shouldn’t be the thing that holds it up. Macy Industries works to turn yours around quickly, so it’s ready when you need it.
Getting started is simple. Send us what you have on the existing curb and the new equipment, and we’ll tell you anything else we need for an accurate fit. The more complete the information up front, the faster we can design, fabricate, and deliver.
Request a quote, and we’ll take it from there.