Replacing a York Rooftop Unit: Curb Compatibility Guide

By Taylor Metals — SMARTCurb Engineering  ·  Updated August 24, 2026  ·  4 min read

47 verified York RTU curb footprints, the Predator-to-Sun Pro rebrand hiding behind the ZF model code, and the Sunline legacy that both of them grew out of.

What SMARTCurb has on file for York

SMARTCurb has verified curb geometry for 47 York rooftop-unit models. Every one has a page with its overall curb footprint and a fabrication-ready adapter path — browse the full list on the York hub.

ZF is a model code, not a product name — and it's outlived a rebrand

If you're standing in front of a York unit with a ZF-prefixed model number, here's the detail worth knowing: SMARTCurb's source documentation identifies the ZF078-150 family as "Predator (2010-era name) / Sun Pro (current name)." York renamed this product line at some point without changing the underlying curb platform, so the same ZF model code shows up on nameplates sold under two different marketing names roughly fifteen years apart. A real example is on the York ZF078C00 page. Practically: don't let the branding on the unit throw you off the model number. The ZF code is what actually pins down the curb.

A transition curb that spans generations

SMARTCurb's atlas even has a record for the retrofit itself — a dedicated Sunline-to-Predator/Sun Pro transition curb (7.5–12.5 ton) that adapts the older Sunline footprint onto the ZF078-150 mounting pattern. Its existence is itself evidence of how directly connected these two eras of York equipment are on the roof, even under different marketing names.

Sunline: the legacy every current line descends from

Sunline is the older platform underneath much of York's current lineup. The atlas includes Sunline (native) ZE/XN/ZF/ZR/XP models on a common 3–6 ton curb, and separately Sunline Plus (DF072), explicitly documented as a legacy, 2007-era, R-22 unit. Further up the tonnage range, the Large Sunline ZT180-276 family is documented as the successor platform to the older "Sunline Magnum/MagnaDRY" ZJ/ZR/ZF units in the 15–25 ton range, sharing the same cabinet and curb. If a York nameplate reads Sunline in any form, it's legacy equipment — SMARTCurb still has the curb geometry on file regardless.

What makes Sunline worth understanding rather than just filing under "old" is how much of York's current catalog traces back to it in one of two ways: either directly superseded on the same curb platform (the ZT180-276 case above), or bridged by a dedicated transition curb built specifically to carry a Sunline-era unit's replacement onto a newer footprint (the ZF078-150 transition curb below). Very little of York's older equipment is a dead end for a like-for-like curb match — it's more often one documented step away from a current platform.

York's current lines

Four current-generation lines round out the modern lineup. Sun Choice (KV/WV/AV/CD-prefixed, 15–27.5 ton) spans several distinct footprint tiers within that tonnage range — real examples sit on the York KV20 page and the York KV28 page, which are two different curb sizes despite both belonging to the same Sun Choice line. Sun Core (KQ/KX/KY/KL-prefixed small- and large-footprint units) is documented as R-454B refrigerant — among the newest equipment in the atlas, reflecting the industry-wide refrigerant transition away from R-410A. Sun Select (vertical-airflow YV/UV-prefixed units) splits into two distinct footprint tiers of its own within the YV28-YV50 range. Sun Premier is the largest-tonnage line in York's atlas entry, 25–80 ton on GZ0-prefixed model codes, with curb lengths running from 333″ at the smallest tier up to 448.3″ at the largest — genuinely large commercial platforms, each on its own distinct curb footprint family separate from the Sunline-descended lines above.

Every York page carries its original pattern drawing

Every York model page in the atlas includes the original curb pattern drawing alongside the verified footprint, viewable directly on the page — a second source to check against your own field measurements before ordering, especially useful given how many of these families trace back through more than one rebrand.

Before you order

Confirm the exact model code on the nameplate first — not just which marketing name is printed on it — then pull the real curb dimensions using the outside-corner datum convention, and cross-check both against the matching model page. A rebrand like Predator-to-Sun Pro changes what's silkscreened on the cabinet; it doesn't change what you need to measure. This matters more for York than for a manufacturer with a cleaner naming history, precisely because so many of its current-generation lines sit downstream of a Sunline-era platform under a different name — the model code, not the marketing name, is what a fabricator actually needs.

When the replacement isn't York-to-York

The adapter SMARTCurb compiles isn't restricted to same-brand pairings. Each model page lists nearest-footprint compatible pairings across manufacturers as a starting point. Open the SMARTCurb workspace, pick your existing York unit and its replacement, and see the real compiled result.