How a scroll compresses
Two interleaved spiral scrolls — one fixed, one orbiting — trap pockets of refrigerant vapor and squeeze them toward the center, where the compressed gas discharges. No pistons, no valves, few moving parts. That simplicity is why scrolls took over the light-commercial market: quieter, more efficient, and more tolerant of real-world conditions than the reciprocating compressors they replaced.
Why manufacturers love them — and your power bill does too
Modern rooftop units hit their IEER ratings largely on the back of scroll technology: tandem scroll pairs stage capacity up and down, and digital or variable-speed scrolls modulate to match part load. For a Greensboro building that spends most of the year at partial cooling load, that staging is real monthly money.
How scrolls fail
Scrolls die from liquid slugging (refrigerant flooding back on a bad charge or metering problem), overheating from dirty condensers or low charge, and reverse rotation after a phase mix-up on three-phase power — a scroll run backward can destroy itself in minutes, which is why phase protection matters. The unforgiving part: a scroll cannot be rebuilt. When it fails, it is replaced.
When one fails in your building
Get the failure diagnosed, not just the part swapped — a scroll that died of slugging or acid will kill its replacement too if the root cause stays. Our $149 trip and diagnostics covers exactly that: what failed, why, and a written price on the fix. On older units we also quote the replace-the-unit option so you can compare honestly.