Rooftop Package Unit Replacement in Granada Hills
Cold Cloud Mechanical replaced an aging rooftop gas/electric package unit in Granada Hills with a new Goodman 3.5-ton R-32 system, including crane placement, a fabricated curb adapter, airtight return rebuild, condensate correction, waterproofing, permit documentation, and HERS coordination.
A rooftop package unit changeout with more than a basic equipment swap
This project covered a complete rooftop package unit changeout at a property in Granada Hills, 91344. The existing gas/electric unit had reached the end of its service life, and the homeowner wanted a clean, code-compliant replacement that also corrected several issues left behind by prior trades.
The replacement is a Goodman GPUM34208031A, a 3.5-ton single-stage gas/electric package unit running on R-32 refrigerant at 13.4 SEER2. Because the new unit dimensions did not match the existing curb footprint exactly, a new curb adapter was fabricated and set before the new system was lowered into place by crane.
Why the curb, return, condensate, and roof penetrations mattered
Granada Hills sits in the northern San Fernando Valley, where summer rooftop temperatures place real stress on package equipment. On this project, the installation details around the unit were just as important as the equipment itself.
The new unit needed a proper curb transition
The Goodman unit did not match the existing curb footprint exactly, so a custom curb adapter was fabricated to support proper seating, weather sealing, and long-term serviceability.
Existing roof and duct details needed correction
The gas line path, condensate routing, return side, and several pre-existing roof penetrations all needed attention to reduce the risk of water intrusion, leakage, and callback issues.
What Cold Cloud Mechanical completed
The project included removal of the existing rooftop unit, crane placement, custom curb adapter work, electrical and gas reconnection, condensate drain correction, waterproofing, airtight return rebuild, startup, commissioning, permit documentation, and HERS coordination.
- Removed the existing rooftop gas/electric package unit.
- Recovered refrigerant in compliance with EPA requirements.
- Hauled off all replaced materials from the project site.
- Completed crane lift of the new Goodman 3.5-ton R-32 package unit to the roof.
- Fabricated and set a new curb adapter to match the new unit dimensions to the existing curb opening.
- Disconnected and reconnected existing electrical, gas, and ductwork at the unit.
- Routed a new gas line through the existing furnace exhaust penetration.
- Replaced and waterproofed roof flashing at the gas line penetration.
- Waterproofed five additional pre-existing roof penetrations from prior third-party roofing work.
- Rebuilt the return side airtight using new ductboard with full mastic sealing on all joints.
- Removed prior rainwater-tied condensate routing and rerouted the drain in clean PVC.
- Installed a condensate P-trap, verified slope, glued and sealed joints, and flow tested the drain.
- Completed nitrogen pressure test, triple evacuation, refrigerant verification, and full commissioning.
- Retained the existing thermostat at the homeowner’s request.
- Pulled the permit package, submitted Title 24 documentation, coordinated HERS testing, and scheduled inspection.
Goodman 3.5-ton R-32 rooftop gas/electric package system
The final installation paired a new Goodman rooftop package unit with a fabricated curb adapter, airtight ductboard return rebuild, new PVC condensate line, and proper startup documentation.
Goodman GPUM34208031A
3.5-ton single-stage gas/electric rooftop package unit using R-32 refrigerant with 13.4 SEER2 efficiency.
40" H × 47" W × 51" D
New equipment dimensions required a fabricated curb adapter for a clean fit on the existing roof curb.
Curb adapter and airtight return rebuild
New fabricated curb adapter and ductboard return rebuild with full mastic sealing at all joints.
PVC drain with P-trap
New PVC condensate line with P-trap, plus 10-year parts limited and 20-year heat exchanger limited warranty.
Rooftop package units depend on the details around the cabinet
A rooftop package unit lives in a harsh environment. Sun load, wind-driven rain, and constant thermal cycling expose every shortcut taken at the curb, roof penetrations, and condensate path.
Addressing the gas line routing, sealing pre-existing roof penetrations, and rebuilding the return airtight removes the failure points that typically lead to early callbacks: water intrusion, duct leakage, and condensate backups. The airtight return rebuild also helps the unit move its rated airflow without fighting cabinet leakage.
Before, during, and after the Granada Hills rooftop package unit replacement
The photos below show the old rooftop package unit, crane lift, curb adapter fabrication, roof preparation, equipment placement, service panel startup, final checks, and completed Goodman R-32 rooftop installation.
A tighter rooftop installation built for long-term performance
This project replaced the rooftop package unit and corrected the supporting details around it: curb fit, return sealing, condensate routing, roof penetrations, startup procedure, and compliance documentation.
Custom curb fit
The fabricated curb adapter allowed the Goodman unit to sit correctly on the existing opening with better weather sealing and proper equipment support.
Airtight return rebuild
The return side was rebuilt with new ductboard and full mastic sealing to reduce leakage and support rated airflow.
Cleaner condensate and roof details
The condensate line was rerouted in PVC with a P-trap, while multiple roof penetrations were waterproofed to reduce future water intrusion risk.
Planning a rooftop package unit replacement?
Cold Cloud Mechanical handles rooftop package unit replacements with crane coordination, curb adapter work, gas and electrical reconnection, condensate correction, return sealing, permit documentation, HERS coordination, and clean startup.