Wildfire Rebuild HVAC Replacement with Daikin DH6 Heat Pumps
Cold Cloud Mechanical completed a two-system Daikin DH6 inverter heat pump installation with zoning, full R-8 ductwork replacement, a dedicated master suite return, room-by-room air balancing, permits, Title 24 documentation, and HERS coordination for an Altadena wildfire rebuild.
A two-system HVAC rebuild for an Altadena foothill home
This Altadena project was part of a wildfire rebuild on a 2,500+ sq ft home. The existing HVAC systems and ductwork were no longer serviceable, so the work covered a complete two-system changeout, full duct replacement throughout the house, and a proper zoning setup on the bedroom side.
Altadena sits in the foothills of the San Gabriel Mountains, where homes contend with hot summer afternoons, cool mountain evenings, and significant temperature swings between rooms depending on orientation and shading. The rebuild created the right moment to correct airflow and zoning issues instead of only replacing what was there.
Why the rebuild needed two systems, zoning, and full duct replacement
A wildfire rebuild gives the homeowner one chance to correct the HVAC design from the ground up. The goal was to match equipment to the actual load on each side of the home and rebuild the air delivery system so the new equipment could perform the way it was rated.
The old systems and ductwork were no longer serviceable
The project required a full removal and replacement approach, not a partial repair. Both HVAC systems and the full duct network had to be rebuilt for dependable long-term operation.
The bedroom side needed real zoning support
The bedroom-side system was configured for two zones, including a dedicated master suite return so the master zone could operate correctly instead of fighting the upstairs thermostat.
What Cold Cloud Mechanical completed
The project included removal of both systems, two new Daikin DH6 heat pump systems, full R-8 duct replacement, zoning controls, motorized dampers, a dedicated master suite return, room-by-room balancing, and permit documentation.
- Removed both existing HVAC systems and the full duct system throughout the home.
- Installed a 4-ton Daikin DH6 inverter heat pump with a Daikin variable-speed air handler for the common areas.
- Configured the common-area system as a single-zone system.
- Installed a 3-ton Daikin DH6 inverter heat pump with a Daikin variable-speed air handler for the bedroom side.
- Configured the bedroom-side system for two zones.
- Ran a new dedicated return from the master suite hallway to the 3-ton air handler.
- Replaced all flex duct with R-8 insulated flex duct upgraded from R-4.
- Mastic-sealed every duct joint and installed rigid straps at intervals of 3 feet or less.
- Installed manual balancing dampers at every branch takeoff.
- Built a new return plenum and trunk sized for the 3-ton system at approximately 1,200 CFM.
- Installed a zoning panel with built-in static pressure modulation.
- Installed two motorized dampers and two thermostats for bedroom-side zoning.
- Performed room-by-room air balancing after startup.
- Walked the homeowner through zone operation.
- Coordinated permits, Title 24 documentation, and HERS testing.
Two Daikin DH6 inverter systems with zoning and R-8 ductwork
The final design gives the common areas and bedroom side separate inverter heat pump systems, with dedicated zoning on the bedroom side and a rebuilt duct system designed to support the equipment properly.
4-ton Daikin DH6 system
Daikin DH6VSA4810A inverter heat pump, R-32, 17 SEER2, matched with a Daikin DFVE48CP0300A variable-speed 115V air handler.
3-ton Daikin DH6 two-zone system
Daikin DH6VSA3610A inverter heat pump, R-32, 16.6 SEER2, matched with a Daikin DFVE36CP0300A variable-speed 115V air handler.
Two-zone control with motorized dampers
Zoning panel with integrated static pressure sensor, modulating blower control, motorized zone dampers, and two zone thermostats.
Full R-8 duct replacement
R-8 flex throughout, mastic-sealed at every joint, with a new 3-ton return plenum, dedicated master suite return, and balancing dampers.
A wildfire rebuild is the right time to fix the system design
Putting modern inverter heat pumps on undersized or leaky ductwork wastes the equipment’s capability and leaves rooms uneven. By replacing the duct system in R-8 flex, sealing it properly, and sizing the return path to match the equipment, the new systems can modulate quietly and hold steadier temperatures.
The dedicated master suite return is the detail that makes the bedroom-side zoning actually work. Without it, the master suite would either starve for air or fight the upstairs thermostat. With it, each zone can operate independently while the blower modulates to match demand.
Before, during, and after the Altadena wildfire rebuild HVAC replacement
The photos below show the existing equipment, duct removal, new duct materials, R-8 ductwork, new Daikin outdoor unit, homeowner walkthrough, and completed before-and-after comparison.
Two properly supported inverter systems for a rebuilt home
This project delivered two Daikin DH6 inverter heat pump systems with full R-8 ductwork replacement, a dedicated bedroom-side zoning setup, proper return sizing, and room-by-room balancing after startup.
Separate systems for different home zones
The common areas and bedroom side received their own Daikin DH6 systems, matched to the way each part of the home is used.
Functional bedroom-side zoning
The dedicated master suite return, motorized dampers, zoning panel, and two thermostats allow the bedroom side to operate as a true two-zone system.
Full duct system reset
New R-8 flex duct, mastic-sealed joints, proper strapping, manual balancing dampers, and return trunk sizing help the inverter equipment perform as intended.
Planning a full HVAC rebuild or duct replacement?
Cold Cloud Mechanical designs HVAC replacements around load, zoning, return sizing, duct performance, comfort goals, permit requirements, Title 24 documentation, and long-term serviceability.