Can my existing ductwork be reused with a heat pump?
Sometimes. We evaluate capacity, condition, leakage, return air, and distribution before recommending reuse.
RESIDENTIAL HVAC · CASTRO VALLEY, CA
Residential HVAC & Heat Pumps in Castro Valley, CA
Whole-home heat pump systems for Castro Valley homeowners planning HVAC replacements, remodels, additions, and substantial comfort upgrades — with mechanical design built around the existing home, distribution system, and site conditions.
Remodels · Retrofits · Heat Pumps · Multi-Zone Systems
Project Inquiry
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- 5.0 Google Rating 5.0 out of 5 stars
- Mitsubishi Electric Diamond Contractor
- C-20 + C-36 Licensed & Bonded
- Serving the Bay Area since 2015
Project fit
Residential HVAC projects we handle in Castro Valley
Whole-home heat pump installations, major HVAC replacements, remodel mechanical scopes, ducted and multi-zone systems, ventilation, and residential projects where the system needs to be evaluated as a whole before equipment is selected.
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New system
Heat Pump Installation
New ducted or ductless heat pump systems sized for your home, comfort goals, and how the house is built.
Heat pump installation -
Full upgrade
Heat Pump Replacement & Conversion
Replace aging furnace and AC together, or convert gas heat to a heat pump with ducts, electrical scope, and controls planned as one job.
Replacement & conversion -
Central
Ducted Heat Pump Systems
Central heating and cooling through existing or updated ductwork, with loads and airflow checked before equipment is selected.
Ducted heat pumps -
Room-by-room
Ductless & Multi-Zone Heat Pumps
Mini-splits and multi-zone layouts when zoning, architecture, or tight routing make ductless or mixed systems the better fit.
Ductless & multi-zone -
Coordinated
HVAC for Remodels & Additions
Mechanical design and rough-in coordinated with your architect or builder while walls and ceilings are still open.
HVAC for remodels -
Fresh air
Ventilation & Indoor Air Quality
ERV/HRV, filtration, and balanced ventilation coordinated with your heating and cooling scope when the project needs it.
Ventilation & IAQ
RELEVANT EAST BAY WORK
Whole-home heat pump remodel
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High-end residential remodel
Hearst Remodel
A representative East Bay residential project showing the whole-home system planning, equipment coordination, distribution decisions, and field execution we bring to Castro Valley projects.
- Home type
- Existing home, remodel for sale
- System
- Fujitsu multi-zone ductless heat pump
- Mechanical scope
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- · Six indoor wall units
- · Two outdoor units
- · Wall-mounted outdoor brackets
- · Refrigerant routing and field coordination
Challenge
- Existing older home with limited equipment placement options
- Outdoor units required side-yard wall bracket mounting
- Finish-sensitive interior installation
- Coordination with the general contractor’s remodel schedule
3RDGEN scope
- Six-zone ductless heat pump installation
- GC-led remodel coordination
- Permit and inspection support
- Startup as part of the completed remodel scope
Outcome
The six-zone Fujitsu ductless system was installed, permitted, inspected, and completed as part of the home’s remodel-for-sale scope — delivering zoned heating and cooling without a conventional ducted retrofit.
Representative published remodel scope — location, photos, and full details on the project page.
View projectBUILT AROUND THE PROPERTY
Castro Valley HVAC projects can be shaped by both the existing home and the site
Castro Valley includes established neighborhoods on the flatter valley floor as well as hillside homes where access, equipment placement, routing, and serviceability can become part of the mechanical design.
3rdGen evaluates heating and cooling loads, existing ductwork, airflow, zoning, equipment locations, electrical requirements, access, and ventilation before determining what should stay, what should change, and how the new heat-pump system should be configured.
The County’s Castro Valley Area Plan specifically describes both built-out flatter neighborhoods and substantial hillside residential development.
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Existing ductwork
Existing ducts should be evaluated for capacity, leakage, return air, layout, and condition before new equipment is designed around them.
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Hillside properties
On sloped sites, stairs, access, outdoor-unit location, routing, and future serviceability can influence the system approach.
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Zoning & comfort
Uneven temperatures can come from distribution, return air, zoning, solar exposure, or system configuration rather than equipment capacity alone.
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Remodels & additions
Changes to floor area, glazing, insulation, ceilings, and room layout should be reflected in the mechanical design.
Castro Valley is unincorporated Alameda County, so building and mechanical permitting is handled through Alameda County.
Homeowner reviews
Trusted by Bay Area Homeowners
5.0
5 out of 5 stars from 207 Google reviews 207 Google reviews
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Mitsubishi mini-split installed with outstanding care. Indoor and outdoor units done right. High efficiency meant a meaningful federal tax credit too.
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Expand
Devin and his crew did a fantastic job installing AC for our whole house. High quality Mitsubishi equipment and a clean installation throughout.
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Devin is meticulous, methodical, and knowledgeable. Professional crew and a heat pump install we trust completely.
Photos from the installs above
Read all 207 reviewsHow we work
Heat pump work, start to finish
On many Castro Valley projects, the important decisions happen around the home, the existing system, and the distribution — not from copying the equipment that came out.
01 — Project review
Plans, goals, existing system, remodeling scope, and known constraints.
02 — Load & system design
Manual J / system sizing where appropriate, zoning strategy, equipment selection, and distribution.
03 — Equipment & routing
Indoor equipment, outdoor equipment, duct / refrigerant routing, ventilation, access, and serviceability.
04 — Permit / coordination review
Equipment locations, GC/architect coordination, and permit requirements where they apply.
05 — Installation
Rough-in and finish installation coordinated around the project.
06 — Startup & closeout
Startup, controls, commissioning checks, inspection coordination, and homeowner handoff.
Complete project delivery
The whole heat-pump project—not just the outdoor unit
A Berkeley electrification project can touch the furnace, ducts, electrical service, controls, equipment locations, permits, and finished interiors. We plan those connections as one scope.
The result is a complete system designed for the home, installed to the plan, and tested before handoff.
Tell us about the project-
Existing equipment and gas heat
Removal and replacement planned around the complete conversion.
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Ducts, zoning, and controls
Reused, modified, or replaced according to what the design requires.
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Electrical and permitting
Capacity, circuits, documentation, inspections, and other trades coordinated with the HVAC scope.
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Startup and commissioning
Operation and airflow checked before the project is handed back to you.
Cost
What a whole-home heat-pump project costs — and what moves the number
Castro Valley projects can range from direct central-system replacements to more involved retrofits. Existing ductwork, hillside access, number of zones, electrical scope, equipment locations, ventilation, and remodel conditions are often what determine the real project scope.
Scope Typical 3rdGen Project Range What drives it
Ducted heat pump, existing ducts usable $20k–$30k Equipment tier, capacity, controls, condenser location and access
Ducted heat pump + duct repair or resizing $25k–$45k Amount of ductwork replaced, crawlspace or attic access, return-air changes
Ductless multi-zone, 3–4 heads $25k–$40k Head type, line-set length, routing, concealment and finish conditions
Whole-home ducted + ductless combination $40k–$80k+ Multiple systems, zoning, ductwork, filtration, ventilation and architectural coordination
New construction system $20k–$50k+ Building size, system count, Title 24/design requirements and coordination with the build
ADU system $8k–$15k Zone count, head type, line-set routing, and whether the ADU shares the main house or stands alone
Electrical panel upgrade, when required $8k–$10k+ Service size, meter location, utility requirements and site conditions
Complex whole-home and design-build projects can exceed these ranges. Rebates and incentives may reduce your net project cost.
Project inquiry
Tell us about your Castro Valley HVAC project
Planning a whole-home heat pump, remodel, addition, or substantial HVAC replacement? Send us the project details and plans if available.
- Reviewed by a project lead, not a dispatcher
- We tell you if your scope is not a fit for us
- No high-pressure in-home sales appointment
Project Inquiry
Inquiry Sent
Thanks — your project details are on their way to 3rdGen. We’ll review them and follow up about the next step.
Project teams
We work with the people designing and building your home
For remodels and additions, early mechanical coordination helps resolve equipment locations, duct routes, framing, ceilings, zoning, and electrical requirements while the project can still accommodate them cleanly.
We work within existing project teams in Castro Valley and across the East Bay — or directly with homeowners when that is the right path.
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Architects
Mechanical systems coordinated around architecture, ceiling conditions, equipment locations, routing, and finish requirements.
Explore HVAC for architects -
General Contractors & Builders
Clear scope, scheduling, rough-in coordination, submittals, inspections, startup, and project handoff.
Explore HVAC for builders & GCs -
Mechanical Engineers
Field execution, equipment selection, controls coordination, submittals, installation, and commissioning aligned with the mechanical design.
Explore engineering coordination -
Homeowners
Already assembling your own project team? We can take ownership of the mechanical scope and coordinate directly with the other professionals involved.
Start a residential project
Mitsubishi Electric
Proud Mitsubishi Electric Diamond Contractor
As a Mitsubishi Electric Diamond Contractor, we design and install ducted, ductless, and multi-zone systems for Bay Area homes, with factory-trained crews and longer warranty options on qualifying residential installs.
Mitsubishi is not automatically the answer to every home. We start with what the project requires and recommend the system that makes sense.
12 Year Parts &
Compressor Warranty
12-year warranty
Extended parts & compressor coverage on qualifying Diamond installations.
Factory-trained crews
Ongoing manufacturer training on the latest hyper-heat systems.
Priority support
Direct factory escalation if anything ever needs attention.
FAQ
Common Questions
Straight answers on heat pumps, whole-home HVAC, and project scope in Castro Valley.
Can you install a heat pump on a hillside property?
Yes. Site access, outdoor-unit placement, routing, drainage, and serviceability simply need to be accounted for during design.
Can you improve uneven temperatures between rooms?
Potentially. We evaluate airflow, zoning, returns, room loads, and system configuration as part of a full-system project.
Who handles building permits in Castro Valley?
Castro Valley is unincorporated Alameda County, so building and mechanical permitting is handled through Alameda County.
Project Inquiry
Inquiry Sent
Thanks — your project details are on their way to 3rdGen. We’ll review them and follow up about the next step.