Can a heat pump work in a Kensington house with no ducts?
Yes. A multi-zone ductless system can heat and cool a house without ducts. If you have a tall enough crawl space or attic, ducted is an option too, and we compare the two.
RESIDENTIAL HVAC · KENSINGTON, CA
Residential HVAC & Heat Pumps in Kensington, CA
Kensington homes sit on steep lots, wind along narrow streets, and often have views worth protecting. We design heat pump systems around the slope, the crawl space, and the way the house was built.
Remodels · Retrofits · Heat Pumps · Multi-Zone Systems
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- Mitsubishi Electric Diamond Contractor
- C-20 + C-36 Licensed & Bonded
- Serving the Bay Area since 2015
Project fit
HVAC work for Kensington houses
Hillside homes from the early and middle 1900s, many with original furnaces and little ductwork to speak of. Here is what we do with them.
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Replace
Gas furnace to heat pump conversions
Take out an aging furnace and add a heat pump with a new coil, matching duct changes and a condensate drain. Gas gets capped and electrical gets sized.
Replacement & conversion -
Ducted
Crawlspace ducted systems on a slope
Downhill-side crawl spaces can be tall enough for an air handler and trunk lines. We measure, check for moisture, and size the ducts before we commit.
Ducted heat pumps -
Zoned
Multi-zone mini-splits for view rooms
Rooms with big glass and upper-floor bedrooms often want their own temperature control. Mini-split heads let each space run on its own schedule.
Ductless & multi-zone -
Manual J
Load calculations for permits and remodels
We produce Manual J and equipment documents for the systems we install, for the County permit or your architect’s plan set.
Manual J load calculations -
Remodel
Whole-house remodel mechanical
Kensington remodels are often full gut jobs. We set equipment locations and duct paths with the architect so finishes and views stay intact.
HVAC for remodels -
Air quality
Smoke and air filtration
Kensington sits in the hills where wildfire smoke can drift in during bad seasons. Upgraded filtration and balanced ventilation help keep indoor air cleaner with windows shut.
Ventilation & IAQ
Current Kensington project
Two ducted heat pumps in the crawlspace (in progress)
View project →
Full-System Residential Retrofit
Kensington Ct, Kensington
This Kensington project, now underway with a repeat general contractor partner, replaces the existing equipment with two Mitsubishi ducted heat pumps: a 2-ton system and a 1.5-ton system, one for each floor. Both air handlers sit on framed platforms in the crawlspace and feed new R-8 flex runs from custom sheet-metal plenums. Asbestos abatement is part of the scope, and a shear wall forced us to reroute the line sets and ducting and relocate the outdoor units.
- Client
- General contractor-led project
- System
- Two Mitsubishi ducted heat pumps (2-ton and 1.5-ton), one per floor
- Mechanical scope
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- · Removal of the existing equipment, with asbestos abatement in scope
- · Mitsubishi SVZ-AP24NL air handler with SUZ-AA24NL outdoor unit (2 tons)
- · Mitsubishi SVZ-AP18NL air handler with SUZ-AA18NL outdoor unit (1.5 tons)
- · Both air handlers on framed platforms in the crawlspace
- · Custom sheet-metal supply plenums and return filter boxes
Challenge
- Asbestos abatement before the new work
- Both air handlers in a crawlspace
- A shear wall in the planned path forced a reroute and new outdoor unit locations
3RDGEN scope
- 3rdGen designed both systems and the duct layout, fabricates the plenums, installs and commissions the equipment, and coordinates the abatement and shear-wall reroute with the general contractor.
Outcome
In progress. When finished, each floor will have its own variable-speed heat pump and thermostat on new, balanced duct distribution.
In progress in Kensington. Photos and full details on the project page.
View projectLocal projects
Recent 3rdGen work in Kensington
Real jobs our own crew designed and installed. Street names only — we keep clients' addresses private.
- Kensington Ct, Kensington · 2026
Two ducted Mitsubishi heat pumps in a tight crawlspace
Two SVZ ducted air handlers (24k and 18k, R-454B) on framed crawlspace platforms, custom sheet-metal plenums, R-8 flex with balancing dampers, condensate pumps and line-hide. Ducts rerouted around a shear wall after asbestos abatement.
Heat pump installation → - Arch St, Berkeley · 2026
Whole-home mechanical with ventilation
Full mechanical scope for a whole-house renovation: heat pump heating and cooling, new supply and return ducting, and dedicated ventilation ducting coordinated with the GC.
Full system replacement → - Capistrano Ave, Berkeley · 2026
60k Mitsubishi multi-zone, mixed indoor units
Mitsubishi 60k multi-zone with branch box feeding a 12k slim ducted unit, an 18k vertical air handler and 9k one-way ceiling cassettes, with fabricated return plenums.
Mitsubishi Diamond Contractor → - West St, Berkeley · 2026
Multi-zone heat pump plus balanced ventilation
Mitsubishi 24k three-port multi-zone with a 12k horizontal ducted unit and a 12k four-way cassette, two Panasonic Intelli-Balance ERVs and 70 ft line sets.
Ventilation & indoor air quality →
Steep lots, small streets
Kensington jobs are won or lost on access and placement
There is no flat ground to speak of. A condenser may need to sit on a bracket, a side deck, or a pad cut into the hillside, and every piece of equipment has to be carried there.
We plan the logistics before we price: stairs, gates, narrow driveways and where a truck can park. That avoids surprises on installation day.
Kensington is unincorporated, so permits go through Contra Costa County, and exterior additions may also pass through the Kensington Design Review process.
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View-side glass
Large windows facing the bay add real cooling load on sunny afternoons. We capture them in Manual J so the equipment is not guessed.
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Crawlspace headroom
Headroom varies widely from one side of a hillside house to the other. We pick duct routes where there is actual room.
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Narrow lots, close neighbors
Outdoor units should sit where sound and exhaust do not point at a neighbor’s window or deck.
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Fire-hazard setting
Wildfire smoke and embers are a real concern in the hills. We discuss filtration and keep equipment away from combustible clutter.
Kensington is unincorporated, so HVAC permits are issued by Contra Costa County. Exterior changes tied to a larger project can also go through Kensington Design Review.
HVAC design in Kensington
Kensington hillside houses call for a plan built around access and airflow
Kensington is a small hillside community of mostly single-family homes, many from the early to mid 1900s, on steep streets above the East Bay flatlands. Equipment placement, the crawlspace on the downhill side, and large view windows tend to matter more than the nameplate tonnage. We start with those and then calculate the load.
Design climate · Title 24 Climate Zone 3
- Winter design temp
- 38°F
- Summer design temp
- 79°F
There is no separate Kensington entry in the LoadCalc data, so we use El Cerrito, its closest neighbor: 38°F heating and 79°F cooling design. Individual lots on the ridge can run cooler or windier, which we account for in the envelope assumptions.
ACCA Manual J design data · El Cerrito (nearest micro-climate station)
What Kensington homes tend to look like
Many houses are older wood-frame homes with wood floors over a raised foundation. On a slope, the crawl space can be a few inches tall on the uphill side and nearly walk-in on the downhill side. That changes where a duct trunk or air handler can live.
Original heating is often a gravity furnace or a forced-air system from a previous remodel. Duct runs are frequently too small for modern comfort and leaky in places we cannot see without opening them.
Large windows and decks reflect how people use Kensington homes. They also create concentrated heat gain and heat loss that a single thermostat cannot manage well.
View glass and zoning
A living room with a wall of glass behaves differently from the bedrooms behind it. We separate loads and often recommend zoning so one space does not drive the whole system.
Manual S on a hill
Equipment selection depends on rated capacity at design temperatures, not just nominal tons. We check capacity tables for the chosen unit against the calculated Kensington load, and we confirm static pressure limits against the real duct layout.
Line-set length and elevation
Hillside layouts can mean long refrigerant runs and elevation changes between outdoor and indoor units. We design to the manufacturer’s limits rather than finding out on install day.
Filtration in smoke season
Kensington’s hillside setting makes wildfire smoke a consideration. Larger filter racks and, where it fits, a filtered ventilation path help keep indoor air manageable.
Condensate and drainage on slopes
Condensate needs somewhere sensible to go. We plan drain routing around the grade and foundation so it does not create a moisture problem.
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Full furnace replacement with a heat pump
Remove the old gas unit, add the heat pump and coil, correct duct issues, and upgrade electrical as needed.
Replacement & conversion → -
Multi-zone systems for glass-heavy rooms
Separate temperature control for view rooms, bedrooms and offices, with equipment placed to suit the lot.
Heat pump installation → -
Load calculations for remodel teams
Manual J, S and D design for the systems we install, coordinated with your architect or builder’s plan set.
Manual J load calculations → -
Mechanical design for whole-house remodels
Equipment and duct locations worked out before framing closes in.
HVAC for remodels → -
Filtration and balanced ventilation
Practical air quality upgrades for hillside homes that deal with smoke or tightly sealed envelopes.
Ventilation & IAQ → -
Mitsubishi Diamond Contractor installation
Factory-trained installers and extended coverage on qualifying Mitsubishi systems.
Diamond Contractor →
Permits, power and rebates in Kensington
Kensington is unincorporated. HVAC permits come from Contra Costa County rather than a city, and projects that include exterior changes may also go through Kensington Design Review. We prepare the load calculation, equipment data and outdoor unit location for the County.
PG&E delivers electricity, and MCE is the default generation provider for unincorporated Contra Costa County. State and regional heat pump incentives are updated regularly and may have eligibility rules, so we confirm what is available when we scope the work.
Where we work around Kensington
Streets throughout the Kensington hills, plus the adjoining areas of El Cerrito, Albany, Berkeley and Richmond.
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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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 reviewsProcess
How we plan a Kensington system
Hillside homes do not forgive guesswork. We confirm what is possible on your property before we draw a single duct.
01 — Walk the property
We look at slope, access, the crawl space, the attic and the existing furnace and panel.
02 — Manual J loads
Every room gets its own load. View windows, ceiling height and insulation quality drive the numbers.
03 — Manual S selection
We choose equipment whose rated capacity at Kensington’s design temperatures matches the load without oversizing.
04 — Manual D and the County permit
Duct sizing or refrigerant routing is finalized and the permit package goes to Contra Costa County.
05 — Careful installation
Gear is carried in, pads or brackets are set, and penetrations are sealed with finish protection in mind.
06 — Test, inspect, hand off
We measure airflow, confirm charge, schedule the inspection, and show you the controls.
What “done” means
A Kensington install covers more than the box on the hill
Hillside work has extra steps: moving equipment, anchoring on a slope, routing line sets and protecting finishes. We plan those parts into the scope and the schedule.
At the end, we verify airflow and charge, and explain the controls.
Tell us about the project-
Staging and access
Carry route planned, finishes protected, old equipment removed.
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Anchoring
Pad or wall bracket installed and equipment fastened for the slope.
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Refrigerant and drain
Line sets, insulation and condensate path run and tested.
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County inspection and handoff
Inspection scheduled and passed, then a walkthrough with you.
Cost
What shapes the cost of a Kensington heat pump project
Steep access, long line sets, hillside pads, tight crawl spaces and electrical upgrades can add real scope in Kensington. A simple equipment swap with usable ducts looks very different from a whole-house conversion with new distribution.
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 $10k–$15k Zone count, head type, line-set routing, and whether the ADU shares the main house or stands alone
Electrical panel upgrade, when required $10k+ Service size, meter location, utility requirements and site conditions
Prices as of November 2026. Complex whole-home and design-build projects can exceed these ranges. Rebates and incentives may reduce your net project cost.
Project inquiry
Planning HVAC work on a Kensington home?
Share the address area, a few photos of the crawl space and side yard, and what you want to change. A project lead will respond.
- 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.
Working with your team
Alongside your architect and contractor
Hillside remodels move through several hands. We bring a mechanical plan early so the designer knows where ducts, chases and equipment will go before drawings are done.
We take on Kensington projects with builders and architects, and with owners who are managing the work themselves.
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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 for Kensington homeowners on slopes, ducts, permits and indoor air.
Where does the outdoor unit go on a steep lot?
Common spots are a wall bracket, a pad on a level section, or a side yard path. We review access, the carry route and neighbor distance before settling on a location.
Who issues the permit in Kensington?
Contra Costa County, since Kensington is unincorporated. Larger exterior changes can also involve Kensington Design Review. We prepare the mechanical documents the County needs.
Which electricity provider serves Kensington?
PG&E delivers the power, and MCE is the default generation provider for unincorporated Contra Costa. Rebates from programs like TECH Clean California and BayREN change over time, so we check current availability with you.
Should I worry about wildfire smoke indoors?
Kensington is in the hills, so smoke events can matter. A heat pump system with a properly sized filter rack, and optionally ventilation with filtration, can keep indoor air cleaner with windows closed.
Our house has big view windows. Do those change the sizing?
Yes. Glass area and orientation affect the cooling load significantly. We model each window in Manual J so the equipment is picked from numbers, not rules of thumb.
Will my panel need an upgrade?
It depends on the existing service and what else you plan to add, such as an EV charger or a heat pump water heater. We calculate the load before we recommend anything.
Nearby service areas
Heat pump and HVAC design near Kensington
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.