Ductless Mini-Splits for Palo Alto homes without ducts
No ducts, a hot upstairs bedroom, an Eichler with radiant floors, or a new ADU in the backyard. A ductless heat pump adds quiet heating and cooling one room or zone at a time.
Call 650-460-3483438 Cambridge Ave, 94306
A ductless mini-split is a heat pump with an outdoor unit connected to one or more indoor heads by a small refrigerant line. In Palo Alto it is the go-to option for Eichlers with radiant floors, room additions, ADUs and older homes without ductwork. Each zone has its own thermostat, so you heat or cool only the rooms you use.
Where ductless makes the most sense
- Eichler and mid-century homes in Greenmeadow, Fairmeadow and other tracts, where radiant floors handle heat but there is no duct system for cooling
- Additions and converted garages that the original system was never sized to reach
- ADUs and backyard cottages, which need their own independent system
- Upstairs bedrooms and home offices that run hot every afternoon
- Older homes in Professorville or Old Palo Alto where adding ducts would mean opening plaster walls
Indoor unit styles
Wall-mounted heads are the most common and the most affordable. Ceiling cassettes sit flush in the ceiling and spread air in four directions, a nice fit for open living spaces. Slim ducted air handlers hide in an attic or soffit and feed two or three rooms through short duct runs, so you don’t see equipment on the wall at all. Floor consoles work under windows and in rooms with low walls.
Designing a multi-zone system
A single outdoor unit can serve several indoor heads, but bigger isn’t always better. Multi-zone outdoor units run less efficiently when only one small room is calling for heat. For some homes, two single-zone systems beat one five-zone system. We size each zone with a load calculation and design line set routes that are clean on the outside of the house, especially on Eichlers, where exposed line sets on beautiful siding are a real concern.
Rebates and permits
A ductless heat pump that replaces a gas heater can qualify for the City of Palo Alto Utilities Heat Pump HVAC rebate. The Rebate Hub doesn’t list mini-splits separately, so we confirm eligibility with CPAU for your specific project. Qualifying installs can use the City’s instant permit for residential heat pumps. See the CPAU rebate guide.
Maintenance
Mini-splits need clean filters (every month or two in heavy use), a yearly coil and blower wheel cleaning, and a clear condensate path. Dirty blower wheels are the most common cause of musty smells and weak airflow. We include mini-splits in our maintenance plans.
Indoor unit styles compared
| Style | Where it goes | Look | Best for |
|---|---|---|---|
| Wall-mounted head | High on a wall | Visible, slim | Bedrooms, offices, ADUs |
| Ceiling cassette | Recessed in ceiling | Flush grille | Open living areas |
| Slim ducted unit | Attic, soffit or closet | Hidden, small grilles | Two or three nearby rooms |
| Floor console | Low on a wall | Compact | Rooms with low walls or under windows |
Single-zone vs. multi-zone
A single-zone system pairs one outdoor unit with one indoor head and is the most efficient choice for one room or an ADU. Multi-zone systems connect several heads to one outdoor unit, which saves exterior space but can run less efficiently when only one small room is calling. ComfortFlow HVAC Palo Alto sizes each zone individually before choosing the layout.
Why Palo Alto homeowners choose ComfortFlow HVAC Palo Alto for ductless mini-splits
ComfortFlow HVAC Palo Alto has served Palo Alto homes for over 10 years from our shop at 438 Cambridge Ave. We install ductless systems in Eichlers, Professorville bungalows, College Terrace ADUs and older homes across the Peninsula, with careful line set routing on every exterior.
- Diagnosis before recommendations. We measure first, then explain what we found in plain language.
- Repair prices up front. You see the cost before any work begins, and replacement only comes up when it makes sense.
- Local know-how. CPAU rebates, the City heat pump instant permit, Eichler radiant systems and Palo Alto’s older housing stock.
- Respect for your home. Drop cloths, protected floors and trim, and a clean work area at the end of every day.
Ductless Mini-Splits, step by step
- WalkthroughWe map the rooms, wall space, line routes and the outdoor spot.
- Zone designLoad calculation per room and the right head style for each.
- Clean installNeat line sets, sealed penetrations, protected finishes.
- SetupRemote and app setup, plus a filter cleaning lesson.
Often paired with ductless mini-splits
Ductless Mini-Splits across Palo Alto and nearby
We’re based at 438 Cambridge Ave and work in every Palo Alto neighborhood. Local notes for each area:
New to us? Start with our overview of HVAC in Palo Alto.
Ductless Mini-Splits questions,
answered.
Answers from the ComfortFlow HVAC Palo Alto team about ductless mini-splits in Palo Alto homes.
Can a mini-split heat my whole house?
Yes, with good design. Whole-home ductless systems are common in Palo Alto’s mild climate. Open floor plans are easiest; closed-off rooms may each need a head or a small ducted unit. Whole-home ductless designs usually combine wall-mounted heads in bedrooms with a ceiling cassette or slim ducted unit in the main living area. Each zone has its own thermostat, so you heat or cool only the rooms you use. ComfortFlow HVAC Palo Alto sizes each zone with a load calculation to avoid oversized heads that short cycle.
How visible are the line sets outside?
We route them as discreetly as possible, using paintable line hide covers and interior routing when walls allow. On Eichlers, we plan routes with the siding and roofline in mind. Line sets carry refrigerant, power and the condensate drain between the outdoor unit and each indoor head. We keep runs short, group them where possible, and use covers that can be painted to match your siding. Inside the home, lines can sometimes run through closets, attics or crawlspaces so the walls stay clean.
Are mini-splits noisy?
Indoor heads are among the quietest HVAC equipment available. Outdoor units are compact, and Palo Alto’s instant permit requires heat pumps rated under 65 dBA. Indoor heads typically run in the low 20s to low 30s decibels at low speed, quieter than a whisper. Outdoor units are compact and use variable-speed compressors, so they rarely run at full power. That makes ductless a good fit for bedrooms, home offices and ADUs on small Palo Alto lots.
Do mini-splits qualify for Palo Alto rebates?
A ductless heat pump that replaces gas heating can qualify for the CPAU Heat Pump HVAC rebate. Mini-splits aren’t listed separately on the Rebate Hub, so we confirm with CPAU for your project. The key requirement for the CPAU Heat Pump HVAC rebate is replacing a gas or fossil fuel heater. If ductless heads take over heating from a gas furnace, wall furnace or gas boiler, the project may qualify. ComfortFlow HVAC Palo Alto confirms eligibility with CPAU before you commit and helps with the application after final inspection.
Can I add a mini-split to an ADU?
Yes, and it’s the most common choice for ADUs because it is independent from the main house and easy to size for a small space. A dedicated system keeps the ADU independent, so tenants or family members control their own comfort and the main house system is not overloaded. Most ADUs need one or two indoor heads. Qualifying ADU heat pump installs can use the City’s instant permit, and we plan the outdoor unit location to meet setback rules.
Let’s make home
feel better.
Tell ComfortFlow HVAC Palo Alto what’s happening with your heating or cooling, and we’ll start with the right questions. Serving Palo Alto, Menlo Park, Mountain View, Los Altos, Stanford and the Peninsula.