Mini Splits
Mini Split (Ductless) Installation, Repair & Replacement
Flexible, efficient comfort — without ductwork.
The short answer
A ductless mini split is a heat pump that heats and cools individual rooms without ductwork, using a quiet outdoor unit and compact indoor units on the wall or ceiling. Green Core Heating & Air installs, repairs, and maintains mini splits, including Mitsubishi systems, for homes, additions, ADUs, and garages across Sonoma and Marin.
Overview
Mini Splits in Sonoma and Marin
Ductless mini splits heat and cool individual rooms without any ductwork. Green Core Heating & Air installs, repairs, and maintains mini splits for homes across Sonoma and Marin counties, and they're especially popular in the area's older homes, additions, ADUs, and converted garages.
Each indoor unit has its own temperature control, so you only heat or cool the rooms you're using. We plan the indoor and outdoor unit locations, line set routes, and electrical work up front so the finished install looks clean and runs quietly.
Benefits
Why homeowners choose this.
No ductwork required
Perfect for older homes, additions, and ADUs.
Zoned control
Heat or cool individual rooms for comfort and efficiency.
Energy efficient
Avoids the losses associated with traditional ducted systems.
Designed for your home
Placement and sizing based on your layout and needs.
Mini split installation
Mini splits are a great fit for homes without ducts, older homes with wall heaters or baseboard heat, additions and ADUs, converted garages, and rooms that never get comfortable on the main system. A single-zone system serves one room; a multi-zone system connects several indoor units to one outdoor unit.
We size each zone, plan clean line set routes with covers, install a dedicated electrical circuit and disconnect, and weigh in the refrigerant charge to the manufacturer's spec.
- Single-zone and multi-zone systems
- Wall, ceiling, and ducted indoor units
- Clean line set routing and covers
Mini split repair
Common mini split problems include an indoor unit that won't heat or cool, water dripping from the indoor head, flashing error lights, and remote or sensor issues. Clogged drains and dirty indoor coils cause a lot of these calls.
Mini split maintenance
Mini splits move a lot of air across small coils, so they need regular cleaning. Clean the filters every month or two, and have the indoor coil, blower wheel, and drain professionally cleaned once a year, more often in kitchens or with pets.
Our work
Recent projects in Sonoma and Marin
Real Green Core jobs for homeowners in Sonoma and Marin, with photos from the job site.
September 2026
Mitsubishi ductless mini split installation in Novato
We installed a Mitsubishi ductless mini split with new line sets, a dedicated electrical disconnect, and a precisely weighed refrigerant charge.
See the job photos
FAQ
Mini Splits questions, answered
Can a mini split heat my whole house?
It can, with a multi-zone system or a few well-placed units, especially in smaller or open homes. For larger homes with good ductwork, a ducted heat pump is often the better choice.
Are mini splits efficient?
Yes. They're heat pumps, so they move heat instead of making it, and because there are no ducts, there's no duct loss.
Where do mini splits work best?
Homes without ductwork, additions and ADUs, converted garages, and rooms that are always too hot or too cold.
How often should I clean my mini split?
Clean or rinse the filters every month or two, and have the indoor coil, blower, and drain professionally cleaned once a year.
Why is my mini split dripping water?
Usually the condensate drain is clogged or the unit isn't level. Turn it off and call us so the water doesn't damage your wall.
What brands of mini split do you install?
We install Mitsubishi ductless systems, among others, and recommend equipment based on your home and budget.
Do mini splits qualify for rebates?
They often do, since they're heat pumps. Availability depends on where you live and current program funding, and we check for you.
Ready to talk mini splits?
Share a few details about your home and we'll reach out with clear, honest options.