Ductless Mini-Split Installation in the East Bay
Heat and cool rooms that have no ductwork
A ductless mini-split is a small heat pump with an outdoor unit and one or more wall, ceiling or floor units inside, joined by a small refrigerant line. It heats and cools a room or zone without any ductwork. We install and service mini-splits for garages, room additions, sunrooms, converted spaces, ADUs and older homes that never had ducts, plus single rooms the main system never keeps comfortable.
Why choose Blue Star
We visit before quoting to size each indoor unit for its room, plan the line set and drain routes, and place the outdoor unit away from sun-baked walls and foot traffic where we can. We mount equipment level and secure, seal every wall penetration, and test the system for leaks under vacuum before charging it. We pull the permit when your city requires one.
- Single and multi-zone systems
- Garages and room additions
- ADUs and converted spaces
- Line set and drain routing
- Wall, ceiling or floor units
- Filter and coil cleaning
Where we work
Mini-splits fit a lot of local situations. Garages and bonus rooms in Brentwood, Oakley and Antioch tract homes bake in July. Older homes in Concord, Martinez and Lafayette often have rooms that were added without ducts. Delta homes and outbuildings in Knightsen, Byron and Bethel Island that run on propane or electric heat can use a mini-split as a cleaner option. In Walnut Creek's Rossmoor, Mutual rules on outdoor unit placement and height apply.
Major corridors
- SR-4
- Lone Tree Way
- Empire Ave
- Delta Rd
- Byron Hwy
- Alhambra Ave
- Rossmoor Pkwy
- SR-24
Find your area
East Contra Costa
Antioch, Pittsburg, Bay Point, Oakley, Brentwood, Discovery Bay, Byron, Knightsen, Bethel Island, Rio Vista
Central Contra Costa
Concord, Clayton, Pleasant Hill, Walnut Creek, Martinez, Saranap, Pacheco
Lamorinda
Lafayette, Moraga
4.9 stars on Google
Read more reviewsColton was great. He found the problem right away and did a temporary fix to get my a/c running until he could get the right part ordered. He also made sure every inside was working well.
Questions we hear
Can a mini-split heat and cool a garage or room addition?
Yes. A single-zone mini-split heats and cools one space without tying into your main system, which is often stretched already. A garage needs some insulation for the unit to keep up on 100-degree afternoons, and we size the unit for the actual space and its sun exposure. For a garage turned into a gym, office or ADU, a mini-split is usually the simplest fix.
How many indoor units can one mini-split outdoor unit run?
Multi-zone outdoor units can run several indoor units, often two to five, each with its own controls. That works well for a few rooms near each other. For a whole house, a ducted heat pump or several single-zone systems is sometimes the better choice, since one multi-zone failure takes out every room it serves. We lay out the options for your floor plan.
Do mini-splits need maintenance?
Yes. Rinse or vacuum the indoor filters every month or two during heavy use. Once a year, the indoor coil and blower wheel should be cleaned, because dust and mold build up where you can't see them, and the outdoor coil should be rinsed, especially with East County's summer dust. We also check the drain line and refrigerant pressures during a service visit.
Do I need a permit to install a mini-split?
In most Contra Costa cities, yes. Adding a mini-split is new mechanical and electrical work, so it usually needs a building permit and inspection, and California's energy code may require ECC verification. Rules differ between cities, and the County handles unincorporated areas. We check with your building department and pull the permit as part of the job.
Are ductless mini-splits efficient?
Yes. They are heat pumps, so they move heat rather than make it, and there are no duct losses. Variable-speed compressors slow down to match the room instead of cycling on and off. Running cost depends on how you use them and how well the space is insulated, and they run most efficiently at steady settings rather than being switched off and on all day.
Related services
All servicesBlue Star Heating & Air is just a call away!
Have a room that never feels right? Call (925) 584-2428 or request a quote for a mini-split.