Ductless Mini Split Systems

Efficient, flexible, and whisper-quiet heating and cooling without the need for ductwork.

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How Ductless Mini Splits Work

A ductless mini split system consists of two main components: a compact outdoor compressor/condenser unit and one or more indoor air-handling units. These are connected by a small conduit that houses the refrigerant tubing, power cable, and condensate drain — requiring only a 3-inch hole through your wall.

In cooling mode, the indoor unit absorbs heat from your room air and transfers it via refrigerant to the outdoor unit, which releases it outside. In heating mode, the process reverses: the outdoor unit extracts heat from the outdoor air (even in cold temperatures) and delivers it inside. This heat pump technology makes mini splits remarkably efficient because they move heat rather than generate it.

The inverter-driven compressor in modern mini splits continuously adjusts its speed to match the precise heating or cooling demand. Instead of cycling on and off like traditional systems, it runs continuously at the lowest speed needed, maintaining your exact set temperature with minimal energy use and virtually no noise.

Benefits of Mini Split Systems

Ductless mini splits offer advantages that conventional HVAC systems simply cannot match.

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Individual Room Temperature Control

Each indoor unit operates independently with its own thermostat, allowing you to set different temperatures in different rooms. Heat the living room to 72 degrees while keeping the bedroom at 68 degrees. Only condition the rooms you’re actually using, and eliminate household thermostat wars for good.

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No Ductwork Required

Mini splits require only a small 3-inch hole through the wall to connect the indoor and outdoor units. There’s no need to install, maintain, or lose energy through ductwork. This makes them the ideal solution for older homes without ducts, room additions, converted garages, and any space where running ductwork would be impractical or expensive.

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Exceptional Energy Efficiency

Modern mini splits achieve SEER2 ratings up to 33.1, making them among the most efficient HVAC systems available. By eliminating duct losses (which account for up to 30% of energy waste in conventional systems) and using inverter-driven compressors, mini splits can reduce your heating and cooling costs by 30-50%.

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Whisper-Quiet Operation

Indoor units operate as low as 19 dB, quieter than a library. You’ll barely know the system is running. Outdoor units are equally subdued, making mini splits the perfect choice for bedrooms, nurseries, home offices, and noise-sensitive environments where traditional HVAC noise would be disruptive.

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Versatile Installation Options

Indoor units are available in wall-mounted, ceiling cassette, floor-standing, and concealed-duct configurations. This flexibility allows you to choose the style that best fits your space, aesthetics, and comfort preferences. Most installations can be completed in a single day with minimal disruption.

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Improved Indoor Air Quality

Without ductwork to collect dust, allergens, and mold, mini splits deliver cleaner air to every room. Advanced multi-stage filtration systems in the indoor units capture particulates, allergens, and odors. Many models include washable filters that are easy to maintain.

Single-Zone vs. Multi-Zone Systems

Choose the configuration that best fits your space and comfort needs.

Single-Zone Mini Splits

A single-zone system pairs one outdoor unit with one indoor unit, providing dedicated heating and cooling for a single room or area. This is the most affordable and straightforward mini split configuration.

Best Applications:

Individual bedrooms or home offices
Garage conversions and workshops
Sunrooms and enclosed porches
Room additions and ADUs
Server rooms and specialty spaces
Supplementing an existing system for problem rooms

Capacity Range:

9,000 to 36,000 BTU, suitable for rooms from 250 to 1,500 square feet.

Multi-Zone Mini Splits

A multi-zone system connects a single outdoor unit to multiple indoor units (typically 2 to 8), each independently controlled. This allows whole-home comfort from a single outdoor unit, with different temperatures in every room.

Best Applications:

Whole-home heating and cooling without ductwork
Multi-story homes with uneven temperatures
Homes with multiple comfort zones needed
Open-concept floor plans with distinct living areas
In-law suites and guest houses
Replacing aging central systems room-by-room

Capacity Range:

18,000 to 60,000+ BTU total, supporting 2 to 8 independent zones.

Our Mini Split Installation Process

Allison Air Comfort Solutions follows a thorough, professional installation process to ensure your mini split system delivers optimal performance from day one.

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Step 1: In-Home Consultation

We visit your home to assess your space, discuss your comfort goals, and perform a Manual J load calculation to determine the exact capacity needed. We’ll recommend the best system configuration, brand, and indoor unit styles for your situation.

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Step 2: System Design & Proposal

We prepare a detailed proposal including equipment specifications, installation plan, pricing, and available rebates. We’ll walk you through every option and answer all your questions before you commit.

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Step 3: Professional Installation

Our certified technicians install your system with meticulous attention to detail. This includes mounting indoor units, placing the outdoor unit, running the refrigerant line set, making electrical connections, and performing a vacuum and pressure test on the refrigerant circuit. Most single-zone installations are completed in one day.

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Step 4: Commissioning & Testing

After installation, we charge the system with the precise amount of refrigerant, test all operating modes, verify airflow and temperature performance, and calibrate the thermostat. We won’t leave until your system is running perfectly.

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Step 5: Walkthrough & Training

We give you a complete walkthrough of your new system, including remote control operation, smart app setup, filter maintenance, and recommended service schedules. We’re always just a phone call away if you have questions later.

Best Applications for Mini Splits

Mini splits are the ideal solution for a wide range of heating and cooling challenges.

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Room Additions & ADUs

Adding a room to your home? Extending your existing ductwork is often impractical and expensive. A mini split provides dedicated heating and cooling for the new space with a simple, clean installation that doesn’t burden your existing HVAC system.

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Converted Garages & Workshops

Garages converted to living spaces, home gyms, or workshops are notoriously difficult to heat and cool. Mini splits deliver powerful, efficient climate control to these spaces without running ductwork from the main house.

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Older Homes Without Ductwork

Many Bay Area homes built before the 1960s lack ductwork entirely, relying on radiators or wall heaters. Mini splits are the perfect retrofit solution, providing modern heating and cooling comfort without the invasive construction required to install ducts.

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Problem Rooms & Hot Spots

That one room that’s always too hot in summer or too cold in winter? A single-zone mini split solves the problem by providing independent temperature control that your central system can’t achieve. It’s the most effective fix for rooms at the end of long duct runs or over unconditioned spaces.

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Sunrooms & Enclosed Porches

Sunrooms and three-season porches experience extreme temperature swings due to their large glass areas. A mini split with heat pump capability transforms these spaces into comfortable, year-round living areas with precise climate control.

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Home Offices & Studios

Remote work demands a comfortable environment. Mini splits provide ultra-quiet, draft-free comfort that’s perfect for home offices, music studios, and creative workspaces. Independent zone control means you can keep your office at the ideal temperature without heating or cooling the entire house.

Mini Split Brands We Install

We carry the industry’s most trusted mini split brands, each with unique strengths.

Feature	Mitsubishi Electric	LG	Bosch
Max SEER2	Up to 33.1	Up to 27.5	Up to 22.0
Indoor Noise Level	19 dB	19 dB	20 dB
Cold Climate Heating	H2i: down to -13°F	LGRED°: down to -13°F	Down to -4°F
Multi-Zone Capacity	Up to 8 zones	Up to 5 zones	Up to 5 zones
Smart Control	kumo cloud app	LG ThinQ app	Built-in Wi-Fi
Indoor Unit Styles	Wall, ceiling, floor, ducted	Wall, ceiling, floor, ducted	Wall-mounted
Compressor Warranty	12 years	10 years	7 years
Best For	Premium efficiency & variety	Smart features & value	Budget-friendly reliability