Request a Quote Special Offers Request Service

OH LIC #38290

Ductless Mini Split

Home > HVAC Services > Ductless Mini Split


Mini-split systems work on the same basic principles as a split system, ducted heat pump. There is an inverter compressor on the outdoor unit (compared to the compressor for your car fan and the Trane XV20i heat pump and air conditioner).


The compressor is responsible for pumping refrigerant through the heat pump system. When the thermostat is calling for more heat or cool, the compressor will pump refrigerant through to meet the demands of the thermostat and once the thermostats demands are met, the compressor will shut off. With inverter technology, the compressor is designed to run at very low speeds and can adjust much like the fan in your car. This prevents the spikes in electrical usages from startup and shut down and also keeps your home a more even temperature, reducing cold drafts.


Mini-split systems have been using inverter technology for years. Due to the inverter technology, mini-split system have a much higher efficiency rating (as high as 26 SEER, compared to a regular split system heat pump rated 20 SEER at most). Mini-split heat pump systems can operate more efficiently at lower outdoor temperatures than your standard heat pump and are also quieter.


Mini-split heat pump systems are widely used across the world. Your will find them used more frequently in other countries where having a basement and yard outside is a luxury. They are used in Florida a lot also. Mini-split systems tend to make the most sense in newly constructed homes in the place of ductwork and homes without ductwork, on a slab, with a crawl, or need to maximize room in the basement.


Every home is different and we strongly suggest getting as much information as possible prior to making a decision. If you are looking at a mini-split system to fix airflow issues, there may be other alternatives. Our comfort consultants are always available to evaluate your home along with your wants and needs for a mini-split system. Westin Air wants to make sure you get the most out of your system.


Commonly used terms:


Seasonal Energy Efficiency Ratio – This is how efficiently your unit operates. The higher the number the more efficient your unit will operate and the lower your electric bill will be. 13 SEER is the lowest rating by law able to be sold and installed. Think of SEER as MPG in a car. It is important to remember that as heat pumps get older, the SEER goes down. In other words, the last heat pump you may have installed may have been a 10 SEER, which was considered high efficiency, but is now 14 years old and now operating at a 6 SEER level. Heat pump’s SEER typically range from 13 – 20.


Heating Seasonal Performance Factor – HSPF is a ratio of BTU heat output over the heating season to watt-hours of electricity used. Like SEER, the higher the HSPF, the higher the efficiency you unit is. Heat pump HSPF usually range from 7-14.


There are two different types of refrigerant: R-22 and R-410A. In accordance with the Clean Air Act, R-22 is being phased out. The production and importation of R-22 has been banned. The price of R-22 continues to go up as less and less R-22 become available. Manufacturers are still producing R-22 units but in order to get around the Clean Air Act, they are shipping them without the refrigerant and the contractor is responsible to evacuate the current system of R-22 and put it back into the new system. Westin Air does not recommend purchasing a dry R-22 unit as when refrigerant comes into contact with the air, it becomes contaminated and can cause problems in the future.


Variable Speed Compressor – This is the most efficient option for compressors for your heat pump. It will give you the most consistent temperature throughout your home as it ramps up and down gradually to meet the demands of the Thermostat. It will run using the least amount of electricity while keeping the thermostat’s demands met. (Variable speed compressor is comparable to "inverter" technology in the video below) Two stage or Dual Compressor – Has two stages of operation – High for hot summer days where low will not meet demands met by thermostat and low for days where it maintains the demands of the thermostat. Ideally, 80% of your heat pump’s run time should be in low. Running in low speed offers a more even temperature without the spikes in temperature like the single stage compressor. This is a more energy efficient option verses a standard single stage compressor. Single Stage compressor – The least energy efficient of all the compressors. It is either on or off. There is no in between and it is high or off. There will be spikes in temperature from when the heat pump turns off from the times it is running. (Single-stage compressor is comparable to "non-inverter” technology in the video below)

Ductless Mini Split Products

Wall-Mounted Units

Floor-Mounted Units

Ceiling-recessed Units

Horizontal-ducted Heat Pumps

Multi Position Ducted Unit

Ductless Mini Split Outdoor Unit

M-Series Single Zone Products These units are ideal for an isolated space that is not connected to a heating or cooling system (add-on, garage, patio, sun room, ect.). They provide heating and cooling for a single zone with an indoor and outdoor unit with the control of a remote.

Wall Mounted

MSZ/MUZ-FE High Efficiency Heat Pump

20.2-26 SEER
10-10.5 HSPF, inverter-driven compressor
Quiet operation as low as 22 dB(A)
Offers a wide vane for a wider angle of airflow, 150° from left to right
Motorized vertical vanes on FE091/12/18 Models
i-see Sensor™ technology on FE09/12 Models
Triple filtration system on FE09/12 Models
H2i® high heat capacbilities ar low ambient temperatures
(MSZ-FE09/18 are 100% capacity at 5°F, FMSZ-FE12 is 92% capacity at 5°F)

MSZ/MUZ-GE/D Heat Pumps

14.5 – 21 SEER
8.2 – 10 HSPF, inverter-driven compressor
Offers a wide vane on wider angle of airflow, 150° from left to right
(On FE12/GE24/D30/D36 Models)

MSY/MUY Air Conditioner

15.1 – 21 SEER, inverter compressor
Offers a wide van for a wider angle of airflow, 150° from left to right
Motorized vertical vanes on GE24/D30/D36 Models
Multiple ENERGY STAR® models available

MS/MU Air Conditioner

13 SEER, non-Inverter rotarty compressor
115 volt, single phase
Hand-held wireless remote controller only

M-Series Multi-Zone Products

MXZ-8B48/2B20/3B24/3B30/4B36 Outdoor Units

Mix and match flexability of indoor unit styles
Wide range of indoor unit capacities that match the room size and requirements
Flexible options to tackle the most challengin multi-room installations
High effiricency, multiple ENERGY STAR® combinations
Simple, quick, and cost-effective installation
Four-ton outdoor unit can support up to eight indoor units using branch boxes
Advanced microporcessor control
Auto restart following a power outage
Self-check function offering intergrated diagnostics
Wired and wireless control options

Ceiling-Recessed, Cassette Heat Pumps

SLZ/SUZ Heat Pumps

15-16 SEER
9.6 HSPF, Inverter-driven compressor
SLZ/SUZ-KA09/1215 1:1 systems are ENERGY STAR® rated
Ventilation air knockouts
Built-in condensate lift mechanism (up to 20″)
Offers a 2, 3, or 4 way airflow pattern

Horizonal-Ducted Heat Pumps

SEZ/SUZ Heat Pumps

15-17.5 SEER
10 HSPF, Inverter-driven compressor
Built-in condensate lift mechanism (up to 22″)
Static capability up to 0.20″ WG
Optional filter box with MERV-8 filters

Wall- Mounted Indoor Units for Multi-Zone System

MSZ-FE High Efficiency Heat Pumps

Quiet operation as low as 22 dB(A)
Offers a wide vane for a wider angle of airflow, 150° from left to right
Motorized horizontal vanes on FE09/12/18 models
i-see Sensor™ technology on FE09/12 models
Triple filtration system on FE09/12 models

Heat Pumps

MSZ-GE Heat Pumps

INVERTER-driven compressor
Provides cooling and heating in a wide range of capacities
Offers a wide Vane for a wider angle of airflow, 150° from left to right
(on FE12/GE24/D30/D36 models)

Ceiling Recessed Indoor Units For Multi-Zone System

SLZ Heat Pumps

INVERTER-drive compressor
Ventilation air knockouts
Built-in condensate lift mechanism (up to 20″)
Offers a 2, 3, or 4 way airflow pattern

Horizonal-Ducted Heat Pumps For Multi-Zone System

SEZ Heat Pumps

INVERTER-driven compressor
Built-in condensate lift mechanism (up to 22”)
Static capability up to 0.20” WG
Optional filter box with MERV-8 filters

Floor-Mounted Indoor Units for Multi-Zone System

MFZ Heat Pumps

Top and bottom discharge vanes
Hot-start technology
Quiet operation
Wireless remote control with smart set feature

HVAC Maintenance Checklist for Spring 2024


Air Conditioning Services


Heating Services


Geothermal Services

Cities we serve

Westerville, OH Powell, OHLewis Center, OH Bexley, OHGahanna, OH Hilliard, OHMount Vernon, OH Columbus, OHWorthington, OH Dublin, OHDelaware, OH Galena, OHGrove City, OH New Albany, OHSunbury, OH Reynoldsburg, OHUpper Arlington, OH Johnstown, OHCenterburg, OH

Brands we install