So, you’ve decided that a ductless mini-split system would be the best air conditioning solution for your needs. However, you can’t make up your mind on what type of mini split to purchase.
You strongly feel that a dual-zone unit would be ideal. However, you’re constantly wondering whether it would be the best decision. Would it be a value-for-money purchase? Why not two single-zone units? Am I leaving better options on the table? These could be just some of the questions running through your mind.
This guide is designed to help you understand dual-zone mini-splits, how they work, and potential benefits over single-zone models and other AC types. We even discuss choosing the right size AC and other factors to consider when buying a dual-zone air conditioner.
What’s a Dual-Zone Mini Split System?
A dual-zone mini-split system is a multi-zone ductless mini-split system designed to serve two independent zones. Dual-zone mini-splits typically comprise a single outdoor compressor and two indoor air handlers.
This is different from typical single-zone mini-split systems that comprise one indoor air handler per outdoor condenser. It’s also a different setup from three-zone, four-zone, and eight-zone systems that comprise three, four, and eight air handlers per outdoor condenser, respectively.
How Do Dual Zone Mini Splits Work?
Dual-zone mini splits work like any other mini-split air conditioning system. The only difference is that instead of serving one indoor air handler, the compressor serves two air handlers.
The process begins inside the house with the indoor air handlers drawing hot, moist air into the AC system via strategic air vents and sends it to the outdoor condenser. A fan system inside the air handler makes this process possible. You can even adjust the fan speed for faster operation.
The outdoor compressor features a condensing system with ice-cold condensing coils. When the warm, moist air passes over these extremely cold coils, the heat is extracted, leaving the air cool and dry.
The now-cool air is then passed back to air handlers and released to the room. The process goes on and on until the thermostat setting is reached, at which point the AC goes off automatically until the thermostat setting requests cooling again.
The on-off cycle helps maintain the desired indoor temperatures. It’s an automatic process that requires no further effort on your part.
In dual-zone ductless mini-split AC configurations, the fresh air is distributed among the two air handlers depending on the BTU rating of each air handler. Indoor air handler sizes typically range from 8,000 BTUs to 36,000 BTUs.
Benefits of a Dual-Zone Mini Split
The main benefit of any multi-zone mini split AC system is serving two or more rooms simultaneously. Dual-zone systems can serve two zones or rooms at a go. Other advantages are as follows;
- Independent zone control: The two zones are entirely independent. Indeed, the best two-zone air conditioners provide a remote controller for each indoor air handler.
- Independent thermostats: The main advantage of having independent thermostats for each zone is that you can even shut off the air handler in one room. It wouldn’t affect air conditioning in the other room. The two units are fully independent.
- Cost savings: Instead of purchasing two different air conditioners for two rooms, you can serve both rooms with one AC, effectively saving the budget for the second AC. The installation cost is also lower compared to installing two separate single-zone air conditioners.
- Easier maintenance: There’s a significant difference between maintaining two air conditioners and maintaining just one.
When is a Two-Zone Mini Split Right for You?
This is the big question. Although dual-zone mini split AC systems are beneficial in many ways, they aren’t always the best solution. You’re more likely to get value for your money if you choose the applications wisely.
We recommend investing in a two-zone mini split air conditioner under the following three circumstances;
- You need an AC for a new addition: If you’ve built an addition that the central AC system won’t serve, then a mini-split system would come in handy. Only buy a two-zone system if you have two new additions (ideally side-by-side).
- You need supplemental air conditioning: Sometimes, the central air system isn’t enough. This is especially true in older homes with older central air systems. Here too, a multi-zone mini split can help. Again, only buy a two-zone model if you need to serve two rooms.
- You don’t have a central AC system: Dual-zone mini-split ACs can also prove valuable in new buildings without a central air system. Many homeowners combine three or four such configurations to air-condition the entire home.
What Size Dual Zone Mini Split Do I Need?
It depends on several factors, especially the size of the room/home, your geographic location (climate), and the number of occupants.
But before we suggest hard numbers, remember that for multi-zone mini-splits, you’ll be dealing with the size of each air handler and the overall size of the AC system (all air handlers put together). We’re primarily interested in the air handler capacity.
In a perfect world, you need about 20 BTUs for every square foot. This roughly translates to 10,000 BTUs for a 500 square-foot room and 20,000 BTUs for a 1,000 square-foot room. A 36,000 BTU air handler would therefore suit a 1,800 square-foot space.
However, perfection is rare. Therefore, you may need slightly higher AC capacities to leave room for maneuver. That’s why you’ll find most HVAC experts recommending 6,000 BTUs for 150 square feet, 12,000 BTUs for 550 square-foot rooms, and up to 18,000 BTUs for 700 square-foot applications.
Consider using an online AC sizing calculator to determine the most appropriate two-zone mini split size for your application to avoid confusion.
Can You DIY a Dual Zone Mini Split Installation?
Yes, you can DIY-install a dual-zone mini-split air conditioning system. However, it’s not recommendable. Instead, it would be best to hire a professional, licensed technician for the installation.
The following are four reasons why;
You may choose the wrong mini split
There are hundreds of dual-zone ductless mini-split systems out there. Choosing the right one is never a straightforward process. For one, you need to find the right size. Then, you need to find a DIY-friendly option. Beyond that, functions and controls are also vital. It’s easy to make a mistake.
Where does the outdoor unit go? What about indoor air handlers? On which wall should you install them? At what height? These are just some of the questions you’ll need to answer. Remember that improper position can compromise function and efficiency.
Electrical wiring issues
Most dual-zone air mini-split systems are rated 208 volts to 230 volts, whereas the power outlets in your home are likely 110-130 volts. It often means that you need to create a 230-volt outlet for your mini-split. This is a delicate task best left to electricians.
Potential damage to your home
Above all, installing a ductless mini-split system often requires drilling holes into your walls and cutting away portions of the ceiling to recess indoor air handlers. If you’re not careful, you could drill or cut areas that may cause more damage to the house in the future.
So, Can You Still DIY-Install a Dual-Zone AC?
The answer is – yes. However, make sure to find a DIY-friendly mini-split system. Often, the manufacturer indicates the initials “DIY” on the product label to let you know that the AC is DIY-friendly.
Additionally, consider letting a professional electrician handle all the electrical connections. Above all, follow the installation manual closely and keep the manufacturer in the loop throughout so they can tell you if you’re doing it right.
Best Dual Zone Mini Splits Reviews
1. SEVILLE SENA-18MO-209 18,000 BTU Dual Zone Split Air Conditioner
One of the best dual-zone mini-split systems is the SENA 18MO-209 from SEVILLE. The 18,000 BTU air conditioner connects to two air handlers – each 9,000 BTU and doubles as a heat pump.
It’s also a very efficient unit, rated 22.5 SEER and 10.5 HSPF. The heating mode is also rated 18,000 BTU. It keeps working down to -22 degrees Fahrenheit.
The unit is Wi-Fi capable. You can easily download the SEVILLE app on iTunes or Google Play and control every AC function from your smartphone. Alternatively, it offers a remote control function. It’s a Follow-Me remote control with a built-in thermostat so that you can get the best climate right where you are.
We love that it has a Turbo Mode for accelerated cooling (or heating). It also features multiple fan speeds, including Low, Medium, and High, and an Automatic Mode that automatically regulates indoor temperatures.
An auto-restart function kicks the unit back into operation in case of a power outage. Meanwhile, the vertical swing louvers ensure that you’re getting maximum airflow from whichever position in the room. The maximum airflow is 418 CFM.
- Powerful at 18,000 BTU
- Doubles as a heat pump
- Rated 22.5 SEER and Energy Star Certified
- 2-year parts warranty
- 7-year compressor warranty
- A little pricey
- No voice control
2. Pioneer Air Conditioner WYS020GMHI22M2 Multi-Split Heat Pump (Dual Zone)
The model WYS020GMHI22M2 air conditioner from Pioneer is another excellent option when shopping for a dual-zone unit. It’s a 19,900 BTU AC with a built-in heat pump rated 23,473 BTU.
Remember that these outputs are adjustable depending on your needs. For instance, you can set it to release as little as 4,197 BTU per hour in cooling mode. It’s a very energy-efficient AC, rated 21.3 SEER and 10.0 HSPF.
One thing going for this AC is that it offers three different indoor air handler combinations. You can opt for two 9,000 BTU indoor units, a 9,000 BTU and 12,000 BTU unit, or two 12,000 BTU air handlers.
Whichever combination you choose, the system comes with 16-foot installation kits for each air handler. Each indoor unit features permanent washable filters to eliminate airborne particles from your rooms.
Other key features of this AC include a flat, front-mount panel and LED display (dimmable), automatic swing air discharge louvers, a multi-speed fan motor, and a multi-function wireless infrared remote controller.
All the systems are safety tested and approved for safety by ETL. The AC is also listed for energy efficiency by AHRI. It comes with a standard Pioneer warranty.
- Powerful at about 20,000 BTU
- Doubles as a 23,000 BTU heat pump
- Wireless remote control
- ETL approved, AHRI listed
- No smart/app control
3. Cooper & Hunter Dual Zone 12,000 + 12,000 BTU Ductless Mini Split AC/Heating System
Cooper & Hunter makes some excellent air conditioning appliances, and the Sophia Series carries some of their best ACs. This particular model, the CH-18MSPH230VO, is a 17,000 BTU AC rated 21.3 SEER. You may need fresh wiring as it’s a 230-Volt appliance. However, once it’s installed, it delivers on its duties diligently and without noise.
It comes with two 12,000 BTU wall-mount air handlers. But, it’s not a fixed choice. You can also choose from several other air handler solutions, including ceiling cassettes, slim ducts, universal floor/ceiling air handlers, and mini floor consoles. Wall thermostats are available for the floor and ceiling air handler products. The package includes a 25-foot installation kit for each air handler.
Other key features that stand out about this air conditioner are the Wi-Fi option (the required adapter is sold separately) and Energy Star certification. It is also AHRI certified. As with most mini-split systems, this unit doubles as a heat pump. The heating goes on down to -13 degrees Fahrenheit.
Each purchase is protected by a 7-year compressor warranty and a 5-year warranty on other parts. However, you’re required to register the warranty for your cover to become effective.
- Powerful 18,000 BTU AC
- Choose from a wide range of air handlers
- Rated 21.3 SEER and Energy Star Certified
- 5-year warranty on parts
- Wi-Fi adapter sold separately
4. DAIKIN Dual (Two Zone) Air Conditioner Heat Pump + Maxwell 15-Foot Installation Kit
DAIKIN has several dual-zone air conditioners. This specific option is the model 2MXS18NMVJU. It’s an 18,000 BTU AC that arrives with a 12,000 BTU and 9,000 BTU wall-mounted air handler.
The unit is rated 18.9 SEER and up to 12.7 EER. It also features a built-in heat pump rated 12.5 HSPF. It continues heating down to 5 degrees Fahrenheit.
Among the things we love about this air conditioner is the inverter variable-speed compressor that reduces energy usage by up to 30%. You’ll also love that you can choose from a wide range of indoor air handler units. Options available include floor-mount units, recessed ceiling units, and concealed horizontal air handlers.
A special anti-corrosion coating on the outdoor unit’s heat exchanger resists salt damage and corrosion from other atmospheric conditions. Meanwhile, an auto-defrost feature allows the unit to operate even in extremely cold conditions without fail.
Other standout features include Wi-Fi control via the DAIKIN control app, 3D airflow, a comfort mode, and a built-in titanium apatite photocatalytic air-purifying filter. It also has an auto-restart function and a hushed Night Mode.
- Powerful at 18,000 BTU
- Choose from different indoor air handlers
- Intelligent infrared sensor
- Industry-leading 12-year warranty
- A tad pricey
- Requires professional installation
5. MRCOOL 24,000 BTU 22 SEER Multi-Zone DIY 2-Zone Ductless Heat Pump Split System
You’ll notice that all the air conditioners we’ve discussed so far require professional installation. Nearly all multi-zone mini-split systems do. So, what if you’re a DIY-enthusiast who prefers to do it all alone? Well, there’s the MRCOOL model DIYM227HPW03B.
This 24,000 BTU air conditioner comes with every accessory for installation and detailed instructions to make DIY installation a breeze. The company also offers exceptional customer support to help you get the installation process right on the first attempt. Above all, the warranty cover remains effective even if you install the unit on your own. For most mini splits, DIY installation instantly voids the warranty.
The AC uses two 12,000 BTU wall-mounted air handlers, each of which can serve areas up to 550 square feet. The air handlers are controllable from the provided remote control device.
Alternatively, you can download the MRCOOL Smart Controller mobile app available on the iOS store and the Android app store. Above all, this AC supports voice control via Amazon Alexa and Google Assistant.
This AC has a drying mode (dehumidification) to eliminate excess moisture from your home, a timer function for programmed control, and automated alerts, so you’re always in control. An auto mode further makes your work easier.
- Powerful AC/heat pump at 24,000 BTUs
- App and smart voice control
- The auto mode makes control easier
- Lifetime tech support
- DIY installation requires technical knowhow
A dual-zone ductless mini-split system could be the solution to your air conditioning (and heating) needs if you’ve got two areas in the home that require supplemental air conditioning.
They also work well for additions. However, you must pick the right size and install the unit properly. If need be, consult an HVAC professional to make the entire process smoother.