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Mitsubishi Multi-Zone Buyer's Guide

How to Pick the Perfect Mitsubishi Mini-Split Condenser

By  |  Product Expert

If you're struggling to keep your home or office comfortable, you are not alone. Extreme shifts in temperature may cause certain rooms to feel like a meat locker while others sweltering like the Sierra Desert. These "thermostat wars" can be downright frustrating, causing inhabitants to lose their cool while wasting energy in the process.

The solution is a multi zone system where you'll enjoy ideal levels of comfort in the rooms you use most. Each zone independently operates so people in different rooms can relish in their own microclimate. If you're looking for a complete comfort solution for several rooms, the M-Series from Mitsubishi is an excellent choice.

Mitsubishi M-SeriesMitsubishi Branch Box
The M-Series is specifically designed with homeowners and small businesses in mind. These mini splits will restore the peace while providing lower energy costs year-round. In fact, most of these INVERTER-driven systems are ENERGY STAR certified and are up to 40% more efficient compared to traditional systems. An M-Series multi-room system is also an ideal choice for supplementing a current system, or new additions and replacing a system within a home or office up to 8 zones.

Choosing an Outdoor Unit

Get the right outdoor unit by following these 3 easy steps:

Determining Cold-Weather Heating

Hyper-Heating technology or H2i, is Mitsubishi's incredible low-ambient temperature heating technology. H2i can also be used to supplement an existing heating system, thereby lowering utility costs. So, if you live anywhere but the southern most region of the country, Hyper-Heating is an excellent choice. Just be aware that higher-capacity units will require the use of branch boxes and do not come in multi-port configurations.


Read: Multi-Port vs. Branch Box Systems
Hyper Heating Chart
Some H2i units are capable of delivering nearly 100% of their heating capacity down to 0° F, and can provide heat even in temperatures as low as -13° F.

What Is a Branch Box?Mitsubishi Branch Box
A branch box is a junction box between the outdoor and indoor units that allows you to harness the power of larger systems and Hyper-Heating units. They also allow for shorter line set runs instead of going all the way back to the outdoor unit while serving as a hub for several indoor units. Without branch boxes, larger systems would be terribly inefficient. Instead, they direct the flow of refrigerant to provide maximum performance and efficiency. Acting as the "brains" of the operation, the branch box "tells" the condenser how much cooling or heating is required and then directs it to each zone.

For all of their brains, branch boxes are quiet brawny too. Typical units are larger than a shoe box measuring-in around 16x21x7 inches. Because branch boxes should be mounted indoors, you'll need to map out your installation so that they'll have ample space for serviceability down the road.

How to Connect Multiple Branch Boxesmini split distribution pipe

If you want to create more than 5 zones on opposite ends of the building, pre-braised distribution pipes help to make it possible by allowing you to plumb-in an additional branch box. Just as a cable-splitter makes watching T.V. in each room possible, separation tubes will allow you to take a line set from the condenser and split it into two usable connections. This makes larger, more spread-out zoned systems possible.

Pro Tip: Both branch boxes and separation tubes are sensitive in the way that they are mounted. Consulting the installation manual is a must when determining how to install them properly. In most cases, branch boxes cannot be mounted upside down and separation tubes need to be installed “flat” - meaning perfectly horizontal or vertical to the ground. Installing either can greatly affect the performance of your system and may even cause damage.

Picking Your Condenser Model

Choosing the perfect Mitsubishi outdoor condenser is easy once you've determined the size, # of zones, and if you require cold-weather heating. Use the chart below to locate your specifications and click on the model needed.


Max # of
Model # Max BTU/h Multi-Port (M) or
Branch Box (B)
2 - MXZ-2B20NA-1 20K M
3 - MXZ-3C24NA2 24K M
3 - MXZ-3C30NA2 30K M
4 - MXZ-4C36NA2 36K M
5 - MXZ-5C42NA2 42K M
8 - MXZ-8C48NA 48K B
8 - MXZ-8C60NA 60K B
2 H2i MXZ-2C20NAHZ2 20K M
3 H2i MXZ-3C24NAHZ2 24K M
3 H2i MXZ-3C30NAHZ2 30K M
4 H2i MXZ-4C36NAHZ 36K B
5 H2i MXZ-5C42NAHZ 42K B
8 H2i MXZ-8C48NAHZ 48K B


Installation Considerations


Installation accessories are a fool-proof way to round out a complete and thorough installation of any M-Series mini-split system. Getting the right parts that are designed to work with your system will ensure quality and performance while preventing delays with your installation process.

Port Adapters Mini Split Port Adapter

In certain situations, it may be necessary to use adapters in order to connect line sets to the condenser unit. Port adapters are included with multi-port systems, but many people mistakenly think that these adapters will restrict the flow of refrigerant and are tempted to either modify the existing line to work or revert back to a "standard" sized line. However, these adapters will not restrict flow and will allow you to use the proper sized line regardless of the fitting size.

Wiring/Communication Wire

Mini Split Communication WireThe utilization of branch boxes may also come with added flexibility when it comes to wiring. In some cases, you won't have to run your electrical wire from each indoor unit all the way back to the condenser. In these situations, the units can be powered independently using a power source closest to them, putting less strain on a single breaker as well.

NEXT: Ultimate Mini Split Buyer's Guide


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