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Considering a Ductless System? Choose Between Multi Split and Mini Split Air Conditioners

Choosing a ductless system to cool your Virginia home can save you money not only on installation, but also on energy expenses. Because these systems don't require ductwork, they're easier to install. Ductless systems also let you install whole-house cooling where the building structure doesn't allow for standard ductwork installation. The ability to cool without ducts improves the system's efficiency, too. Air leaks and heat transfer through ductwork can reduce a system's efficiency by up to 30 percent, but ductless cooling is free from this problem.

Not all ductless systems are the same, though. If you've decided to install one of these systems, you'll need to choose between a mini split and a multi split system. While the two designs are similar, a multi split model offers control options a mini split model doesn't.

How Ductless Systems Work

In a traditional ducted air conditioning system, a single outdoor unit and indoor air handler are used to cool your home's air. The air handler is usually hidden in the walls of your living space or in the basement, attic or garage. A blower fan in the air handler forces cool air through the ducts to each room, then out into the rooms through the floor registers. The floor registers are the only part of the system visible in your rooms.

Avoiding the expense and effort of installing ducts is one of the main reasons for choosing a ductless system. Cost isn't the only consideration, though. Even if you already have a ducted system, that system may not have the capacity to cool additional space, such as a renovated attic. Extending ductwork isn't always practical, either. Ductless air conditioning systems offer a way around these problems. These systems use one or more outdoor condenser units and one or more indoor air handler units. The indoor air handler is a small, unobtrusive device typically mounted on a wall. This unit contains the evaporator coil, fan and air filter, so it both cools air and distributes the air directly into the room.

If you need multiple air handlers, you can choose from a number of different air handler designs for each room. Air handlers can be mounted on the wall, recessed into the ceiling, suspended from the ceiling or placed on the floor. The variety of design options ensures you get sufficient cool air in every room and from units that work well with each room's design.

Mini Split Systems: Convenient and Affordable

The typical mini split air conditioning system consists of a single outdoor condenser unit and one or more indoor air handlers. If you want to cool a small area, such as an addition or a small apartment, one indoor air handler is likely enough. Mini split systems work especially well for additions and renovated attics, basements and garages.

For larger spaces, you'll need multiple air handlers. Many models can run up to four or even six indoor air handers from a single outdoor unit. Because these systems provide no way to control the indoor units' temperatures individually, every unit will provide cool air at the same temperature.

Of course, these systems have their limitations. You could have six air handlers, but if you have eight rooms, you may still end up with areas that don't get cool enough. In a large home, cooling efficiently with a mini split system may require choosing a different configuration. For properties with enough space outdoors, it's possible to install multiple outdoor units, each with its own group of indoor air handlers. The systems can operate at the same time to cool even a very large building. This type of system lets you control the temperature of each group of air handlers separately. What you can't do is control the temperature of each individual indoor unit.

Choosing a ductless system like this will work well if your entire home has similar cooling needs throughout all the rooms. Another positive aspect of a system with multiple outdoor units is that if one unit malfunctions, the other will still run, so you'll still have some cooling in your home.

Where Mini Split Systems Fall Short

Few large homes have consistent cooling demands throughout the entire building. In a multi-level home, for instance, the upper levels tend to get hotter than the ground floor. Areas with south- and west-facing walls will require more cooling than those with north- or east-facing walls. The personal preferences of your family members come into play, too. An elderly member of your household or one who has health concerns may need especially warm or cool temperatures for comfort and health.

Mini split systems don't allow the level of control you need to cool each area of your home to the ideal temperature. To compensate, you may end up turning down the thermostat to keep the hottest part of your home cool, which means the naturally cooler areas end up chilly. That's not only a waste of money, it also reduces your comfort.

Fortunately, a mini split design isn't your only option when choosing a ductless system. If you have a large home or one with a variety of cooling demands, a multi split system may be a better choice.

Multi Split Systems: Greater Control for Greater Comfort

Like a mini split system, a multi split air conditioning system also consists of an outdoor condensing unit connected to one or more indoor air handlers. The difference is that a multi split system allows for precision zoning. The condensing unit is fitted with multiple compressor circuits. Each individual compressor circuit is directed to a separate air handler. This makes it possible to control the temperature of each air handler individually, creating separate temperature "zones" (rooms or groups of rooms). A separate thermostat controls the temperature in each zone. Some Mitsubishi systems can be configured for up to eight zones.

Choosing a ductless system with this capability gives you precise control over the temperature in each part of your home. You'll be able to turn down the temperature in one area without overcooling another. A zoned multi split air conditioner is appropriate for a number of situations.

  • Hot and cold spots - Especially in large homes, it's not uncommon for one area to heat up while other areas remain cool. Sometimes the reasons for these hot and cold spots are easy to see, such as a certain room receiving intense afternoon sun. Other times, the causes are less obvious, such as poor insulation in one part of the house. While you can even out the temperatures by installing blinds or better insulation, these steps aren't always enough. A multi split system will help make up the difference, cooling each area exactly as needed.
  • Large homes - Large homes often have widely differing cooling demands in different areas. Because warm air rises, the upper floors of multiple-story homes tend to have greater cooling demands. Even single-floor homes can have a variety of indoor temperatures if the floor plan is particularly sprawling. In this case, some areas may be exposed to direct sunlight while others are shaded.
  • Specific design features - Choosing a ductless system with zoning capabilities is often the best choice when home design features cause indoor temperature variations. Spaces with vaulted and cathedral ceilings, bay windows and other large areas of glass, as well as exceptionally large rooms, all have different cooling demands from more typical rooms.

Choosing a ductless HVAC gives you the flexibility to design a system that's effective and economical for your home. If you're cooling a small space, a mini split system with a single outdoor unit will probably be enough. Even if you've got a sprawling, two-story home, though, you can still enjoy control over your cooling by choosing a multi split system.

For professional help choosing a ductless system for your home, consult with a local Mitsubishi Electric contractor first. An experienced contractor will help you find the design option that best meets your needs. To get started, contact a Mitsubishi Electric Cooling & Heating contractor near you today.

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