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How Ductless Mini-Split Heating and Cooling Systems Work

A ductless HVAC system is an air conditioning or heating system featuring an indoor and outdoor unit connected by electrical wiring and copper refrigerant. The indoor unit is typically wall-mounted and heats or cools a specific area in your home. Some ductless systems feature multiple indoor units that connect to one outdoor unit.
Ductless mini-split systems are among the most efficient heating and cooling solutions for several reasons. They rely on the same heating and cooling process as most central AC systems: heat pumps. However, a central AC system delivers cool air throughout your home using one centrally located indoor unit and a system of ducts and vents. In contrast, a ductless HVAC system blows cool or hot air directly into a room.
A basic ductless mini-split system features two elements:

  • An indoor unit with a blower fan and evaporator coil
  • An outdoor unit with a fan, condenser coil and compressor

Electrical wiring and copper refrigerant connect these two units. There are four types of indoor units for ductless mini-split systems.

  • Wall-mounted units that sit high on an interior wall
  • Floor-mounted console units for rooms where you can’t on prefer not to wall-mount the unit
  • Ceiling-mounted cassette units that hang from the ceiling
  • In-ceiling units that go inside the ceiling, out of view

Single- and Multi-Zone Ductless Mini-Split Systems

Ductless HVAC systems fall under two broad categories, single-zone and multi-zone systems, each suitable for different applications, such as additional rooms, garages, sunrooms, etc.

  • Single-Zone Ductless Systems. The outdoor unit sends power and refrigerant to one indoor unit via a small pipe that runs through a small hole in the wall.
  • Multi-Zone Ductless Systems. The outdoor unit powers several indoor units, which operate independently.
  • The installation of single-zone systems has minimal impact on your home. As for multi-zone systems, you can control each indoor unit separately using a remote control. So, you can vary the temperature from one room to another. Depending on the maximum number of units your outdoor unit can connect to, you can add indoor units later. Many multi-zone systems can accommodate up to five indoor units.


    What To Consider if You’re Thinking About Getting a Ductless Mini-Split System?

    Ductless mini-split systems are highly versatile. These HVAC systems also heat and cool areas that traditional duct systems can’t reach. Ductless mini-split systems are the perfect heating and cooling solution if you add a new room to your home or convert your garage, attic or basement into a living space.
    There are several ways to configure a ductless system, with several indoor units to choose from for a comfortable, customized solution. Installing them is quick and easy as they don’t feature any ductwork. You can add a ductless system to an existing heating and cooling system to increase functionality and energy efficiency.
    The pros of a ductless mini-split system:

  • Highly energy-efficient
  • Easy installation
  • No ductwork-related hassles, such as painting or patching
  • No indoor electrical wiring
  • Great HVAC solution for home renovation (added room, converted basements, etc.)
  • Works well with existing HVAC systems
  • Installation costs can be higher than a traditional ducted system
  • Ductless systems are more visible than ducted systems
  • Keep in mind that while installing a ductless HVAC system may cost more than installing a traditional ducted system, ductless systems cost less to use over time because they’re more efficient. Also, even though they’re more visible than ducted systems, you can get a sleek-looking indoor unit that matches the room’s interior.

    The Benefits of Ductless Mini-Split Systems

    1. They’re Easy to Install

    The absence of ducts means you need not worry about painting or patching. Installing ductless mini-split systems is a straightforward process. The only drilling needed is a tiny hole in the wall through which you pass a pipe that connects the compressor unit outside to the indoor unit. You don’t need additional wiring because the indoor unit draws power from the outdoor unit.

    2. They Provide Efficient Heating and Cooling

    Ductless mini-split systems provide heating and cooling efficiency even in extreme conditions, so you can use them throughout the year. Some ductless mini-split systems even heat at 80% capacity at temperatures as low as -22 degrees Fahrenheit and cool at 100% capacity at outdoor temperatures of up to 130 degrees Fahrenheit.

    3. They Provide flexible Heating and Cooling

    Regardless of where you place your ductless mini-split system, it controls the temperature with high precision. It can warm up your bedroom while cooling your living area. One of the main benefits of ductless mini-split systems is room-specific temperature control, meaning you can maintain different temperatures at different rooms to match your needs and preferences.
    You can further improve the precision of your ductless mini-split system using inverter compressor technology. In this case, an inverter-controlled variable-speed compressor serves as cruise control for your temperature control, substituting traditional single-stage systems that constantly shift the temperature up and down.

    4. They Run Silently

    An air conditioning system is even more comfortable when it operates quietly. You want your system operating silently in the background. Ductless outdoor units featuring variable-speed inverter-controlled compressors run lower-speed, longer and quieter cycles for enhanced comfort. Likewise, long refrigerant lines let you install the outdoor unit farther away from outdoor living spaces, such as patios and decks.

    5. They’re Better for Allergy Control

    Each indoor unit in a ductless mini-split system has filters, meaning they’re highly effective in cleaning the air in each room. Ductless mini-split systems are known not only for precisely controlling air temperature but they’re also great at controlling air quality. These systems eliminate cross-contamination between rooms because they confine air circulation within the room. As a result, ductless mini-split systems are more effective for allergy control.


    Professional Ductless Mini-Split System Installation

    With all you’ve learned about ductless mini-split systems in this article, you may want to get one for your home. A reliable and reputable HVAC service provider like Chicagoland can help you identify the best ductless system for your needs and budget and install it for you.