Looking at Ductless Mini Splits? 4 Things to Know

Published on: February 18, 2014

Ductless systems are getting more popular all the time, but the technology is still largely unknown to many American homeowners. Read on to see how ductless mini splits deliver big heating and cooling solutions, comfort and energy savings for a growing number of home and business owners.

Point-of-Use Installation

Ductless mini splits are point-of-use heat pumps and air-conditioning systems. Sleek air-handling units (AHUs) are installed inside the living space (zone) to monitor temperature, heat, cool, filter the air and dehumidify the zone independently from any other system that is installed in the home.

Like conventional air-source heat pumps and A/C systems, ductless mini splits use the principle of refrigeration to extract and transfer heat energy between the inside and outside of a home. However, ductless systems are refrigerant distribution systems, rather than air distribution systems like typical forced-air heat pumps and A/Cs. These are the components:

  • Indoor AHU – The indoor AHU consists of the heat-exchange coil, a multi-speed fan, condensate drainage, air filtration system, and other electronics and sensors to monitor functions and room temperatures.
  • Outdoor unit (compressor/condensing unit) – The outdoor unit of a ductless mini split contain similar components as the AHU, and, like conventional systems, houses the compressor and outside coil.
  • Conduit piping – A flexible conduit houses the refrigerant distribution line, condensate drain line and power supply.

These components offer versatile installation options to accommodate virtually any home-improvement plans on the table. With a ductless mini split, you no longer have to grapple with the decision of how to heat and cool remodeled spaces, new additions and more.

The conduit may extend up to 100 feet, depending on the selected model. It’s routed inside walls, the attic, basement and/or crawl space (protected and out of sight) to link the outdoor unit to the indoor AHU. The indoor AHU offers many installation options to match interior design specifications, including the following:

  • Concealed – A concealed mounting installation is the least obtrusive in the living space, but requires more details and work behind the scenes. The AHU is concealed inside the ceiling, wall or floor, and the air vent is the only component visible inside the zone. This installation offers the smooth aesthetics of conventional forced-air systems, with the energy efficiency and zoning qualities of ductless technology.
  • Universal – The universal mounting installation is the most common type of mounting style of ductless installations. It is a straightforward installation that places the AHU on the surface of the wall (low or high), the ceiling, or on the floor, using a special mounting kit.
  • Cassette – A cassette-style AHU mounting is a hybrid of sorts with concealed and universal mounting. The AHU is recessed into the wall or ceiling, or hung flush in the panel of a drop ceiling. Cassette mounting offers better aesthetics than universal mounting, and still allows common access to AHU components, such as the air filter and coil, for cleaning and maintenance.

The outdoor unit of a ductless mini splits offers a significantly smaller footprint than the large outdoor unit of a heat pump or A/C system. These are the installation options, features and tips to help drive peak ductless performance from the compressor and condenser when installing the outdoor unit:

  • The cabinet may be mounted firmly on a small concrete slab, mounted to the wall of the home or mounted on a flat roof.
  • The cabinet needs four feet or more clearance of obstructions for free airflow to the sides and top.
  • Consider installing an over-hang or other protecting feature for the top, being careful to not cover or block airflow.
  • Check the unit for snow and ice accumulation during inclement weather. Poor heating performance is a sign of snow and ice obstructions during the heating months.
  • Make sure the roof or gutter system do not leak water on the unit.
  • Check for leaves, grass clippings and other debris that may obstruct airflow. Poor cooling performance is a sign that something is restricting airflow at the cabinet.
  • Check the conduit and piping entering the home from time to time to ensure it has not become damaged.

Ductless Zones: Mini, Multi and More

Ductless systems were originally designed as a space-saving alternative to ducted forced-air systems, and a more energy-efficient heating and cooling method than noisy and obtrusive window units. Ductless technology has well exceeded these early expectations of four decades ago, and offers home and business owners heating and cooling solutions for practically any home-improvement project, new home design and commercial application.

  • Mini split – Ductless mini splits remain the most popular residential installation for ductless systems, offering high-efficiency heating and cooling for a host of applications, such as heating and cooling a home office, guest room, garage and more.
  • Multi split – Ductless multi split systems utilize a compressor/condenser combination that is compatible to link up with two or more indoor AHUs to heat and cool more than one zone inside the home. Ductless multi splits are excellent options for supplementing an existing system, conditioning retrofitted spaces and conditioning multiple applications, such as an outbuilding, guest room and home office.
  • Flex zoned – A flex zoned configuration may be either a mini or multi split installation that utilizes a short duct run to provide greater airflow through a larger zone, such as a master bedroom and walk-in closet, or a long hallway. The duct run offers air supply and air return vents mounted flush to the ceiling, wall or floor.
  • Modular configuration – More home and business owners are discovering the versatile power of ductless heating and cooling, and are seizing on this technology to build energy-efficient new homes and heating and cooling for office suites, restaurants and more. A modular configuration involves a network of outdoor units linked to multiple indoor AHUs.

A modular configuration and multi split system offer advantages for exceptional energy savings and comfort by allowing the homeowner to heat and cool zones independently and simultaneously, depending on need.

For instance, you  may heat only the bedrooms on a cold winter night instead of wasting energy to heat the entire home. The freedom to heat and cool your home and business with zoned point-of-use systems is an attractive feature largely unavailable with other systems.

These are some common situations where ductless systems are superb solutions:

  • Older homes – Many older homes in the Southeast U.S. were not constructed with a ductwork system in place. This can create discomforts and a challenge for heating and cooling a home comfortably and efficiently.
  • Sun rooms – Have you thought about converting your deck to a sunroom? Ductless mini splits provide efficient year-round comfort.
  • Outbuildings – Ductless mini and multi splits are ideally suited for guest houses, pool houses and workshops.
  • Spare rooms – Do you have spare bedrooms that are seldom used? Install a ductless system for occasional visitors to your home, and save energy the rest of the year.
  • New additions and remodels – Mini and multi splits are perfect for attic conversions, conditioning new additions to the home, and keeping your home office the perfect temperature so you may be productive (or relax in comfort).

Additionally, each indoor AHU is sized specifically for its zone. Over-sizing conventional systems is a common problem that wastes energy and can actually cause the system to fail early. When you hire a reputable Southeast U.S. contractor, your ductless system will be designed just for your project.

Continuous Comfort, Continuous Savings

The two technologies that drive ductless heating and cooling are inverter-driven compressors and high-efficiency refrigerant (ozone-friendly R410A). These two technologies provide ample heating when outside temperatures are sub-zero and deliver comfortable cooling and dehumidification when outside temperatures top 100 degrees.

Inverter compressors are variable-speed compressors that modify output to match a zone’s heating and cooling load in real time. The compressor prepares and pumps the precise amount of high-efficiency refrigerant needed to maintain temperature settings continuously, rather than the start/stop action of conventional single-speed compressors. These are some of the benefits of inverter technology and high-efficiency refrigerant:

  • Inverter-driven compressors offer whisper-quiet operation.
  • Variable-speed output means less electricity consumption, saving you BTUs by the ton.
  • High rotation start-up quickly gets the zone to target temperature.
  • Low rotation provides continuous comfort at target temperature.
  • High-efficiency refrigerant delivers super-heat/super-cool capacity well beyond decades old R22 (Freon), and it’s safe to the environment.

Features to Consider

High air quality, comfort and convenience are exceptional features in anybody’s design plans. Consider these features and upgrades for your ductless mini or multi split installation:

  • Indoor air quality (IAQ) – Each AHU is outfitted with reusable air filters. Some models of ductless systems offer self-cleaning filters for care-free air cleaning, or three-phase filtration to remove odors, viruses and allergens from the air.
  • Comfort controls – Hand-held wireless controls are typically standard with ductless mini splits. You may also opt for a wired wall-mounted control device, or design a system to link multiple AHUs.
  • Airflow – Optional oscillation features are available, in addition to the five-speed fans housed in the stylish AHUs.

For more information about ductless mini splits, please contact us to find a contractor near your region of the Southeast U.S.