Mini System


In summer, air conditioners work to provide cooling and dehumidification. They extract heat from inside the home and transfer it outside. AC typically use a vapor compression cycle. This cycle circulates a refrigerant, a material that increases in temperature significantly when compressed and cools rapidly when expanded. The exterior portion of a typical AC is called the condensing unit and houses the compressor, the noisy part that uses most of the energy, and the condensing coil. An air-cooled condensing unit should be kept free from plants and debris that might block the flow of air through the coil or damage the thin fins of the coil. Ideally, the condensing unit should be located in the shade. However, do not block air flow to this unit with dense vegetation, fencing or overhead decking. The inside mechanical equipment, called the air-handling unit, houses the evaporator coil, the indoor blower, and the expansion, or throttling valve. The controls and ductwork for circulating cooled air to the house complete the system.

What is a ductless mini split air conditioner systems?

Mini split systems have no ducts. They have two main components, an outdoor compressor and an indoor air-handling unit. The two units are linked by a conduit which stores the power cable, suction tubing, refrigerant tubing and a condensate drain. Indoor units can be wall or ceiling mounted. Ductless splits can be used to cool one zone or multiple zones applying two to four indoor units to one condenser. The indoor units can all be used independently of each other.

How to choose a ductless split air conditioner?

The most important factors when choosing a ductless split air conditioner are:

  • BTUs (British Thermal Units)
  • Number of cooling zones
  • Installation type

Where can mini-splits be used?

Just about any place that requires comfort.

BTU chart based on room size
Area (ft²) BTU's Required
100 to 150 5,000 BTUs
150 to 250 6,000 BTUs
250 to 300 7,000 BTUs
300 to 350 8,000 BTUs
350 to 400 9,000 BTUs
400 to 450 10,000 BTUs
450 to 550 12,000 BTUs
550 to 700 14,000 BTUs
700 to 1,000 18,000 BTUs
1,000 to 1,200 21,000 BTUs
1,200 to 1,400 23,000 BTUs
1,400 to 1,500 24,000 BTUs
1,500 to 2,000 30,000 BTUs
2,000 to 2,500 34,000 BTUs
Add 20% BTUs for ceilings higher than 8 ft. and poorly insulated areas
Add 30% BTUs for climates with seasonal temperatures over 90℉

Multi zone ductless mini split system.

The Ductless Multi-Zone Mini Split Air Conditioners allow you to enjoy ideal levels of comfort in the rooms you use most. Each room (zone) operates independently with its wireless/wired remote control. People in different rooms – the kitchen, master bedroom, or living room – can enjoy temperature settings that make each room most comfortable. Plus, you have the option of not heating or cooling rooms that are not being used. If you’re looking for a complete comfort solution for several different rooms, the multi-zone system is the right choice. The system is flexible enough to conform to a particular cooling and heating need and offers numerous different indoor unit combinations.

Advantages of Ductless Air Conditioners

Many models can have as many as four indoor air handling units (for four zones or rooms) connected to one outdoor unit. The number depends on how much heating or cooling is required for the building or each zone (which in turn is affected by how well the building is insulated). Each of the zones will have its own thermostat, so you only need to condition that space when it is occupied, saving energy and money.
Don't waste money cooling and heating the ducts in your walls and attic. Mini-split systems are ductless, meaning they install easily and won't take up valuable closet space. Since mini-splits have little to no ducting, they forego those energy losses typically associated with central forced-air systems. Duct losses in a central air system can easily account for more than 30% of energy consumption, especially if the ducts are not sealed tight or in an unconditioned space such as an attic or crawlspace.
Mini splits offer flexibility because they can be suspended from a ceiling, mounted flush behind a drop ceiling, hung on a wall or floor-standing. Ductless heat pumps allow for a peaceful inside environment by enabling the contractor to install components like compressors and motors outdoors.
Installing a traditional, ducted system can take several weeks and disrupts daily activities in the home. Ductless systems are far less invasive to install, and depending upon the number of indoor and outdoor units required, can be up and running in as little as one day.

Multi-split systems run on small pipes that require a mere three-inch hole. That means homeowners don’t have to worry about rebuilding walls or ceilings around ductwork and there is no loss of precious square footage.
Often, the quality of indoor air can be lower than the quality of outdoor air. With traditional HVAC systems, air ducts must be professionally cleaned on a regular basis, and even after cleaning, dust and allergens are left behind. Ductless systems, on the other hand, offer multi-stage filtration that can drastically reduce dust, bacteria, pollen, allergens and other particulates in the air.
Due to the lack of combustion the mini-splits have a low fire risk.

Disadvantages of Ductless Air Conditioners

The primary disadvantage of mini splits is their cost. Such systems cost about $1,500 to $2,000 per ton (12,000 Btu per hour) of cooling capacity. This is about 30% more than central systems (not including ductwork) and may cost twice as much as window units of similar capacity.
Proper system sizing and installation is critical to getting the touted benefits from a ductless system. A mini split installation is not easy for the common homeowner. It will take a qualified HVAC contractor to come out to a home, assess the space and determine whether or not such a system can be installed.
Many homeowners are hesitant to install ductless because the units aren’t necessarily design-friendly. They come in standard white or beige and can’t be covered. But in our experience, ductless customers who are initially reluctant because of aesthetics report that after installation, they forget the unit is even there.
To maintain your system, you’ll have to wash each unit’s filter monthly (more often if you smoke or have pets). Don’t skip it: ductless fans can’t handle accumulating debris, and if you ignore maintenance and a professional cleaning is required, you’ll spend hundreds of dollars and possibly shorten the life of your system.