Ductless air conditioning systems can be substantially more efficient and compact than a central air conditioning counterpart
With so many different HVAC systems available in the market these days — especially on the AC side — it can be hard to know which system will work best for your home and your family. It can also be hard to know when you should consult a contractor, embark on a DIY installation project, or merely upgrade your current system with a few modifications. If you’re looking for an upgrade or am entirely new systems that won’t completely disrupt your home, you may want to consider a ductless air conditioning unit.
Some ductless AC basics
Ductless air conditioning systems are also referred to as mini split-system air-conditioners (mini splits or often, just splits.) They offer a number of potential applications in residential, commercial, and institutional buildings. One of the more common settings where you will find splits is in multifamily housing or as a retrofit add-on to houses that don’t have ducted heating/cooling systems.
Like central air conditioning systems, mini splits have two main components: an outdoor compressor/condenser, and an indoor air-handling unit. A conduit (which houses the power cable, refrigerant tubing, suction tubing, and a condensate drain) links the outdoor and indoor units. This tubing can be designed to allow the internal air handler (what pushes cooler air into a desired space) to be moved or positioned in a number of flexible applications.
Ductless AC Pros
The main advantage of selecting a mini split air conditioning system is that these systems are generally smaller in size and offer more flexibility for zoning or cooling individual rooms or select spaces. Many popular split models can have as many as four indoor air-handling units (for four zones or rooms) connected to a single outdoor unit. The number depends on how much cooling is required for the building or each zone (which in turn is affected by how well the building is insulated). Each air-handling unit comes with its own thermostat, so you only need to set a desired temperature for a space or room when it is occupied, saving you energy and money over the long run.
Ductless mini split systems are also often easier to install than other types of air conditioning systems. For example, the hook-up between the outdoor and indoor units generally requires only about a three-inch (eight-centimeter) hole through a wall for the conduit. Most split system manufacturers provide a variety of lengths of connecting conduits. If necessary, you can locate the outdoor unit as far away as 50 feet (15 meters) from the indoor evaporator. This makes it possible to cool rooms on the front side of our house with a compressor installed at a more convenient or inconspicuous place on the outside of your home.
Mini splits have no ducts (this the tag ductless) and therefore avoid the energy loss associated with the ductwork of central forced air systems. Duct losses can account for more than 30% of energy consumption for central air conditioning, especially if the ducts are in an unconditioned space such as an attic.
Compared with other add-on systems, mini splits offer more flexibility in interior design options. The indoor air handlers can be suspended from a ceiling, mounted flush into a drop ceiling, or hung on a wall. Floor-standing models are also available. Most indoor air-handler units have profiles measuring seven inches (18 cm) deep and usually come with sleek, high-tech-looking jackets. Many also offer remote controls to make it easier to turn the system on and off when it's positioned high on a wall or suspended from a ceiling. Split-systems can also help to keep your home safer, because there is only a small hole in the wall. Through-the-wall and window mounted room air-conditioners are often an open invitation to unwanted intruders and burglars.
These units are also usually quieter, as they run using substantially lower current.
Ductless AC cons
One drawback many people mention when considering mini split air conditioning systems is aesthetics. People routinely complain about the appearance of the indoor part of the system. While less obtrusive than a window room air conditioner, these splits seldom have the built-in look of a central air conditioning system. There must also be a place to drain condensate water near the outdoor unit, which can be an inconvenience for some households.
Another challenge to the homeowner when considering a mini split air conditioning system is that whoever installs the unite must also correctly size each indoor unit and judge the best location for its installation. Oversized or incorrectly located air-handlers often result in what’s known as short-cycling (the unit turning on and off more frequently than necessary) which wastes energy and does not provide proper temperature or humidity control.
The primary disadvantage of mini splits is…cost. Standard ductless air conditioning systems cost an average of about $1,500 to $2,000 per ton of cooling capacity. This is about 30 percent more than central air conditioning systems and can be twice as much as window units of similar capacity. Remember, however, that these costs don’t take into account the cost (and hassle) of having to design and install ductwork in your home to accommodate a central air conditioning unit.
Ductless heat pumps…another option
Just as a central heat pump offers homeowners (in certain circumstances) the efficiency in having a single unit provide both heating and cooling, there is a comparable ductless option. Ductless, mini-split-system heat pumps are available on the market today and like the mini split air conditioning units, they make good retrofit add-ons to houses with "non-ducted" systems. They can also be a good choice for room additions where extending or installing distribution ductwork is not feasible, and very efficient new homes that require only a small space conditioning system.
Like standard central air-source heat pumps, mini splits have two main components: an outdoor compressor/condenser, and an indoor air-handling unit. A conduit (housing the power cable, refrigerant tubing, suction tubing, and a condensate drain) links the outdoor and indoor units.
The pros and cons of a ductless heat pump system line up similarly with the pros and cons of a ductless air conditioning unit:
Ductless heat pump pros
The main advantages of mini split heat pumps are their small size and flexibility for zoning or heating and cooling individual rooms. 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 and air sealed).
Each indoor air-handler unit comes with its own thermostat, so you only need to condition occupied spaces. This will save energy and money.
Ductless mini-split heat pump systems are easier to install than some other types of space conditioning systems. As with air conditioning only systems, the hook-up between the outdoor and indoor units on a ductless heat pump generally requires only a small hole be drilled through a wall to accommodate the conduit, and the indoor connecting conduits can be tailored to various lengths.
The lack of needed ductwork reduces energy loss and improves the security of your home. Ductless heat pumps offer more interior design flexibility since the indoor air handlers can be suspended from a ceiling, mounted flush into a drop ceiling, or hung on a wall. Floor-standing models are also available.
Ductless heat pump cons
The cost of installing mini split heat pumps can be higher than some systems, although lower operating costs and rebates or other financial incentives (available in many areas) can help offset the initial expense.
Just as with the ductless air conditioning units, ductless heat pumps have some aesthetic shortcomings for some homeowners. While they are less obtrusive than a window room air conditioner, they don’t have the built-in look of a central AC system. There must also be a place to drain condensate water near the outdoor unit. DIY opportunities with a ductless heat pump are limited as the installer must correctly size each indoor unit and determine the best location for its installation.
Mini splits or ductless air conditioning units were invented and popularized in Japan, so it’s no surprise that the leading models come from leading Japanese manufacturers. While self-installation or full DIY is not always advisable for some of the more complex ductless air conditioning units, you can find many of the leading brands sold through home improvement retailers like Home Depot, Lowe’s and Sears. (While you may not feel completely comfortable purchasing and installating a unit by yourself, a quick trip to one of these retailer’s stores or websites can help you start comparing costs.)
Leaders in the ductless, mini split air conditioning market include:
In recent years, some of the leading providers or more traditional air conditioning and heating unites have begun to offer s limited supply of mini split and ductless systems, including:
- Carrier air conditioning – currently teams up with Toshiba to offer a handful of ductless air conditioning systems, it also offers residential, commercial and combined-use systems in it Performance and Comfort series of products.
- Lennox air conditioning – currently offers one mini split air conditioning system and two ductless heat pump systems for residential application.
- Trane air conditioning – currently offers one mini split air conditioning system and several ductless heat pumps for residential, commercial or mixed-use applications.
Qualified installers and service personnel for mini splits and ductless HVAC systems may not be easy to find. There is a sort of built-in disincentive for more traditional HVAC contractors and service personnel when it comes to ductless systems. Most conventional heating and cooling contractors have made substantial investments in the tools and training needed for designing and installing sheet metal duct systems. (In fact, many HVAC contractors have a sheet metal fabrication shop as either a subsidiary or related business that serves as a separate profit center for the company.) They need to use and charge for these tools, resources and investment in ongoing education to earn a return on their investment. A more traditional contractor may not recommend a ductless system or even let you know it’s an option. But you should ask.
A solid ductless AC system is definitely a viable option for homeowners, property managers and business concerns. They're smaller and more efficient, which is good for just about everybod, and can prove to be more cost effective in the long run. Find a professional contractor in your area and receive free quotes on products and installation costs.
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