Ductless units go by a number of names, most of them referring to the lack of ductwork necessary for distribution of the warmed or cooled air. A few of the other names commonly used are mini-split, mini-splits, and split-ductless.
Where Ductless A/C and Heating Can Be A Solution
These units typically work best in situations such as: room additions, garage enclosures, basement renovations, sunroom additions, workshops and garage apartments. Primarily they are used in retrofits or replacement of small non-ducted indoor cooling and heating. For smaller homes ductless can be a good choice for replacing space heaters and window units. These can also be a solution where duct installation is either physically not possible, or not cost effective. Finally, there are some indoor environments where ductwork needs to be avoided for health considerations, such as severe asthma cases or in hospitals.
A Brief History of Ductless HVAC Units
These clever units were developed in Japan, where the dense population and high energy costs called for features that window units or ducted systems did not provide.
Features and benefits
- As the name indicates, there no duct work. Since there is no ductwork, there is no loss of heating or cooling due to leaks in ductwork, or ducts being located in unconditioned space. With these units,very high efficiency is available, up to 26 SEER.
- The units tend to be quiet, because the compressor sits outside instead of closer to you, as in window units or other package units do. Certain ductless models will qualify for 30% federal tax credit, up to $1,500, for 2009 and 2010 on parts and labor costs. Be sure to get the qualifications of your unit in writing before purchasing.
- Some models have up to four indoor air handling units connected to one outdoor unit. This means the one outdoor unit can handle up to four rooms or zones. This depends on how much heating or cooling the structure or each zone needs. As is always the case in HVAC , the amount of insulation, the climate, and other conditions of the envelope (structure) affects the heating or cooling capacity required.
- Since each zone gets a separate thermostat, this gives more flexibility on comfort and ways to save energy.
- Some models offer features for added humidity control and air filtration.
Considering Buying A Ductless Unit Online?
On their website for the Mr. Slim ductless Mitsubishi states that they do not authorize or provide warranty for the online retail selling of its Mr. Slim air-conditioning and heat pumps. The company gives a number of reasons, with the upshot being you are much more likely to be satisfied with the performance if the unit is sized and installed by a professional HVAC technician. This is consistent with all our research and feedback. Unlike the older window units or portable models, although they have no ducts, they still require the running of lines for coolant, drainage, etc., and they have to be charged with refrigerant. While reading the latest on this topic, we did notice some Mistubushi mini-splits being sold online. If you are considering buying a unit online and having it installed for you by a licensed technician, you should ask for a copy of the warranty to be sent to you before purchasing. From what we have consistently read and heard, you will be better off going through a local HVAC service company you trust for everything.
Brands Of Ductless AC and Heating Units
If you want to compare features, below are some of the leading manufacturers and brands.
Intital Cost vs. Lifetime Operating Costs
According to the U.S. Department of Energy, ductless equipment costs more per unit of cooling: 30% more than a central split system and 50% more than a window unit. Of course, the absence of ductwork and future costs related to it (periodic checking for leaks, cleaning, and eventual replacement) must be factored in. Also, ductless units are available in some of the highest efficiency ratings that can be purchased. The savings in energy costs will offset the higher initial cost. To determine the extent of that offset, ask your professional installer for an estimate of the monthly and total cost of ownership over the projected life of the unit.
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