Ductless Mini-Split AC Units

In the beginning:

Old Style window acOnce there was a single choice for providing cool, comfortable air conditioning in a home or business. That choice was a single purpose window air conditioning unit or a central air conditioning system. Each had its pluses and minuses which we’ll describe below.



Larkin Admin BldgThe design for office buildings with air conditioning was initially developed in 1906 by Frank Lloyd Wright’s Larkin Administration Building in Buffalo. It used a non-flammable carbon dioxide as a refrigerant. Further developments in the chemistry of refrigerants led to several versions on what is commonly known as Freon. In the 1960s US Government regulations required CFC-Free refrigerants in not only buildings but automobiles, trains, and other transportation means available

In residential applications, the window air conditioner provided comfort primarily for bedrooms, since most homes were empty during the day while adults were working and children were at summer school or day camp. It was relatively easy to install, assuming that the house wiring capacity could handle the amps required to run the compressor and cooling fan.

Central AC schematicIn the 1960’s home builders in predominantly, hot summer regions of the US began to develop centrally-based cooling systems which added modern thermostats which were able to be set to keep the home or office at a comfortable temperature during the work day, and then lowered significantly to avoid a complete restart of the cooling process each day. This was the reverse of what home-based units were set to do.

Not only did the central air cooling system work efficiently, it also eliminated when many considered an ugly-looking box sticking out of windows. It also could be a hazard if not removed during winter months, as a build-up of snow and ice could strain a window frame-mounted AC unit.

The Hotel box:

Often, a desire to retrofit an older home or business would give the designer a single option often called the hotel box. Anyone who has spent time in an older hotel knows the hum and rattle that comes out of the unit stuffed into a corner of the room. Not only was it extremely noisy, they were not particularly efficient and took up valuable floor space in cities where square footage could run $500-$1000 or more. They have certainly improved over time and noise level and cooling/heating capability are far better. However, there’s no getting around valuable floor space that they take up


The Next Advance: the ductless Mini-Split air conditioning system.

Mitsubishi Mini-SplitWhile everything was perfect when a central air system was installed, in the event of an expansion or a retrofit to a home not built with central air, and the hotel box was a poor choice both cosmetically and efficiently, the mini-split became the best of both worlds. It allowed the compressor and cooling mechanics to be installed outside, while the fan and controls for speed and temperature inside. It could be mounted on a wall and was completely ductless. The Mitsubishi Company offered both heating and cooling in their mini-split, and installation, not including and local inspections, could be completed in a single day. Other companies such as LG introduced their Art-Cool line, which gave the owner the option of installing a family portrait print in a built-in frame, and changing it at their leisure.

Disadvantages of the ductless Mini-Split Units

The single biggest disadvantage of mini-splits is their cost. Typically they can run 40-50% higher to move the same BTUs. Other problems include each indoor blower of a ductless cooling system contains a fan, a set of coils and a small air filter. Should anything malfunction with any of these components, the operation of the blower can be affected. The indoor blowers of a ductless system connect to the outdoor unit via a conduit through an exterior wall that contains a power cord, a refrigerant line, and a condensate drain line. Because the condensate and refrigerant lines can be rather long, they can sometimes be more prone to developing leaks or clogging.

Call a Pro

Muccia ShieldMuccia Plumbing is certified as a mini-split authorized and trained servicer for Mitsubishi and other mini-split brands. If you are considering installing a mini-split, call Muccia Air Conditioning at (201) 440-3322, and we’ll happily schedule a service call with one of our techs.