This article was updated on 09/03/18.
I recently received an email asking what the difference is between ductless air conditioners and mini-split A/C units. In a nutshell, nothing! Most homes, at least in the southern US where I live, use from central HVAC systems.
They employ large evaporator coils and condensers and distribute circulated air via ductwork, usually insulated flex. However, there is no reason why they couldnt benefit from a ductless model.
Specifically, since minis are designed for cooling a dedicated area rather than a whole home, installing one in a room addition could be a good solution. It really depends on the situation. Obviously, the tonnage will have to be increased. If it is not time to upgrade the central unit this might be the way to go.
How Ductless Air Conditioners Function
As I have mentioned, these units may have different names (is that a regional cultural thing?), but both names are accurately descriptive in their own way.
First, they is no ductwork involved. Secondly, they are comparatively smaller in size than central HVAC systems (hence the term mini), and finally, the two components are split apart.
An important component is the evaporator. It is secured to the wall on the interior of the house, typically either close to the ceiling or at floor level. This component houses a blower fan that pushes the cool air into the room.
It is typically adjusted using a remote control. The next component is the compressor and it is situated outside the house. The two units are joined together with tubes, the purpose of which is to remove condensate (moisture or humidity) from the interior of the home and to circulate refrigerant. And that is about all there is to it!
To improve the efficiency of the condenser and save money on both electric bills and wear-and-tear on the unit it makes sense to shell out $100 or so for an A/C misting system. It works by lowering the ambient air temperature.
Benefits of Mini-Split Air Conditioners
There are many advantages offered by these units. As mentioned above, it makes sense in the case where an addition is made as part of a remodeling project or in the situation where a garage is converted into a home office or a mother-in-law apartment.
True, its natural to inquire, But why not simply use a window unit?
While window AC units are inexpensive to buy and easy to install, they should be removed during cold weather. Who wants to bother with that annually?
Window units are unsightly and can be noisy.
Window units are not secure. Crooks can easily remove them and gain entry to the home to conduct their nefarious business.
Ductless units are much more energy efficient. The Mitsubishi website tells us, “We have 15 new Energy Star rated systems with dramatic increases all the way up to 26 SEER. And we have nine new systems that qualify for a federal tax credit of up to $1500.”
Minis are much more quiet than window air conditioners. Several Mitsubishi models are as quiet as 19 decibels. To put this in perspective, this is lower than a normal human whisper.
Unlike central units, there is no wrestling an evaporator and furnace up into the attic. Likewise, there is no need to run rigid metal ductwork or insulated flex. There is no need to cut into drywall ceilings to install vents or defusers. This all serves to rein in labor costs.
Have you had any experience with these systems that you feel would help other readers. Good brands or lemons? Please consider sharing your opinions in the suggestion box below!