Ductless Air Conditioning: A Basic Guide

When you think of air conditioning, you probably think of a clunky system with ducts running through every room.

You also expect central air-conditioning, which can be a nightmare when people in the house fight over the thermostat. But what if one system could address both these concerns? With a ductless air-conditioning system, you can!

The Key Elements

A ductless air-conditioning system, also called a mini-split, has two portions.

The heating unit contains an evaporator, and is installed inside the house, in every room. This is different from traditional duct-based systems, where a single unit like a heating pump or a furnace is installed in the basement or attic, and connected to the entire house through ducts.

Regardless, the job of this unit is to collect all the (hot) air in the room, and route them through its refrigerant cooling coils.

The cooling unit is installed outside the house, and has a condenser which collects the hot air (from the evaporator). This is run through cooling coils present in a refrigerant, and the cooled air is re-routed back into the house.

Advantages of Ductless AC Systems

The first big advantage is the lack of ducts. This is especially useful if you want to revamp your HVAC system, or cool a new addition to the house (like a garage/ extra room), without the hassle of installing ducts.

In fact, it is ideal for rooms without windows, as the evaporator unit can be installed almost anywhere (like the ceiling, or mounted on a wall/ floor).

Second, ducts can lead to almost 30% loss of energy efficiency, due to the way in which they are installed (including cracks surrounding ducts). So in converse, you can expect 30% more energy efficiency with a ductless AC.

Since these units are installed in every room, the temperature can also be maintained exactly for that room. This is especially useful if you have a large house, where some of the rooms are not in use for a significant part of the season. In this case, you can even turn off the AC in those unused rooms.

Finally, a typical ductless AC is called single zone, for obvious reasons. A multiple-zone ductless AC can be used to heat/cool several rooms at once, but comes at a higher cost.

Disadvantages of Ductless AC Systems

People are sometimes hesitant to use a ductless AC, as the evaporator unit is clearly visible (unlike duct-based systems that are hidden behind drywall). But a few days post installation, they typically become oblivious to its presence.

Ductless AC systems are also more expensive than duct-based ACs, not including the cost of the ducts. Hence, if you already have a duct-based system running through your house, it may be cheaper to add AC for a new room using existing ducts.

Also, ductless ACs will require more maintenance, including frequent cleaning of air filters. In some cases, this can also translate to higher maintenance costs. However, these extra costs are often offset by the energy savings provided by the system.