How Do Ductless ACs Work? A Phoenix Tech Explains

Ductless ACs work just like central ACs, in that they blow cool air into your home.

However, ductless ACs differ from central air conditioners because they don't use ductwork to push cool air throughout an entire home. They simply blow cool air directly into one area or room.

Below, we’ll break down the details of how a ductless AC works, as well as:

• The pros and cons of installing a ductless AC system
• Why a homeowner would choose to install a ductless AC system

Let’s break down the details of how a ductless AC system works:

Step 1: The indoor unit pulls in warm air and blows it over cold evaporator coils. These coils contain a heat-absorbing substance called “refrigerant.”

Step 2: The refrigerant inside the evaporator coils absorbs heat from your home’s air. The result is cool, dry air that’s blown back into your home.

Step 3: The refrigerant then travels to the outdoor unit, where it dumps all the heat it absorbed into the outdoor air.

Step 4: After this heat-dumping process, the refrigerant travels back to your indoor unit to repeat steps 1-3 until your home is cooled to your set temperature.

Some pros of installing a ductless AC system include:

• Ductless systems can both heat and cool- Unlike a central AC system, a ductless AC system can both heat and cool your home. How? Most ductless ACs are "heat pumps," which are air conditioners that can reverse the flow of refrigerant to both cool and heat a home.
• Ductless systems are energy efficient- Ductless AC systems are more energy efficient than central AC systems because they don’t have ducts. A home can lose 20 to 30 percent of conditioned air that blows through duct systems because of leaks, holes, and gaps between ducts.
• Ductless systems have built-in zoning- Because there is a separate indoor unit for each room you want cooled, a ductless AC system has built-in zoning.

Some drawbacks to installing a ductless AC system include:

• Visible units- Unlike the indoor units of central AC systems, which are installed in concealed areas like an attic or closet, the indoor units of a ductless system are installed on walls, ceilings or near baseboards. This may bother homeowners as these units can take up wall space and are not necessarily appealing to look at.
• Indoor units can only cool one room- However, you can install up to 8 indoor units to one outdoor unit, so you could potentially cool your entire home with one outdoor unit and multiple indoor units.
• Ductless units are more expensive than central AC units- Ductless systems are more expensive than central AC systems (unless you need to install whole-home ductwork, which can cost anywhere from $2,000 to $5,000+). You can learn more about the cost to install a ductless AC unit on our blog, “The Cost to Install a Ductless Mini-Split Air Conditioner in Arizona.”

You may want to consider investing in a ductless AC system if:

• You have a new or existing room that isn't connected to the duct system- As we mentioned above, installing ducts can be very expensive. A ductless AC system is a cost-effective alternative to adding ductwork to a new room or a garage.
• Your home doesn’t have ducts- If your home doesn’t have a duct system at all, a ductless system may be a good option due to the cost of installing ductwork.

If you’re stuck between installing a ductless AC system or a central AC system, you can learn more on our blog, “Ductless vs Central AC: Which is Best for My Phoenix Home?”