HVAC Basics: How Do Ductless Heating and Cooling Systems Work
By Anne Fonda with expert review by Ryan Goodwin, Senior Product Manager, Ductless and Side Discharge Products
Ductless systems, also known as mini-split systems, work to heat and cool areas of your home by connecting an outdoor unit (mini-split heat pump or ductless heat pump) with one or more indoor units. Unlike a traditional heating and air conditioning system, a mini-split system does not use ductwork.
Instead, the indoor and outdoor units are connected by electrical wires and refrigerant lines threaded through a small hole in an exterior wall or the roof. The refrigeration cycle works just like it does in a standard heat pump system to heat and cool your home.
Enjoy the flexibility of a ductless mini-split system
Installing new ductwork can be expensive. With a ductless system, you avoid the extra expense. Indoor units can be mounted in many different ways, including high on the wall (most common), on your ceiling, or on the floor. You can control each unit with either a wall controller, a remote controller, or a mobile app on your phone.
American Standard recommends Mitsubishi mini-splits. Mitsubishi Electric pioneered ductless systems in Asia in the late 1950s. We have partnered with Mitsubishi to offer the industry’s most comprehensive ductless mini-split product lineup to American homeowners.
DUCTLESS MULTI-SPLIT TYPES
Single-zone mini-split vs multi-zone mini-split
With a mini-split ductless system, you can control the temperature in one room (or “zone”). This system connects one indoor unit to one outdoor unit. This can be a mini-split air conditioner or a mini-split heating and cooling unit.
A multi-zone mini-split ductless system, on the other hand, can connect multiple indoor units to one outdoor unit. With a multi-zone setup, you control the heating and cooling in several rooms (or “zones”) individually.
SINGLE-ZONE VS MULTI-ZONE LOCATIONS
When should I use each system type?
A single-zone mini-split system is a great option when you want to heat or cool a specific room, like a garage, bonus room, home office, sunroom, or even a tiny home. If you only need air conditioning to cool a garage, for example, single-zone mini-split AC systems are available. You may have a ducted system for the rest of your home, but that one area needs a boost.
A multi-zone ductless system is a great option for older homes without ductwork, a lake cabin, or a home addition that doesn’t have existing ductwork. This system adapts easily and is very energy efficient, so you can individually change each room’s temperature. All zones will be either heating or cooling – you can’t do both at the same time.
2-zone mini-split systems and 3-zone mini-split systems are very common, but you can connect up to 8 indoor units for a whole-home solution.
Professional mini-split installation is key
If you decide to go with a ductless mini-split system, it’s critical that you hire an HVAC professional who is experienced in designing and installing these systems. Poor design and installation can lead to an unsightly setup, unexpected comfort problems, and early repairs.
Work with your American Standard dealer to design a system that meets your heating and cooling needs. This will include choosing the optimal locations for the indoor unit(s) and the outdoor unit.
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Anne Fonda, Content Writer
A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need.
She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism.
When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.