Ductless mini-split air conditioners are highly efficient systems that promise great convenience and exceptional energy efficiency. Moreover, mini-split systems are compact and beautiful appliances that rarely occupy the house’s floor space.
As a result, more people install mini-split systems in new buildings and replace older central air systems.
However, a common question among homeowners exploring mini-split systems is whether a single mini-split can cool multiple rooms as a central air system does. Can a single mini-split system serve the entire home, for example?
Read on to find out the answer and learn many other tips to help you select the best mini-split system for your application.
Can One Mini Split Cool Multiple Rooms?
Yes, a single mini-split air conditioning system can cool multiple rooms. This is because a single mini-split system can connect to multiple indoor air handlers, each of which is installed in a separate room or zone. A mini-split with multiple air handlers is known as a multi-zone mini-split.
What’s a Mini-Split System?
Mini-splits aren’t too different from everyday air conditioners. The major difference is that a mini-split is a “split system” with two separate components – an outdoor unit and an indoor air handler.
The two parts are connected via a refrigerant line and electrical wiring running through an exterior wall.
A blower system inside the air handler(s) draws warm indoor air into the air handler, passing it over extremely cold refrigerant lines.
Here, the refrigerant (which easily absorbs heat) absorbs most of the heat from the air, leaving the air relatively cold. The now-cold air then returns to your home, lowering indoor temperatures.
Meanwhile, the now-warm/hot refrigerant travels to the outdoor unit, where pressure changes force it to release most of the heat to the surrounding air via a heat exchanger. This warm air is then expelled from the outdoor unit into the environment.
Then the cold-again refrigerant flows back into the house to absorb more heat from indoor air, and the cycle continues on and on.
Central air systems and other traditional air conditioners work the same way, but with two main differences;
- Single vs. split packaging: While mini-splits comprise two distinct parts, other air conditioning systems pack all the components, including the compressor, evaporator, and air handlers, into one box. The unit is typically located outside the house or installed within the wall or on the window.
- Ductwork vs. no ductwork: Unlike central air systems, mini splits don’t connect to the home’s main ductwork system. Instead, supply and return air via the integrated air handler, typically installed on the wall, floor, or ceiling.
Single Zone vs. Multi-Zone Mini Splits
The original mini-split system had one outdoor unit and one indoor air handler. This configuration is known as a single-zone mini-split.
However, advancements in mini split technology later gave birth to the possibility of connecting multiple indoor air handlers to a single outdoor unit. This means you can now connect one outdoor unit to two, three, or more air handlers.
Some mini-split systems serve up to eight separate indoor air handlers. Such a configuration is known as a multi-zone mini-split system.
How Multi-Zone Mini Split Systems Work
Multi-zone mini-split air conditioning systems work the same way as single-zone systems, except they comprise multiple indoor air handlers.
Each indoor air handler is connected to the single outdoor component via a dedicated refrigerant line and set of wiring. This allows each unit to operate independently. It also means that each indoor air handler comes with its thermostat.
Therefore, assuming you have a 3-zone mini-split system with air handlers in the kitchen, sitting room, and bedroom, you can independently control the temperatures in each room from the dedicated thermostat.
For instance, you can head to the kitchen, set the thermostat to 74°F, then head to the bedroom and set the thermostat to 76°F. This allows you to choose the most comfortable setting based on your needs. So, it’s not just about having multiple air handlers.
What makes independent temperature control possible is that each air handler has its blower motor. So, you can adjust the blower motor speed in one room/zone without affecting the performance in the adjacent room/zone. Adjusting the motor speed increases or slows down the rate of cooling.
Multi-Zone Mini-Split Systems vs. Multi-Split Systems
You may have heard the two terms multi-zone and multi-split. Some people even use the two terms interchangeably – and correctly so.
The two aren’t completely different. However, there are a few things you need to know to make an informed choice.
Multi-split systems are advanced multi-zone mini-split systems that offer far better zone control. Although conventional multi-zone mini splits are good, too, a multi-split puts even more power in your hands, allowing you to achieve what’s known as “true zone control.”
One true zone control hallmarks is controlling all the indoor air handlers from a single remote control. This is a massive advantage because you may not always have the time to run to the kitchen, the bedroom, and other rooms to change the temperatures manually.
Fortunately, true zone control with a multi-split allows you to adjust temperatures in any of the rooms from the comfort of your sofa.
However, remember that multi-split systems are still multi-zone mini split air conditioners. The basic working mechanism is unchanged.
Advantages of Ductless Multi-Zone Mini Splits
Ductless multi-zone mini split air conditioning systems come with several advantages over their single-zone counterparts and traditional air conditioners, by extension.
The following are just some of the advantages;
- Enhanced comfort: Ductless air conditioners guarantee “gentler” heating with fewer starts and stops, unlike central air systems. This eliminates temperature swings/extremes, thus greater comfort.
- Significant energy savings: Mini-split systems are up to 30% more energy-efficient than central air and other conventional air systems. They are also cheaper to install and run than several single-zone systems in different rooms.
- Greater control overheating and cooling: Multi-zone mini-splits afford homeowners greater control over cooling (and heating). Multi-split systems, in particular, allow you to control temperatures throughout the house from a single remote control.
Multi-Zone Mini-Split Drawbacks
Unfortunately, multi-zone mini-split air conditioning systems aren’t without fault. The two main drawbacks of a multi-zone mini split system are;
- Expensive to buy: Multi-zone mini split air conditioners are significantly more expensive than single-zone systems and similar-sized central air systems. According to the Department of Energy, multi-zone mini split systems cost 30% more (upfront) for the same cooling capacity.
- Challenging to install: Multi-zone mini splits are also more expensive to install than single-zone systems and central air systems. While it costs $1,200 to $5,000, on average, to install a multi-zone mini-split, a single-zone unit only costs $300 to $1,500 to install.
How Many Zones Can You Cool with a Mini-Split?
You can cool up to eight zones with a single multi-zone mini-split. However, keep two things in mind. First, the number of supported zones varies from one mini-split to another. For instance, single-zone mini splits can only handle one zone. It all depends on your needs.
Secondly, “zones” are not the same as “rooms” in air conditioning. A single room can have two or more zones.
Can Multi-Zone Mini-Splits Cool and Heat at the Same Time?
Technically, yes. Advanced mini-split systems known as Variable Refrigerant Flow (VRF) and Variable Refrigerant Volume (VRV) systems can cool one room and heat the next at a go. However, these systems are typically found in industrial settings.
Standards mini-split systems, designed for everyday use, don’t have this capability. A standard mini-split system can only cool or heat but not simultaneously.
Can One Mini Split Cool Multiple Rooms FAQs
How Many Rooms can a Mini-Split Cool?
A ductless mini-split air conditioner can cool up to eight rooms, though most units cool between one and four. Mini-splits designed for a single room are known as single-zone systems, while those designed for two or more rooms are multi-zone mini-splits.
Can a Single Mini-Split Cool a Whole House?
Yes, a single mini-split system can cool the entire house. But, of course, it depends on the size of the house. However, a home with eight rooms or less, excluding hallways, can be fully served by one multi-zone mini-split.
Do you Need a Mini-Split in Every Room?
Not Necessarily. Of course, you can install a single-zone mini-split in every room in your home if you wish. However, a more cost-effective and more efficient approach is to purchase a single multi-zone mini split with multiple air handlers to serve all your rooms.
Are Multi-Zone Mini Splits Worth it?
Yes, multi-zone mini split air conditioners are worth the investment. They might cost more upfront (to purchase and install). However, they are more energy-efficient in the long run and afford you a level of convenience you can never have with single-zone and central air systems.
Yes, one mini-split system can cool multiple rooms. Systems that do so are known as multi-zone mini split air conditioners.
A multi-zone mini split has an outdoor unit and multiple (up to eight) indoor air handlers, each of which goes into a different room/zone. So, you need to choose the right multi-zone mini split system based on the number of rooms you need to cool.