Many mini-splits also have a reversible design, which means they can operate as air conditioners during summer and as heat pumps during winter. This means you’re combining two mechanical systems into one, saving on both equipment purchases and installation costs.
As you might imagine from their name, mini-splits are composed of an indoor unit and an outdoor unit, which are connected by insulated refrigerant lines.
Mini-splits are called “ductless” because they don’t need air ducts like traditional HVAC installations, and “split” because they are divided into an indoor and outdoor unit.
The indoor unit circulates air from the room where you install it, lowering or raising its temperature according to the thermostat settings.
Here we will discuss the main advantages of mini-split units when compared with traditional window-type air conditioners and ducted systems. We will also review some of the best mini-split brands available in now for the upcoming year.
Pro Tip: Before upgrading your space heating or air conditioning system, make sure your home is properly insulated and seal any air leaks. This will reduce the workload on the new HVAC equipment, and you will achieve even greater energy savings.
Understanding Energy Efficiency Metrics for Mini-Split Units
When purchasing any type of equipment, having a numerical value that describes energy efficiency is very useful.
For example, we look at the gas mileage value (MPG) when comparing different types of cars, to get an idea of their fuel consumption. In the case of mini-split units, there are two energy efficiency metrics we need to consider.
- The Seasonal Energy Efficiency Ratio or SEER describes the efficiency of a mini-split air conditioner.
- The Heating Seasonal Performance Factor of HSPF describes the efficiency of a mini-split heat pump.
A reversible mini-split capable of operating as either an air conditioner or a heat pump will have both metrics, a SEER for cooling mode and an HSPF for heating mode.
In both cases, a higher efficiency rating translates into less power consumption and lower electricity bills. Understanding these metrics is important before comparing mini-splits from different manufacturers.
The SEER can be defined as the average cooling output per unit of electricity consumed, during the season when air conditioning is typically used.
The cooling output is measured in British Thermal Units (BTU), while the electricity input is measured in watt-hours. This means you can estimate power consumption by dividing the rated cooling output (BTU/hour) by the SEER value.
- As a quick example, consider a mini-split air conditioner with a rated cooling capacity of 12,000 BTU/hour and SEER 24 efficiency.
- Dividing both values, you get an average power consumption of 500 W or 0.5 kW.
Assuming you use this air conditioner for 2,000 hours in a year, you can expect an electricity consumption of around 1,000 kWh. At an electricity tariff of 16 cents/kWh, this adds $160 to your annual power bills.
You should look for the highest possible SEER rating, regardless of the mini-split brand since high efficiency can save you hundreds of dollars in cooling over time.
If you repeat the calculation with the same cooling capacity (12,000 BTU/h) but a lower SEER rating of 13, the annual cooling cost increases to nearly $300.
The HSPF used by heat pumps is a similar concept: the average heating output per unit of electricity consumed. In the case of reversible mini-split units, you will notice that the HSPF for heat pump mode is typically lower than the SEER for air conditioning mode.
While the most efficient mini-split air conditioners reach a SEER of over 30, the most efficient mini-split heat pumps offer an HSPF of around 13-14. This happens because cold weather limits the efficiency of the refrigeration compression cycle used by mini-splits.
The Best Mini-Split Brands
The ENERGY STAR Most Efficient list is an excellent reference before purchasing home appliances and equipment. The ENERGY STAR program is managed by the US Environmental Protection Agency, and they have rigorous testing requirements for equipment.
To get the ENERGY STAR label, a product must be tested by federally approved laboratories that are completely independent from manufacturers. The ENERGY STAR label serves as proof of high performance and efficiency since equipment manufacturers cannot add it on their own.
The ENERGY STAR Most Efficient list is divided by equipment categories. As for mini-split units, the following brands have been featured in the latest edition of the list:
- American Standard
The ENERGY STAR provides detailed information about all the equipment featured in the latest Most Efficient list edition.
Here we will review the main features offered by four product lines from well-known brands: Carrier Infinity Series, Daikin LV Series, Fujitsu Halcyon LZAS1 Series, and Mitsubishi KJ Series.
Carrier is a leading brand in the HVAC industry, and their Infinity series includes both mini-split and central systems. The Carrier Infinity 38MPRA single-zone heat pump + the 40MPHA indoor unit is one of the most efficient combinations you can find in the industry:
- SEER 42 air conditioning efficiency
The Carrier Infinity 38MPRA + 40MPHA combination is available in four sizes, all offering superior energy efficiency in both cooling mode and heating mode. As you might expect, all four sizes are ENERGY STAR Certified:
|Carrier Infinity 38MPRA Series||SEER||HSPF|
The Carrier Infinity 38MPRA offers a wide operating temperature range: -22°F to 122°F in cooling mode, and -22°F to 86°F in heating mode.
For comparison, most heat pumps are limited to a minimum temperature of around -4°C. The outdoor unit is equipped with a basepan heater to prevent ice formation, which means the unit can continue operating at temperatures where other heat pumps are affected by frosting.
The Carrier 40MPHA indoor unit is designed for silent operation, capable of reducing its noise output to only 29 decibels.
The unit also offers WiFi compatibility with smart thermostats from Carrier and third-party manufacturers. The 40MPHA is also equipped with a relative humidity sensor, to achieve better control over indoor air humidity.
Carrier is a global provider of HVAC and cold storage systems, with more than 58,000 employees and net sales of over $20.6 billion last year. They have over 80 brands, and they have been launching over 100 products annually, for seven consecutive years.
Daikin is another top brand when you’re looking for a high performance mini-split system. Their LV Series comes in smaller sizes than the Carrier Infinity series, making it suitable for single rooms and other small spaces.
The Daikin LV Series ranges from 9,000 BTU/h to 15,000 BTU/h, and all units can operate as either heat pumps or air conditioners.
The LV Series is compatible with the Daikin One+ smart thermostat, which helps you achieve greater energy savings by keeping an optimal temperature setting.
The One+ thermostat is cloud-connected, and it can help you control air quality and humidity in addition to temperature.
The following table from ENERGY STAR summarizes the capacity ratings available in the Daikin LV Series, along with efficiency ratings, and typical operating costs and savings.
|Daikin LV Series||SEER||HSPF||Annual Operating Cost||% Savings|
The percentage savings are specified with respect to the minimum federal baseline, just like in the previous table covering the Carrier Infinity Series.
Daikin has more than 90 years of experience with HVAC and refrigeration equipment for residential, commercial, and industrial applications. The company is present in 150 countries, with over 67,000 employees and annual sales of over $26 billion last year.
This mini-split line from Fujitsu is characterized by its superior energy efficiency ratings, reaching up to SEER 33.1 and HSPF 14.2. When used in heat pump mode, this mini-split can operate with outdoor temperatures as low as -5°F.
- The built-in FGLair app gives you greater control over temperature settings and efficiency, and it can be used on smartphones and tablets.
- The Fujitsu Halcyon series has built-in diagnostics, system monitoring, and filter alerts.
The Energy Star table below lists the capacity ratings available, efficiency metrics and typical operating costs per year, along with percentage savings with respect to US federal standards:
|Fujitsu Halcyon LZAS1 Series||SEER||HSPF||Annual Operating Cost||% Savings|
Founded in 1935, Fujitsu provides consumer electronics and IT hardware in 180 countries, and their product offering includes high-efficiency HVAC equipment. The company has more than 130,000 employees and their last year’s revenue was over $32 billion.
The KJ Series mini-splits from Mitsubishi also offer superior efficiency in both heating and cooling modes, reaching up to SEER 28.2 and HSPF 13. The indoor unit is floor-mounted, and it achieves faster heating and even temperatures with its multi-flow vane technology.
The KJ Series is compatible with the kumo cloud mobile app from Mitsubishi, offering you greater control over temperature and comfort. This mini-split unit is also characterized by its silent operation, reaching noise levels as low as 21 dB.
The following table from Energy Star summarizes the capacity ratings available when purchasing mini-split units from the Mitsubishi KJ Series:
|Mitsubishi KJ Series||SEER||HSPF||Annual Operating Cost||% Savings|
Mitsubishi Electric is a leading equipment provider in multiple industry sectors. Their product offering ranges from HVAC and home automation systems to heavy industrial and power plant equipment.
Mitsubishi has over 145,000 employees worldwide, and their last year’s revenue exceeded $31.4 billion.
How Do Ductless Mini-Split Units Compare to Other HVAC Systems?
In general, mini-split heating and cooling units are more energy efficient than window-type units, packaged terminal units, and central ducted units.
When compared to the central air heat pump units, mini-splits give you the advantage of only heating and cooling one room, not the entire home. This means mini-split units not only save on power bills with their higher efficiency, but also by providing localized or targeted heating and cooling.
However, since mini-split units don’t have ducts or wall openings, they cannot provide ventilation by themselves – they simply circulate indoor air. This means you must install a separate ventilation system to meet the requirements of local building codes.
Below is an example of a high-efficiency central aka ducted heat pump as an alternative to a ductless mini-split system:
Carrier 25VNA4 Infinity Series with Greenspeed Intelligence (Central Heat Pump, not a ductless system)
This product line from Carrier offers superior performance in both cooling mode and heating mode.
The Infinity Series comes in four capacity ratings from 24,000 BTU/h to 58,500 BTU/h, so you can choose the best option according to the heating and cooling needs of your home.
The Greenspeed Intelligence system uses a speed control inverter to improve energy efficiency and reduce noise.
The Carrier 25VNA4 Infinity Series offers up to SEER 24 efficiency in air conditioning mode, and up to HSPF 13 efficiency in heat pump mode.
The 24,000 BTU/h unit has a typical energy usage of 1549.4 kWh per year, offering 44% savings with respect to the minimum federal requirement.
The following table summarizes the four capacity ratings available when purchasing the Carrier 25VNA4 Infinity Series with Greenspeed Intelligence, including rated efficiency (SEER and HSPF), typical operating cost per year, and percentage savings compared to the federal baseline.
|Carrier 25VNA4 Infinity Series||SEER||HSPF||Annual Operating Cost||% Savings|
Did You Know? Mini-split heat pumps are very efficient in heating applications, but their performance is diminished in extremely cold weather/climate. The same is true for central (aka ducted) heat pumps, though.
If you live in a place with very harsh winters, you may need a traditional gas furnace or resistance heater as backup. There are also mini-splits with built-in defrosting systems for their outdoor units, allowing operation at lower temperatures.