Are Mini-Splits More Energy Efficient Than Traditional HVAC Equipment?

Mini-split heat pumps are becoming recognized as an energy-efficient, low-cost option for heating and cooling residential homes.

Along with lowering your utility bills, you can reduce your carbon footprint by switching to a mini split system.

Of course, this might not be the best option for every home and it is important to talk with an HVAC professional to find the best solution for your home.

That being said, let’s take a look at the difference in energy efficiency between mini splits and more traditional HVAC options.

If you’re interested in how much energy mini-splits require, you can read our article here.

Are Mini-Splits More Efficient Than Traditional AC?

Variable speed mini-split heat pumps are more energy efficient than traditional central air systems, partly due to the absence of ductwork, which is responsible for around a 30% energy loss.

The other big reason is the system’s ability to modulate its output using variable-speed compressors.

Essentially, these systems are capable of adjusting their operating speeds on their own to best fit the heating and cooling requirements of the space. It’s a form of “smart technology,” if you will.

This ability to “self adjust” reduces your power usage, which lowers your monthly utility bills.

	Mini-Splits	Traditional HVAC
Duct System	No ductwork	Usually in the attic or crawlspace
Compressor	Outside	Outside
Condenser	Outside	Outside
Electrical Needs	110v	208/230v
Zone Control	Yes	Certain Models

How Does a Mini-Split Work?

A mini-split heat pump is a clever system that homeowners can install to provide year-round heating and cooling.

It has two main elements.

1. Outdoor unit housing the compressor that pumps refrigerant around the system
2. One or more indoor units that blow conditioned air into each room or zone. These indoor units are also known as air handlers, evaporators, or head units.

The heat pump collects heat from the cold side of the system and moves it along the refrigerant lines that connect the two units to the warm side of the system, where the heat is released.

In heating mode, heat is collected outside the building and moved inside to heat the home.

In cooling mode, the system is reversed and operates like a standard air conditioner to collect heat from the living space and dump it outside via the condenser coil in the outdoor unit.

The mini-split makes use of the refrigeration cycle to move heat very efficiently. The refrigerant absorbs the heat in the evaporator coil and carries it along the refrigerant lines between the outdoor and indoor units.

To make this happen, the refrigerant fluid is taken through a series of steps that alter its phase, changing it from gas to liquid and back again by compressing, condensing, expanding, and evaporating it.

This process is the refrigeration cycle. The speed the compressor runs at governs how quickly these processes take place, determining the rate of cooling or heating that the heat pump provides.

Compressor is the heart of the system. It is a vital element of the heat pump, and its performance significantly impacts the system’s efficiency.

Why Is a Mini-Split Heat Pump More Efficient?

Efficiency is relative, so before we talk about why a variable speed mini-split is more efficient, we need to look at the alternative.

Fixed Speed HVAC

In the past, most HVAC systems operated at a single speed, or perhaps two speeds. There are still plenty of systems operating in this way.

These systems have compressors that start up when the AC is running and continue to run until the thermostat satisfies. They do not self-adjust.

Maintaining indoor temperature means the air conditioner has to start up and run whenever the indoor air temperature rises above the thermostat setting. This means it is constantly turning on and off.

This can be tough on the compressor because each time the compressor starts up, it must overcome the initial inertia of its moving parts.

These units are effective at cooling, but their operation is not the most efficient form of energy use. This is a greater issue for homeowners who live in hot and humid environments and rely heavily on their AC for home comfort.

Traditional air conditioners can be quite costly to run for long periods of time.

Variable Speed Inverter-Driven Compressor

Mini-splits usually have inverter-driven variable-speed compressors. Some units, particularly older ones, might have a single-speed version, but they are a rarity these days.

Mini-splits with inverter-driven variable-speed compressors can ramp up and down according to the heating or cooling output demanded.

Once the temperature has reached the setpoint, the compressor will be modulated down to a much lower speed that maintains the desired temperature.

This is much more efficient than a fixed-speed compressor, which turns on and runs at high speed, overshooting the setpoint until it turns off. It then sits idle until it is needed again to bring the temperature under control.

This stop-start routine is inefficient compared to a variable-speed compressor that can run very slowly using only a fractional amount of energy.

Zonal Heating

Individualized heating is one of the critical benefits mini-splits offer.

With this system, each room or zone in your home can have its own temperature setting. That means you can tailor the temperature to meet your needs in each space.

This feature gives you maximum control over your energy usage as you won’t need to heat or cool areas you don’t need to at the time.

Additionally, it can provide a more comfortable environment for occupants, as everyone can customize the temperature to their liking.

Mini-Splits Don’t Require Much Space

Ductless heat pumps don’t require much space, making them excellent for small homes or apartments.

Additionally, they can be installed in various locations, including closets, attics, and crawl spaces.

Most mini-splits are also ductless, which means they don’t have the same energy losses associated with ducted HVAC systems. Depending on the state of the ducts, energy losses can be 30% or more.

Pro Tip: When shopping for a mini-split, be sure to look for a model that is Energy Star-certified. Approved units are the most energy-efficient models on the market and can help you save money on your energy bills.

Summary

Mini splits are typically more energy efficient than central, ducted HVAC systems. They are useful for a variety of applications in residential spaces.

For greater climate control in individual rooms and small spaces, they are often the perfect choice. However, it is important to weigh all options when making home HVAC decisions.