How Efficient Are Ductless Mini-Split Systems?

April 26, 2023
Ductless mini-split in Seattle, WA

Energy efficiency is currently a top concern when choosing new heating and cooling equipment. If you’re planning to upgrade your heater or air conditioner, you may be curious about ductless mini-splits. Although these systems were first introduced in 1959, they’re fast increasing in popularity as residents of Seattle, WA search for ways to lower their carbon footprints. Read on to discover just how efficient ductless mini-splits are and why.

The Benefits of Installing Ductless Mini-Splits in Western Washington

Consistently ranked as having one of the longest and heaviest rain seasons in the continental United States, Seattle and the greater King County area are known for their temperate winters and summers. Temperatures in the region rarely rise above 100 degrees and heavy snow is historically uncommon. For these and other reasons, countless properties throughout Western Washington were built without central HVAC ducting. Whether you own an older home, an older condominium, or a multi-tenant apartment building, there’s a good chance that you will have baseboard heaters installed and no whole-house air conditioning.

For properties like these, ductless mini-splits are ideal. There is no need to pay the excessive costs of having your home retrofitted with ductwork post-construction, and there’s no need to sacrifice indoor space or aesthetics. Ductless systems are installed by drilling a single, three-inch hole in the exterior wall of each room that will have its air handler. Each air handler is then connected to an outside condenser/compressor unit via wiring and refrigerant tubing. Ductless mini-split installation is both quick and minimally invasive. Best of all, it gives homeowners access to zoned heating and cooling.

Zoning Contributes to the Efficiency of Ductless Mini-Split Systems

The provision of zoned heating and cooling is one of several ways in which ductless mini-splits frequently outperform standard, central HVAC systems in efficiency. With zoning, homes are broken down into several service areas or zones, each with its own indoor air handler and thermostat. Every air handler and thermostat is controlled independently of the others. As such, you don’t have to waste money on heating or cooling rooms that no one is actively using, and you don’t have to establish a single, uniform temperature throughout the entire building. Zoned heating and cooling also make it possible for each person in the house to create their own preferred temperature in the areas that they’re occupying.

Avoid Energy Loss With Direct Air Distribution

In addition to zoned heating and cooling, ductless mini-split systems provide direct air delivery. With a central heating and cooling system, hot and chilly air is produced a significant distance away from the point of distribution. For instance, warm air from a furnace must travel through many feet of metal ducting before it’s pushed out of air registers, grilles, or vents and into rooms. As hot air moves through HVAC ductwork, it invariably loses a marked amount of heat. As a result, furnaces must work longer to compensate for ongoing heat losses, and they use additional energy along the way.

With a ductless mini-split, air handlers distribute warm air right where it’s sourced. There’s no complex or lengthy path of metal ducting for heated air to traverse and no heat loss. This means no wasted energy, shorter heating and cooling cycles, and less waiting for indoor comfort. Regarding home energy waste, HVAC ductwork consistently ranks among the top contributors.

The Energy-Savings Gained by Using Heat Transfer for Heating and Cooling

The third way in which ductless mini-splits consistently provide impressive levels of efficiency lies in how they get their job done. Whether ducted or ductless, air conditioners don’t produce cold air. Instead, these units harness warm air from the building interior and transfer it outside while bringing cool air to replace it. When a ductless mini-split uses this same cooling method, it’s paired with the additional efficiency gains of direct air delivery and zoning.

However, many ductless mini-splits aren’t air conditioners. Ductless mini-split heat pumps provide heating and cooling due to their ability to operate in reverse. During the winter months, the same ductless heat pump that supplied cool air in summer can switch its operations to pump cold indoor air out and move heat from outside into the building. A ductless heat pump can be even more efficient than a high-efficiency furnace in moderately cold wintertime temperatures. According to some estimates, certain ductless mini-split heat pumps have efficiency levels as high as 300%. This means they provide three times the amount of heat energy they consume in electrical energy.

Compare this to a high-efficiency furnace with an annual fuel utilization efficiency (AFUE) rating of over 98% that loses approximately 2% of the energy it consumes during conversion. When making this comparison, it’s important to account for the additional heat losses as the resulting heat is moved through HVAC ducting. Now, imagine that this same high-efficiency furnace is also part of a central HVAC system that has not been zoned. All-in-all, ductless heat pumps are the superior choice for consumers seeking to lower their energy waste and spending.

Just How Efficient Are Ductless Mini-Splits Overall?

There is, however; one especially important caveat when measuring the efficiency of ductless mini-splits. Although ductless heat pumps are remarkably efficient in ideal conditions, their efficiency levels decline in conditions that make it difficult to source outside heat. For instance, if you use a ductless mini-split heat pump as your sole heating solution, this unit will reliably heat your home with minimal energy use if the outside temperature is at or above 30 degrees Fahrenheit. When the temperature falls much lower, most mini-split heat pumps will struggle to source sufficient heat to maintain acceptable temperatures. Freezing outdoor temperatures causes heat pumps to work harder and longer to get their job done.

In Seattle, wintertime temperatures rarely drop below 20 degrees Fahrenheit and remain that way for a long time. For homeowners interested in using ductless heat pumps as their sole source of winter heating, high-performing heat pumps can continue functioning at elevated levels of efficiency even when outside temperatures are well below freezing. Moreover, if you currently use baseboard heaters as your whole-house heating solution, most ductless mini-splits can match and exceed their efficiency.

Is Upgrading to a Ductless Mini-Split a Good Way to Cut Your Carbon Footprint?

Ductless mini-split air conditioners and heat pumps are flexible and adaptable enough to meet a broad range of needs. These units can be installed with a single air handler or as many as eight air handlers for larger buildings. They’re more than just an efficient alternative to central heating and cooling.

Many homeowners use ductless mini-splits to supplement their central HVAC systems by adding service to areas that lack adequate ducting. For instance, if you have a central HVAC system that doesn’t service your garage, your recently refinished basement, or a remote attic bedroom, you can use a mini-split heat pump or air conditioner to make this area more habitable. Ductless mini-splits are much more efficient than window air conditioners in this capacity. They’re also safer, quieter during operation, and more effective at regulating indoor humidity and air quality.

Since 1987, we’ve been helping residents of Seattle, WA and the greater King County area lower their carbon footprints, improve their home comfort, and enjoy impressive energy savings. We offer air conditioner, heater, and heat pump installation, repair, and maintenance services. We also provide electric services, air duct cleaning, and water heaters. To find out more about ductless mini-split technology or to schedule service, give Brennan Heating & Air Conditioning a call today!

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