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By now, there’s a good chance you’ve heard about mini split heat pumps.
Maybe you’ve heard they’re more efficient than standard heat pumps.
Maybe you’ve heard they’re quiet. Or that you can install them practically anywhere.
All of these things are true. And when it comes to efficiency, a mini split will definitely cost less to operate when compared to a central air system, all else being equal.
But that’s the thing. All else is rarely ever equal.
Why mini split HVAC systems are more efficient than central air systems
There are three main reasons why mini split heat pumps are are more efficient than central air systems:
1. No ducts
Most mini split systems are ductless, which means none of the heat loss or gain normally attributed to ductwork.
Leaky ducts allow lots of conditioned air to escape. Poorly insulated ducts allow lots of heat transfer between the air inside the ducts and the ambient environment. And even if your ducts are really well sealed and insulated, there’s always some heat transfer as the air moves from the air handler to your living space.
Ductless mini splits, like typical split central air systems, have an outdoor unit and an indoor unit. The difference is that the indoor unit resides within your living space. There’s no need to move the air from the air handler via a network of air ducts.
The result is a friendlier electric bill when compared to central air systems.
2. Inverter-powered variable speed compressors
While some new central air heat pumps use an inverter-driven design, most don’t. Mini-split heat pumps do use an inverter, which powers their super efficient variable speed compressors.
This kind of design is much more efficient than a typical ducted split system. The variable speed compressor also improves efficiency by running at a low speed most of the time and only ramping up to full capacity when you have serious heating or cooling needs.
3. Zoning by default
Since mini split systems are designed to heat and cool relatively small spaces, you get automatic zoning when you install one. For example, you wouldn’t use a single mini-split for your whole house (unless you live in just one medium-sized room). Instead, you would have an indoor unit for the living room, one for the kitchen, one for each bedroom, and so on.
Each of these indoor units create its own heating/cooling zone. When you’re not using a particular room, you can change the thermostat setting so that the mini split system doesn’t continue heating or cooling that space very much.
Doing this saves a lot of energy, resulting in a much lower electric bill when compared to a central air system.
But are you really going to deck out your house with mini split units?
Most people won’t. While the idea of an all-mini split house might be appealing, most people prefer a central air system that distributes air via ducts that are invisible from inside the living space.
Also, most homes already have ductwork. It’s more economical to just use the ducts you have – not install a bunch of mini split units.
In addition, some people don’t like how mini splits look. The indoor units usually mount to the wall, although ceiling cassettes are available with some systems. With central air systems, you don’t see the indoor unit inside the home. It’s usually in the crawlspace, attic, or basement, or else hidden away elsewhere
This is why the mini split vs central air electric bill question is a little misleading.
Yes, mini splits are super efficient. No, you’re not likely to live in a house where mini splits are your only source of heating and cooling.
When to use a mini split system instead of a central air system
Mini split heat pumps are great for many situations, such as:
- Additions to your home:
- Supplemental heating and cooling:
- Finishing a previously unfinished space:
- Detached garages, studios, or workshops:
You may not have the HVAC capacity to heat the new room you added on. When you don’t, a mini split heat pump is perfect! You can heat and cool the new space without having to run new ductwork.
Maybe you have a problem room or area of your home that just never stays comfortable. In the past, people would use window unit ACs and space heaters to deal with this problem. A mini split is the perfect alternative! You get cooling in the summer and heating in the winter, but it’s quiet and doesn’t block out a window.
If you want to bring a basement or attic into the building envelope, a mini-split is often the way to go.
Mini splits are great for these spaces. This is usually just one large “room” or HVAC zone, so you will probably just need a single mini split.
You can also use mini split heat pumps if you’re building a custom home and want the room-by-room zoning that they offer. They’re also useful for quirkier, less conventional builds, such as tiny houses.
And yes, a house with mini splits will, in theory, have a lower electric bill versus an identical one with a central air system. It’s just that you probably won’t use mini splits all throughout your house.
Got more questions about mini splits, central air systems, and your electric bill?
We can help with that! At PV Heating & Air, we’re big fans of mini split heat pumps. However, we’re even bigger fans of making sure you get the right HVAC system for your home, whether that’s a central air system, a mini split, or some combination.
We’re also an official Carrier Ductless Contractor. That means our technicians are certified to install and commission mini split heat pump systems from Carrier.
If you live in Metro Atlanta and are looking for a quote for a mini-split heat pump system, a central air system, or just want to talk about your HVAC concerns, call us at (404) 994-2229 today or fill out the form below!
