Knowing the most efficient way to run a mini split will help you get the most out of your investment. Mini split heat pumps are known for their efficiency. But, it’s important that they’re properly controlled and maintained to maximize savings.
Weather, size and placement, maintenance, home efficiency, and how you control your mini split can all affect its efficiency.
We’ve put together 10 easy-to-follow tips for the most efficient mini split operation. But first, let’s learn some basics about mini splits.
Do Mini Splits Heat and Cool?
This depends on the brand, model, and type of your mini split. Some mini split air conditioners are designed to only handle air conditioning. However, mini split heat pumps are quite popular, which both heat and cool a home.
Mini splits are ductless systems that consist of two main parts: 1) an indoor air handling unit, and 2) an outdoor compressor or condenser unit. Each indoor air handler has its own fan and evaporator coil, and is connected to the outdoor unit by refrigerant lines.
To cool a room, the indoor unit pulls air inside, which passes over evaporator coils filled with refrigerant. Any absorbed heat is transferred to the outdoor compressor unit and cooled air goes back out into the room.
When your mini split heats a room, the opposite happens. The outdoor compressor unit absorbs heat from outside and moves it inside using the refrigerant coils. (Refrigerant is very cold, so it can find outdoor heat even at very low temperatures).
Mini split heating and cooling is all just a transfer of energy!Regardless of the model you choose, mini split efficiency is about 30% higher than central ducted systems. Part of the reason for this is based on how inefficient a central system can be, often due to leaky ductwork.
Since they’re efficient at both cooling and heating, using mini splits as a primary heat source is a smart move. But, in colder climates it’s necessary to have a secondary heat source like electric baseboard heaters for extreme temperatures. (More on this later!)
How Much Electricity Does a Mini Split Use?
If you’re wondering about the most efficient way to run a mini split, a common question might be, do mini splits use a lot of electricity? This depends on many factors, including the number of indoor units you have and use at the same time.
If you have a single zone mini split, you can expect to use anywhere from 500 to 700 watts of electricity per hour. For multi zone mini splits, multiply this by the number of zones in use at one time.
Outdoor temperatures, the size of your home, mini split capacity, home insulation, and if you use other heating or cooling sources will also affect how much electricity your mini split uses.
Are Mini Splits Expensive to Run?
Knowing how much your ductless mini split heat pump will cost to run depends on all the same factors mentioned above, plus your local electricity rate.
For example, in Toronto, current energy costs are:
8.2¢ per kWh during off-peak hours
17.0¢ per kWh during on-peak hours
Using an average between the two (about 13¢ per kWh) and assuming you have a 2-ton mini split that runs for 16 hours a day, 7 days a week, and the outdoor temperature is around 24°C (75°F), your approximate costs are $8.78 per day or $258.13 per month.
10 Tips for the Most Efficient Way to Run a Mini Split
Now that you know the basics of how they work, let’s get into mini split heat pump efficiency. Here are 10 tips of how to use your mini split efficiently:
1. Properly Manage Mini Split Run Time
Central HVAC systems cycle on and off every 15 minutes or so, but this isn’t the case with a mini split. You may be tempted to turn your mini split on and off or to dramatically adjust temperature settings to conserve energy. But that isn’t always the way to go.
While that would be a smart way to save when using other HVAC systems, mini splits operate best when used consistently. It’s kind of like a car getting better miles per gallon at a constant speed. Instead of making major changes, smaller adjustments are a better option to save.
So, Should I Leave my Mini Split on all the Time?
Should you run your mini split 24/7? Yes! A ductless mini split heat pump will use less energy when you let it run continuously. And, as a bonus, it will keep your temperatures more consistent. But, you can still make small changes to save energy.
For a traditional HVAC system like a furnace or baseboard heaters, it’s smart to schedule a temperature setback of 4-5 degrees celsius overnight and then resume your preferred temperature before you wake up in the morning. This way, you save while you sleep!
However, mini splits work a little differently. Having them ramp up or down with major changes can cause them to be less efficient. Instead, try setting a smaller setback temperature overnight, so your mini split doesn’t have to work as hard in the morning to bring the room temperature back up to normal.
One exception to the above would be if you’re going to be away from home for an extended period of time. Even if it’s just for a few days, turning off your mini split can help you save.
Also, it may be tempting to use your mini split’s air conditioning all summer long, however this adds to your annual energy costs. Instead, try not use mini split air conditioning on days where it’s not needed
2. Optimize Mini Split Settings
Optimizing your mini split’s settings will also help increase efficiency.
To start, pick a comfort level. Adjust your temperature settings until you reach your desired degree of comfort. Keep in mind that a mini split measures temperature closer to the ceiling where it’s installed, so you may have to set the temperature a little higher than you’re used to.
Next, choose the ‘AUTO’ fan setting. Mini split auto mode will allow your system to change fan speed based on the weather and your temperature setting. So, be sure to use auto mode, it’s the best setting for mini split efficiency!
3. Effectively Direct Airflow
Warm air rises and denser, cooler air sinks. So, the most efficient way to run a mini split would be to direct airflow to account for this.
Adjust your mini split’s air handlers in summer when you’re using AC to cool your home by directing airflow upwards. In winter, direct airflow towards the floor (since that’s where you are) to optimize your mini split’s heating efficiency. This simple change will allow for better airflow, and will help heat and cool your home more effectively.
4. Consider Outside Temperatures
Do mini splits work in cold weather? Yes! But, extreme hot or cold outside temperatures will affect mini split efficiency. If you live in a region that faces more than the odd day or two of extremes, your home should have a secondary heating or cooling source like electric baseboard heaters, a furnace, or a portable air conditioner.
Mini split heat pumps are generally an ideal heating or cooling source year round. However, when it’s extremely hot or cold outside, this will cause a mini split to work a lot harder than normal to maintain indoor temperature. If it’s calling for temperatures below 5°F (-15°C) or above 115°F (46°C), it’s more efficient to use a secondary heating or cooling source.
5. Maintain Mini Splits Regularly
Regular maintenance is key to ongoing mini split efficiency. Here’s a simple checklist:
Clean and dry or replace the air filter about every 4-6 weeks.
Clean the condenser coil about every 4-6 weeks. Before doing this, turn off the power and let the system sit for at least an hour. Your condenser coil is located in the outdoor unit, and you’ll need to remove the cabinet first. Use a soft, dry cloth to wipe down the coil.
Keep the area surrounding the unit clean. Make sure there’s nothing close to the inside or outside unit that could potentially block airflow. This includes vegetation, toys, snow, fallen leaves, etc.
Ensure proper drainage. Your mini split’s evaporator collects condensation through suction tubing. Make sure the outdoor unit is draining properly.
On top of the above, you should have an HVAC professional service your equipment at least every two years. If your mini split is freezing up or not heating, this also means it’s time for a professional check-up.
6. Consider Comfort
As mentioned above, room temperature is measured by your mini split high on the ceiling. Remember, hot air rises and cool air sinks, so the temperature you’re feeling may not be the same as what your mini split is reading.
You have a few options to improve your mini split temperature control. One option is to play around with temperature settings to find one that works best.
Another option is to invest in a smart mini split thermostat (also known as a smart mini split controller), which will read the temperature closer to where you are and communicate that to your mini split. This way, your mini split temperature setting and the temperature you feel in the room is more consistent.
7. Get Smarter Control
There are many other benefits to getting a smart mini split thermostat that will help you find the most efficient way to run your mini split, for example:
Mini split app control and smart features allow you to monitor and control your mini split’s settings from anywhere.
You can set schedules, so your mini split automatically adjusts if you have a planned vacation or weekend getaway.
Features like Energy Insights track usage information like humidity, ambient temperature, and runtime, so you can find ways to save.
A feature like thermostatic control measures temperature close to where you are, so you’re more comfortable.
8. Ensure Proper Mini Split Size & Placement
As with any HVAC equipment, proper sizing is imperative. Heating and/or cooling equipment that’s too small will cause the system to overwork. This negatively affects the life of the system and means it may not be able to produce enough warm or cool air.
On the flip side — is it OK to slightly oversize a mini split? Ideally, no. Equipment that’s oversized won’t run efficiently and will likely cause short cycling, poor humidity control, and waste energy (and money).
Asking yourself how big of a mini split AC do I need?
Proper sizing involves measuring the size of the room you’d like to heat or cool and calculating capacity of the mini split needed to handle that area. Considering the high level of investment, this process should be done by a professional HVAC technician. But here are some general guidelines:
|Size of Your Room:
|Mini Split Capacity
|500 to 650 sq. ft.
|1 ton mini split (about 12,000 BTU)
|800 to 1,300 sq. ft.
|2 ton mini split (about 24,000 BTU)
|1,000 to 1,650 sq. ft.
|3 ton mini split (about 30,000 BTU)
|1,200 to 2,000 sq. ft.
|4 ton mini split (about 36,000 BTU)
|1,400 to 2,300 sq. ft.
|5 ton mini split (about 42,000 BTU)
|1,600 to 2,650 sq. ft.
|6 ton mini split (about 48,000 BTU)
|1,850 to 3,100 sq. ft.
|7 ton mini split (about 56,000 BTU)
Mini Split Outdoor Unit Placement
There are two major considerations here: Space for service access and to allow plenty of airflow.
Manufacturers may have requirements for things like how far away the refrigerant pipe and wiring connections should be, so pay attention to this because it could void your warranty.
Units can be mounted on the exterior of a home or on the ground. For ground installation, make sure that the unit is placed on a concentrate slab or other sort of stand that’s at least 4 inches above ground. This will help protect it from sitting in puddles and snow.
It’s also a good idea to position the unit on top of rubber pads to eliminate vibration noise. Finally, consider protecting it with a cover in the wintertime.
9. Check Home Energy Efficiency
The condition of your home has a significant impact on the efficiency of your HVAC equipment. The most efficient way to run a mini split is in a home that’s properly sealed and insulated, so it doesn’t let warm or cool air escape. This includes ensuring your home has:
Sufficient insulation in the walls, attic, basement, etc.
Windows and door are properly installed and sealed
There are no interior or exterior wall openings
Not sure what else you should be on the lookout for? Check out our home energy audit checklist for more tips and tricks.
10. Use Windows & Blinds to Help with Efficiency
Another simple tip to increase the efficiency of your ductless mini split heat pump is to use windows and blinds to help control the temperature of your home.
When the sun shines through your windows, it creates radiant heat. In the summer, you’ll want to reduce this effect, so it’s a good idea to keep window coverings closed. But, in the winter, keeping blinds open to allow the sun in will naturally warm up your home. This simple trick helps your mini split run more efficiently.
Additionally, it’s important to keep windows closed when using AC. Open windows will make your air conditioner work harder, which will lead to unwanted increases in your energy bill.
Efficient Mini Split Control
Mini splits are very efficient. But, as you can see there are many ways you can help your system run more smoothly.
Hopefully, these rules of thumb for ductless mini split operation will help you find the most efficient way to run your mini split and help you save.
If you’re interested in learning more about how to stay efficient at home, subscribe to Mysa’s email list — we send educational content each month : )