Should I Leave My Mini Split On All The Time? – ACLab

Mini-split air conditioners are effective at controlling the temperature in a single room or small spaces. They usually come with two key components, an evaporator (indoor) and a condenser/compressor (outdoor).

These units have a relatively easy installation mechanism and most commonly require a single three-inch hole to accommodate all the cables. You can pull through copper tubing, communication and power cables, and the drain line for condensation that links the indoor and outdoor units.

Furthermore, mini-split systems are almost or entirely ductless; therefore, they avoid energy costs expected with central forced air systems. More than 30% of the consumption in energy is due to duct losses for space conditioning, mainly when set up in an undefined space like a basement or an attic.

Should I Leave My Mini Split On All The Time?

Even though a mini-split system usually does not run 24 hours a day, it can operate longer than conventional HVAC systems. This is because, more often than not, they run at a low-power mode instead of at their maximum capacity.

People accustomed to continuously switching their central air conditioner or a furnace on or off might notice that their new split system is constantly running.

Moreover, the unit automatically switching to low power may also make some people believe that it is broken and may not last longer than it should.

Meanwhile, it can be quite a hassle if your mini-split air conditioning system does not have an inverter, as it might drain a lot of energy. This technology can maintain your home’s temperature while using less power.

You might also notice that the air handler functions to optimize the indoor temperature. After which, your system would switch towards a low-power mode.

Through this, your home’s temperature is maintained all the time. It is entirely different from switching the unit on and off while continuously resetting the thermostat, like on central systems.

This low power mode also ensures less wear and tear through less toggling on the start-stop function. This helps the system to last for a more extended period.

Leave Mini Split AC Running

How Long Should A Mini Split Actually Run?

Essentially, mini split units were designed to be used in offices, meeting the office hour needs. However, with increasing popularity, their features were optimized to help them last even longer.

Also, keep in mind that the duration each unit should adhere to is also affected by the size of the mini split acquired for the size of the space.

Keep in mind that if you want to have your mini-split on for more extended periods while maintaining the same low temperature, you should only run it for sixteen hours maximum, adding a break for one to two hours.

And even if you plan on staying inside the room the whole day, the internal temperature will not be affected in a single hour, and at no point will you feel uncomfortable.

Costs To Run A Mini Split Vs Central Air System Per Hour?

There are multiple ways to reduce the cost of running an air conditioner; the most prevalent ones are:

On average, the cost of running an air conditioner varies between 0.06 USD to 0.88 USD per hour.

To help calculate this, each AC unit comes with its unique energy-efficiency profile. Hence, here is a formula to help you estimate the mini-split AC cost to run:

Cost Per Hour = Power Air Conditioner (in W) * Electricity Cost Per kWh / 1,000

Also, the BTUs for the most prevalent types of air conditioners are as follows:

Mini SPlit AC Running Cost

Presuming that all three of these air conditioners have an estimated EER rating of 10, and the typical electricity cost in the USA is 0.1319 USD per kWh, you can easily estimate the price for running these three types of air conditioners.

Let us take an example of a portable air conditioner with 10,000 BTU which runs on 1000 W. As a result,  you can employ the formula to calculate the air conditioner operating cost:

Cost Per Hour = 1000W * $0.20 / 1,000 = $0.20 per hour

Remember, this is only a theoretical assumption and estimation. Practically, the air conditioner drains lesser energy since they do not always operate at 100% efficiency.

Here is a table depicting mini split AC cost to run:

Mini Split AC Unit (BTU)Estimated Cost Per Hour
12,000 BTU (1 ton)0.16 USD
24,000 BTU (2 ton)0.32 USD
36,000 BTU (3 ton)0.48 USD
48,000 BTU (4 ton)0.64 USD

Running Costs – Mini Split VS Central AC

Installing a central air conditioning unit might cost a staggering amount of money, depending on the area and the extent of work. The cost of running a central air conditioning unit also comes with its ups and downs. Depending on the watts consumed, how often you run your unit, and the charge of the electric service provider.

A central air conditioning system normally uses 3500 watts; therefore, according to those numbers, assuming the system is run for eight hours a day, the system will cost around USD 3.70 per day. Furthermore, that comes around to $110.88 per month, and with an area of 1200 square feet, it can go around $245 per month.

In contrast, a split system running at similar conditions would only amount to $28.50 per month.

Tips for Efficiency When Running Mini Split AC

In The Summer

Maximizing efficiency, enhancing comfort, and lowering energy costs are the go-to ways to get the best out of your mini-split heating pump system during summer. Here are some tips on how to achieve that:

1. Continuously Running The System

During the summer, it is better to run the air conditioner for a prolonged period. Lesser energy is used by mini-split systems when maintaining a consistent temperature, and this is possible only when the split ac runs constantly.

Regularly turning it on and off causes higher energy loss as compared to constant running. This is also why offices are known to have conservative AC routines.

2. Routine Maintenance

Performing routine maintenance ensures that cool air is circulated through the system effectively and efficiently. Also, regularly cleaning and servicing your split system will keep it running efficiently.

We do not use our ACs as much or at all through the colder months. Long periods of inactivity is bad for the unit as it collects dust, harbors pests, and becomes rife for decay.

3. Drainage Check

Since the mini-split ac system is responsible for effectively cooling your house, the condensation commonly accumulates on evaporator coils, compelling the need for outdoor drainage.

Therefore, it is vital to check for drainage as often as possible; if the condensate is not draining, it might be time to check on it.

In The Winter

Similarly, the most efficient way to run mini split AC during the winters can be achieved via the following tips:

1. Back-Up Heating Source

Your mini-split heat pump can also function as a backup heating option during the cold days of winter. Of course, it may not be strong enough to serve as your primary heating system; however, it can still do the job when you’re desperate for some quick heating.

This provides a convenient and completely safe solution for heating while keeping it energy efficient.

2. Setting Temperature For Maximum Comfort

The temperature sensor on a mini-split indoor unit is located on the unit itself; therefore, they are installed higher than traditional thermostats. This entails that they are commonly situated towards the ceiling, where the air is typically warmer.

Due to this, you can set the temperature a bit higher to achieve maximum comfort.

Efficiency Tips When Running Mini Split AC

People Also Ask (FAQ)

What Temperature Should I Set My Mini-Split?

It is best to set your mini-split air conditioner between 77 to 80 degrees for cooling in the summer and between 64 to 68 degrees for heating in the winter.

Do Mini-Splits Control Humidity?

Yes, a mini-split air conditioner can effectively control the room’s humidity. Two settings help control humidity; the cool mode and the dry mode. And with an inverter, this process becomes more energy-efficient.

How Many Square Feet Can A Mini Split Cool?

A mini-split air conditioner can typically cool four rooms with collective square feet of 400 to 650. The higher the tonnage of an AC unit, the more area it can cool.

What Is The Benefit Of Having Separate Thermostats In A Mini Split System?

They help in spot cooling and heating, operating independently of a central system. In many newer systems, these smart WIFI thermostats allow the unit to calibrate to a pre-decided temperature automatically.


The age-old question of should I leave my mini-split on all the time has confused many. Therefore, this guide aims to provide you with a conclusive answer to this question. A mini-split AC’s efficiency depends on multiple factors, and they are pretty easier to achieve.

Josh Mitchell

Josh Mitchell

My name is Josh and I am obsessed with DIY and improving my family home. HVAC topics can be tricky for homeowners so I decided to share my knowledge on the subject. When I am not working on DIY projects, you can find me at the beach or my local coffee shop.