Should I Leave My Mini Split On All The Time?

Ideally, yes, you should. Although it may feel wiser to turn it off on occasion, such as when you’re going to sleep or leaving for the weekend, studies show that there’s greater benefit in letting it run throughout the cooling season.

We’ll discuss the main reasons you should consider letting it run throughout shortly. First, but perhaps we should begin with why we’re sometimes tempted to turn it off.

Turning it OFF has its Advantages

Most of the time, people turn off the air conditioner mid-season for three reasons, i.e., to save energy, turn off the noise, and minimize wear and tear.

  • Save energy: In an ideal world, turning off the air conditioner for at least a few hours a day should save you at least a couple of dollars and perhaps a few hundred over a year. That’s because the air conditioner doesn’t draw any power when it’s off.
  • Keep the noise out: The air conditioner can be a bit noisy. Depending on the age and quality of maintenance, it may even be a menace. Therefore, turning it off seems a good solution to keep out the noise – at least for a while. This can especially seem beneficial during the night when you need quiet.
  • Minimize wear and tear: Keeping the AC running throughout obviously puts extra strain on the system. The moving parts are especially likely to wear out faster. Therefore, turning the system off for a few hours every day may seem like a good idea to slow down the wear and tear process.

Unfortunately, It’s Now Always What You Think

Although turning off the air conditioner for at least a few hours may seem like a good way to cut energy costs, keep out the noise, and minimize wear and tear, continuously running it may be even more beneficial in the long run.

You may save even more energy

You’re probably wondering how. The main reason is the high energy consumption during the first few seconds of startup.

According to Jennifer Thorne Amann, MES, Buildings Program Director at the American Council of Energy-Efficient Economy (ACEEE), air conditioning systems are most efficient when running at full speed.

The startup process and the period when you’re lowering the indoor temperature to the thermostat setting can be extremely costly –energy-wise. Some studies show that the AC draws as much as 10X more energy for the first several seconds to get the AC going than running at full speed. The unit may then draw about 3-5X more energy for several minutes to reach the thermostat setting.

It means that you’re not saving much at the end by turning the AC off for an hour or two every day. Indeed, you may even save more if you keep the unit running continually.

ACs make even more noise when starting/stopping

There are three explanations here. First, all air conditioners, even the most efficient models, make the most noise when starting and stopping because the ducts are expanding and contracting, respectively. 

Why? Because AC ducts are typically made of metal. When you start the system, the ducts will naturally expand due to temperature and pressure changes. When you stop it, the metal ducts naturally contract. The contraction can produce rattling noises.

The other explanation is that faulty compressor motors are noisiest when the AC is starting up. Granted, you’ll also get a few signs and noises when the unit is at peak speed. However, the noise is loudest at startup, the same way a faulty AC tends to struggle to pick up the pace during startup but can run just well once it gets going.

Finally, noise from the dampers is loudest when the dampers are closing when you shut off the AC. It’s usually a slamming noise.

ON-OFF Cycles have a bigger impact on wear and tear

It may seem counterintuitive. But it’s the truth. The air conditioner’s moving parts are disturbed the least when the system is running at full speed.

Added Benefits of Running the AC Continuously

Aside from saving on energy, experiencing less noise, and subjecting your AC to less wear and tear, running the AC round the clock may also have the following benefits;

Consistent indoor temperatures

Unless you don’t care about dips in indoor temperatures, you’ll want to keep the air conditioner running throughout.

As soon as the AC goes off, temperatures shoot. Depending on where you live, this could mean that indoor temperatures turn to 100˚F or higher. This can happen in less than 30 minutes – depending on prevailing weather.

If you’re home, it creates severe discomfort for you and your visitors. It may also reverse most of the gains made during cooling. For instance, if you were cooling to avoid sweating, turning off the AC for 30 minutes would have you sweating again. It also exposes you to the risk of heatstroke.

You can raise the thermostat setting

One tactic you can use to lower energy use in the home is to raise the thermostat setting during the cooling months. For instance, if you typically have the thermostat at 75˚F, you can save a bit on electricity by raising the setting to 80˚F.

However, you must also keep in mind that lowering the thermostat setting means that the room will be warmer. That small difference (from 75F to 80F) could leave you feeling a little uncomfortable. Keeping the AC running round the clock allows you to lower the thermostat setting without a noticeable rise in indoor temperatures.

The reason is that we tend to feel hotter and sweatier when coming from a scorching hot environment. After staying in a cool room for a few hours, you may even feel a little chilly, thus may feel more comfortable at a slightly higher temperature.

Better dehumidification

Finally, running the air conditioner round the clock may also result in better and more even humidity levels in the home.

Think of it this way…, air conditioners also function as dehumidifiers. As they remove the hot, sweaty air from your home, they also remove excess moisture from the air. Indeed, nearly every air conditioner has a specially designed drain system, often comprising a drain pipe and drain pan, to drain the excess moisture.

When you keep turning the AC on and off, humidity levels can build up fast. Within an hour, the room could be back to its sweaty, humid state. Keeping the air conditioner running 24/7 eliminates this problem.

The AC Has an ON/OFF Cycle in Any Case

If you’re worried about the air conditioner not getting enough rest if you run it round the clock, you may not be aware that modern air conditioners naturally cycle ON and OFF.

They use inverter compressors that keep the motor running until the thermostat setting is achieved and then automatically switch off the air conditioner until temperatures rise beyond the thermostat setting, at which point cooling resumes.

The on-off cycling is primarily designed to optimize energy consumption by keeping the AC on only when cooling is needed. However, it also gives the air conditioner sufficient breathing space to prevent overworking.

Typically, the AC runs for 10 minutes, rests for the next 10 minutes, then runs again for 10 minutes, and the cycle continues throughout. So, it gets plenty of rest.