Yes, it’s best to leave the mini split air conditioner running 24/7 during the cooling season. It may sound surprising. However, ductless mini splits use less energy and keep temperatures in the house most consistent when they’re left to run round the clock.
You’ll occasionally come across experts with different opinions. For instance, some people believe that the mini-split needs to rest too, thus recommend that you run it for a maximum of 16-20 hours per day and let it rest for the remaining 4-8 hours.
While these people have a point about the need for mini splits to get some rest, the benefits of letting your mini-split run continuously are greater. Also, although the mini-split, and every other electrical appliance, needs rest, you don’t necessarily need to turn it off to give it rest. Read on to find out more.
Why Mini Splits Don’t Need “OFF” Time
Let’s begin by debunking the myth that mini split air conditioners need “off-time” to cool off and recover.
You’ve likely heard the word “inverter compressor” mentioned when discussing mini split air conditioners. Inverter (DC) compressors are the latest technology in air conditioner compressor design. It’s also found in other AC types, from window units to portable air conditioners.
The inverter controls the speed of the compressor motor to regulate the temperature continually. However, it’s a little different from previous compressor technologies.
The DC inverter unit has a variable-frequency drive comprising an adjustable electrical inverter to control the speed of the electromotor. The electromotor controls the compressor and heating/cooling output. This drive converts incoming AC into DC power, and then a modulation process in the inverter produces a current of the desired frequency.
The inverter drive works closely with a microcontroller inside the AC, which constantly samples ambient air temperatures and adjusts the compressor’s speed accordingly. This allows the compressor to slow down or speed up the cooling process depending on ambient temperatures in the home.
What does this have to do with mini-split “OFF” time?
Inverter compressors are designed such that the air conditioner pretty much goes off at times and resumes operations automatically when necessary. This usually happens after the thermostat setting is reached. The air handler inside the house will go “off” to save energy. This is known as the “OFF Cycle.”
It’s worth noting that a mini-split doesn’t stop operating during the OFF cycle. It’s almost similar to your phone screen going off when you’re not actively using the phone. Phones are designed to switch off automatically after a specified period of inactivity to save energy. Mini-splits also go “off” temporarily when not in active use to save energy.
How long does the AC rest between cooling cycles?
An air conditioner in good operating condition and running in standard summer climate cycles for 15-20 minutes two or three times per hour. This means that it could run the entire hour without stopping or for just 30 minutes every hour. It also means that your AC can rest for zero minutes per hour or up to 30 minutes per hour.
Cycling time is mainly dependent on temperatures inside the house. If the temperatures remain consistently high for the better part of the day, the AC will cycle round the clock with no off periods. More energy-efficient air conditioners also tend to have longer cooling cycles, thus shorter breaks.
However, in the end, most mini-split systems are “off” at least 15 minutes every hour, translating to 360 minutes or six hours every 24 hours. This is more than enough rest for a mini-split. You don’t need to turn it off for further rest.
Further Benefits of Keeping Mini-Splits On Round the Clock
Aside from the fact that mini-split air conditioners, especially modern models with inverter DC compressors, get enough rest, letting the mini split-run continuously has two other key benefits;
Increased energy conservation
This may sound confusing. But it shouldn’t be. While turning the AC off for a few hours every day can also boost energy savings, you could save even more by letting it run continuously round the clock?
Why? There are reasons. First, the first few minutes during AC start-up consume the most power. Research shows that the average AC consumes 10 to 15 times more power on start-up than when running.
Secondly, it takes a lot more energy to raise indoor temperatures to the thermostat setting than to maintain the temperatures at the same setting. It’s why the AC can afford to “sleep” for a few minutes between cycles without much harm.
Longer AC life
This may also seem counterintuitive. However, it’s true. Turning the AC off for a few hours every day may shorten the life of the appliance. Although keeping it running throughout also accelerates the wear and tear, too many stop-start cycles are even worse.
The most significant risk is short cycling. Short cycling occurs when the cooling cycle is shorter than usual. So, for instance, if your AC usually cycles for 15-20 minutes, but you realize that it’s now cycling for 10 minutes or less, it may be a sign of short cycling.
Turning the AC on and off usually forces the compressor to run at lower speeds for longer, which can cause unexplained restarts as the AC struggles to “catch on. This can easily result in short cycling.
Short cycling is the worst thing that can happen to a previously good air condition. It stresses the compressor, accelerating wear and tear. It can also compromise energy efficiency, leaving you with higher power bills.
So, Should Mini Splits Stay ON All The Time?
The short answer is – Yes! This doesn’t mean that there are no dangers to keeping the mini-split running round the clock. Faster wear and tear, constant AC noises (even if low), and power consumption issues are just some of the drawbacks of keeping your mini-split running throughout.
However, all these issues are worsened when you switch the AC off after every few hours to rest. The AC will consume more energy starting up and even make more noise.
Moreover, turning the AC on and off frequently increases the risk of short-cycling. So, it’s better to keep it running throughout the cooling season. It gets more than enough rest in spring anyway.