We all want to make sure we’re using aircon effectively, safely, and as cost-effectively as possible. For some, that means unplugging an air conditioner when they’re not using it.
In theory, unplugging your aircon saves you money and negates the risk of electrical shocks and fires.
But is this really worth doing?
<h2> Does unplugging an out-of-use aircon save electricity?
Yes, unplugging an out-of-use aircon will save electricity but only a little. Your air conditioner uses some electricity while its turned off to run electrical components like its remote control and to maintain a circuit through the device.
But the costs of leaving your air conditioning plugged in and turned off are negligible. Most air conditioning units have a stand-by energy consumption of 1 – 2 watts an hour. That’s watts and not kilowatts to be super clear.
The cost of one-kilowatt hour is $0.23 at current us rates. Historically, it’s cost more like $0.13. That means that one standby hour costs you $.00023 on your electricity bill. Assuming you leave your aircon on standby mode every hour of the year, the cost would come to $2.02 annually.
The upshot is that unplugging your aircon will not save you very much money.
<h2> Is leaving an aircon plugged in a safety risk?
No, leaving your aircon plugged in is not a safety risk. Air conditioners are designed to be plugged in for extended periods of time.
That’s not to say there’s no electrical risk with an air conditioner. These problems just don’t come from leaving your air conditioner plugged in when you’re not using it.
Instead, here’s a list of actual electrical risks to consider for air conditioner safety:
- Exposed wiring: The biggest risk for an electrical shock or fire is exposed wiring. An exposed wire means that anyone who touches the cable is touching a live electrical current. Make sure the rubber outer casing of your wires are fully intact to minimize this risk.
- Power surges: Power surges are a concern for air conditioners during lightning storms. Surging power can damage the electrical components in your air conditioner. Make sure your circuit breaker is working properly and consider unplugging your air conditioner during intense lightning.
- Use a grounding plug: Grounding plugs are designed to provide an alternative route for an electrical current in the case of a fault. Otherwise, electricity and heat can build up in a circuit and cause problems. Make sure the plug you’re using to connect your aircon to its power source is a grounding plug.
<h2> Do you save money by leaving AC on 24/7?
Leaving your AC on 24/7 will not save you money on your air conditioning costs.
This is a common myth that has spread because it has a compelling logic. The argument is that it uses a lot of energy to take a space from hot to cold. You don’t need as much energy to keep a space at a comfortable temperature once its already there.
So why not just leave your AC running and save money by only needing a little bit of electricity over a longer period of time?
The problem is that air conditioning systems don’t change the amount of electricity they use hour to hour. Air conditioners are binary – they’re either on or off.
The only way your air conditioner modulates its output is by shutting off when your home hits its target temperature.
So running your air conditioner for an additional hour will cost you the same amount no matter how warm your home is. Leaving your air conditioner on 24/7 will cost you more money than just running the AC for 8 hours a day.
But what’s the difference? For the sake of argument, let’s say that it takes 3 hours to bring your home down to a comfortable temperature.
A window AC costs $0.20 – $0.32 per hour to run. Most window ACs will cost $4.97 – $7.73 for an entire 24-hour period.
Turning off your AC while you to go work for 8 hours a day would save you $1.60 – $2.56 for that time period.
A central air system costs $16.56 – $22.08 to run for 24 hours. That same 8-hour turn-off period costs $5.52 – $7.36 for a central air system. The main difference between these two types of air conditioning is how powerful they are.
But you’re not going to shut off the air conditioning for a full 8-hour period. You need to leave your AC running for at least an hour so your home is cool when you return.
For 5 hours, central air would cost $3.45 – $4.60, and $1 – $1.60 for a window AC.
Mark is a journalist who has written about home products for two years. He holds a masters degree with distinction from the London School of Economics and an undergraduate degree from the University of Edinburgh.