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Is It Safe To Leave The Air Conditioner On All Day? (AC Safety)

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This year is proving to be a very hot summer and for many seniors, that means running their air conditioners for longer than they may have done so in the past.

Some seniors may wonder if it’s safe to leave their air conditioner on all day. As long as the air conditioner filters are properly fitting and clean, the HVAC system is in good condition, and the thermostat is set properly so that the unit turns on and off throughout the day, it is safe to leave an air conditioner on all day.

This is true for a central air unit or a portable air conditioner.

I have gone to visit elderly family members in Florida during the summer and although the temperature outside was in the low 90’s, they did not have their air conditioner on!

Needless to say, I did not spend a long time visiting.

Why did they keep their AC unit off? Well, mostly for two reasons:

  1. Many elderly adults feel the cold more acutely than younger people.
  2. Because it costs money to run the AC unit.

Since many seniors are living on a limited budget, they do all they can to save wherever they can.

But what many don’t realize is that it may end up costing them more if they turn their air conditioner off for long periods of time.

Is It Bad To Turn The AC Off In The Summer?

Even though leaving the air conditioning unit off during the summer or any time of the year may save you money on your energy bills, is it a good idea to turn if off in the summer time?

No! For many reasons, as you can see:

In addition to cooling down the home, ACs also remove humidity. If your air conditioner is not running for hours, your home can become extremely humid. This is bad for both home furnishings and the house itself. Mold and mildew are more likely to grow, and wood or paper can warp. Any delicate electronics may get damaged. Another potential problem is that the extra high inside temperatures caused by shutting off your AC can be dangerous to other living beings. If you have a pet or a lot of houseplants, it is not a good idea to turn off your air conditioning.

McGowan’s Heating & Air Conditoning

Besides affecting the comfort levels of the home’s residents, there are other disadvantages as well to turning off your AC during hot summer days.

  1. Air conditioners also have an important function, regulating humidity levels so that it’s no higher than 50%. This ensures optimal comfort and health for you and your family!
  2. Humidity levels higher than 50% in a house can result in problems like peeling paint, warped wood furniture, floors, paneling and promotes mold growth. Dry foods can get stale, clothing can get a musty smell, cans can rust. Plumbing and mechanical objects can develop rust and fungus as well.
  3. Refrigerators work to keep your food cold and frozen but if the home’s temperature is high – then that forces your fridge to work overtime thus putting stress on the appliance.
  4. All those wonderful electronics in your home such as computers, televisions, alarm systems, etc. all require circuits and motors to work. High temperatures in a house can result in these items being damaged.

The bottom line is, you may just end up paying much more to repair any of these issues if you turn off your AC when your outside temperature is over 90 degrees.

The best approach is to set your air conditioner to about 78 degrees (F) when you’re not home. This is a number quoted by the Department of Energy because it strikes a good balance between keeping your home comfortable and saving electricity.

Is It Cheaper To Leave The Air Conditioner On All Day?

As I mentioned earlier, it just seems logical that if your air conditioner runs all day long, that your electricity bill would be higher.

But the truth is that it’s a bit more complicated that that. It all depends on the following:

  1. How hot is it outside? If the outdoor temperature is 90 degrees or more the amount of humidity that can accumulate while the AC is off can actually end up causing more damage to your home (and your health) and end up costing you money to repair it.
  2. How long did you leave the AC off? If you left your AC unit off for 30 minutes, there may not be a problem but if you left it off for several hours or days – well – the damage that could be done to your house due to the high humidity may cost you.
  3. Your AC unit will have to work harder once you turn it back on. Again, depending on how long you leave it off – your unit will have to work much harder to get the room / house back to a lower temperature so that puts a lot of stress on that unit which in turn can end up costing you because you may have to replace it much sooner.

These are all true whether you are using a portable ac unit or a central air system.

This of course does NOT mean that you need to keep your AC running all day at full blast.

The best way is actually to change your thermostat settings so that it’s lowered to 78 degrees during the day when you’re not home.

This can help to keep the humidity down just enough so that nothing gets ruined.

Note that some individuals prefer a set temperature a bit lower than 78 degrees.

I would recommend to speak with your HVAC expert to get their recommendation for your specific area.

When you are home, you can also turn on your ceiling fan which can help to cool down the room as well and help the AC unit from running longer.

A better option is to use a programmable thermostat.

This is the easiest way to save some money and keep your home safe and comfortable at your desired temperature.

If you don’t have a programmable thermostat that you can set specific temperatures at specific times, consider replacing it with one of the newer models that can do that.

You may even want to consider a smart thermostat like the Google Nest or this Emerson model.

Smart thermostats are app enabled devices that allow you to control it remotely through your smart phone.

These are a great way to have full control over your air conditioning units.

Here are some thermostats to consider.

How Many Hours Should The AC Run Per Day?

Normally, your air conditioning unit will run in increments of 15 to 20 minutes to get the temperature to what you set it at on your thermostat.

Then it turns off until the temperature again rises past your setting.

But – when the days are in the 90’s or higher – it may take your AC unit longer to get the temperature in your house down so don’t be surprised it it ends up running a few hours at a time.

There are two primary reasons that an AC unit would have a harder time to cool down your house.

  1. You have poor insulation in your home.
  2. Your AC unit is either old or inefficient.

If you want to save money in the long run, I would recommend to contact an HVAC company to see if you can improve these situations.

Or to find out if there is another possible reason that your AC is just not working as well as it could be.

You can save as much as 10% a year on heating and cooling by simply turning your thermostat back 7°-10°F for 8 hours a day from its normal setting. The percentage of savings from setback is greater for buildings in milder climates than for those in more severe climates.

Is It Safe To Leave The Air Conditioner On All Night?

If you are like most people, you will probably run your air conditioner for several hours throughout the day, especially during those hot summer days.

This is perfectly fine and can keep things cool and comfortable.

But what about when nighttime comes? Is it safe to leave your air conditioner on all night long?

The answer is Yes. It’s perfectly safe to leave the air conditioner running throughout the night. No matter if it’s a central AC unit or a window unit.

Experts tell us that it is safe to have your window air conditioner running 24/7. No part inside the air conditioner will get too hot and melt if you keep it running all day. The performance of the air conditioner, too, won’t suffer if your forget to turn it off.

Is It Safe For Seniors To Sleep With The Air Conditioner On?

It can certainly be safe for older adults to sleep with the AC unit on all night and of course, it’s usually much safer than suffering from the effects of heat-related illnesses.

But, for many seniors (like my mother and mom-in-law) having cold air blow on them for a length of time is uncomfortable.

So it seems logical that if the bed is situated in such a way that the cool air from the AC unit is blowing on you – then you would more than likely turn if off!

Elderly people tend to be more susceptible to the cold and heat than younger adults.

The older we get, our body’s ability for thermoregulation changes so it is not unusual that older adults suffer the most from heat waves or cold snaps.

The solution is not to turn off the AC unit, but to do all you can to either move the bed away from the direct air or use an air deflector for vents like this one on your central AC vent.

I use a deflector and love it because it keeps the cold air from blowing on me

Should I Turn The AC Unit Off When Not At Home?

If you’re going to be away from home for a length of time during hot weather days, it’s best to simply turn the thermostat down while you are away for several days vs. completely turning off your air conditioning unit.

The recommended temperature is 78 degrees Fahrenheit (25.5 degrees Celsius). Programming it at a higher temperature than that may be unnecessary.

This would also apply if you are leaving the house to go to work or run errands, etc.

Final Thoughts

It’s certainly safe to keep your air conditioning unit on at all times, as long as it does not run continuously. It’s also important to change your air filters at least every 6 months and I would certainly recommend regular maintenance by hiring HVAC experts to come in and give it a check up every year.

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