Air Conditioner Minimum Temperature Settings
Most air conditioners have minimum thermostat settings at around 60 degrees. Most manufacturers simply assume you wont turn the air conditioner on if the temperature outdoors is 60 degrees. Some older units dont have anything physically stopping you from turning the air conditioner on at this point, though. However, you run the risk of damaging your air conditioner.
Heres how it goes.
Say the temperature outside is below 60 degrees yet you decide to crank up your air conditioner for whatever reason. If the manufacturer incorporated low ambient controls, nothing will happen. The air conditioner wont run. If those controls arent in place, however, the low ambient temperatures will make your air conditioner compressors lubricants too thick to function. Whenever anything mechanical runs without proper lubrication, you end up with excess wear and tear that shortens your air conditioners lifespan. The bottom line? Dont run your air conditioner when the temperature is lower than its minimum, which is usually 60 degrees. Refer to the owners manual for the exact minimum temperature.
Of course, heat pumps are not subject to these same limitations. While some people think of them as air conditioners, theyre not really in the same category. Read more here. You can run your heat pump year round without issue, although it may be inefficient at cooling and heating if you live in an area where temperatures get extreme.
Does Outside Temperature Affect Air Conditioners
When summer temperatures become extreme your air conditioning system might begin to experience problems. Most air conditioning systems are designed to function with outside temperatures of 100 degrees or less. When temperatures outside become higher than 100 degrees Fahrenheit, the air conditioning system can consume more energy and begin to malfunction or fail.
When outside temperatures become 95 degrees or higher, your air conditioning system will run at its maximum capacity. When this happens, temperatures inside your home will remain about 78 to 80 degrees. Lowering your thermostat will not improve the effectiveness of your air conditioner. In fact, lowering the thermostat will cause your air conditioning system to work even harder without actually being able to change the temperature inside your home.
When outside temperatures soar everyone in an area begins to lower their thermostats in an attempt to cool their homes. The increase in energy usage can cause power grids to overload, leading to widespread power outages. Additionally, the constant use of your air conditioning system can cause your utility bills to be fifty percent higher during periods of extreme heat. To avoid power outages and higher utility bills during the summer, set your thermostat to 78 degrees Fahrenheit when you are home and 82 degrees when you are away.
Hot summer temperatures can lead to many problems with your air conditioning unit including:
Is 60 Too Low For Ac
In most cases, especially in residential applications, you should not run your air conditioner when outdoor temperatures are below 60 degrees. The air conditioner does function, but you are going to burn out the compressor fairly quickly.
Can I turn my AC on at 60 degrees?
Before you turn on your AC for the season, be sure that the outside temps are consistently above 60 degrees. Running your air conditioner when the outside temperature is below that can cause major damage to your unit. And remember to turn off your AC on those nights when the temperature drops below 60 degrees.
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Should Air Conditioners Be Covered During The Winter
As the weather begins to cool off, many homeowners start to prepare their homes for winter. One common task is to cover up or otherwise protect outdoor AC units with an air conditioning unit cover. However, there is debate over whether this is actually necessary.
Some experts argue that it can help to prevent ice and snow buildup, which can damage the unit. Others contend that most modern air conditioners are built to withstand the elements and that covering them is simply an extra step that isnt necessary. Ultimately, the decision of whether or not to cover an air conditioner during the winter months is up to the homeowner. However, it is important to consult with the manufacturers instructions before taking any action.
Is It Cheaper To Leave An Ac On All Day

During the warmer months, you never want to turn your air conditioner off completely, even when youre not home. Youll end up being tempted to run it more powerfully than needed. Rather, the Department of Energy recommends keeping your air conditioner at 78 degrees when youre at home and turning it slightly lower when youre not.
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Best Temperature To Set Your Thermostat In Summer
Once you have the right size air conditioner, theres still an ideal temperature range to consider. Its best to not set your thermostat lower than 70 to 72 degrees. Most units are not designed to cool a house below that point, and you risk the system freezing up.
I recommend trying to keep your house below 80 degrees at all times during the summer. At 80 degrees, theres a good chance the humidity level in your home will be very high. This is not only uncomfortable but inefficient. When you turn your air conditioning back on, its going to have to work not only to reach your ideal temperature again but also to regulate the humidity level.
What Temperature Can I Turn My A/c On
With this unseasonably warm spring, Ive already gotten several calls from clients asking if it is safe to turn on their air conditioners not the question that I expected during the middle of March! So when can you turn on your air conditioning? A standard system that has the proper refrigerant charge and correct airflow can be turned on at outdoor temperatures at or above 65 degrees. Running a standard air conditioner below 65 degrees and/or with insufficient ductwork or refrigerant charge can significantly reduce the life of the equipment so the best recommendation is to have a trained professional come to your home and perform preseason maintenance to prevent expensive problems in the future and make sure your a/c is running at its max efficiency. Lower electric bills and a cleaner planet, go ahead and hug your polar bear.
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Testing Ac In Cold Weather
Many HVAC professionals and air conditioning manufacturers agree that outdoor condensing units shouldnt run during cold weather at any time for any reason. This is because the oil used for lubricating the compressor doesnt lubricate properly if it is cold. A home air conditioning units lubricant is similar to your cars lubricant. This is why it is best to wait until the weather is warmer before testing your AC.
Why Your Ac Wont Cool Your Home More Than 20 Degrees
You walk out of the sweltering heat outside into your cool, comfortable, air-conditioned home, only to find that its not as cool and comfortable as you had hoped. After spending a whole day in nearly 100-degree weather and high humidity, youre ready for North Pole temperatures. So, you walk over to your thermostat and see that your AC is keeping your home a cool, comfortable 80 degrees? Unacceptable! So you turn your thermostat down to 65 degrees and wait. An hour later you come back and, even though your AC is definitely running, the thermostat still reads 80 degrees.
Before you decide that your AC is broken and call for air conditioner repair in Panama City, FL, we want to reassure you that your AC is not broken. In fact, its doing a great job, considering the fact that it cant cool your home by more than 20 degrees.
Your AC doesnt work that way
If its over 100 degrees outside, were sorry to say your home will never be less than 80 degrees. Why? Because your AC is only designed to cool your home to about 15 to 20 degrees less than the outside temperature. So unless its only 85 degrees outside to begin with, you will never get that cool 65 degrees you want. Your AC is simply not designed to work that way.
More than 20 degrees is too much
Use this knowledge to save moneyand your AC
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Is It Too Cold Outside To Run My Ac
Sharing
An interesting question, asked and answered on The Wall:
Hi All,
Im new here and hope that you can help me with some questions.
I just had a Heil H4A836GKD / FVM4X4800A installed in my home at the very end of March. A couple of weeks ago it was fairly warm for April in New England and our inside house temp was about 75 degrees. Outside temp was about 63-65 degrees maybe slightly lower. Because my wife has bad allergies and I was anxious to try out our new AC I decided to turn it on. It came on for about three minutes, and then it turned off for about two minutes, and then it came back on for about five seconds. This cycle of off for about two minutes and on for five seconds continued. I had my AC on, but my house was getting warmer. I went on the Internet and what I read made it sound like it was cycling and that it was best for me to turn it off and call the company who installed the unit. So I turned it off and called the installer on Monday .
We were told they could come out in a week and a half to test it this was a little annoying considering we had paid good money for this and the first time we go to use it it did not work but it is not the heat of the summer yet so I can be patient. They were supposed to come yesterday but they called and said it will be too cool for them to test because it is setup to not operate below a certain outside temperature .
Does that sound reasonable?
Thanks in advance for your help.
Paul Fredricks comments:
Ken answers:
How Low Should I Set My Air Conditioner
Now that you know how cold your air conditioner can get, you may be wondering how to actually go about determining the right temperature setting. Believe it or not, the U.S. Department of Energy actually has some recommendations in this regard. They say you should set your air conditioner to 78 degrees and turning it slightly lower when youre away from home. The goal is to set your thermostat as high as is comfortable since a lower differential between its setting and the outdoor temperature will, predictably, lead to lower cooling expenses. Keep in mind that, much like when choosing an air conditioner size, you have to adjust for factors such as how shaded your home is. If it doesnt get much direct sunlight, you may be able to run your air conditioner at even less-aggressive settings.
Once you find the ideal settings, consider installing a programmable thermostat that will adjust itself throughout the day based on your routine.
To reiterate a point made earlier, never set your air conditioner to an extremely low temperature thinking it will cool your house down faster. Thats not how it works and youll just end up wasting energy.
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How Much Air Does Your Home Air Duct Lose
In fact, per Energy Star, on average home duct systems lose between 20 and 30% of the air that passes through it air that you have paid to use energy to cool off. Just like a blocked air duct, you should leave a leaky air duct to the professionals.
What should the temperature of my AC be?
Well, theres not a universal, fixed temperature your AC should always be blowing. The temperature your AC puts out is relative to the temperature you set on your thermostat. So even though theres no single ideal temperature, you do want a 16°22° F difference from the supply air and return air.
What Is A Low Ambient Condition

In the HVAC industry, outdoor low temperatures are referred to as low ambient conditions.
In many commercial applications, like manufacturing facilities and buildings with high occupancy, the HVAC system has to operate when temperatures outside are cooler than 60 degrees because of the added heat gain for the conditions. The units are either of special design or a component is added called a “low ambient kit” to assist the unit with operation to safeguard the compressor. So, it is not out of the question for your home’s air conditioner to run without problems when outdoor temperatures drop. You just need to make sure the low ambient component is added to safeguard the compressor.
In most cases, especially in residential applications, you should not run your air conditioner when outdoor temperatures are below 60 degrees. The air conditioner does function, but you are going to burn out the compressor fairly quickly. Our team is ready to assist you if you would like to continue running your air conditioner during cool temperatures outside. The cost of adding a low ambient kit to your system varies but should run below $300.00. Each air conditioner and application is different and whether a kit can be added would depend on the manufacturer.
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Running Ac Below Freezing
Running your AC below freezing comes with risks. If the temperatures are moderately cold, it is perfectly acceptable for AC units to run in different modes. However, if the temperatures are lower than 60 degrees Fahrenheit, using your air conditioner will result in some risks. Here are some of the issues associated with running your AC unit below-freezing temperatures:
- Frozen coiling coils
You might see some water that drips from your outdoor unit when your AC is in use. This water is the condensation from outdoor copper coils. During winter, the condensed water could freeze and accumulate over the coils. Once ice freezes over the coils, the air wont heat up as it is thrown to the room. The louvers will only release cold air.
The outdoor unit might also get damaged if freezing occurs. Running your AC unit when it is frozen might create punctures on the cooling coils that might require replacement soon.
- Loss of lubrication
An integral part of your AC is the compressor and this must be in tiptop shape to continue functioning as desired. Lubricants can help in the smooth operation of the compressor so that it will function with no faults. However, the lubricant may thicken in winter and fail to function as expected. With no proper lubrication, seizure and damage might occur in the compressor.
- Low Ambient Temperature Sensor
- Overheating Compressor
What To Do If Your Air Conditioner Is Not Blowing
Solution: Contact an AC professional to inspect your homes ductwork. A dirty blower, above, can decrease the amount of air that comes through your AC vents. Your air conditioning system relies on a blower to pull in air from your home, run it over the evaporator coil, then push it back into your home as cold air.
Well, theres not a universal, fixed temperature your AC should always be blowing. The temperature your AC puts out is relative to the temperature you set on your thermostat. So even though theres no single ideal temperature, you do want a 16°22° F difference from the supply air and return air.
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Running Ac Under 65 Degrees Useful Facts You Need To Know
This post may contain affiliate links, if you purchase through these links I might earn a small commission. This is at no additional cost to you. See the Disclaimer for full details.
Many people turn on their AC units to stay comfortable when the weather starts getting warmer. But running AC under 65 degrees could cost you more money than necessary. In addition, there are also environmental implications to consider with the amount of energy used as well as potentially damaging your air conditioning unit.
What Should Ac Be Set At Depends On Humidity Levels
The main thing we need to understand when setting an AC thermostat is the effect of humidity on our comfort levels. Humidity levels explain why we generally set the thermostat temperature lower in the summer than in the winter.
Heres the thing:
At high humidity levels, the same temperature feels hotter. Example:74°F feels like 71°F at 20% humidity levels. If the humidity levels would be much higher say 80% 74°F feels like 77°F. Thats a 6-degree difference in how our bodies perceive the thermostat temperature due to different humidity levels.
This Human Temperature chart details how different thermostat temperatures are perceived depending on humidity levels:
This chart gives us an insight into how we can think about what temp should air conditioner be set at.
At a 75°F thermostat setting, our bodies will perceive this temperature as:
- 70°F at 10% humidity levels.
- 72°F at 20% humidity levels.
- 73°F at 30% humidity levels.
- 74°F at 40% humidity levels.
- 75°F at 50% humidity levels.
- 76°F at 60% humidity levels.
- 77°F at 70% humidity levels.
- 78°F at 80% humidity levels.
- 79°F at 90% humidity levels.
- 80°F at 100% humidity levels.
In short, at very low humidity levels, a 75°F AC setting will feel like 70°F. At very high humidity levels, the same 75°F air conditioner setting will feel like 80°F.
For homeowners with ceiling fan: Note that a ceiling fan does not cool the air but it can lower our perception of temperature by as much as 4 degrees, according to the DOE:
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