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Should an Air Conditioner Be on Auto or Fan?


As the summer season is slowly approaching, most of us are worried about what to do with the heat. Knowing which aircon setting is suitable for the weather and raising it to the right temperature setting will help keep us cool and comfortable. This leads us to the question, should the air conditioner be on auto or fan?

Before anything else, here’s your ultimate guide to which thermostat setting can help you beat the heat.

What Do These Settings Mean?

auto or fan setting

You have two air conditioner settings to consider: auto or fan. These thermostat settings control the AC blower fan in the air handler located inside your AC system. The blower fan pulls the warm air into the air conditioner for a cooling effect, then blows the produced cool air back to your home.

Basically, it helps circulate cold air throughout your home.

If you turn on the fan, the AC will constantly blow air even when the air conditioning system is off. Meanwhile, selecting the automatic thermostat setting means the fan will automatically run and shut off when the set temperature is reached.

The difference between the auto and fan lies in how the blower fan is operated. It can further be differentiated through its effect on your air conditioner, surroundings, and overall living condition.

Auto or Fan: What is the Right Setting For You?

There are many factors to consider when choosing the right air conditioner setting for your home. While both may have their own advantages and disadvantages, it is important to know which suits your living condition the most. 

To know what’s right for you, start by weighing your options. 

Fan Setting 

There are situations where it is necessary and more beneficial to use the fan setting. Here are some of the considerations to take note of when you keep the AC fan on:


Evenly Distribute Heating and Cooling

As the air conditioner constantly blows air, it can keep the temperature inside your home consistent and balanced.

Provide Clean Indoor Air

Your home’s air filtration system can be used to ensure that the air inside your house is clean. The airborne particles, like dust and dirt, can easily be pulled by your air conditioner filter.  

Extend the Lifespan of the AC Fan

Since the fan is running, your AC fan will have fewer stop-and-start cycles. As a result, the air conditioning system can exert little to no stress to start its cooling process. 


Consume Higher Energy

If the fan is always running, you can expect an increase in your electricity since it needs to keep the fan running all throughout. This will cost more money rather than help you save. 

Increase Humidity in Your Home

Your house will feel humid since the fan setting does not remove moisture from the air. This can cause moisture to build up on your window and, even worse, mold issues.

May Clog Air Handler

As the air flows constantly, it can clog the filter of your air handler more often. As a result, you may need to clean or change the filter consecutively or within a short period of time.

Auto Setting 

If you’re someone who would like to conserve energy, the automatic setting is definitely for you! Here is a list of the advantages and disadvantages of the automatic setting. 


Consume Lower Energy

The automatic setting will help you lower your electricity bill as the air conditioner will only run when needed and turn off when it reaches the set temperature. 

Control Humidity in Your Home

Acting as a dehumidifier for your home, the automatic setting can take the moisture from the cooling coils and eventually drain and drip it outside.

Reduce Wear and Tear on AC Components

Unlike in the fan setting, air filters do not need to be cleaned or changed from time to time since the components are not worn out from running constantly.


Develop Hot-and-cold Spots

As the system shuts down once the desired temperature is reached, it is relatively harder to cool all rooms or the entire house in the same manner. This results in less even air distribution in your home.

Increase in System Stress

If you put too much stress on your air conditioning system, it can easily break or malfunction. That said, the frequent starting and stopping of the AC fan can cause this system stress.

Final Thoughts

Setting your thermostat to auto or fan setting can make a huge difference to your comfort, electricity bills, and even the lifespan of your air conditioner. 

In short, you must use the automatic setting if you want to save energy and money. On the other hand, turn your fan on if you want to have cleaner indoor air.

The bottom line is that you should be able to choose the thermostat setting that best suits your preference and your living conditions.

Do you enjoy reading our guides? For more air conditioner tips, you can check our website, Aircon Experts.

JP Reyes

JP has been in the aircon industry for almost as long as he has been alive. As a child JP would help his tatay fix aircon units at their junk shop in Cavite. After graduating UP in the early 2000's, JP then started his own Aircon servicing business and within 5 years had 10 shops in 8 different cities. Fast forward to today and JP brings all his experience and expertise online to give readers trustworthy advice and reviews about Air-conditioning buying, servicing, cleaning and repair in the Philippines.

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