I love using the air conditioning at home and, just like you, was curious about what uses more electricity – AC or a fan. I wanted to know not just which one uses more but by how much.
So I decided to do real-world measurements and show you which of the two draws the most power. I was pretty darn surprised by what I found!
- Why I made my own measurements
- Products tested
- The results: AC vs fan electricity comparison data
- How air conditioners work
- How fans cool you and your room
- Recommended fans for cooling
Why I made my own measurements
Have you tried figuring out power specifications for air conditioners or fans? If so, you have my sympathy! It’s often a pointless, time-wasting, and confusing process. Even worse, if you find listed specs they’re often not correct. I decided to find out for myself what I was dealing with.
Unfortunately, when searching for power consumption data from manufacturers you’ll find it’s either totally unavailable or somewhat incorrect (based on theoretical estimates). I don’t want to rely on estimates.
It’s rather frustrating to find out that very few if any air cooling product manufacturers offer decent specifications. Most have little to none available in my research.
In fact of the ones that do provide power ratings, often it’s only for the maximum (high-speed) settings. Lower speed settings such as low and medium had no specifications available at all!
Better just to find out for sure
In order to figure it all out and give you the best and most helpful information, I decided to take a hands-on approach.
I measured and compared the power consumption of an air conditioner and a fan that I own. They’re good, typical examples of what many people would buy, and are a great reference point.
For test purposes, I made power measurements using 2 typical products as examples. Left: A 5,000 BTU (small room) budget AC unit, the Emerson Quiet Kool window air conditioner. Right: A typical box fan used for cooling and white noise. Both are good choices as they’re popular and fit the price range many people shop in. They’re also around the same electrical power usage as many similar products on the market.
In order to get real-world data I knew it was important to measure power and collect data from real products in use.
What better way than with 2 of my air cooling products that are very much like the ones you might use? To get good data, I measured electricity used from both my air conditioner and fan for a variety of power and speed settings.
To make it simple for you to see what it all means, I’ve provided a clear comparison graph and a measurement table as well below.
Measuring power use
Rather than guess or rely on questionable manufacturers’ specifications, I used an inexpensive little energy meter to check power consumption. Using the meter I was able to record accurate and reliable data to compare AC and fan power use.
I compared electricity used by recording measurements from a great little Kill-A-Watt P4400 energy meter I picked up. It’s accurate to 2% and is fantastic for monitoring a variety of power supply details including power consumption in Watts.
In the image I’ve provided below you can see for yourself the measurements I took when testing. There’s an amazing amount of difference between the two!
I’ll cover this more in detail later.
From top to bottom: Low, medium, and high settings I measured for power readings. You can see here the power use I observed for the air conditioner (left) and the box fan (right), measured in Watts. Notice how much more electricity the AC unit requires to run when cooling even when on low speed!
The results: AC vs fan electricity comparison data
I already had suspected that an air conditioner would draw more electricity to work than a standard ceiling fan or box fan, but I wasn’t ready for what I discovered!
As you can see below, not only does an AC unit use more electricity, but it requires a huge amount of power compared to a fan. Even when the cooling mode (compressor) isn’t in operation it’s at least almost the same power requirement as a fan at low speed.
How to read the measurements
Don’t worry, it’s actually quite simple! I just want to be sure there’s no confusion about what the numbers mean.
For the air conditioner, two main modes are available:
- Fan only (no cooling): low, medium, and high
- Cooling modes (compressor is in use): low, medium, and high
For the box fan, 3 speeds are available:
- Low, medium, and high
I measured and recorded data for these settings for comparison in the table you see below. “Fan only” means the air conditioner is only powering the fan and isn’t actually cooling the air. While that’s a feature on many air conditioners, it’s not typically used often.
However, I measured the power consumption for those modes as well for reference purposes. I was dying to know more about how much power the air conditioner would draw when not cooling.
The most important values are at the bottom: these are a comparison of the low, medium, and high cooling settings used on both a fan and AC unit.
Those are what you should look at when comparing the two. (Note: “N/A” means not applicable, as a standard fan only has speeds to choose from as opposed to “cool” and “fan only” modes like an air conditioner).
AC vs fan electrical power comparison table
|Measured / Setting
|Fan only (Low)
|Fan only (Med.)
|Fan only (High)
AC vs fan electrical power comparison chart
As you can see in the graph, for similar settings an air conditioner uses a TREMENDOUS amount of electricity vs a fan. So much so that even when the AC unit’s fan is set to low there’s very little benefit – the power draw is within a few watts or so still. You can see how much more efficient a fan is than an air conditioner using my data here. I was blown away by what I measured!
What I discovered from my testing is that not only do air conditioners (yes, it’s very obvious!) use more electricity than fans, but they can use up to almost 9 to 10 times as much as a fan does!
As you can see, it is true that the power use of a ceiling fan instead of AC, for example, is much more budget-friendly for your electric bill.
What surprised me was how much an air conditioner uses when it’s on the low setting. It was only a few watts below medium or high!
Fan only modes
Although air conditioners do have a “fan only” mode, usually it’s simply not helpful to cool you and your room like a traditional fan can.
That’s because (1) the built-in fan has a lower airflow rate than those you buy and (2) they can’t be adjusted to blow air directly where it’s needed for effective cooling.
In the real world, an air conditioner needs to be left in the cool mode in which the compressor is in use. Because a compressor is essentially a motor-driven pump, it requires a substantial amount of power to work and produce cold air.
That’s why air conditioners need so much electricity: they use a compressor to move pressurized refrigerant. This requires a large amount of mechanical force and a substantial amount of electrical energy.
In fact, you can see this happen with a car: using the air conditioner requires the engine to do more work and will increase fuel consumption over time.
How air conditioners work
Indoor air conditioners work by circulating refrigerant which, when forced through an expansion valve, creates a temperature drop that is used to blow cold air into the room. The room’s warm air is pulled out through the front panel and released into the outside. Fans are used to blow cold air into the room as well as blow warm air from the condenser into the outside atmosphere.
Air conditioners work using some amazing – yet extremely important – principles of physics. When a high-pressure liquid (in this case refrigerant circulated under pressure from the AC unit’s compressor) is forced through an expansion valve a large temperature drop occurs.
This temperature drop results in a cold refrigerant side which is piped through a section called a condenser. A high-speed fan, commonly called a blower, then blows cold air into the room.
The existing warm air in a room is also drawn out and blown into the outside air.
Unfortunately, it takes a lot of electrical energy to drive the motor which turns the compressor which circulates refrigerant. That’s a big disadvantage that comes with using an air conditioner.
How fans cool you and your room
Did you know? Fans don’t actually cool the air. They work by blowing across surfaces and removing heat into the nearby air, causing a temperature drop and a cooling sensation. Because they don’t need any heavy electromechanical devices as air conditioners use, they’re much more efficient in terms of electricity use. Note that certain fans are better than others depending upon your needs.
You might not be aware of it, but fans don’t actually cool you by blowing cool air. In fact, fans aren’t designed to drop the temperature of the air around you at all.
Instead, they rely on the concept of forced convection.
What is convection cooling? How do fans cool you?
Does that sound like a strange or somewhat complicated concept? Don’t worry – it’s not. It simply means that forced convection cooling relies on moving air across your body and other surfaces in a room to move heat away into the surrounding air.
By doing so, the temperature is effectively reduced and you feel cooler.
Additionally, fans (depending upon the type, design, and features) can keep the air in a room continuously circulating which will prevent heat from building up.
Because of how they work, fans have to be pointed at the surfaces you want to cool in order to work well. They also will need to run continuously.
Once they’re shut off, the cooling effect stops since there’s nothing to transfer heat away from you.
Fans that have an oscillation mode are especially effective because they can continuously move automatically and blow air within a wide area in a room. Tower fans are especially helpful in this way and are very energy-efficient, too.
Recommended fans for cooling
Tower fans are a unique kind of cooling fan. Because of their tall design, they’re good cooling fans and offer a nice “wall” of soothing air in a room. Most use an oscillating feature to cover a very large area with circulating air for optimal cooling. Many also provide more advanced features that simpler models don’t.
For home cooling purposes, I recommend a tower fan. They’re especially well-suited for cooling you and your room because of their design.
Unlike traditional fans, they have a rotary fan blade design that has a very tall shape. When running they produce a very tall vertical area of air that’s great for cooling.
Additionally, most feature a side-to-side oscillation movement mode which allows them to blow a wide area of air within a room. Unlike standard circular or pedestal fans, they’re often better suited for keeping you comfortable.