Many people are already shopping for air conditioners in preparation for the summer season. It might seem early. But, the longer you wait, the more expensive these products become. Moreover, shopping early gives you more time to test multiple products to pick the best one for your needs.
As you compare the different products, we strongly recommend that you consider the wattage too. It might not be the first thing that comes to mind, but, in the end, AC wattage has a massive impact on your energy bills and air conditioning efficiency.
We’ll discuss more on wattage shortly, including how many watts the average air conditioner consumes and steps you can take to minimize your energy usage. But first, the following are six excellent choices when shopping for a low-wattage air conditioner.
Air Conditioner Power Consumption
The air conditioner is used in the home and commercial applications to lower indoor temperatures. These appliances work by drawing hot air from inside the house, extracting the heat, and returning the now-cool air into the house while the heat is dumped outside.
ACs rely on electric power to deliver on this duty. They draw electric power from the house’s supply for two primary purposes, i.e., to power the refrigerant cycle and turn the fans inside the AC.
The average air conditioner running 9-hours/day consumes 3,000 to 5,000 watts during the cooling season, equivalent to 27,000 watts/per hour to 45,000 watts/hour. In the US, the average figure is around 3,500 watts/hour for 24,000 BTU air conditioners.
This consumption rate often means that the air conditioner is the highest consumer of electricity in the average home. A central AC consuming 27,000 watts per day would cost about $3.618 to run per day, assuming the current electricity prices of about $0.13/kilowatt-hour. This translates to over $108/month.
It’s a situation you can’t ignore. Fortunately, there are steps you can take to minimize your spending on AC power. Let’s begin by understanding how much power your AC uses.
How to Calculate Air Conditioner Electricity Usage
The easiest way to determine your AC wattage (how many watts it draws per hour) is to check the Energy Efficiency Rating (EER). The EER rating is the ratio of the air conditioner’s cooling capacity to the appliance’s wattage.
Therefore, a two-ton (24,000 BTU) air conditioner with an EER of 10.0 draws 24,000/10 = 2,400 watts per hour. An 11 EER, 36,000 BTU unit draws 36,000/11 = 3,272.72 watts per hour.
You can also find the wattage rating on the energy label, which now mandatory for all home heating and cooling appliances. Simply check for “STD Input Power” on the label. This is the appliance’s wattage rating.
The “Max. Input Consumption” often refers to the maximum watts it can draw at any point during operation. It’s often only reached during initial startup, and the current draw at the maximum rate only lasts a few seconds. Therefore, it’s irrelevant to your electric bill.
If you can’t readily find your appliance’s wattage rating, simply divide the capacity (measured in British Thermal Units (BTU) for air conditioners) by the EER value. As you can already tell, the higher the EER, the lower the watts consumed per hour.
Average AC Power Usage Across the US
Many calculators have been developed recently to help consumers calculate how many watts their air conditioners use per day. These calculators will even tell you how much you spend on AC cooling per day and month and the likely cost over a full cooling season.
However, if you don’t have the time, the following are the rough monthly AC power consumption estimates across the United States.
- 5,000 BTU (0.41 ton/1.4kW) ACs = 51 to 59 kWh
- 9,000 BTU (0.75 ton/2.6 kW) ACs = 71 to 95 kWh
- 12,000 BTU (1.0 ton/3.5 kW) ACs = 92 to 122 kWh
- 18,000 BTU (1.5 ton/5.2 kW) ACs = 169 to 185 kWh
- 24,000 BTU (2.0 ton/7 kW) ACs = 228 kWh average
Remember that these are averages for very efficient window and mini-split air conditioners. The figures are much higher for larger central air conditioners, which are also traditionally less energy efficient.
To determine the cost of running your AC per day, multiply the kWh figures by the average cost per kilowatt-hour, i.e., $0.134. So, for a 24,000 BTU air conditioner, the average cost of running the AC = 228 x $0.134 = $30.55.
What Affects How Many Watts an Air Conditioner Uses?
The list of factors likely to affect your AC power consumption in the home is virtually endless. However, seven things quickly come to mind;
- The size of the AC: As we’ve seen, the larger the AC, the more power it’s going to consume. A Keeping all else constant, a 24,000 BTU, 10 EER air conditioner will consume 2,400 watts per hour while an 8,000 BTU unit rated 10 SEER draws 800 watts per hour.
- AC Energy Efficiency: Higher efficiency logically translates to lower power consumption. Assuming you’re shopping for a 12000 BTU air conditioner, a 9 EER model would draw 1,333.33 watts per hour, while a 12 EER model draws 1,000 watts per hour.
- The number of people in the room: Humans emit a lot of heat. Therefore a room housing 20 people need more air conditioning than one with two people. The AC running faster to deliver the required cooling in the crowded room means higher energy bills.
- The temperatures outside the house: Air conditioners run more when it’s hotter outside. Why? Because some of the outside heat always finds a way indoors. It takes a lot more effort to cool a hotter room down to the desired temperatures.
- The size of the room: Larger rooms demand more air conditioning. Why? Because a larger room has a greater volume of air inside. Raising the temperature of a larger volume of air takes more effort and likely more time. An AC running faster, for longer means more electricity is used.
- Electrical appliances in the room: All electrical appliances in the house emit heat, including the refrigerator and energy-saving lights you just acquired recently. The more electrical appliances you have running, the more the AC needs to work to cool down the house.
- Other objects in the room: All other objects in the room, including furniture, such as chairs, and the clothes we wear, all absorb heat and become a little too warm for our liking during the sunny season. The number of such objects in your home will determine how much air conditioning is required to achieve the desired indoor temperatures.
Lowest Wattage Air Conditioner Reviews
1. Pioneer Air Conditioner WYS012A-19 Wall-Mount Ductless Inverter + Mini Split
Let’s kick off with the majestic model WYS012A-19, 12,000 BTU mini-split from PIONEER. The first thing you need to know about the model WYS012A-19 is that it’s an ultra-high efficiency inverter+ ductless mini-split rated 19.5 SEER and 9.5 HSPF. The HSPF rating means it generates 9.5 BTU per watt, which is one of the highest performances.
The mini-split’s key features include a smart control board for convenient remote control and a built-in follow-me temperature sensor in the remote controller that senses the surrounding temperature and automatically adjusts the room temperature for maximum comfort. It also features refrigerant leak detection capabilities and an anti-cold function to prevent discomfort.
The mini-split is very silent at 28 dB (low speed) and features three operating speeds. The outdoor unit is rated 55dB. With a low ambient cooling temperature of -15˚C, it will continue adding heat to your home even in the middle of winter.
It arrives with a complete 16-foot installation kit with flare connections, interconnecting signal wiring, and a wall sleeve liner and cap. Putty, wrapping tape, and drain line extension are also included. It’s recommended for 350-450 square feet.
- It’s an AC, heater, dehumidifier, and ventilator
- Smart auto restart function
- Includes Night and Auto mode
- 5-year parts, 5-year compressor warranty
- No smart/Wi-Fi/App control
2. Frigidaire FFRA0511R1E 5,000-BTU 115V Window-Mounted Air Conditioner
This second option, the Frigidaire FFRA0511R1E, is a window-mounted air conditioner (the window mounting kit is included).
The 5,000-BTU air conditioner plugs into the standard 115V electrical outlet and cools quickly, reaching up to 136 CFM and 1,1 pints per hour in humidifier mode. It has two cool speeds, two fan speeds, and boasts bi-directional airflow.
It’s very energy efficient at 11.1 EER and 11.0 CEER. Indeed, it only consumes 450 watts at 4 amperes. The noise performance is another standout point. Though most window air conditioners tend to be a tad noisy, this model operates at about 56.5 dB at the highest speed and can be as quiet as 50 dB in the low-speed setting.
You can easily change/adjust the speed settings via the two mechanical control knobs found on the left-hand side. The knobs are clearly marked for your convenience. It features an antimicrobial mesh filter with side/slide-out access for easy maintenance. The filter is washable.
This AC is designed for 23-36-inch windows (about 13 inches high) and comes sealed with prop 65 Labeling. It’s also approved by the UL and CUL. The manufacturer offers a 1-year parts/labor warranty and a 4-year warranty on the sealed system.
- Powerful 5,000 window AC + humidifier
- Quiet, energy-efficient performance
- CL and CUL approved
- 4-year warranty on sealed system
- No remote/smart control
- No Sleep or Quiet Mode
3. SEVILLE 9,000 BTU SENA-09HF/Z Energy Star Mini Split Air Conditioner
This AURA Series 9,000 BTU unit is another worthy option when shopping for an air conditioner with low wattage. The SENA-09HF/Z is an Energy Star Certified air conditioner and heat pump that you can rely on for all-year comfort. It’s rated 25 SEER (CEE tier 3), meaning it saves 58% of energy costs than a 10 SEER appliance. The heat pump is rated 8.6 HSPF5.
There’s plenty more to love about the SENA-09HF/Z AC+ heat pump. For instance, it features an in-built humidifier function that removes excess moisture at 1liter/hour.
It can also operate as a fan. Remember that all four functions can be used separately. An auto-switch mode (cooling to heating and back) is available. A turbo Mode is also available for accelerated cooling.
It’s an extremely quiet air conditioner, rated at 45 decibels for the max speed level (24.5 for the Low-speed level). Meanwhile, the outdoor unit is rated 55dB. With built-in Wi-Fi compatibility and control from an Android or iOS app, you can control the air conditioner from virtually anywhere.
The 620-watt (cooling) appliance arrives with all the necessary installation accessories, including a pre-charged 16-foot connection kit with a wiring harness. It’s ETL and AHRI approved and backed by 3-year parts and a 7-year compressor warranty.
- It’s a 4-in-1 AC, heat pump, fan, and dehumidifier
- Smart control with Android/iOS app
- Includes pre-charged 16-foot installation kit
- 3-year parts, 7-year compressor warranty
- Best for small-space applications (100-250 sq. Ft.)
4. MRCOOL DIY 12K BTU 22 SEER Ductless Heat Pump Split System
Designed for 500-600 square-foot rooms, this 3rd Generation MRCOOL is another low-wattage air conditioner. It also functions as a heat pump. The unit has a capacity of 12,000 BTU and features an auto-start feature such that cooling/heating operation is resumed at the previous settings in the event of a power outage.
It’s a very efficient air conditioner, rated 19 SEER and 10.0 HSPF. More importantly, it boasts multiple intuitive features for your convenience. An Auto Mode allows it to automatically choose the best cooling or heating level based on the ambient room temperature.
Meanwhile, a Sleep Mode allows you to program the system for energy-saving heating/cooling overnight. The extra low ambient cooling temperature, i.e., 5˚F, is worth highlighting.
Other key features of the air conditioner mini split include follow-me remote control, remote app Wi-Fi control, and louver position memory.
Air filter cleaning and replacement alerts notify the user to clean the AC (after every 240 and 3,000 hours of use, respectively). It also features an automatic leak detection function that alerts you in case of a refrigerant leak.
The durable mini-split features a gold fin condenser for a long life of reliable use. It’s backed by 5-year parts and a 7-year compressor warranty.
- Voice control with Alexa and Google Assistant
- Very efficient at 19 SEER, 10.0 HSPF
- Installation kit includes 25-foot pre-charged line set
- 5-year parts, 7-year condenser warranty
- The cheap line guard set
5. BOSCH Ultra Quiet 12K BTU 230V Mini Split Air Conditioner & Cooling System
The Generation-2 Model 8733948004 BOSCH is a reliable, energy-efficient 12,000 BTU air conditioning and home heating solution. The 22-SEER, 12.5 EER appliance features a sleek indoor air handler and a compact outdoor condenser.
The required 16-foot connecting line set is included, as are the other necessary installation components. The line-set is pre-charged with refrigerant to make your work easier.
It installs effortlessly and is perfect for spaces where you cannot have ductwork. Once installed, the energy-saving features ensure that you’re paying very little for power consumption.
The 12k BTU cooling capacity means it’s sufficient for spaces up to 400 square feet, while the powerful 9.6 HSPF heat pump remains reliable down to -13˚F. Cooling goes on up to 122˚F.
Other key features of the mini-split include a wireless back-lit remote with a follow-me function and Silent mode. These two functions greatly enhance convenience. You’ll also love the timer function (for programmed heating and cooling) and Turbo Mode setting for ultra-fast cooling and heating.
It has three-speed settings – Low (165 CFM), Medium (229 CFM), and High (271 CFM) and is very quiet at 26 dB (Low) and 39 dB (High).
Remember that this is a 230-volt appliance. Therefore, some electrical wiring may be required. It’s backed by 5-year parts and a 7-year compressor warranty.
- Energy-efficient 22-SEER, 9.5 HSPF mini split
- Follow-me remote control
- Very quiet at up to 26 decibels
- 5-year parts, 7-year compressor warranty
- Professional installation required
- No smart/app control
6. KEYSTONE 6,000 BTU 115-Volt Portable Air Conditioner
Finally, the model KSTAP06D Keystone AC is a 6,000 BTU 2-in-1 air conditioner and dehumidifier designed for spaces up to 200 square feet.
It features three modes to keep you comfortable – cool, fan, and dry and comes with manual front louvers for air direction. An LED screen with touch buttons and a remote control device make it easy to adjust and change the settings.
It’s a reasonably powerful unit at 170 CFM. Convenient Low and High-speed settings allow you to adjust the performance for optimal air conditioning. It’s also moderately quiet at 50 dB on Low setting, though we believe the manufacturer could do better. However, a Sleep Mode setting that’s even quieter is available for a peaceful sleep.
There are many other features to like about the model KSTAP06D Keystone. These include an automatic restart function that restores previous settings if the power goes out and omnidirectional caster wheels to roll the unit easily from room to room. It also has a timer for programmed air conditioning and utilizes washable air filters for your convenience.
The 8.9 EER air conditioner conveniently plugs into the standard 115V power outlet and consumes a paltry 676 watts. Although it’s not Energy Star certified, it is UL listed. Each purchase is backed by a 5-year sealed system warranty and a 1-year parts/labor warranty.
- Portable with casters for mobility
- Uses washable air filters
- Functions as a dehumidifier
- UL listed for safety
- 5-year sealed system warranty
- Not ideal for large spaces
Air Conditioning Tips to Save Energy
Your heart is likely racing after seeing the figure above. There’s no need to panic. You can take several steps to minimize your AC power usage and consequently reduce your spending on air conditioning.
Buy the right size AC
As we’ve seen, air conditioner sizing is critical. You must pick the right size for your application. Otherwise, you’ll see a high energy bill every month for no good reason. As a rule of thumb, you need 20 BTUs for every square foot. This translates to 12,000 BTU for the average 600 square-foot room.
Buy an Energy-Efficient AC
Air conditioner energy efficiency is measured in many different ways. The two most important are the Seasonal Energy Efficiency Ratio (SEER) and Energy Efficiency Ratio (EER). You want to go as high as possible in both cases. If you can find an 18+ SEER unit rated at least 11 EER, it would be a good buy.
Inverter ACs are the better choice
You’ve likely heard about inverter air conditioners. Unlike standard air conditioners that are either off or operating at 100% capacity, inverter ACs cycle on and off without shutting down the AC to maintain the thermostat temperature with the highest efficiency. The best part is that the on-off cycling happens automatically!
Insulate your house
A poorly insulated house that leaks air from every corner will likely require more air conditioning in the summer, just as it would do heating in the colder months. If you want to use less electricity, consider insulation. Ideally, consider hiring an HVAC professional to measure the R-Value (insulation rating) and keep on insulating to achieve a higher R-Value.
Pair the AC with a Fan
Although the air conditioner can work independently to achieve the desired cooling conditions, a standby fan can help a lot, especially in larger rooms. Fans create a cooling effect without consuming much power and allow you to turn up the thermostat, even if slightly, to reduce air conditioning costs.
Set the thermostat wisely
Sometimes it’s all about the temperature setting on the thermostat. If the setting is lower, the air conditioner will work harder, resulting in increased power usage. Lower settings also mean the thermostat runs on longer. Some studies show you could waste as much as 16% for every degree Celsius that you turn down the thermostat below 25%.
Cool only areas you need to cool
There’s no need to cool areas of the home that you’re not actively using. If you’re not using the garage, don’t cool it. If you’re not actively using the basement, don’t pump too much cool air there. Also, don’t turn on the AC when entering a room if you’re only going in there for a few minutes. It’s a complete waste. You only want to cool areas that you’re actively using.
Air conditioning power usage is a sensitive topic and an important one, too, given that cooling and heating contribute to more than 50% of energy costs in the home. Some people end up paying $100+ each month on cooling alone.
If you believe this is money you can put to better use, take action today and invest in a low-wattage AC for higher energy savings and lower cooling costs.