Thinking of installing a Window AC? Or you want to know how many watts does a Window AC use? Nowadays, saving energy costs wherever possible is important, and a Window AC is much more affordable than a central AC or split AC.
Moreover, Window ACs are a great option because you need a good window; they don’t take up a lot of space and can fit into compact places. They don't come with separate outer units; everything a Window AC needs is inside one unit. Plus, it’s really portable.
Our guide has everything you need to know about using Window AC, electrical units, and an AC with a solar generator. If you have solar generator like the BLUETTI AC200P, that’s all you need to run your AC with the solar generator.
Key Terms: BTU, Watts, Running Watts, Rated Watts, Watt-Hours
BTU: Referred to as a British Thermal Unit, BTU measures the heating or the cooling output of a HAVC system, like an AC, furnace, or heater. Simply put, 1 BTU is the energy you need to lower the temperature of 1 pound of water by 1 Fahrenheit.
Watts: It’s the rate of energy consumption or production. We multiply amps with volts to find wattage. Watts = Amps x Volts.
Running Watts: The amount of continuous watts that keep an appliance. It’s the watts that an appliance needs to operate normally. It’s the real consumption of electricity at any given time.
Rated Watts: It’s the electricity consumed when the Window AC Unit is running at full cooling capacity,
Watts-Hours: It’s the watts consumption over a period of time. An AC that uses 1000W for 6 hours will have used 6000-watt-hour. Watts-hour = Watts x Hours.
How Many Watts Does A Window AC Use?
How many watts does a window AC use depends on a few factors, like the size of the AC, the outside temperature (hot or moderate), and the room size.
A small window AC uses around 500 watts, while a medium-sized one uses 900 watts, and a larger window AC can use 1440 watts or more. An average window AC at 5000 BTU (or 1465.36W) consumes 500W of energy at full capacity. It consumes 11720 watts-hour power in 8 hours.
The below table shows the estimated wattage against BTU and 9 hours for 3 different window ACs:
AC BTU |
Estimated Wattage Daily |
KiloWatts-Hour for 8 hours period |
500 |
147 |
1176 |
2000 |
586 |
4688 |
8000 |
2345 |
18760 |
How to Calculate the Power Consumption of a Window AC?
Before powering an existing window AC unit with solar power, you need to find out the Window AC power consumption. You can convert the BTU values into watts or multiply amps with volts. KWh is the unit your bill comes in. Follow the below steps to find your power consumption in kWh, and we will calculate the total cost from the kWh value.
Finding Window AC Wattage:
We can use two methods to find the wattage of a Window AC.
BTU to Watts:
1 BTU=0.29307107018321 watt-hours. Let us assume your Window AC has a BTU rating of 5000 BTU/hour.
Watts = BTU x 0.29307107018321
5000 x 0.29307107018321 = 1,465.355W.
Multiply Ampere by Voltage:
A device operating on 12.21A at 120V would consume Watts = Amps x Volts
12.21 x 120 = 1,465.355
Convert to KiloWatt and KiloWatt-hour:
Watts to KiloWatts
- kiloWatts = watts / 1000
- 1,465.355/1000 = 1.465 kW
KiloWatts to KiloWatt-hour:
- Kilowatt-hour = kiloWatts x hours
- 1,465kW x 6 hours = 8.79kWh per day
Total Cost of Power Consumption:
Multiply kWh by the rate of electricity in your state. We assume it is $0.12 per kWh
Daily Cost = Energy consumption x Cost per kWh
8.79kWh x $0.12 = $1.055 per day
You can check to get an estimate of the daily cost by looking at the amperes or the wattage. Still, the BTU to kWh conversion gives us a much clearer and more accurate value.
Tips for Reducing Window AC Energy Usage
After determining your Window AC’s power consumption, the next step is to adopt effective tips to reduce energy costs.
Regular Maintainance and filter Cleaning:
Regular maintenance and cleaning of the filter results in more efficient cooling. It works more effectively when your AC doesn’t have to worry about blocked airflow or dirty vents. Always clean the filters regularly and make sure nothing is clogging them.
Plus, don’t skip out on regular maintenance due to the added expense. AC technicians fix worn-out electronic components, replace wires, and clean components. All this makes your AC maintain its cooling capacity.
Proper Installation:
Make sure that your AC is properly installed. It should be level so that it drains correctly, and follow the user manual to place it in such a way as to avoid outside air intrusion, or hire a professional for this job.
Avoid Direct Sunlight on Window AC:
You have to make sure that your Window AC outdoor unit isn’t installed in direct sunlight. Also, the room where you’ve installed your AC should have fewer or smaller windows to minimize sunlight and hotness in the room. Direct sunlight and a hot room increase the performance load on your AC, reduce efficiency, and increase power consumption.
Set Suitable Temperature on Thermostat:
Instead of setting your AC at 24 or 26, place it at a comfortable temperature like 26 or 29. The lower the thermostat setting, the less power consumption your AC takes. So setting it up a few degrees, between 26-29, will consume less electricity than your AC at 24.
Room Setting:
Make sure that all gaps, like under the door, windows, etc., are properly sealed to prevent warm air from coming inside. Moreover, you should use thermal curtains or blinds on your windows. This will help prevent sunlight from penetrating easily and keep the room cool.
Similarly, it’s a good idea to have ceiling fans in your room, too. Ceiling fans help to distribute the cold air and keep your room cooler even at a lower AC setting.
Programmable Stopping Timer:
If you’re AC has a smart thermostat, you should train it to turn off when no one is in the room and maintain an appropriate temperature at all times. You can program it to turn off when you leave and start around when you return home. Smart thermostats and programmable timers help you save on Window AC energy costs and help you reduce your electricity bill.
Upgrade to a New AC:
Is your AC Ancient? Well, if you’re serious about cutting down on energy costs, it’s time to say goodbye to your old AC. Look for newer models of Window ACs with ENERGY STAR labels that are more energy-efficient and will lower your power consumption. And you can look for ACs with smart thermostats and programmable timers.
How Many Watts of Generator Do I Need for a Window AC?
With the ever-increasing cost of electricity and power outages, it doesn’t hurt to have a backup power option for your Window AC. Moreover, instead of petrol or diesel generators, you should opt for solar generators.
Solar Generators like BLUETTI AC200P + 3*PV200 Solar Generator Kit is friendly to the environment, noise-free, and cost-effective in the long term. It has a 2000 Wh capacity, 4800W surge, 17 outputs for multiple devices and seven different ways to recharge, via AC or solar or car, etc.
Whatever generator you choose should be able to stand the wattage of your AC, and so a generator should have a higher wattage than your AC. You can run a medium Window AC unit with a 1000-watt generator. Still, for a larger unit, you should go for a 2000-watt Solar Generator.
Plus, you have to consider the battery capacity because you have to take care of power consumption over time. A battery capacity of 1500 watt-hours will run a Window AC at 600W for only 6 hours, so battery capacity matters.
After determining that your desired solar generator uses higher watts than your AC unit (both starting and running watts), divide battery capacity in watt-hours with the AC power consumption in watts to get the duration of time.
Time (hour) = battery capacity (watts-hour) / power consumption (watts)
If you want to increase the battery capacity of your current solar generator, you can look up the BLUETTI B300 Expansion Battery. It has a 2000W maximum loading scale, 100W USB-C, a USB-A port, and 12V/10A car output, and so much more. But make sure your solar generator supports an extension battery.
Final Thoughts
Now you know everything there is to know before buying a solar generator for your window AC unit. Don’t have a Window AC? Think again. Investing in a modern, ENERGY STAR Window AC will reduce your energy consumption.
And, pairing it up with a solar generator is the icing on the cake. Even after going solar, you still need to regularly maintain and clean your AC and follow evergreen tips to reduce power consumption and live more energy-efficiently.
FAQ:
Q. Will a 2000-watt generator run a window air conditioner?
If your AC has a starting wattage below 2000 watts, a 2000-watt generator can run your window AC. Window AC has a starting wattage 2-3 times higher than the running wattage, but that’s just the initial wattage it needs to turn on. Always check your AC specification to prevent cause for overloading.
Q. How much electricity does a 10000 BTU window AC use?
An AC at 10000 BTU typically uses around 700-1200 watts per hour when running. To find usage in kilowatts, multiply wattage by duration and divide by 1000. If your 10000 BTU AC uses 1000 watts for 5 hours, it would consume 5kW power. You should always check the AC specifications and consult your electricity bill for estimated appliance costs.
Q. Does a window AC use a lot of electricity?
Compared to central AC units, a Window AC doesn’t use that much electricity. On average, a window AC requires 500-1440 watts, while a typical central AC uses 3500+ Watts. However, a Window AC can use more electricity on hot days, and continuously using it can increase costs, too. If properly maintained, a Window AC is a cheaper option.
Q. Does window AC consume more electricity than split AC?
Generally speaking, Window AC consumes more electricity than split AC due to some factors. Split AC has an advanced design and better heat exchange systems that allow it to cool a room quickly. In contrast, Window ACs have all their components, like the compressor, in a single unit, which can lead to inefficient cooling and more power consumption.