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A 5 ton air conditioner is the ideal size for 2500-3000 sq. ft. homes. It will keep your place cool even during those hot summer days. Of course this begs the question of how many watts a 5 ton AC uses.
A 5 ton air conditioner consumes 5000-6000 watts an hour. You can calculate the wattage by dividing its BTU with its EER rating. If the AC is 60000 BTUs with a 10 EER, that would be 60000 / 10 = 6000 watts.
How to Calculate 5 Ton AC Power Consumption
The easiest way to check the power usage of any AC is to look at the manual. There you’ll find its consumption in watts and/or kilowatts. This info is also on the specifications sheet.
If you prefer to do manual calculations the steps are provided here. All you need is some information and a bit of math. You can use this method for any air conditioner.
Follow these steps.
Step 1. Find the Ton ( BTU)
Find out how many BTUs or tons the AC is. You can obtain this in the manual. You can search for this online by looking up the AC make and model.
A 5 ton AC is 60000 BTUs. Use the table below if your AC is a different size.
Step 2. Find the EER
Find the AC EER rating. EER is short for energy efficiency rating. The higher the EER rating the more energy efficient the air conditioner is.
To find the EER of an air conditioner, divide the BTU by its watts. if you have a 60000 BTU running at 5000 watts, it has EER 12.
60000 / 5000 = 12
In other words you just need to divide the AC capacity (BTU) with its power (watts) and you get the EER.
This means that for each watt supplied to the air conditioner, it produces 12 BTU cooling.
But what if your AC consumes 6000 watts? Since 5 ton ACs have a 60000 BTU capacity, we use the same formula:
60000 / 6000 = 10
You get an EER 10 which means the AC produces 10 BTU cooling per watt. This is less efficient than EER 12 which yields 12 BTU per watt. Modern AC units are more energy efficient than older models. If you are going to buy an AC, check its EER rating.
Starting and Running Watts
The figure above is only for the running watts. Air conditioners consume twice that when it starts up. So if your AC uses 6000 running watts, it needs at least 12000 watts during start up. Possibly more.
The older the model the more starting watt power is needed. Some ACs demand as much as four times its running watts. So if you have an old 5 ton unit running at 6000 watts, its startup requirement could be 24000W.
Air conditioners use less watts when running compared to starting because of their on/off cycle. This is similar to refrigerators that have higher startup than running watt requirements.
Can Solar Panels Run a 5 Ton Air Conditioner?
A 5 ton AC uses 6000 watts an hour. You will need 22 x 300W solar panels to run it on solar power alone.
This is only an estimate because there are a lot of factors that affect the power usage of a 5 ton AC. We’ll take a look at them shortly.
If you’re going to run an AC on solar, I recommend Renogy solar panels as these are very efficient and durable. By using the information here you’ll learn how many solar panels are needed.
With other appliances it’s easy because they run constantly. A laptop for example, uses 200-300W an hour. Multiply that by the number of hours you’ll run it and you get an idea how many solar panels are required.
Air conditioners are different because they cycle on and off. To find out its power usage you need to do some averaging.
The easiest way to do this is with the Kill A Watt device. Let it run for 24 hours and take note of the AC power consumption. It will be displayed in kilowatts.
How Many Solar Panels to Run a 5 Ton AC
Generally, each AC ton (equal to 12000 BTU) needs 1200 watts to run. For a 5 ton AC that is 6000 watts an hour.
For this example we will be using 300W solar panels. There are 200-250W solar panels available but 300W is the most popular among homeowners.
You need the following:
- AC power consumption
- Solar panel size
- How many hours you’ll run the AC each day
If a 5 ton AC runs for five hours a day it will use 30000 watts (30 kWh). Since 20 x 300W solar panels can produce 6000 watts an hour, why did I say you need 22 x 300W solar panels?
Because solar panels cannot always produce the output they are rated for. By installing 22 x 300W solar panels, you have additional power in case it’s needed.
Solar panel ratings are based on ideal conditions. Of course that’s not always going to be the case, so there will be times solar panels won’t produce maximum output.
If your AC only runs during the hottest times of the day, you’re in luck because that’s when solar production is at its peak. There’s a good chance you’ll get maximum output or close to it.
But this isn’t guaranteed so it’s better to have more power available. With 22 x 300W panels it can produce up to 6600 watts an hour. So even if the weather is less than ideal there’s still power to keep your AC going.
For this to work your solar panels must be installed correctly and regularly maintained.
Do You Need Batteries to Run a 5 Ton AC on Solar?
Air conditioners don’t just run during the day. Anyone who’s tried to sleep through a hot summer evening knows how much an AC helps.
Whether you need batteries or not depends on your setup.
- If you are on the grid, batteries are not needed. You can use the grid if solar power is unavailable.
- If you are off the grid, batteries are required to store solar power for use when the sun goes down.
Now if your AC is going to run for 6 hours at night, it will use 7200 watts an hour or 43200 watts for 6 hours.
How Many Batteries to Run a 5 Ton AC?
To calculate how many batteries you’ll need, take the number of hours the AC will run when the sun sets.
Next decide what solar battery to buy. You have to look at two elements:
- Capacity (measured in ah)
To find the watts equivalent of amp hours:
volts x amps = watts
A 300ah 12V can store 3600 watts
300 x 12 = 3600
Two of these can store 7200 watts. In reality you need 7 x 300ah batteries to keep a 5 ton AC going for 6 hours.
If we do the math, 6 x 300ah batteries seems enough (7200 x 6 = 43200). But that would be mean fully discharging the batteries which manufacturers don’t recommend.
Lead acid batteries have a 50% depth discharge so you can only use 50% of its capacity. AGM batteries have an 80% DOD and some lithium batteries 85-95%.
When it comes to solar it’s always good practice to have more power available. This is true with batteries as well.
With 7 x 300ah batteries the system can produce up to 50000 watts. Even if you don’t fully discharge them there is plenty of power available.
Don’t forget to use the Kill A Watt as ACs cycle on and off. With plenty of batteries and energy efficient model, your AC might run longer than six hours.
I am an advocate of solar power. Through portablesolarexpert.com I want to share with all of you what I have learned and cotinue to learn about renewable energy.