In this article, I’ll be talking about the power usage, energy consumption, running costs, and amp draw of 15000 BTU RV air conditioners.
Whether you’re looking to size equipment, such as solar panels, batteries, an inverter, or a generator, or you simply need to know the expenses of running your RV air conditioner, this article will provide all the examples and estimates you’ll need.
Let’s get started.
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How many watts does a 15000 BTU RV air conditioner use?
Generally speaking, a 15000 BTU RV air conditioner uses about 1400 to 1800 Watts of power when both the fan and the compressor are running. However, the exact power usage of the RV AC will generally depend on the age and efficiency of the model.
To figure out the power usage of the RV air conditioner, you can use two important electrical details: the Voltage (Volts) and the Total Amperage (Amps) of the unit.
You can usually find these specifications on the nameplate attached to the side of the air conditioner. To calculate the power usage, you just multiply the Voltage by the Total Amperage:
Power Usage (Watts) = Voltage (Volts) x Total Amperage (Amps)
To give you an example, here’s a nameplate of a 15000 BTU rooftop RV air conditioner:
If we look at the specifications provided by the manufacturer, we can see that a typical voltage of 115 Volts is specified, along with a few Amperage ratings.
Now, when the air conditioner is providing cool air, 2 of its components are doing work:
- The Compressor, which compresses the refrigerant and facilitates heat exchange.
- The Fan Motor, which in this case, drives both the condenser fan and the blower fan.
In the case of our example, the compressor has an RLA (Running Load Amps) rating of 10.9 Amps, and the fan motor has an FLA (Full Load Amps) rating of 2.8 Amps.
The blower fan’s amperage is not usually specified on the same nameplate, however, it’ll likely have the same amperage as the condenser fan (2.8 Amps).
So, when the air conditioner is in cooling mode, the total amount of current (Amps) that it draws is:
Total Amperage (Amps) = Compressor RLA (Amps) + Fan motor FLA (Amps)
Total Amperage (Amps) = 10.9 Amps + 2.8 Amps
Total Amperage (Amps) = 13.7 Amps
To determine the Power usage of the 15000 BTU air conditioner in cooling mode, we’ll simply multiply this total amperage by the voltage of the unit:
Power Usage (Watts) = Voltage (Volts) x Total Amperage (Amps)
Power Usage (Watts) = 115 Volts x 13.7 Amps
Power Usage (Watts) = 1,575.5 Watts
Notice that the manufacturer also specifies that the amperage of the “Optional Electric Heater” is 13.2 Amps.
If you choose to use the RV AC’s heating option, the 2 components that’ll be drawing current are the heating element and the blower fan. Therefore, the total amperage of our 15000 BTU RV AC in heating mode is:
Total Amperage (Amps) = Electric Heater Amps (Amps) + Blower’s Fan Motor FLA (Amps)
Total Amperage (Amps) = 13.2 Amps + 2.8 Amps
Total Amperage (Amps) = 16 Amps
The power usage of the RV AC in heating mode is:
Power Usage (Watts) = Voltage (Volts) x Total Amperage (Amps)
Power Usage (Watts) = 115 Volts x 16 Amps
Power Usage (Watts) = 1840 Watts
Now, either way, what we’ve just calculated is the running wattage of the air conditioner. However, it is important to note that in cooling mode, your 15000 BTU RV air conditioner will require a higher amount of power to start up.
The reason behind this is that the AC’s compressor, like any other device with a motor, experiences what is known as “Surge Wattage,” “Starting Wattage,” or “Peak Wattage.” This surge in power consumption lasts only for a brief moment, but during that time, it can be 3 to 7 times higher than the normal running wattage.
In this case, the starting wattage of this particular 15000 BTU AC is close to 6 times its running wattage.
But, how do we know that?
Well, let’s take a second look at the nameplate from our previous example:
Notice that the manufacturer specifies a certain “Compressor LRA” of 60 Amps.
LRA stands for “Locked Rotor Amps”, and what that means is when the compressor is trying to start, it will sometimes require up to 60 Amps of current to “unlock” its rotor.
This surge in amperage causes a surge in power usage, which can be calculated as follows:
Compressor’s Starting Wattage (Watts) = Voltage (Volts) x LRA (Amps)
Compressor’s Starting Wattage (Watts) = 115 Volts x 60 Amps
Compressor’s Starting Wattage (Watts) = 6900 Watts
According to our calculations, the compressor might require as much as 6900 Watts during start-up. However, when you turn on the AC, the fan motor, which can draw up to 322 Watts (2.8 Amps x 115 Volts = 322 Watts), will kick on first.
This means that the actual “potential” starting wattage of the AC is:
Potential Starting Wattage (Watts) = Compressor’s Starting Wattage (Watts) + Fan Motor’s Running Wattage
Potential Starting Wattage (Watts) = 6900 Watts + 322 Watts
Potential Starting Wattage (Watts) = 7222 Watts
Now, in reality, this 15000 BTU air conditioner’s starting wattage will typically be closer to 3500-4000 Watts, but if for any reason the compressor’s rotor gets locked, the AC might require the full 7222 Watts to start up.
Please note that the Running, and Starting wattage of your 15000 BTU RV air conditioner should both be taken into consideration if you’re trying to size an inverter or a generator that can run the AC.
For example, a 2000 Watt inverter like the Renogy inverter might be able to run the air conditioner, but since it only has a Peak Power rating of 4000 Watts, it may have problems starting the AC down the road.
On the other hand, there are 4000 Watt inverters available with a Peak Power rating of 8000 Watts or more. These inverters not only have the capacity to run the air conditioner but also provide enough power to start it smoothly.
Click here to learn more about sizing an inverter for your RV air conditioner.
When it comes to generators, similar considerations apply. For instance, the Honda EU2200ITAN generator has a rated output of 1800 Watts and a Peak output of 2200 Watts. While it might be able to handle running a 15000 BTU RV air conditioner, it might struggle with the startup process.
In contrast, a larger generator like the Westinghouse generator, with its peak wattage of 7500 Watts and running wattage of 6000 Watts, will certainly be able to start and continuously run the air conditioner without any issues.
However, if you don’t really need the extra 4000 Watts and the added weight of 150 lbs, a more advantageous option to consider is using a Soft Starter device.
A Soft Starter device, like the SoftStartRV or the EasyStart, can effectively limit the inrush current that your air conditioner draws when starting up. The high initial demand of 50 – 60 amps and 5500 – 7000 Watts, potentially to start the RV AC unit, is reduced to about 20 Amps and 2500 Watts.
Now that we’ve covered the Power Usage (Watts) of 15000 BTU RV air conditioners, let’s shift our focus to their Energy Consumption (kWh).
How much electricity (energy) does a 15000 BTU RV air conditioner use?
The actual amount of electricity that an appliance consumes over a specific period is known as Electrical Energy, measured in Watt-hours (Wh), or more commonly, kiloWatt-hours (kWh) where 1 kWh is equal to 1000 Wh.
The energy usage of an RV air conditioner over a certain timeframe depends on various factors such as:
- The outdoor temperature.
- The temperature setpoint.
- Insulation quality.
- And the age and efficiency of the air conditioner.
However, as a general estimate, a 15000 BTU air conditioner typically consumes about 1.2 kWh (1200 Wh) of energy per hour of operation. So, if you run the RV AC for 8 hours daily, it will use around 10 kWh of energy each day.
The daily energy consumption of your RV air conditioner will be key if you’re planning on running the air conditioner on solar panels or batteries. This is because these types of equipment are sized based on energy consumption (kWh) rather than Power Usage (Watts).
As I explain in the next section, the energy consumption of your 15000 BTU air conditioner can also be used to estimate the cost of running the AC.
A quick way to estimate this energy consumption is to use the following rule of thumb:
Energy Consumption (kWh) = (Power Usage (Watts) x Usage Duration (hours) x 0.8) ÷ 1000
For example, let’s say that your 15000 BTU air conditioner has a power rating of 1600 Watts. Let’s also make the assumption that you typically run the AC for 6 hours a day.
The daily energy consumption of the air conditioner can be estimated as follows:
Daily Energy Consumption (kWh) = (Power Usage (Watts) x Daily Usage Duration (hours) x 0.8) ÷ 1000
Daily Energy Consumption (kWh) = (1600 Watts x 6 hours x 0.8) ÷ 1000
Daily Energy Consumption (kWh) = (7680 Watt-hours) ÷ 1000
Daily Energy Consumption (kWh) = 7.68 kWh
Now that we have some perspective on the energy consumption of these air conditioners in kWh, you might also be interested in the electricity costs associated with that.
How much does it cost to run a 15000 BTU air conditioner?
With an average energy consumption of approximately 1.2 kWh per hour and based on the U.S. national average cost per kWh of around 16 cents, running a 15000 BTU RV air conditioner will amount to about 20 cents per hour.
If we assume the same hourly energy consumption, cost per kWh, and a daily usage duration of 8 hours, the RV air conditioner will cost approximately $1.6 per day to run or approximately $47 per month.
However, it is important to note that the exact cost of running the RV AC over a specific period will depend on the exact energy consumption of the air conditioner during that timeframe, as well as the exact electricity rates in the area.
This can be expressed as follows:
Cost ($) = Energy Consumption (kWh) x Cost per kWh ($/kWh)
For example, let’s say your air conditioner has an average energy consumption of 1.4 kWh an hour, and let’s assume that you typically run it for 8 hours a day. The daily energy consumption of the AC is:
Daily Energy Consumption (kWh/day) = Average Hourly Energy Consumption (kWh/hour) x Daily Usage Duration (hours/day)
Daily Energy Consumption (kWh/day) = 1.4 kWh/hour x 8 hours/day
Daily Energy Consumption (kWh/day) = 11.2 kWh/day
Let’s also make the assumption that the RV is plugged in somewhere in Alabama, where according to the EIA (Energy Information Administration), the average cost per kWh is 14.5 cents/kWh ($0.145/kWh).
With these assumptions in mind, the daily cost to run the air conditioner can be calculated as follows:
Daily Cost ($/day) = Daily Energy Consumption (kWh/day) x Cost per kWh ($/kWh)
Daily Cost ($/day) = 11.2 kWh/day x $0.145/kWh
Daily Cost ($/day) = $1.62 per day
Now, to save you some time, I’ve put together a calculator that estimates the daily and monthly cost of running your 15000 BTU RV air conditioner based on its daily usage (in hours), and on the location of the RV:
How many amps does a 15000 BTU RV air conditioner use?
In general, a typical 15000 BTU RV air conditioner draws around 12.5 to 16.5 Amps. The compressor, which is responsible for cooling, usually has an Amperage rating of 10 to 13 Amps, while the fan motor draws about 2.5 to 3.5 Amps when running at full speed.
You can find the accurate Amperage of your air conditioner by checking the nameplate attached to the roof unit. The compressor’s amp draw is typically specified as “Compressor RLA (Running Load Amps)”, and the fan motor’s amp draw as “Fan Motor FLA (Full Load Amps)”.
As previously explained, your 15000 BTU RV air conditioner will have another amperage rating, known as “Compressor LRA (Locked Rotor Amps)”, which indicates the potential amp draw during start-up.
For 15K BTU units, the startup amperage rating is usually between 55 and 65 Amps, representing the potential amount of current required to get the compressor running.
It is worth noting that if your RV’s electrical system is rated for 30 Amps, you might encounter challenges when trying to run both the air conditioner and other high-current appliances simultaneously, such as water heaters and microwaves.
However, appliances like refrigerators, freezers, TVs, laptops, and other electronics require lower amounts of current and should have no issues running alongside the air conditioner.