While it is generally NOT recommended to use an extension cord for your air conditioner, if absolutely necessary, it should be used as a temporary fix rather than a permanent solution.
Using an extension cord for your air conditioner is generally NOT recommended, and it is often better to avoid it if possible.
Air conditioners draw significant current, and improper use of extension cords can lead to safety hazards, fire risks, and may void warranties and affect homeowner’s insurance.
In hot weather, the fire risk from melting plugs and receptacles increases. Extension cords can get dangerously hot, particularly when covered by carpeting or taped to the wall, or, pose tripping hazards if left uncovered.
Hence window air conditioners should be installed close enough to an outlet to allow the cord to reach.
Select an extension cord that is sufficiently heavy-duty to handle the load. And keep in mind that extension cords are recommended exclusively for temporary use with an air conditioner.
Ensuring optimal power supply: Choosing the right extension cord size for your air conditioner
To select the right size of the extension cord, you need to know how much power your air conditioner consumes, information readily available on the air conditioner’s label or sticker.
Window air conditioners typically operate within a wattage range of 900 to 1,500 watts.
Extension cords are rated by the number of amperes (amps) they can handle, however, you have to convert the wattage to current.
To do this, simply divide the wattage by the voltage displayed on the label, which should be 120 volts.
Use this formula:
For example, a 1,500-watt unit equates to 12.5 amps (1,500 / 120 = 12.5).
Choosing the right extension cord for 5,000 air conditioners
Air conditioners designed for small rooms, such as those in college dormitories or small apartments, typically fall within the 5,000 to 6,000 BTU range, drawing approximately 5 to 7 amps of power.
The surge power of a 5,000 BTU air conditioner is generally 1.5 to 2 times its running, depending on the manufacturer.
The extension cord should have a current rating that is equal to or greater than the rating of the socket. In most cases, these are plugged into a wall socket that is serviced by a 15 amp breaker.
You can operate a 5,000 BTU window unit (120V) as long as the extension cord has an adequate gauge or wire size. Most standard cords are 14 0r 12 gauge, with a lower number indicating a larger wire size.
The performance depends on the unit’s amperage draw and the extension cord’s length; a larger diameter and shorter cord are preferable.
While a 14-gauge extension cord can handle this current, it is essential to consider that air conditioners, like most appliances, experience a higher current draw during startup.
For improved performance and to mitigate voltage drop issues, it is advisable to opt for a 12-gauge cord.
| 12 gauge 10 ft extension cord UL certified | 14 gauge 6 ft extension cord UL certified |
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| Buy it on Amazon | Buy it on Amazon |
Ensure to check the manufacturer’s label (where the model and serial numbers are located).
Find the amperage information to determine the actual current the appliance runs at, not just the size of the breaker it requires.
Understanding wire gauge and applications: A comprehensive guide
Different wire types are designed for specific purposes; however, understanding the appropriate wire size, or gauge, is crucial in determining amperage, which is essential for selecting the right cord.
The American Wire Gauge (AWG) system determines wire size, with the gauge representing the physical dimensions of the wire.
Wire gauge is a numerical designation indicating the physical size of the wire, and it runs inversely to the diameter of the conductors. In simpler terms, a smaller wire gauge number means a larger wire diameter.
Common wire sizes include 16, 14, 12, 10, 8, 6, and 2 gauge, and the wire size determines the safe capacity for current to pass through. So, out of all these options, a 16 gauge wire is going to be the smaller one.
Amps measure electrical current, and each wire gauge has a maximum safe carrying capacity. For Standard Non-Metallic (NM) cables, these amperage and wire gauge capacities aid in determining the appropriate wire size.
NM cables in residential constructions come in 5 color schemes: white, yellow, orange, black, and gray, making it easy to identify them.
(Gray sheathing indicates cable designed for underground installation with strong water resistance and potential ratings for oil and sunlight resistance.
Check the packaging and jacket printing to ensure the cable’s wire gauge aligns with your requirements, as the gray color alone does not indicate wire size.)
For NM-B cable below 6 AWG or bigger than 14, there is no designated color code.
While the color coding of the wire sheath is optional, the majority of manufacturers typically follow this specific color scheme.
Color-coded jackets were introduced in 2001 for type NM-B cable to facilitate the identification of conductor sizes.
This coding system was designed to assist those who sell, install, and inspect these type of cables, making it easier to identify the cable size and minimize errors associated with the use of incorrect conductor sizes.
The table below depicts the amperage handling capacities for different wire gauges of NM electrical cables
| Wire | Amperes | Use | Color Code | Commonly used for |
| 16-gauge | 13 amps | Light duty | – |
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| 14-gauge | 15 amps | Medium duty | White | 14/2:
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14/3:
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| 12-gauge | 20 amps | Heavy duty | Yellow | 12/2:
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12/3:
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| 10-gauge | 30 amps | Extra heavy duty | Orange |
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| 8-gauge | 45 amps | Black |
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| 6-gauge | 60 amps | Black |
(A lower gauge signifies a higher capacity for electrical current in the cord.)
Window air conditioners typically use a 12-gauge wire capable of carrying up to 20 amps of current, because air conditioners, like most appliances, experience a higher current draw during startup.
If you do decide to use an extension cord, ensure it is specifically rated for air conditioner use.
Invest in a reliable cord with high-quality ends to avoid poor connections that can generate heat. After installation, run the unit for 15 minutes and double-check to see if the extension is hot.
Special extension cords designed for AC units are available at hardware stores, and on Amazon, typically in 6 to 15-foot lengths with both 120 and 240 volt options.
While longer cords (up to 15 feet) may be acceptable based on your unit’s wattage, ensure they have 12 or 14 gauge cables for higher amperage draws exceeding 900 watts.
For prolonged use, consider hiring an electrician to install a dedicated outlet closer to the AC unit, as extension cords are intended for temporary use.
Extension cord safety awareness: Risks, regulations, and recommendations
Based on information from the Electrical Safety Foundation (ESFI), approximately 3,300 home fires stem from extension cords annually, resulting in 50 fatalities and 270 injuries.
Yet, extension cords are not required to undergo certification or testing (as per the rule outlined in section 15(j) of the Consumer Product Safety Act (CPSA))
According to ESFI, it is advisable to purchase extension cords approved by independent testing laboratories like Underwriters Laboratories (UL) to guarantee that the cord can effectively handle its rated current.
Extension cord safety guide: Essential tips for home and workplace protection
To prevent potential fires caused by improper use, it is crucial to adhere to these essential tips for safeguarding your home and workplace:
- Never plug an extension cord into another extension cord, as this can cause the extension cords to overload, making them overheat, and creating a fire hazard.
- Ensure that extension cords are appropriately rated for their designated use, whether indoor or outdoor. Never use an indoor cord for outdoor use.
- Ensure that the extension cord you are using can handle the amount of electricity that the AC will draw. Check both the amperage and gauge of the extension cord to confirm compatibility.
- Ensure outdoor extension cords are free from snow and standing water at all times
- If you frequently resort to using extension cords, that means you do not have enough outlets to meet your requirements. Consult with a licensed and qualified electrician to install additional outlets.
- Before use, examine the cords for any signs of damage. Look for cracked or frayed sockets, loose or exposed wires.
- Do not nail or staple extension cords to walls
- Do not run extension cords through walls, doorways, ceilings, or floors, under furniture of carpets
- Choose a three-prong extension cord to match the typical three-prong connection found in most air conditioner cords.
- Do not use three-prong plugs with outlets featuring only two slots; do not cut off the ground pin to force compatibility.
- Extension cords are not suitable substitutes for proper electrical wiring and home outlets, their role is temporary, not a permanent solution.
- Do not use extension cords designed for PCs, washing machines, and other appliances with an air conditioner.
- Do not run an extension cord through doors or windows, as it may cause damage to the cable and hinder the smooth closing and opening of doors or windows.
- Do not use extension cords if the distance is too long; consider replacing the original wire and plug instead.
- Thoroughly inspect all extension cords for damage before use and regularly during use.
- Replace an extension that has any visible damage.
- If the extension cord feels hot during use, it may be overloaded. Verify if the cord is appropriately rated for the connected air conditioner, and inspect it for any signs of damage along its length.
- Always unplug an extension cord when not in use. The U.S. Consumer Product Safety Commission (CPSC) warns that a plugged-in extension cord retains electrical current, making it prone to overheating and potential fire hazards even during periods of inactivity.
Final Note
Check the manufacturer’s recommendations for your specific air conditioner model.
Ideally, it is best to have a dedicated and properly installed electrical outlet for your air conditioner to ensure safety, efficiency, and optimal performance.
If you are unsure or have specific concerns, consult with a qualified electrician to assess your electrical setup and provide guidance on the safest and most efficient solution for powering your air conditioner.