How To Buy A Used Air Conditioner

Buying a used air conditioner can be a cost-effective way to stay cool during the hot months, but it requires careful consideration and thorough inspection to ensure you get a reliable and efficient unit. This comprehensive guide will walk you through the entire process of purchasing a used air conditioner, covering everything from initial research to installation and maintenance. By the end of this guide, you’ll be well-equipped to make an informed decision and find a great deal on a used air conditioner.

Table of Contents

Helpful Picks

SaleBestseller No. 1
BLACK+DECKER Air Conditioner, 14,000 BTU Air Conditioner Portable for Room up to 700 Sq. Ft., 3-in-1 AC Unit, Dehumidifier, & Fan, Portable AC with Installation Kit & Remote Control
  • Portable AC: Take this personal air conditioner (16.5" x 11.7" x 27.9") into any room of your choice. Stay cool in the hot summer months and sleep well with this BLACK+DECKER ac unit for bedroom.Controller type:Remote Control
  • 3-in-1: Our 14000 btu portable air conditioner includes a dehumidifier & fan. This portable air conditioner (62.4 lbs.) has a convenient remote control & top mounted control panel with LED display.
  • Impressive Features: Set the temperature just right with this ac portable air conditioner. Our ac unit portable also has a slide-out washable filter, auto water evaporation, & 24-hour timer.
  • Easy Mobility: With casters on the bottom & side handles on this small air conditioner, this air cooler & portable ac 14000 btu portable air conditioner can be moved from room to room without hassle.
  • Installation Kit: When it comes to fans that blow cold air, this indoor ac unit includes an easy-to-install window kit. A large, vented airflow outlet ushers in cool air bypassing window installation.
Bestseller No. 2
Humhold 14000 BTU Portable Air Conditioners with Remote Control, 3-in-1 Free Standing Cooling AC Unit with Fan & Dehumidifier, Cools Room up to 700 sq.ft, Smart/Sleep Mode,3 Speed,Auto Swing,24H Timer
  • ❄️【14000 BTU Powerful Cooling Efficient】Humhold Powerful Portable AC unit owns a cooling capacity of 14,000 BTU(ASHRAE) / 10,000 BTU(SACC), has an most energy efficient compressor that can supply cool air to 700 square feet of large space in your living room, bedroom, apartment, home kitchen, garage, basement and office, stable and efficient way to make you feel cool all the time in the hot summer. In addition, you can maintain temperatures from 61°F to 88°F with a variety of controls, allows to customize cooling experience to your needs.
  • ❄️【3-in-1 Cooling/Dehumidify/Fan Function】 The smart portable air conditioner offers the convenience of 3-in-1 functions, including Cooling, 3-speeds Fan, and Dehumidify, which meets your daily needs. You can freely adjust the temperature in cooling mode, ranging from (61℉ ~ 88℉) in hot seasons. The dehumidifier capacity of 95 Pints/day can effectively reduce the humidity in small room, and as a fan to circulate indoor air at all times, removing excess moisture and releasing fresh air for a healthy and comfortable environment.
  • ❄️【Front LED Display & Remote Control】 Our self evaporating portable ac unit is equipped with an easy-to-read Front LED Display,combined with full-function remote control which has LED display and up to 23 feets control distance, you can easily set the temperature and wind speed you want while sitting on the sofa or lying on the bed, no need to get close or stand up, maximize the convenience of mobile air conditioners.
  • ❄️【No Need To Drain】With Built-in water self-evaporation system, there is no need to drain water for daily use, the water will automatically evaporate through hose. If it is placed in humid environment such as basement, laundry room, it needs to drain every 8 hours, or the machine will stop for the water tank inside is full, you need to unplug the drain plugs on the back and connect household pipe to drain, then start the machine again. The filter is design to easy disassemble without any tools and can be washed directly by water flushing.
  • ❄️【Smart & Sleep Mode with 24H Timer for Enery Saving】 Built-in internal temp-sensor, Smart Mode enables the inverter ac unit run in Cool or Fan mode based on the room temperature, Keep the room at the most comfortable temperature 73F-77F. Sleep Mode will maintain an optimal temperature in low speed, and provide you less than 48dB quiet bedroom. You can also preset to stop the ac unit after 0.5-24 hours, all these funtional modes are money-saving and let you have a suitable temperature for relaxation and good sleep in the wonderful summer.
SaleBestseller No. 3
Portable Air Conditioners 16000 BTUs, 5-in-1 Portable AC Unit for Large Room 800 Sq.ft with Wifi App Control Cooling/Dehumidifier/Fan/Heat/Auto Swing/Sleep/24H Timer Remote & Window Kit Included
  • Powerful Cooling Capacity: Our 16,000BTU portable air conditioner boasts impressive cooling capabilities, making it suitable for rooms or office spaces up to 800 sq.ft. Whether you're enduring hot summers or dealing with high humidity, this ac unit can swiftly and effectively cool down your space, ensuring your comfort and keeping you cool at all times.
  • 5-in-1 Portable AC Unit: Our portable air conditioners, providing the ultimate year-round solution for comfortable living. It offers cooling(61℉-88℉)/dehumidification/fan/heating/sleep/auto swing(0-80°Wide)/App control & a 24-hour timer function, all in one compact design. Take control of your comfort and create the comfort place for any season.
  • Smart App Control & LED Display: Our smart room portable ac unit, equipped with app control, an LED display & a full-featured remote control with a range of up to 25 feets. With ease, you can effortlessly set your desired mode, temperature, and fan speed while sitting on the couch or lying in bed, maximizing the convenience of our portable AC without the need to approach or get up close.
  • The large air conditioner portable built-in intelligent temperature control. It will automatically adjusts fan speed & cooling capacity based on room temperature, ensuring optimal comfort, efficient dehumidification, refreshing airflow, and a ultra-quiet sleep mode at 35dB. Set a timer to automatically turn off the portable AC after 0.5-24 hours, maximizing cooling performance while minimizing energy consumption.
  • Easy Installation & Portability: Our room air conditioner offer a hassle-free installation process, complete with installation window kits and step-by-step instructions, ensuring a quick and easy setup experience. And built in 360° heavy-duty wheels and sturdy handles. This allows you to effortlessly move the device to any desired location in your room/office/bathroom/cloak room/garage/kitchen or any other space.

Why do you need an air conditioner?

Air conditioning is essential for maintaining comfort during the hot months. While new air conditioning units can be expensive, buying a used unit can provide significant savings. However, purchasing a used air conditioner requires careful consideration to ensure you are getting a unit that will be reliable and efficient. This guide will provide you with all the information you need to make a smart purchase.

Understanding Air Conditioners

Before diving into the process of buying a used air conditioner, it’s important to understand how air conditioners work and the different types available. Air conditioners remove heat from the indoor air and expel it outside, using a refrigerant to cool the air that is then circulated inside the room or building.

Basic Components of an Air Conditioner

  • Compressor: Compresses the refrigerant and circulates it through the system.
  • Condenser Coil: Releases the heat absorbed by the refrigerant to the outside air.
  • Evaporator Coil: Absorbs heat from the indoor air.
  • Expansion Valve: Regulates the flow of refrigerant into the evaporator coil.
  • Fans: Circulate air over the evaporator and condenser coils.

Types of Air Conditioners

  • Window Air Conditioners: Compact units installed in a window opening, ideal for cooling single rooms.
  • Portable Air Conditioners: Freestanding units that can be moved from room to room, vented through a window or wall.
  • Split System Air Conditioners: Consist of an outdoor compressor and an indoor unit, ideal for cooling individual rooms.
  • Central Air Conditioners: Provide cooling for an entire building through a system of ducts.

Advantages and Disadvantages of Buying Used


  • Cost Savings: Used air conditioners are significantly cheaper than new ones.
  • Environmental Impact: Reusing an air conditioner reduces waste and the demand for new manufacturing.
  • Immediate Availability: Used units are often available for immediate purchase, avoiding waiting times for new units.


  • Limited Warranty: Used units may not come with a warranty, or the warranty may be limited.
  • Potential for Hidden Issues: Without proper inspection, used units may have underlying problems that are not immediately apparent.
  • Lower Efficiency: Older units may be less energy-efficient compared to newer models.

Assessing Your Needs

Before purchasing a used air conditioner, it’s important to assess your cooling needs to ensure you select the right unit.

Room Size

Measure the size of the room or area you need to cool. Air conditioners are rated by their cooling capacity, measured in British Thermal Units (BTUs). A unit that is too small will struggle to cool the space, while a unit that is too large will cycle on and off frequently, wasting energy.

Energy Efficiency

Consider the energy efficiency of the air conditioner. Look for units with a high Energy Efficiency Ratio (EER) or Seasonal Energy Efficiency Ratio (SEER). These ratings indicate how efficiently the unit uses electricity to cool the air.

Additional Features

Think about any additional features you may want, such as programmable thermostats, remote controls, or air purifiers. These features can enhance the functionality and convenience of your air conditioner.

Where to Find Used Air Conditioners

Online Marketplaces

  • Craigslist: A popular platform for buying and selling used items locally.
  • eBay: Offers both local and nationwide listings for used air conditioners.
  • Facebook Marketplace: A convenient way to find used air conditioners being sold by people in your local area.

Retailers and Specialty Stores

  • Thrift Stores: Some thrift stores sell used appliances, including air conditioners.
  • Appliance Stores: Some appliance stores sell refurbished units with a limited warranty.
  • HVAC Contractors: Contractors may have used units available from previous installations.

Local Classifieds

  • Newspaper Ads: Check the classifieds section of your local newspaper.
  • Community Bulletin Boards: Look for postings in community centers, libraries, and grocery stores.

Key Factors to Consider

When evaluating a used air conditioner, there are several key factors to consider to ensure you are making a smart purchase.

Age of the Unit

Air conditioners typically last between 10 to 15 years. Check the manufacture date of the unit to ensure it still has a reasonable amount of useful life remaining.

Condition and Maintenance History

Ask the seller about the unit’s maintenance history and any repairs that have been performed. A well-maintained unit is more likely to be reliable and efficient.

Energy Efficiency

Older units may be less energy-efficient, leading to higher operating costs. Compare the energy efficiency ratings of the used unit to current models to determine potential savings.

Brand and Model

Research the brand and model of the air conditioner to check for any known issues or recalls. Some brands are known for their durability and reliability, while others may have a history of problems.


Find out if the unit is still under warranty or if the seller offers any kind of guarantee. A warranty can provide peace of mind and protect you from unexpected repair costs.

Inspecting a Used Air Conditioner

Before finalizing your purchase, it’s important to thoroughly inspect the used air conditioner to ensure it is in good working condition.

Visual Inspection

  • Exterior Condition: Check for any signs of damage, rust, or wear on the exterior of the unit.
  • Coils and Fins: Inspect the evaporator and condenser coils for dirt, debris, or damage. Clean coils improve efficiency.
  • Electrical Components: Look for any signs of wear or damage to the electrical components, including the power cord and plug.
  • Filters: Check the air filters for dirt and replace them if necessary.

Functional Inspection

  • Power On: Test the unit to ensure it powers on and runs smoothly.
  • Cooling Performance: Measure the air temperature at the vent to ensure the unit is cooling effectively.
  • Noise Level: Listen for any unusual noises that may indicate mechanical issues.
  • Thermostat and Controls: Test all controls and settings to ensure they are functioning properly.

Negotiating the Price

When negotiating the price of a used air conditioner, it’s important to be well-informed and prepared.

Research Market Prices

Research the market prices for similar models in similar condition. Use this information to set a reasonable budget and negotiating range.

Highlight Potential Issues

If you identify any issues during your inspection, use them as leverage to negotiate a lower price. Be polite but firm in discussing any concerns.

Be Prepared to Walk Away

If the seller is unwilling to negotiate or the price is too high, be prepared to walk away. There are many used air conditioners available, and it’s important to find a deal that fits your budget and needs.

Transporting Your Air Conditioner

Transporting a used air conditioner requires careful handling to avoid damage.

Use Proper Equipment

Use a dolly or hand truck to move the unit, and secure it with straps to prevent it from tipping over during transport.

Protect the Unit

Wrap the air conditioner in moving blankets or bubble wrap to protect it from scratches and damage. Secure it in your vehicle to prevent it from shifting during transport.

Installation Guide

Proper installation is crucial for the efficient and safe operation of your air conditioner.

Window Air Conditioners

  • Measure the Window: Ensure the air conditioner fits the window opening.
  • Install the Mounting Brackets: Follow the manufacturer’s instructions to install the mounting brackets securely.
  • Place the Unit: Carefully lift the air conditioner into the window opening and secure it to the brackets.
  • Seal the Gaps: Use foam or weather stripping to seal any gaps around the unit to prevent air leaks.

Portable Air Conditioners

  • Choose the Location: Place the unit near a window and a power outlet.
  • Install the Exhaust Hose: Connect the exhaust hose to the unit and vent it through the window using the window kit provided.
  • Secure the Hose: Ensure the hose is securely attached and free from kinks.

Split System Air Conditioners

  • Consult a Professional: Split system installations are complex and typically require professional installation.
  • Choose the Location: Select an appropriate location for both the indoor and outdoor units.
  • Install the Mounting Plate: Secure the mounting plate for the indoor unit.
  • Connect the Units: Run the refrigerant lines, electrical wiring, and drainage hose between the indoor and outdoor units.
  • Test the System: Ensure the system is functioning properly after installation.

Maintenance and Care

Regular maintenance is essential to keep your air conditioner running efficiently and extend its lifespan.


  • Filters: Clean or replace the air filters regularly to maintain airflow and efficiency.
  • Coils: Clean the evaporator and condenser coils to remove dirt and debris.
  • Drainage: Check the drainage system to ensure it is clear and functioning properly.


  • Electrical Connections: Inspect the electrical connections for signs of wear or damage.
  • Refrigerant Levels: Check the refrigerant levels and top up if necessary.
  • Thermostat: Ensure the thermostat is calibrated and functioning correctly.

Seasonal Maintenance

  • Spring: Perform a thorough inspection and cleaning before the cooling season begins.
  • Fall: Clean and inspect the unit before shutting it down for the winter.

Troubleshooting Common Issues

Even with regular maintenance, you may encounter some common issues with your air conditioner.

Unit Not Cooling

  • Check the Thermostat: Ensure the thermostat is set to the correct temperature.
  • Clean the Coils: Dirty coils can reduce cooling efficiency.
  • Check the Refrigerant Levels: Low refrigerant levels can affect cooling performance.

Strange Noises

  • Inspect the Fan: Check for any obstructions or damage to the fan blades.
  • Tighten Loose Parts: Loose parts can cause rattling or banging noises.

Water Leaks

  • Check the Drainage System: Ensure the drainage system is clear and functioning properly.
  • Inspect the Seals: Check for any gaps or cracks in the seals around the unit.

Frequently Asked Questions

What should I consider when buying a used air conditioner?

When buying a used air conditioner, consider factors such as the unit’s age, condition, maintenance history, energy efficiency, brand reputation, and whether it has a remaining warranty. Ensure the unit suits your cooling needs in terms of capacity (BTUs) and fits your space.

Where can I buy a used air conditioner?

You can buy used air conditioners from online marketplaces like Craigslist, eBay, and Facebook Marketplace. Thrift stores, appliance stores, HVAC contractors, and local classifieds are also good sources.

How do I determine the right size of air conditioner for my space?

To determine the right size, calculate the square footage of the space you need to cool and consult a BTU (British Thermal Units) chart. Larger spaces require higher BTU ratings.

What are the different types of air conditioners?

The main types of air conditioners are window units, portable units, split systems, and central air conditioners. Each type has different installation and space requirements.

How do I inspect a used air conditioner before buying?

Inspect the exterior for damage, check the coils and fins for cleanliness, and ensure the electrical components are intact. Power on the unit to test its cooling performance, listen for unusual noises, and verify the functionality of the thermostat and controls.

Why is energy efficiency important in an air conditioner?

Energy efficiency determines how much electricity the unit consumes to cool your space. More efficient units lower your energy bills and are better for the environment.

What are Energy Efficiency Ratio (EER) and Seasonal Energy Efficiency Ratio (SEER)?

EER measures the cooling output divided by the power input at a fixed outside temperature. SEER is the ratio of cooling output during a typical cooling season divided by the total electric energy input. Higher EER and SEER ratings indicate more energy-efficient units.

How can I check the age of an air conditioner?

You can check the age by looking at the manufacture date on the unit’s label or serial number. Researching the model number online can also provide this information.

What should I ask the seller about the air conditioner’s history?

Ask about the unit’s age, previous repairs, maintenance history, reasons for selling, and if there’s a warranty or guarantee.

How do I transport a used air conditioner?

Transport the unit using a dolly or hand truck, secure it with straps, and protect it with moving blankets or bubble wrap. Ensure it is secured in your vehicle to prevent shifting during transport.

What are common issues to look for in a used air conditioner?

Common issues include refrigerant leaks, dirty or damaged coils, worn electrical components, and unusual noises during operation. Ensure the unit powers on and cools effectively.

Is it better to buy a refurbished air conditioner?

A refurbished air conditioner may offer better reliability than a used unit, as it has typically been inspected and repaired by professionals and may come with a limited warranty.

Can I install a used air conditioner myself?

Window and portable units can usually be installed by homeowners. However, split systems and central units often require professional installation to ensure proper setup and efficiency.

How do I negotiate the price of a used air conditioner?

Research market prices for similar models, highlight any issues you found during inspection, and be prepared to walk away if the seller is unwilling to negotiate.

What are the benefits of buying a used air conditioner?

Benefits include cost savings, immediate availability, and reduced environmental impact by reusing an existing unit.

What are the risks of buying a used air conditioner?

Risks include potential hidden issues, limited or no warranty, and lower energy efficiency compared to new models.

How often should I clean and maintain my air conditioner?

Clean or replace the filters monthly during peak usage, and clean the coils and drainage system annually. Regular maintenance can extend the unit’s lifespan and improve efficiency.

What should I do if the used air conditioner doesn’t work after purchase?

Contact the seller to discuss any return or exchange policies. If the unit has a warranty, reach out to the manufacturer or retailer for repair or replacement options.

Are there specific brands known for durable air conditioners?

Brands like Carrier, Trane, Lennox, and Mitsubishi are known for producing durable and reliable air conditioners. Researching specific models and customer reviews can provide additional insights.

How can I check if an air conditioner is energy efficient?

Check the unit’s EER or SEER rating, which should be listed on the unit’s label or in the user manual. Higher ratings indicate better energy efficiency.

What additional features should I look for in a used air conditioner?

Look for features such as programmable thermostats, remote controls, air purifiers, and energy-saving modes. These can enhance functionality and convenience.

Can a used air conditioner affect indoor air quality?

Yes, if the unit is not properly maintained, it can harbor mold, dust, and allergens. Ensure the unit is clean and well-maintained to maintain good indoor air quality.

How do I find out if a used air conditioner is still under warranty?

Ask the seller for proof of purchase and warranty documents. You can also check the manufacturer’s website using the model and serial number to verify warranty status.

What are some signs of a failing air conditioner?

Signs include reduced cooling capacity, frequent cycling on and off, unusual noises, leaks, and high energy bills. These issues indicate the unit may need repair or replacement.

How long do air conditioners typically last?

Air conditioners typically last between 10 to 15 years, depending on usage, maintenance, and the quality of the unit.

Can I use an air conditioner immediately after transport?

Allow the air conditioner to sit upright for at least 24 hours before using it. This allows the refrigerant to settle and prevents damage to the compressor.

What is the cost difference between used and new air conditioners?

Used air conditioners can cost significantly less than new ones, often saving you 50% or more. However, the exact savings depend on the unit’s age, condition, and features.

How do I determine the BTU rating I need for my space?

Calculate the square footage of the space and refer to a BTU chart to determine the appropriate cooling capacity. Consider factors like ceiling height, insulation, and sun exposure.

Can I return a used air conditioner if it doesn’t work?

Return policies vary by seller. Some may offer a limited return period, while others sell units “as is.” Clarify the return policy before purchasing.

Are there any regulations for buying used air conditioners?

There may be local regulations regarding the sale of used appliances. Check with local authorities or consumer protection agencies to ensure compliance.

How can I make my used air conditioner more energy-efficient?

Improve efficiency by regularly cleaning and maintaining the unit, using programmable settings, and ensuring proper installation and insulation around the unit.

What tools do I need for installing a window air conditioner?

Tools needed include a measuring tape, screwdriver, level, and weather stripping. Follow the manufacturer’s installation instructions for best results.

How do I clean the coils on a used air conditioner?

Turn off the power, remove the outer casing, and use a soft brush or vacuum to clean the coils. For stubborn dirt, use a coil cleaner spray.

What is the difference between window and portable air conditioners?

Window air conditioners are installed in a window opening, while portable units are freestanding and can be moved between rooms, vented through a window or wall.

How do I check the refrigerant levels in an air conditioner?

Checking refrigerant levels typically requires a professional with the proper tools and knowledge. Low refrigerant levels can affect cooling performance and indicate a leak.

Can I use a used air conditioner in a rental property?

Yes, you can use a used air conditioner in a rental property, but ensure it meets any specific requirements set by the landlord or property management.

How do I dispose of an old air conditioner?

Dispose of old air conditioners according to local regulations. Many areas have special disposal programs for appliances due to the refrigerant they contain.

What is the average cost to repair a used air conditioner?

Repair costs vary depending on the issue and unit type. Common repairs can range from $150 to $500. It’s often worth comparing repair costs with the price of a replacement unit.

Are there any tax credits or incentives for buying used air conditioners?

Tax credits and incentives are typically available for new, energy-efficient units. However, some local programs may offer incentives for refurbished or energy-efficient used units. Check with local authorities for available programs.

What are the benefits of professional installation for a used air conditioner?

Professional installation ensures proper setup, which can improve efficiency and extend the unit’s lifespan. It also reduces the risk of damage or improper installation.


Purchasing a used air conditioner can be a cost-effective way to stay cool, but it requires careful consideration and thorough inspection to ensure reliability and efficiency. By understanding your cooling needs, researching the market, and conducting a detailed evaluation of potential units, you can find a great deal that meets your requirements.

Regular maintenance and proper installation will further enhance the performance and longevity of your used air conditioner. With this comprehensive guide, you’re well-equipped to make an informed decision and enjoy the benefits of a comfortable, cool environment.