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What are the disadvantages of a window AC?

Window air conditioners are a popular cooling solution for many, offering a balance of convenience, cost-effectiveness, and flexibility.

Ideal for small spaces, temporary setups, or individual room cooling, these units provide a straightforward way to beat the heat without the need for extensive installation or high upfront costs.

However, like any appliance, they come with their own set of advantages and disadvantages, from ease of installation and affordability to potential issues with energy efficiency and noise.

In this article, we’ll explore both the benefits and drawbacks of window AC units to help you make an informed decision based on your specific cooling needs and living situation.

Disadvantages of Window AC

Window air conditioners, while convenient and cost-effective for cooling small spaces, come with a range of disadvantages that can affect their overall functionality and impact on your living environment.

  • Low Capacity: Window AC units are generally designed with a lower capacity, making them suitable only for individual rooms or small spaces rather than providing a solution for cooling larger homes or multiple rooms efficiently.
  • Blocks Window: Installing a window AC unit means sacrificing the full use of the window it occupies, limiting natural light and fresh air flow, which can affect both the ambiance and air quality of the room.
  • Low Energy Efficiency: Many window AC models, especially older ones, have lower energy efficiency compared to other cooling systems. This can lead to higher energy bills and a larger environmental footprint over time.
  • Limited Cooling Capacity: The cooling effect of window ACs is often confined to the immediate area around the unit, making them less effective for larger spaces or for maintaining consistent temperatures across multiple rooms.
  • Obstruction of Windows: The presence of a window AC can obstruct views and reduce the amount of natural light entering the space, potentially diminishing the aesthetic and functional value of the window.
  • Noise: Operational noise is a common issue with window AC units. The sound level can vary but often includes humming, buzzing, or rattling, which can be disruptive to peace and quiet within the home.

These disadvantages highlight the importance of considering your specific needs, the size and layout of your space, and your priorities regarding comfort and convenience before choosing a window air conditioner as your cooling solution.

Low capacity

Window air conditioners generally have a lower cooling capacity than permanent air conditioners like split AC or central air systems. The average cooling capacity of a window AC is 8,000 – 12,000 BTUs. That’s about enough for a single large room or a small one-bedroom apartment.

Window ACs are not designed to cool entire homes. You usually have to purchase multiple window air conditioners if you want to cool larger homes.

There are some premium window AC models that are able to cool larger spaces. The biggest models you can buy typically have 24,000 BTUs of cooling power. That’s enough for an apartment with 2-3 bedrooms.

By contrast, 24,000 BTUs is a fairly typical output for traditional air conditioning systems. You can buy split AC units with 30,000+ BTUs fairly easily. 

Blocks window

Another downside of a window AC is that it blocks the view out your window. You have to literally install the unit in an open window, so you can’t see out of it for the duration of the winter.

That might not be a massive problem if you have lots of sources of natural light in your apartment and several windows. But not everyone has that luxury. Blocking a window could be a major concern in properties with limited natural light.

Low energy efficiency

Window AC units are often less energy-efficient than other cooling systems, impacting both environmental sustainability and household energy costs. Many of these units, especially older models, use outdated technology and lack advanced features like programmable thermostats, leading to higher energy consumption. Improper installation can further reduce efficiency, as gaps allow cool air to escape.

To combat this, opt for newer, ENERGY STAR-certified models and ensure a proper seal during installation. Despite these measures, window ACs may still fall short in efficiency compared to more modern cooling solutions.

Limited Cooling Capacity

Window AC units are best suited for cooling single rooms or small spaces due to their design and power limitations. They struggle to maintain comfortable temperatures in larger areas or multiple rooms, often requiring the use of several units which can lead to increased energy consumption and costs.

For those in larger homes or with open floor plans, central air or ductless mini-split systems might offer more efficient and effective cooling solutions. Consider the size of the area you need to cool and your overall cooling requirements before opting for a window AC unit to ensure it meets your needs without unnecessary expense or inefficiency.

Obstruction of Windows

Installing a window air conditioner comes with the significant downside of losing the full functionality and benefits of your window. This obstruction impacts not just the view, but also natural light and ventilation:

  • Blocked Views and Natural Light: Once a window AC is installed, it can significantly block the view from the window and reduce the amount of natural light entering the room, potentially making the space feel smaller and more enclosed.
  • Reduced Ventilation: With a window unit in place, the option to open the window for fresh air is eliminated. This can lead to decreased air quality and ventilation, making the indoor environment less comfortable, especially during cooler days when natural air flow would be beneficial.
  • Aesthetic Impact: Window AC units can detract from the aesthetic appeal of both the interior and exterior of your home. They can be seen as unsightly additions, especially in areas where the exterior appearance of homes is valued.

The choice to install a window AC should be weighed against these considerations, especially in rooms where the view, natural light, and ventilation are important for your comfort and the room’s ambiance.


A common drawback of window air conditioners is the noise they generate during operation. This noise can range from a low hum to a more pronounced buzzing or rattling, potentially disrupting the tranquility of your living space:

  • Operational Sounds: Even at low settings, window AC units produce a constant background noise that can be distracting, particularly in quiet environments or during activities that require concentration, such as reading, studying, or sleeping.
  • Vibration and Rattling: In some cases, especially with older or less well-maintained units, vibrations can cause additional noise, such as rattling of the unit itself or the window frame. This can exacerbate the disruption caused by the unit’s operational sounds.
  • Impact on Comfort and Productivity: Persistent noise can affect comfort levels, disturb sleep patterns, and reduce productivity, making it an important consideration for those sensitive to sound or working from home.

When choosing a window AC, it’s advisable to look for models with lower decibel ratings and features designed to minimize noise, such as insulated construction or “quiet mode” settings, to mitigate this issue as much as possible.

Advantages of Window AC

Window air conditioners offer several benefits that make them a popular choice for immediate, cost-effective cooling in various settings:

  • Affordability: Window AC units are generally more affordable than central air systems, both in terms of initial purchase price and installation costs, making them accessible for a wide range of budgets.
  • Ease of Installation: These units can be installed without significant modifications to your home’s structure, making them a convenient option for renters or those in temporary housing.
  • Portability: Many window AC models are designed for easy removal and reinstallation, allowing for flexibility in cooling needs and the ability to take the unit with you if you move.
  • Energy Efficiency for Small Spaces: For small rooms or apartments, window ACs can be more energy-efficient than cooling an entire house with a central system, especially when only one room needs to be cooled.
  • Independent Operation: Each unit operates independently, providing the ability to cool specific areas as needed without affecting the temperature in other parts of the home, leading to potential energy savings.
  • Variety of Sizes and Features: Window AC units come in a range of sizes and with various features to suit different room dimensions and personal preferences, including adjustable settings, remote controls, and programmable timers.

These advantages make window air conditioners a versatile and economical choice for targeted cooling, particularly in smaller living spaces or during transitional weather periods.