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Window AC vs Portable AC

Picking out a new air conditioner is a daunting task. All types of air conditioners have radically different functions and installations. How do you decide which is right for your property?

We put together this series of articles to help you find the perfect air conditioner for your home. This article covers the differences between window AC and portable AC.

What’s the difference  between window AC and portable AC

The difference between a window AC and a portable AC is that a window AC sits in an open window while a portable AC connects to your window via an exhaust tube.

Both a window AC and portable ACs are single-unit air conditioners. That means that they have both heating and cooling components in a single unit.

Most air conditioners work with separate units – an indoor unit that removes heat from your home and an external unit that deposits heat outside. 

Window ACs and portable ACs both vent air out an open window in your home. They have to get rid of the heat produced during the air conditioning process otherwise your home’s temperature would not change.

The difference is in how they vent heat. A window AC sits in an open window so that its “heating” components are literally hanging out the window. A portable air conditioner connects to an open window via an exhaust tube and a window kit.

Installation and Space Requirements

The difference between a window AC and a portable AC is that a window AC sits in an open window while a portable AC connects to your window via an exhaust tube. Window ACs are generally considered more permanent fixtures and may require more effort in installation compared to portable ACs, which are designed for flexibility and ease of movement.

Ventilation and Heat Exhaust

Both types of ACs vent heat out of an open window, but they do so differently. A window AC’s heat exchange components are outside, which can be more effective at expelling heat. Portable ACs, on the other hand, may struggle with heat leakage due to the exhaust hose design.

Suitability for Different Types of Rooms

Portable ACs can be moved from room to room and are ideal for spaces where traditional window units are not feasible. Window ACs are better suited for rooms where window space is available and a more permanent solution is desired. 

Cooling Capacity

Window air conditioners are slightly more powerful than portable air conditioners. A typical window AC has 8,000 – 12,500 BTUs of cooling power while a typical portable AC has 5,000 – 10,000 BTUs. 

That means that window ACs and portable ACs are probably a good fit for similar properties. But, a window AC may be a better choice if you need a unit in the 10,000 – 14,000 range. You’ll have more options at that size.

But what does 10,000 BTUs even mean? An air conditioner’s BTU rating is a measure of how much indoor space that AC unit can effectively cool. 

A 10,000 BTU air conditioner can cool 400 – 450 square feet of indoor space, for example.

You would be fine with either a window AC or portable AC if you need to cool a room of up to 550 square feet. For a space of 600 – 750 square feet, you might be better off looking for a window AC.

Remember that these are only typical sizes. You can find models of both window AC and portable AC units with cooling capacities as high as 24,000 BTUs. That’s enough to comfortably cool an apartment with a few rooms. 

Understanding BTUs and Cooling Efficiency

BTUs, or British Thermal Units, measure an air conditioner’s ability to remove heat from a room. Higher BTU ratings indicate a greater cooling capacity, which is crucial for effectively managing the climate in larger spaces.

Room Size and AC Selection

The size of the room you wish to cool plays a significant role in choosing between a window and a portable AC. This section explains how to match the BTU rating with the square footage of your space.

High-Capacity Models for Larger Spaces

For those needing to cool larger areas, high-capacity models of both window and portable ACs are available. This subsection would delve into options for cooling spaces larger than the standard room sizes.


Window ACs are more expensive than portable air conditioners. A window AC costs $200 – $600 and a portable AC costs $100 – $400.

Among air conditioners, these are the two most affordable options by a long shot. That’s because neither system needs professional installation. So, you just have to pay for the units. You can install either in less than 30 minutes.

You’ll notice there’s a lot of overlap in the price ranges I provided. That’s because cooling capacity is a more important factor than air conditioner type when it comes to window and portable ACs. 

Expect to pay about $100 for a window AC compared to a portable AC with the same cooling capacity. 

Initial Purchase Price Comparison

This subsection compares the upfront costs of window and portable AC units, highlighting the price ranges and what factors contribute to the cost difference.

Long-Term Cost Considerations

Beyond the purchase price, the long-term costs such as energy consumption and maintenance are important to consider. This part explains how these factors can affect the overall affordability of an AC unit over its lifetime.

Installation and Maintenance Costs

The ease of installation for portable ACs can lead to savings in installation costs. However, maintenance costs over time can vary between the two types of units, which is an important consideration for buyers.

Energy efficiency

Window ACs are more efficient than portable ACs. The former has an energy efficiency ratio (EER) of 10 – 13 and the latter of 7 – 11.

An EER is a measure of air conditioner energy efficiency. It’s an air conditioner’s BTU cooling capacity divided by its power usage in kilowatts. A higher EER means an AC is more efficient. 

There are several reasons why window ACs are more efficient than portable ACs. Prime among them is that a window AC has heating components inside your home. 

The hot air is pumped out via an exhaust tube but some of that heat will leak into your living space, undermining cooling efficiency.

EER Ratings and What They Mean

This subsection explains the energy efficiency ratio (EER) in more detail, providing a clearer understanding of why a higher EER is preferable and how it translates to cost savings.

Design Differences Affecting Efficiency

The design of window ACs generally allows for better insulation and less heat leakage, making them more energy-efficient. This part would explore the design elements that contribute to the efficiency of window ACs over portable ones.

Cost Savings Over Time

Investing in a more energy-efficient window AC can lead to significant savings on utility bills over time, despite the higher initial cost. This section would provide a cost-benefit analysis over the lifespan of the units.

Should I buy a window AC or a portable AC?

You should buy a window AC over a portable AC unless you are very tight on budget or lack the appropriate window space. Window ACs are more efficient than portable ACs and have more options in terms of cooling capacity.

The difference in price between the two units is relatively marginal – just $100 for most cooling sizes. So energy efficiency will matter more in the long run than the upfront price.

A portable AC may be a better choice if you only need occasional air conditioning. But most places in the US get hot enough during the summer that you need air conditioning for months at a time. 

Assessing Your Air Conditioning Needs

This part helps the reader assess their specific needs based on room size, installation possibilities, and cooling requirements to make an informed decision between window and portable ACs.

Pros and Cons of Each Type

A detailed comparison of the advantages and disadvantages of window and portable AC units provides a comprehensive overview to aid in the purchase decision.

Climate Considerations and Usage Patterns

The climate of your area and how often you’ll use the AC can influence which type is better for you. This subsection discusses how to choose based on these factors.

Frequently Asked Questions (FAQs)

What are the main factors to consider when choosing between a window AC and a portable AC?

The choice between window and portable AC units hinges on installation requirements, room size, cost, energy efficiency, and ventilation needs. Window ACs are fixed and ideal for cooling larger rooms efficiently, while portable ACs offer flexibility and are suitable for spaces where window installation isn’t feasible. Cost-wise, window ACs are a bigger initial investment but tend to be more energy-efficient, which may lead to long-term savings.

How do I calculate the right BTU rating for my room?

Calculate the BTU rating by multiplying the room’s square footage by 20 for a baseline number. Adjust this figure based on specific room conditions like sunlight exposure, room height, and occupancy. For example, add 10% more BTUs for sunny rooms or reduce by 10% for shaded rooms. Remember to adjust for additional factors like extra people or kitchen placement.

Can I install a window AC or portable AC unit myself?

Most window and portable AC units are designed for DIY installation. Window ACs require secure mounting in a suitable window, while portable ACs need a proper venting setup using the included window kit. Follow the manufacturer’s instructions carefully for safe and correct installation.

Are there any additional maintenance requirements for window or portable ACs?

Yes, both types require regular maintenance. Window ACs need monthly filter cleaning and a proper seal check, while portable ACs may require frequent emptying of the condensate tank and hose maintenance. Regular upkeep is crucial for optimal performance and longevity of the unit.

What should I do if my room doesn’t have a suitable window for a window AC?

If your room lacks a suitable window, consider a portable AC, which can vent through smaller openings or alternative vent kits for different types of windows or sliding doors. For rooms without any venting options, a ductless mini-split system might be a viable alternative, requiring only a small hole for installation.