Choosing between a window air conditioner and a through-wall unit depends on your space, installation preferences, and long-term needs. Window units are easier to install and more affordable, making them ideal for renters or temporary cooling, while through-wall models offer a permanent, streamlined solution with better insulation and less obstruction. For durability and efficiency in fixed locations, through-wall ACs win—but if flexibility and cost matter most, window units are the clear choice.

Key Takeaways

• Choose window units for easy DIY installation and lower upfront cost.
• Through-wall ACs offer permanent, weatherproof cooling with better efficiency.
• Measure opening size carefully—through-wall units need custom framing and sealing.
• Prioritize noise levels: through-wall models run quieter due to exterior placement.
• Check local codes before installing through-wall units; permits may be required.
• Window ACs suit renters—no structural changes needed for removal or relocation.

Window Air Conditioner vs Through Wall: Which Is Better for You?

It’s the middle of July, and the heat outside feels like a warm hug from a dragon. You’re sweating through your shirt just standing in the kitchen, and your ceiling fan is doing little more than pushing hot air around like a lazy breeze. You’ve finally decided it’s time to invest in an air conditioner—but now you’re stuck at a crossroads: window air conditioner vs through wall? Which one is right for your home, your lifestyle, and your sanity during those sweltering summer months?

You’re not alone. Thousands of homeowners and renters face this same decision every year. Both window and through-wall air conditioners offer cooling relief, but they come with different installation requirements, costs, and long-term implications. One might be perfect for a renter in a city apartment, while the other could be ideal for a homeowner looking for a permanent, energy-efficient solution. The good news? You don’t have to guess. In this guide, we’ll break down everything you need to know—from installation and energy use to noise levels and aesthetics—so you can make a confident, informed choice. Whether you’re cooling a single room or trying to beat the heat in a cozy studio, we’ve got you covered.

Understanding the Basics: What Are Window and Through-Wall AC Units?

Before diving into the pros and cons, let’s make sure we’re on the same page about what these units actually are. Both window and through-wall air conditioners are types of room air conditioners—meaning they cool a single room or small space, unlike central air systems that cool an entire house. They work by pulling in warm air, cooling it using a refrigerant, and then blowing the chilled air back into the room. The warm air and moisture are expelled outside through the back of the unit.

What Is a Window Air Conditioner?

A window air conditioner is exactly what it sounds like: a self-contained unit designed to fit snugly into a standard window frame. These units are popular because they’re affordable, easy to install, and widely available. Most models come with adjustable brackets and side panels that expand to fill the window opening, creating a seal that keeps hot air out and cool air in. They’re typically mounted on the lower half of a double-hung or sliding window, and the front grille faces into the room while the back vents heat outside.

For example, imagine you live in a third-floor apartment with old windows. You don’t own the place, and you can’t make permanent changes. A window AC unit is your best bet—it’s removable, doesn’t require drilling into walls, and can be taken with you when you move. Brands like Frigidaire, LG, and Honeywell offer models ranging from 5,000 to 12,000 BTUs, suitable for rooms from 150 to 550 square feet.

What Is a Through-Wall Air Conditioner?

A through-wall air conditioner is a more permanent solution. As the name suggests, it’s installed directly into an exterior wall, with the front of the unit inside the room and the back protruding outside. These units require cutting a hole in the wall—usually about 24 to 28 inches wide and 14 to 18 inches tall—and securing the AC with a metal sleeve or frame. Because they’re built into the structure, they’re less likely to be stolen and offer a cleaner, more integrated look.

Let’s say you own a small home with a sunroom that gets scorching hot in the afternoons. You want a reliable, long-term cooling solution that doesn’t block your view or take up window space. A through-wall unit might be ideal. It’s out of the way, doesn’t interfere with window treatments, and can be paired with a wall sleeve for easy removal during maintenance. However, installation is more involved and usually requires professional help, especially if electrical work is needed.

Installation: Ease, Cost, and Who Should Do It

One of the biggest differences between window and through-wall air conditioners is how they’re installed. This isn’t just about convenience—it affects cost, safety, and long-term usability.

Window AC Installation: Simple but Limited

Installing a window air conditioner is something most people can do themselves in under an hour. Here’s how it typically works:

• Open the window and place the unit on the sill.
• Slide the side panels outward to fill the gaps.
• Secure the unit with brackets or screws (if allowed by your landlord).
• Plug it into a dedicated outlet and turn it on.

It’s straightforward, but there are limitations. You need a window that’s the right size and orientation—most units fit double-hung or sliding windows, but not casement or awning styles. Also, the window must be able to support the weight (most units weigh 50–80 pounds). If you live in an apartment with strict rules, you might need permission to install one. And if your window faces a busy street or gets direct sunlight, the unit may work harder and wear out faster.

Pro tip: Use a support bracket or stand underneath the unit for extra stability, especially on higher floors. This prevents the AC from tipping out—a real safety hazard.

Through-Wall AC Installation: More Work, More Permanence

Installing a through-wall air conditioner is a bigger project. It involves:

• Choosing the right location on an exterior wall (preferably shaded and accessible).
• Cutting a precise hole through the wall, including insulation and siding.
• Installing a metal sleeve or frame to hold the unit.
• Securing the AC and sealing gaps to prevent air leaks.
• Running electrical wiring if needed (often requires a licensed electrician).

This process can take several hours and cost anywhere from $200 to $800 in labor, depending on your location and the complexity of the job. If you’re not comfortable with power tools or electrical work, hiring a professional is strongly recommended. Mistakes can lead to water leaks, structural damage, or even fire hazards.

On the plus side, once installed, a through-wall unit is rock-solid. It won’t shift or fall, and it won’t block your window view. It’s also less vulnerable to theft since it’s built into the wall. For homeowners planning to stay put for years, this permanence can be a major advantage.

Performance and Energy Efficiency: Cooling Power and Costs

When it comes to cooling your space, both window and through-wall units can get the job done—but how efficiently they do it varies. Let’s look at performance, energy use, and long-term costs.

Cooling Capacity and Room Size

Both types of units are rated by BTUs (British Thermal Units), which measure how much heat they can remove per hour. The right BTU rating depends on your room size:

• 150–250 sq ft: 5,000–6,000 BTUs
• 250–350 sq ft: 7,000–8,000 BTUs
• 350–450 sq ft: 9,000–10,000 BTUs
• 450–550 sq ft: 12,000 BTUs

For example, a 10,000 BTU window unit can cool a medium-sized bedroom or home office, while a 12,000 BTU through-wall model might be better for a large living room with high ceilings. Oversizing or undersizing your unit can lead to inefficiency—too small, and it runs constantly; too big, and it cycles on and off too frequently, wasting energy and reducing comfort.

Energy Efficiency and Operating Costs

Energy efficiency is measured by the Energy Efficiency Ratio (EER)—the higher the EER, the less electricity the unit uses to produce cooling. Most modern window and through-wall units have EERs between 8 and 12. Look for models with the ENERGY STAR label, which meet strict efficiency guidelines set by the EPA.

Here’s a quick comparison:

Unit Type	Average EER	Annual Energy Use (kWh)	Estimated Annual Cost*
Window AC (10,000 BTU)	10.5	700	$84
Through-Wall AC (10,000 BTU)	11.0	650	$78

*Based on 8 hours of daily use and $0.12 per kWh.

As you can see, through-wall units tend to be slightly more efficient because they’re better sealed and less prone to air leaks. Window units, especially older models, can let warm air sneak in around the edges, forcing the compressor to work harder. However, newer window models with improved insulation and weatherstripping have closed this gap significantly.

Another factor: through-wall units often have better airflow design, with dedicated intake and exhaust paths. This can lead to more even cooling and faster temperature recovery after opening a door or window.

Noise Levels: How Quiet Is Too Quiet?

Let’s be honest—nobody wants a noisy air conditioner buzzing in the background while they’re trying to sleep or watch TV. Noise is a real concern, especially in bedrooms or home offices.

Decibel Ratings and Real-World Sound

Air conditioner noise is measured in decibels (dB). Here’s a quick reference:

• 30 dB: Whisper
• 40 dB: Quiet library
• 50 dB: Moderate rainfall
• 60 dB: Normal conversation
• 70 dB: Vacuum cleaner

Most window air conditioners operate between 50 and 65 dB. That’s noticeable, especially on low settings. Cheaper models may have louder compressors or fans that rattle over time. Higher-end units, like the LG LW1016ER or Frigidaire FGRC1044T1, use inverter technology and sound-dampening materials to reduce noise to around 45–50 dB—quieter than a refrigerator.

Through-wall units generally run quieter, often between 40 and 55 dB. Because they’re mounted in the wall, there’s less vibration transmitted into the room. The fan and compressor are also farther from your ears, which helps. Some models even have “sleep mode” settings that reduce fan speed and noise at night.

For example, if you’re a light sleeper, a through-wall unit might be worth the extra installation cost just for the peace and quiet. But if you’re in a noisy urban area or don’t mind a little background hum, a modern window unit could be perfectly fine.

Placement Matters

Where you install your AC affects how much noise you hear. A window unit in a bedroom window will be louder than one in a living room window across the hall. Similarly, a through-wall unit placed near a bed should be positioned so the airflow doesn’t blow directly on you—this can cause discomfort and increase perceived noise.

Tip: Use acoustic foam or weatherstripping around the unit to dampen vibrations. For window units, consider installing a sound blanket (a removable cover designed to reduce noise) during the night.

Aesthetics and Space: How They Look and Fit

Let’s face it—air conditioners aren’t exactly stylish. But how much they impact your home’s look and feel can influence your decision.

Window Units: Functional but Obtrusive

Window air conditioners are visible from both inside and outside. They block part of your window, which can be a problem if you love natural light or have a great view. They also interfere with curtains, blinds, and window treatments. In historic homes or buildings with strict appearance rules, a bulky window unit might not be allowed.

On the plus side, they’re removable. When winter comes, you can take the unit out, store it, and enjoy your full window again. This flexibility is a big win for renters or seasonal users.

Through-Wall Units: Sleek and Integrated

Through-wall air conditioners are much more discreet. Once installed, only the front grille is visible inside the room—often just a slim vent with adjustable louvers. Outside, the unit blends into the wall, especially if painted to match the siding. This makes them ideal for homes where curb appeal matters.

They also free up your windows completely. You can hang curtains, install blinds, or even add window boxes without interference. For sunrooms, studios, or rooms with limited window space, this can be a game-changer.

However, the installation hole is permanent. If you ever remove the unit, you’ll need to patch the wall and possibly install a cover plate. This isn’t a dealbreaker for homeowners, but it’s something to consider if you might move or upgrade to central air in the future.

Cost Comparison: Upfront and Long-Term Expenses

Money matters. Let’s break down the costs of both options so you can budget wisely.

Initial Purchase Price

Window air conditioners are generally cheaper upfront. A basic 8,000 BTU model can cost as little as $200, while high-end smart units with Wi-Fi and quiet operation run $400–$600. Through-wall units are more expensive, typically starting around $400 and going up to $800 or more for premium models.

Installation Costs

This is where the gap widens. Window units cost almost nothing to install—maybe $20 for a support bracket. Through-wall units, however, require professional installation, which can add $200–$800 to your total cost. If electrical work is needed (like running a dedicated 240V line), that could push the price even higher.

Long-Term Savings

Over time, the more efficient through-wall unit may save you money on electricity. Based on our earlier example, a through-wall AC could save you $6–$10 per year compared to a window unit. Over 10 years, that’s $60–$100—not a huge amount, but it adds up. Plus, through-wall units often last longer because they’re better protected from weather and theft.

Maintenance costs are similar for both: annual cleaning, filter replacement, and occasional servicing. However, accessing a through-wall unit for repairs can be trickier, potentially increasing labor costs.

Which Is Right for You? A Practical Decision Guide

So, window air conditioner vs through wall—which should you choose? The answer depends on your living situation, budget, and priorities. Here’s a quick guide to help you decide:

• Renters or short-term residents: Go with a window unit. It’s affordable, easy to install, and removable.
• Homeowners planning to stay long-term: Consider a through-wall unit for better efficiency, noise reduction, and aesthetics.
• Limited window space or view concerns: Through-wall is the way to go—it won’t block your windows.
• Budget-conscious buyers: Window units win on upfront cost and installation ease.
• Noise-sensitive environments: Through-wall units are generally quieter and more discreet.
• Historic homes or strict HOA rules: Check regulations—some places ban window units but allow through-wall installations.

For example, Sarah, a freelance writer in a downtown apartment, chose a 10,000 BTU window unit because she rents and values flexibility. She uses it from May to September, then stores it in her closet. Meanwhile, Tom, a homeowner in Arizona, installed a through-wall unit in his home office. He wanted a permanent, quiet solution that wouldn’t block his mountain view—and he was willing to pay more upfront for long-term comfort.

Final Thoughts: Making the Smart Choice

Choosing between a window air conditioner and a through-wall unit isn’t just about cooling power—it’s about matching the right solution to your lifestyle, space, and budget. Both options have their strengths: window units offer affordability and flexibility, while through-wall models provide efficiency, quiet operation, and a cleaner look.

Take the time to assess your needs. Measure your room, check your windows, and consider how long you’ll be in your current home. Read reviews, compare energy ratings, and don’t hesitate to consult a professional if you’re unsure about installation.

At the end of the day, the best air conditioner is the one that keeps you cool, saves you money, and fits seamlessly into your life. Whether you go window or through-wall, you’re taking a smart step toward beating the heat—and reclaiming your comfort, one cool breath at a time.

Frequently Asked Questions

What’s the main difference between a window air conditioner and a through-wall unit?

A window air conditioner sits in a window frame, while a through-wall unit is installed directly into a wall sleeve, offering a more permanent and streamlined fit. Through-wall models often require professional installation, whereas window units are DIY-friendly.

Which is more energy-efficient: window air conditioner vs through-wall?

Through-wall units are typically more energy-efficient due to a tighter seal and better insulation, reducing air leaks. However, high-efficiency window air conditioners with ENERGY STAR ratings can offer comparable performance at a lower upfront cost.

Can I install a through-wall air conditioner in any wall?

Not all walls are suitable—exterior walls are required, and the structure must support a sleeve installation. Check for obstructions like pipes or wiring, and consult a professional if unsure.

Are through-wall air conditioners quieter than window units?

Generally, yes. Through-wall units are set deeper into the wall, dampening noise, while window air conditioners can vibrate against the frame. Look for decibel ratings when comparing specific models.

Is it cheaper to buy a window air conditioner vs through-wall unit?

Window units are usually more affordable upfront, but through-wall models may save money long-term due to better efficiency and durability. Factor in installation costs if opting for a through-wall system.

Do through-wall air conditioners increase home value?

Yes, they can be seen as a built-in upgrade, especially in climates where cooling is essential. Unlike portable or window units, they’re considered permanent fixtures and often appeal to buyers.