Through the wall air conditioners offer a permanent, energy-efficient cooling solution ideal for rooms without windows or limited space. Top models combine high BTU performance, quiet operation, and smart features like remote controls and programmable timers for maximum comfort and convenience. Choose a properly sized unit and ensure professional installation for optimal efficiency and long-term reliability.

Key Takeaways

• Measure your wall opening accurately: Ensure a proper fit to avoid air leaks and inefficiency.
• Choose the right BTU rating: Match cooling capacity to room size for optimal performance.
• Prioritize energy efficiency: Look for ENERGY STAR models to reduce electricity costs.
• Check noise levels: Select units with low decibel ratings for quieter operation.
• Install with a proper seal: Prevent drafts and moisture with secure, insulated mounting.
• Maintain regularly: Clean filters and vents to sustain efficiency and air quality.

What Is a Through the Wall Air Conditioner?

Imagine this: It’s the middle of summer, and your apartment feels like a sauna. You’re sweating through your shirt, fanning yourself with a magazine, and dreaming of a cool breeze. But your window is too narrow for a standard window AC, and you don’t want to block your only source of natural light. Enter the through the wall air conditioner—a sleek, permanent solution that cools your space without sacrificing views or airflow.

Unlike traditional window units, these ACs are installed directly into a wall, usually in an exterior wall, and vent hot air outside while circulating cool air indoors. They’re ideal for apartments, older homes, or rooms where window units just don’t fit. Whether you’re a renter with limited options or a homeowner looking for a clean, built-in look, a through the wall AC might be your summer savior. In this guide, we’ll walk you through everything you need to know—from how they work to the best models on the market and how to install them safely and efficiently.

How Through the Wall Air Conditioners Work

The Basic Mechanics

At first glance, a through the wall air conditioner looks like a window unit that’s been “squeezed” into a wall. But the truth is, it’s a bit more sophisticated. These units are designed to sit in a custom sleeve—a metal or plastic housing—that’s built into the wall. The sleeve seals the unit and directs airflow properly, keeping cool air in and hot air out.

The AC draws in warm indoor air, passes it over refrigerant-cooled coils, and pushes the cooled air back into the room. Meanwhile, the heat extracted from the indoor air is expelled outside through the back of the unit. Most models also include a fan-only mode, a dehumidifier setting, and remote controls for convenience.

One key difference from window units? Through the wall ACs are permanent. Once installed, they stay put. That means you need to plan carefully—choose the right wall, ensure proper electrical access, and consider future removal (especially if you’re a renter).

Ventilation and Airflow: The Secret to Efficiency

Efficient airflow is what separates a good through the wall AC from a dud. Look for models with dual exhaust fans or multi-directional vents that spread cool air evenly across the room. Some units even have oscillating louvers that gently sweep side to side, mimicking a ceiling fan’s motion.

For example, the Frigidaire FHTC103WB1 has a 3-speed fan with auto-oscillation, which means no more hot spots in the corners of your bedroom. It’s like having a personal cooling breeze that follows you around the room.

Another thing to watch: air filter placement. Most through the wall units have washable filters on the front or side. Easy access means you can clean them monthly—keeping your air fresh and your AC running efficiently. A clogged filter can reduce cooling power by up to 15%, so don’t skip this step!

Energy Efficiency and BTU Sizing

BTU (British Thermal Unit) is the magic number when choosing any AC, but it’s especially important for through the wall models. Too small, and it’ll run nonstop, driving up your electric bill. Too big, and it’ll cool too quickly without removing humidity, leaving you with a cold, damp room.

Here’s a simple rule of thumb:

• 150–250 sq. ft.: 6,000–8,000 BTU
• 250–400 sq. ft.: 8,000–10,000 BTU
• 400–650 sq. ft.: 10,000–14,000 BTU

For example, a 10,000 BTU unit like the Keystone KSTAW10A is perfect for a medium-sized bedroom or home office. But if you’re cooling a large open-concept living room, you might need a 14,000 BTU model—or even two smaller units in different areas.

Pro tip: Look for the Energy Efficiency Ratio (EER). The higher the EER (usually 9.0+), the less electricity the unit uses. Some models, like the LG LW1017ERSM, have EER ratings over 12.0—great for eco-conscious users and lower utility bills.

Top 5 Through the Wall Air Conditioners in 2024

1. LG LW1017ERSM – Best Overall

The LG LW1017ERSM is a standout for a reason. With 10,000 BTU, it cools rooms up to 450 sq. ft. efficiently. It features:

• Smart cooling with Wi-Fi control via the LG ThinQ app
• Energy Star certified (EER: 12.1)
• Quiet operation (as low as 50 dB)
• Washable, anti-bacterial filter

One user in a 400 sq. ft. studio said, “I can control it from my phone when I’m on my way home. By the time I walk in, it’s like walking into a crisp fall day.”

The only downside? It requires a 230V electrical outlet, so older homes may need an electrician to upgrade the circuit.

2. Frigidaire FHTC103WB1 – Best for Small Spaces

If you’re cooling a small bedroom or office, the Frigidaire FHTC103WB1 (10,000 BTU) is a solid choice. It’s compact, easy to install, and has:

• 3 fan speeds and 4-way air direction
• Auto-restart after power outages
• 24-hour programmable timer
• Remote control included

It’s not Wi-Fi enabled, but that’s fine if you don’t need smart features. Plus, it runs on a standard 115V outlet—no electrician needed.

One reviewer noted, “I installed it myself in a day. The sleeve was pre-cut, and the instructions were clear. It’s quiet enough to sleep with on low.”

3. Keystone KSTAW10A – Best Budget Pick

For under $400, the Keystone KSTAW10A delivers solid performance. It’s 10,000 BTU, Energy Star rated, and includes:

• Electronic controls with LED display
• Sleep mode (gradually increases temperature over time)
• Washable filter with filter alert

It’s a bit louder than premium models (55 dB), but for the price, it’s hard to beat. Ideal for renters or those on a tight budget.

Note: The sleeve is sold separately, so factor that into your total cost (around $50–$70).

4. Friedrich UCT12B10A – Best for Large Rooms

Need to cool a big space? The Friedrich UCT12B10A (12,000 BTU) handles up to 650 sq. ft. with ease. It’s built for durability, with:

• Heavy-duty compressor for long-term use
• Corrosion-resistant cabinet
• Remote control with thermostat sensor (adjusts cooling based on your location in the room)

One user in a 600 sq. ft. apartment said, “It cools the whole place in under 20 minutes. The remote’s ‘follow me’ mode is genius—I don’t have to keep adjusting the temp.”

The downside? It’s pricier (around $600–$700) and requires a 230V outlet.

5. GE AHY10LZ – Best for Easy Installation

If you’re a DIY newbie, the GE AHY10LZ is your friend. It comes with a universal fit sleeve that works with most standard wall openings. Features include:

• 10,000 BTU cooling
• 24-hour timer and sleep mode
• Washable filter with indicator light
• 115V operation

One reviewer wrote, “I’m not handy at all, but the sleeve was easy to install. The unit slid in like butter. No leaks, no noise issues.”

It’s not the quietest (56 dB), but it’s reliable and user-friendly.

Installation Guide: DIY or Hire a Pro?

DIY Installation: What You Need to Know

Installing a through the wall AC yourself is possible, but it’s not a “plug and play” job. You’ll need:

• A stud finder
• Level
• Jigsaw or reciprocating saw
• Drill
• Measuring tape
• Weatherproof sealant (like silicone caulk)

Here’s a simplified step-by-step:

1. Choose the wall: Pick an exterior wall, ideally shaded or away from direct sun. Avoid walls with plumbing or electrical wiring.
2. Check the sleeve size: Most units require a 26″ x 16″ opening, but check your model’s manual.
3. Cut the hole: Use a jigsaw to cut through drywall and siding. Be careful—this is permanent!
4. Install the sleeve: Slide the metal or plastic sleeve into the hole. Secure it with screws and seal all edges with caulk to prevent drafts and water leaks.
5. Mount the AC: Slide the unit into the sleeve. Connect the power (if it’s 230V, hire an electrician).
6. Test and seal: Turn it on, check for airflow, and seal any gaps with foam insulation or caulk.

One user shared, “I spent a Saturday installing mine. The hardest part was cutting through the stucco. But once it was in, it looked so clean—like it was meant to be there.”

When to Hire a Professional

DIY is great for handy folks, but there are times when you should call in a pro:

• Electrical work: If your unit requires a 230V outlet and you don’t have one, hire a licensed electrician. Messing with circuits can be dangerous.
• Structural walls: Cutting into a load-bearing wall or brick/concrete requires expert knowledge.
• Leaks or poor insulation: If you notice water inside the room or drafts, it’s likely a poor seal. A pro can fix it with proper flashing and sealing.
• Rental properties: Some landlords require professional installation to maintain warranties or insurance.

One installer told us, “I see 5–10 botched DIY jobs a year. Most are fixable, but it costs more to repair than to do it right the first time.”

Maintenance Tips to Extend Lifespan

Like any appliance, a through the wall AC needs care. Here’s how to keep it running smoothly:

• Clean the filter monthly: Rinse with warm water and let it dry before reinstalling.
• Check the exterior vents: Make sure nothing is blocking the airflow (like leaves or debris).
• Inspect the sleeve seal: Every spring, check for gaps or cracks. Re-caulk if needed.
• Drain the condensate: Some units have a drip pan. Empty it if water pools.
• Schedule a yearly check: A technician can clean coils, check refrigerant, and ensure everything is working safely.

One user said, “I clean my filter every month and haven’t had a single issue in 4 years. It’s still as efficient as the day I bought it.”

Through the Wall vs. Window AC: Which Is Right for You?

Space and Aesthetics

Window units are great for renters who want a temporary fix. But they block natural light, take up window space, and can look bulky. A through the wall AC, on the other hand, sits flush with the wall. It’s sleek, clean, and doesn’t obstruct your view.

Example: A friend installed a through the wall unit in her home office. “Now I have a full wall of windows,” she said. “I can see the garden, and the AC blends right in.”

Noise Levels

Through the wall units are often quieter than window models. Why? The compressor is mounted in the wall, away from the room. Plus, the sleeve acts as a sound buffer. Most through the wall ACs run between 50–56 dB—about as loud as a quiet conversation.

Window units, by contrast, sit right at head level. Even “quiet” models can be 55–60 dB, which might be disruptive in a bedroom.

Energy Efficiency and Cost

Through the wall units are generally more energy-efficient. They’re better sealed, so less cool air escapes. Plus, they don’t rely on flimsy window seals that degrade over time.

But they’re more expensive upfront. A window unit might cost $200–$300. A through the wall AC? $350–$700, plus $50–$100 for the sleeve and potential electrical upgrades.

Over time, though, the energy savings can offset the cost. One study found that a 12,000 BTU through the wall AC uses 10–15% less electricity than a comparable window unit.

Installation Flexibility

Window ACs can be installed in almost any window. Through the wall units need a specific hole in an exterior wall. That means they’re less flexible if you move or renovate.

But if you’re in a long-term space and want a permanent, efficient solution, through the wall is the way to go.

Data Table: Through the Wall AC Comparison

Model	BTU	EER	Voltage	Noise (dB)	Price (Approx.)	Best For
LG LW1017ERSM	10,000	12.1	230V	50	$550	Smart homes, energy efficiency
Frigidaire FHTC103WB1	10,000	10.8	115V	52	$450	Small rooms, easy install
Keystone KSTAW10A	10,000	10.5	115V	55	$380	Budget buyers
Friedrich UCT12B10A	12,000	11.2	230V	54	$650	Large rooms, durability
GE AHY10LZ	10,000	10.9	115V	56	$420	DIY beginners

Final Thoughts: Is a Through the Wall AC Worth It?

Let’s be honest: A through the wall air conditioner isn’t for everyone. It’s a commitment—a permanent change to your home. But if you’re tired of window units that leak, block light, or just don’t fit, it’s a game-changer.

You get a cleaner look, better efficiency, and quieter operation. Yes, installation is more involved, and the upfront cost is higher. But think of it as an investment in comfort. Once it’s in, you’ll enjoy cool, consistent air for years—without the hassle of seasonal setup.

And remember: through the wall air conditioners aren’t just about cooling. They’re about creating a space where you can relax, sleep, and live without sweating through your sheets. Whether you choose a smart LG, a budget-friendly Keystone, or a heavy-duty Friedrich, pick the one that fits your space, your needs, and your lifestyle.

So, next time you’re sweltering in the heat, don’t settle for a temporary fix. Consider a through the wall AC. It might just be the upgrade your home—and your sanity—deserves.

Frequently Asked Questions

What is a through the wall air conditioner?

A through the wall air conditioner is a self-contained unit installed directly into an exterior wall, offering efficient cooling without taking up window space. Unlike window units, these are designed for permanent or semi-permanent installation and often provide better insulation and quieter operation.

How do I choose the right size through the wall air conditioner?

To select the correct size, calculate the square footage of the room and match it to the unit’s BTU (British Thermal Unit) rating—typically 8,000–14,000 BTUs for standard rooms. A properly sized through the wall air conditioner ensures optimal efficiency and comfort without overworking the system.

Can I install a through the wall air conditioner myself?

While possible, professional installation is recommended due to the need for precise wall cutting, electrical wiring, and sealing to prevent air leaks. DIYers with advanced skills can manage it, but improper installation may void warranties or reduce efficiency.

Are through the wall air conditioners energy efficient?

Yes, many modern through the wall air conditioners have high CEER (Combined Energy Efficiency Ratio) ratings and features like programmable thermostats or eco modes. Look for ENERGY STAR® certified models to maximize energy savings and reduce utility costs.

Do through the wall air conditioners require maintenance?

Regular maintenance includes cleaning or replacing filters monthly, checking the condenser coils, and ensuring the wall sleeve is sealed and debris-free. Proper upkeep extends the unit’s lifespan and maintains peak performance.

What are the best brands for through the wall air conditioners?

Top brands include Friedrich, Frigidaire, and GE, known for reliability, quiet operation, and advanced features like remote controls and smart compatibility. Always compare warranties, noise levels, and customer reviews when choosing a model.