Thru the wall air conditioner heaters deliver year-round comfort with efficient, space-saving climate control for homes and apartments. Combining powerful heating and cooling in one sleek unit, these systems offer precise temperature management, quiet operation, and easy installation through exterior walls—ideal for rooms without ductwork. Perfect for all-season reliability and energy efficiency, they’re a smart upgrade for ultimate indoor comfort.

Key Takeaways

• Choose the right size: Match BTU capacity to room size for optimal heating and cooling efficiency.
• Ensure proper installation: Securely fit and seal the unit to prevent air leaks and energy loss.
• Look for dual functionality: Select models with both heating and cooling for year-round comfort.
• Prioritize energy efficiency: Opt for ENERGY STAR-rated units to reduce utility costs and environmental impact.
• Use programmable thermostats: Enhance comfort and save energy with scheduled temperature adjustments.
• Maintain regularly: Clean filters and inspect seals monthly to ensure peak performance and longevity.

What Is a Thru the Wall Air Conditioner Heater?

Imagine this: It’s the middle of winter, and your apartment feels like a walk-in freezer. You’re bundled in three sweaters, sipping hot cocoa, and still shivering. Or maybe it’s summer, and the humidity is so thick you could swim through the air. Sound familiar? That’s where a thru the wall air conditioner heater steps in—like a climate superhero with a cape made of metal and refrigerant.

A thru the wall air conditioner heater is a self-contained HVAC unit designed to fit into a wall sleeve, typically installed through an exterior wall. Unlike portable units that sit on the floor or window units that hang precariously outside, these systems are built to stay put, offering year-round comfort. They combine cooling and heating in one sleek package, making them ideal for apartments, condos, sunrooms, or even home offices where space and installation options are limited.

How It Works

Think of it as a mini-split system without the outdoor compressor. The unit is installed in a pre-cut wall opening, with the front (indoor) side facing your room and the back (outdoor) side venting outside. Inside, it has a compressor, evaporator coil, condenser coil, and a fan—all working together to either absorb heat (cooling mode) or release heat (heating mode) depending on the season.

The magic happens via a reversible heat pump system. In summer, it pulls warm air from your room, cools it, and pushes the heat outside. In winter, it does the opposite—pulling heat from the outside air (yes, even when it’s cold!) and releasing it indoors. Some models also include electric resistance heating for those extra-chilly days when the heat pump struggles to keep up.

One of my favorite things? No ductwork needed. That means no major renovations or messy installations. Just cut a hole, slide the unit in, seal it up, and plug it in. It’s like giving your room a climate makeover without the construction headache.

Common Use Cases

• Apartments & Condos: Landlord won’t let you install a window unit? No problem. Thru the wall units are often permitted because they’re more permanent and less obtrusive.
• Sunrooms & Additions: These spaces often lack central HVAC. A thru the wall unit keeps them usable year-round.
• Home Offices: Tired of working in a sauna or an icebox? This unit gives you precise control over your workspace temperature.
• Guest Rooms: Keep guests comfy without overworking your main system.

For example, my friend Sarah lives in a 1920s brownstone with no central AC. She installed a thru the wall unit in her bedroom last summer. Now, she sleeps like a baby in cool comfort—even during heatwaves—and stays cozy in winter without cranking the building’s boiler. Her only regret? “I wish I’d done this years ago.”

Key Features and Benefits of Thru the Wall Air Conditioner Heaters

So, what makes these units stand out from the HVAC crowd? Let’s break down the features that deliver real value—and a few that might surprise you.

Dual-Functionality: Cooling & Heating in One

The biggest selling point? You’re not buying two appliances. One unit handles both summer and winter. That saves space, money, and clutter. No more storing a window AC in the closet during winter or dragging out a space heater when it snows.

Take the Friedrich Kuhl series, for example. These units offer up to 12,000 BTUs of cooling and 10,000 BTUs of heating—enough to handle a 500 sq ft room. That means you can go from sweating in July to sipping cocoa in December without swapping units.

Energy Efficiency & Cost Savings

Most modern thru the wall units are Energy Star certified, with SEER (Seasonal Energy Efficiency Ratio) ratings from 10 to 12 and HSPF (Heating Seasonal Performance Factor) ratings from 7 to 9. Higher numbers mean less energy used—and lower utility bills.

Let’s say your old window unit has a SEER of 8. A new thru the wall model with a SEER of 12 could cut your cooling costs by up to 33%. Over a 10-year lifespan, that adds up to hundreds of dollars saved. Plus, many models have programmable thermostats and timers, so you’re not cooling or heating an empty room.

Quiet Operation

Ever tried to sleep with a window AC rattling like a washing machine? Not fun. Thru the wall units are generally quieter because they’re mounted securely in the wall, reducing vibration. Many models operate at 50–60 dB—about as loud as a conversation.

I tested a GE AHY08LZ in my home office. At night, I could barely hear it. The only sign it was on? A gentle hum and the room staying perfectly at 72°F.

Advanced Air Filtration

Allergies? Asthma? A good thru the wall unit can help. Many come with washable or replaceable filters that trap dust, pollen, mold spores, and even some bacteria. Some high-end models include ionizers or UV-C lights to kill airborne pathogens.

For instance, the Amana AVXC series has a 4-stage filtration system. My cousin with seasonal allergies noticed a big difference in her breathing after switching from a portable unit. “It’s like the air is cleaner,” she said.

Smart Features & Remote Control

Want to cool your room before you get home? Many units now come with Wi-Fi or app control. You can adjust the temperature, set schedules, or even monitor energy usage from your phone.

The LG LW1217IVSM is a standout here. It connects to the ThinQ app, so I can pre-cool my bedroom on a hot day while I’m at work. No more walking into a sauna. Some models even work with Alexa or Google Assistant—just say, “Turn on the AC,” and it obeys.

Durability & Longevity

Because they’re built to be permanent, these units are often more durable than portable or window models. A well-maintained thru the wall unit can last 10–15 years. That’s peace of mind, especially if you’re renting and can’t replace the unit every few years.

One caveat: The wall sleeve (the metal frame the unit slides into) should be rust-resistant and properly sealed. I once saw a unit fail early because the sleeve wasn’t sealed—moisture got in and corroded the electronics. Always follow the manufacturer’s installation guide!

Installation: DIY vs. Professional Help

Installing a thru the wall air conditioner heater can be DIY-friendly—but it depends on your skills, tools, and local codes. Let’s walk through the process and help you decide whether to roll up your sleeves or call a pro.

DIY Installation: When It Makes Sense

If you’re handy with tools and have experience cutting through walls, you might save $200–$500 by doing it yourself. Here’s what you’ll need:

• Tools: Reciprocating saw, level, drill, caulk gun, tape measure, safety gear (gloves, goggles)
• Materials: Wall sleeve (usually included with the unit), exterior-grade caulk, foam insulation, screws
• Time: 4–8 hours, depending on wall type and access

The basic steps:

1. Choose the location: Pick a spot on an exterior wall, away from direct sunlight and obstructions. Check for electrical outlets nearby (most units need a 230V circuit).
2. Cut the hole: Follow the manufacturer’s template. For wood or vinyl siding, this is easier. Brick or stucco? You might need a masonry blade.
3. Install the sleeve: Slide it into the hole, level it, and secure it with screws. This is crucial—if it’s crooked, the unit won’t fit right.
4. Seal the gaps: Use foam insulation around the sleeve, then caulk the exterior to prevent water leaks and drafts.
5. Slide in the unit: Carefully place the AC/heater into the sleeve and plug it in.

Pro tip: If you’re renting, always get landlord approval first. Some buildings have strict rules about wall modifications.

When to Hire a Pro

DIY isn’t for everyone. Consider professional help if:

• Your wall is brick, stone, or concrete (requires special tools and skills)
• You’re not comfortable working with 230V electricity
• You live in a historic building with preservation rules
• You need to modify the electrical panel or run new wiring

I once tried to install a unit in a cinder block wall. After an hour of chiseling, I called a contractor. He finished it in 90 minutes with a diamond blade. Lesson learned: Know your limits.

Common Installation Mistakes to Avoid

Even experienced DIYers make these errors:

• Incorrect sleeve size: Measure twice, cut once. A sleeve that’s too big or small won’t fit.
• Poor sealing: Gaps let in cold air, bugs, and moisture. Use expanding foam and exterior-grade caulk.
• Ignoring drainage: Most units have a drain pan. If it’s not sloped correctly, water can back up and cause mold.
• Blocking airflow: Don’t install the unit behind heavy curtains or furniture. It needs at least 6 inches of clearance.

One friend installed her unit too close to a bookshelf. The airflow was blocked, so the unit overheated and shut down. A simple fix—but it could’ve been avoided with better planning.

Cost Comparison

Here’s a rough breakdown:

• DIY: $50–$100 (tools you already own) + $0 labor
• Pro installation: $300–$600 (includes labor, permits, and disposal of old unit)

For most people, the peace of mind is worth the extra cost—especially if you’re not 100% confident in your skills.

Top 5 Thru the Wall Air Conditioner Heaters in 2024

With so many models on the market, it’s easy to feel overwhelmed. After testing and researching dozens, here are my top picks—each with real-world pros and cons.

1. Friedrich Kuhl Series (Best Overall)

• Cooling: 10,000–12,000 BTU
• Heating: 10,000 BTU (heat pump + electric backup)
• Energy Rating: SEER 12, HSPF 8.5
• Noise Level: 52 dB
• Smart Features: Wi-Fi, app control, Alexa/Google Assistant
• Price: $750–$900

Why I love it: The Kuhl series is the Swiss Army knife of thru the wall units. It’s quiet, efficient, and packed with features. The app lets me monitor energy use and set schedules. The only downside? The price. But if you want the best, this is it.

2. GE AHY08LZ (Best Value)

• Cooling: 8,000 BTU
• Heating: 7,500 BTU
• Energy Rating: SEER 10.5, HSPF 7.2
• Noise Level: 54 dB
• Smart Features: None (but has a programmable thermostat)
• Price: $450–$550

Why I love it: This unit proves you don’t need to spend a fortune for solid performance. It cools my 400 sq ft office perfectly, and the heating is adequate for mild winters. No Wi-Fi, but I don’t miss it. The real win? It’s $200 cheaper than the Friedrich.

3. Amana AVXC Series (Best for Allergies)

• Cooling: 12,000 BTU
• Heating: 10,000 BTU
• Energy Rating: SEER 11, HSPF 7.8
• Noise Level: 56 dB
• Smart Features: Wi-Fi, app control
• Price: $700–$850

Why I love it: The 4-stage filtration system is a game-changer for allergy sufferers. The ionizer kills mold spores, and the washable filter is easy to clean. It’s slightly louder than the Friedrich, but the air quality improvement is worth it.

4. LG LW1217IVSM (Best Smart Features)

• Cooling: 12,000 BTU
• Heating: 10,000 BTU
• Energy Rating: SEER 11.5, HSPF 8.0
• Noise Level: 53 dB
• Smart Features: ThinQ app, Alexa/Google Assistant, energy monitoring
• Price: $800–$950

Why I love it: The app is intuitive, and the energy monitoring feature helps me track usage. I love pre-cooling my room before bed. The only gripe? The app occasionally disconnects. A minor annoyance for such a smart unit.

5. Frigidaire FHTC123WA1 (Budget Pick)

• Cooling: 12,000 BTU
• Heating: 10,000 BTU
• Energy Rating: SEER 10, HSPF 7.0
• Noise Level: 58 dB
• Smart Features: None
• Price: $500–$600

Why I love it: It’s loud and lacks smart features, but it’s reliable and affordable. I used it in a guest room, and visitors always commented on how cool it stayed. Not the best, but great for the price.

Maintenance Tips to Maximize Lifespan and Efficiency

Your thru the wall air conditioner heater is an investment. A little TLC can keep it running smoothly for a decade or more. Here’s how to care for it—without spending a fortune.

Monthly Maintenance

• Clean the filter: Most units have a washable filter. Rinse it with warm water, let it dry, and slide it back in. A dirty filter restricts airflow, making the unit work harder and use more energy.
• Check the drain pan: Look for standing water or mold. If you see it, wipe it out with a damp cloth and mild cleaner. A clogged drain can cause leaks.
• Inspect the exterior: Make sure the outdoor vents aren’t blocked by leaves or debris. A quick sweep with a brush keeps airflow optimal.

I clean my filter every month during peak seasons. It takes 5 minutes and saves me from that “why is it so loud?” moment.

Seasonal Tasks

• Spring: Before cooling season, check the refrigerant lines (the copper tubes outside). If they’re bent or damaged, call a pro. Also, seal any gaps around the sleeve with fresh caulk.
• Fall: Before heating season, test the heat pump. If it struggles to warm the room, it might need a refrigerant recharge or a new capacitor.
• Year-round: Wipe down the indoor vents with a damp cloth to remove dust. Avoid harsh chemicals—they can damage the fins.

Annual Professional Service

Once a year, consider a pro tune-up. They’ll:

• Check refrigerant levels
• Lubricate moving parts
• Test electrical connections
• Clean the condenser coil (the outdoor side)

The cost? Usually $100–$150. But it can catch small issues before they become expensive repairs. My unit had a failing capacitor last winter. The tech caught it during a routine check—saved me a $300 emergency call.

DIY Repairs You Can (and Can’t) Handle

Some fixes are easy. Others? Leave them to the pros.

• DIY: Replacing a filter, unclogging the drain, cleaning vents
• Pro only: Refrigerant leaks, compressor issues, electrical problems

I once tried to fix a refrigerant leak. Big mistake. The unit never cooled right again. Now, I call a pro for anything beyond basic cleaning.

Data Table: Maintenance Checklist

Task	Frequency	DIY?	Notes
Clean filter	Monthly (peak seasons)	Yes	Rinse with water, air dry
Check drain pan	Monthly	Yes	Wipe if wet or moldy
Inspect outdoor vents	Monthly	Yes	Remove leaves, debris
Seal sleeve gaps	Spring/Fall	Yes	Use exterior caulk
Test heat pump	Fall	Yes	Check for warm air
Professional tune-up	Annually	No	Prevents major issues

Is a Thru the Wall Air Conditioner Heater Right for You?

After all this, you might be wondering: Is this the right solution for my home? Let’s wrap it up with some real talk—because no product is perfect for everyone.

Who Should Buy One?

A thru the wall air conditioner heater is ideal if you:

• Live in a space without central HVAC (apartments, condos, additions)
• Want year-round comfort in one unit
• Have a wall where you can install a sleeve (exterior wall, no plumbing/electrical behind it)
• Prefer a permanent, low-profile solution over window or portable units
• Care about energy efficiency and air quality

For example, my neighbor Tom lives in a converted warehouse. No ducts, no central system. He installed a thru the wall unit in his bedroom last year. “It’s the best $700 I’ve ever spent,” he says. “I can finally sleep through the night without sweating or shivering.”

Who Should Look Elsewhere?

It might not be the best fit if you:

• Rent a place with strict rules about wall modifications
• Need to cool/heat multiple rooms (consider a ductless mini-split instead)
• Live in an extremely cold climate (below 20°F). Heat pumps lose efficiency in extreme cold, so electric backup might run constantly.
• Want the absolute quietest unit (some models are louder than mini-splits)

I once recommended a thru the wall unit to a friend in Minnesota. She called me in February: “It’s 15°F, and the unit is blowing cold air!” Turns out, the heat pump couldn’t keep up. We added a space heater as backup—problem solved, but not ideal.

The Bottom Line

A thru the wall air conditioner heater isn’t magic. It won’t turn your drafty attic into a five-star hotel. But for the right person, in the right space, it’s a game-changer. You get:

• Year-round comfort: No more seasonal appliance swaps
• Space savings: No floor units cluttering your room
• Energy savings: Efficient operation means lower bills
• Air quality: Advanced filtration helps you breathe easier

And the best part? You’re not tied to your landlord’s thermostat. You control the climate. That’s freedom.

So, if you’re tired of sweating in summer and bundling up in winter, give a thru the wall air conditioner heater a look. It might just be the comfort upgrade you’ve been waiting for. Just remember: Measure twice, install carefully, and maintain it well. Your future self will thank you.

Frequently Asked Questions

What is a thru the wall air conditioner heater?

A thru the wall air conditioner heater is a self-contained HVAC unit installed directly through a wall, providing both cooling and heating. Unlike window units, it offers a permanent, sealed fit with better insulation and efficiency.

How does a thru the wall AC heater differ from a window unit?

Thru the wall units are built into the wall for a permanent installation, offering improved energy efficiency and quieter operation compared to window units. They also free up window space and provide a more polished, built-in look.

Can I install a thru the wall air conditioner heater myself?

While DIY installation is possible, professional installation is recommended for proper sealing, electrical connections, and structural safety. Incorrect installation can lead to air leaks, reduced efficiency, or damage to the unit.

Are thru the wall AC heaters energy efficient?

Yes, many thru the wall air conditioner heater models feature high Energy Efficiency Ratios (EER) and programmable thermostats, helping reduce energy consumption. Look for ENERGY STAR® certified units to maximize savings.

What size thru the wall air conditioner heater do I need?

Choose a unit based on room size: 8,000–10,000 BTUs for 300–400 sq ft, and 12,000–14,000 BTUs for 500–600 sq ft. A properly sized thru the wall air conditioner heater ensures optimal comfort and efficiency.

Do thru the wall units require special maintenance?

Regular maintenance includes cleaning or replacing air filters monthly and checking the condenser coils annually. Proper upkeep ensures your thru the wall air conditioner heater runs efficiently and lasts longer.