Is a Through-the-Wall Air Conditioner Right for Your Home?

🏠 What Is a Through-the-Wall Air Conditioner?

A through-the-wall air conditioner, also known as a TTW AC, is a self-contained cooling unit that is installed directly into a wall. Unlike a window AC, which rests on your sill and sticks out both sides, TTW units sit snug inside a wall sleeve and are permanently mounted.

Key features:

• Installed through a wall cutout with a wall sleeve

• More secure and sealed than a window unit

• Doesn’t block your window or view

• Common in condos, apartments, hotels, and older homes without central air

🧱 Why They Exist

Not every home is built with ducts or central air in mind. In fact, many older properties—or even new apartments with limited space—need a cooling solution that doesn’t involve tearing apart walls for ductwork or mounting big compressors outdoors.

That’s where TTW ACs come in. They bridge the gap between window units and ductless mini-splits.

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💡 Who Should Consider a Through-the-Wall AC?

✅ Ideal Candidates:

🧰 Tony says: “If your home wasn’t built with air conditioning in mind, this might be the best ‘set-it-and-forget-it’ system short of a ductless mini-split.”

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⚖️ TTW vs. Other AC Types: How Do They Stack Up?

Here’s how a through-the-wall AC compares to other cooling systems:

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🛠️ Pros and Cons: Real-World Considerations

Let’s break it down:

✔️ Pros

✅ Doesn’t Block Your Window

TTW units keep your window free for light and airflow—ideal if you have limited window access.

✅ Better Security

No one can “push in” a wall unit from outside like they can with a window unit. Plus, it’s more weather-tight.

✅ Long-Term Durability

With the right wall sleeve and maintenance, a through-the-wall unit can last longer than many window ACs.

✅ Cleaner Look

No awkward overhanging window boxes. You get a more finished, integrated look inside and out.

✅ Energy Efficient Models Available

Units with high EER and SEER2 ratings are available and some qualify for Energy Star.

👉 Check Energy Star’s certified wall units

❌ Cons

❗ Wall Cutting Required

You’ll need to either retrofit an old wall sleeve or cut a hole in your wall—framing, insulation, and all.

❗ Not Easily Portable

Once installed, the unit stays there. You can’t easily move it from room to room like a portable or window AC.

❗ Electrical Load Needs Checking

Larger TTW units may need a dedicated 220V line—not every wall outlet is going to cut it.

❗ Professional Help Might Be Necessary

Unless you’re handy with framing and electrical, this isn’t a full DIY install.

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📐 Sizing a TTW AC Unit for Your Space

Before you buy, you need the right BTU rating for your space.

🔢 BTU Guidelines

🧰 Tony says: “Undersize it and it’ll run all day. Oversize it and you’ll get cold fast—but with no humidity control. Get the sizing right.”

🌞 Factor in:

• Ceiling height

• Sun exposure (southern-facing = hotter)

• Kitchen or heat-generating appliances

• Number of people in the room

👉 Energy.gov’s BTU calculator

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🔌 Electrical Requirements

Wall units vary between:

• 115V (standard household plug)

• 230V (requires special circuit)

🧯 Safety Considerations:

• Dedicated outlet

• Proper grounding

• Outdoor drip control

👉 GE’s installation PDF for TTW units

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🧱 What About Existing Wall Sleeves?

If your home already has a sleeve (common in older buildings and condos), make sure:

• Your new unit matches the dimensions

• You verify the airflow design (some units vent on sides vs. rear)

• Drainage and insulation are still functional

👉 Friedrich’s compatibility guide is helpful for retrofits.

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🔧 Installation Tips (DIY or Pro?)

Installing a through-the-wall AC is doable for experienced DIYers, but it's not simple. Key steps include:

1. Choose the location: Ideally on an exterior wall, with clear airflow inside and out.

2. Frame the hole: Support with 2x4s and install a weatherproof sleeve.

3. Insulate around the sleeve: Keeps bugs, water, and outside air out.

4. Slide in the unit and seal edges

5. Secure to power source and test

If you’re not confident cutting into your wall or running electrical, call a licensed HVAC tech or general contractor.

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💰 Cost Breakdown

Here’s a real-world price guide:

Total average installed cost: $800 – $2,000

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🧼 Maintenance: Keep It Running Cool

Wall units are easier to maintain than central air systems, but still need care.

🧽 DIY Checklist:

• Clean or replace air filter monthly

• Check drainage path for clogs

• Vacuum inside coils each season

• Reseal sleeve edges every 2–3 years

👉 Consumer Reports’ AC maintenance guide

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🌎 Energy Efficiency and Rebates

Many through-the-wall units now offer:

• Energy Star certification

• High EER (Energy Efficiency Ratio)

• Smart thermostats & WiFi control

Some states offer rebates for qualifying models:
👉 DSIRE’s state-by-state rebate database

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🔄 When NOT to Get a TTW Unit

You might want to skip through-the-wall ACs if:

• You rent and can’t cut into walls

• You move often and want portability

• You have multiple rooms to cool and may be better off with central air or a mini-split

• Your walls are concrete or load-bearing—making installation complicated or costly

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🛍️ Where to Buy

You can buy top TTW air conditioners at:

• The Furnace Outlet

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🧠 Final Take: Should You Go Through-the-Wall?

Yes, if:

• You own your home or unit

• You want permanent, secure cooling

• You value a quiet, efficient unit with a clean look

• You have a room that’s hard to keep cool

No, if:

• You’re renting or planning to move soon

• You want portability or whole-home cooling

• You’re not comfortable with wall modifications

🧰 Tony says: “It’s not for everybody—but if it’s right for you, it’ll cool better, look cleaner, and last longer than a window shaker.”

In the next topic we will read about: How to Size a Through-the-Wall AC: BTUs, Square Footage & Efficiency