Pre-Install Checklist — Sizing Tools and Must-Have Gear Before You Cut

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✏️ Measure Twice, Cut Once — The Wall Unit Way

The first time I installed a through-the-wall air conditioner, I had that nervous mix of excitement and dread. I could already picture the comfort it would bring — steady cooling, quiet operation, no more clunky window units. But there was one very permanent part of the process that made me hesitate: cutting a hole in my wall.

I remember standing there with a pencil, tape measure, and growing anxiety, thinking: “What if I mess this up?”

That’s when I learned my first rule of wall installs:

“You only get one shot at a clean cut — and it starts with the right prep.”

Over the years, I’ve helped friends, neighbors, and clients install through-the-wall units like the Amana 11,900 BTU model, and I can confidently say 90% of the problems people face (noise, leaks, poor cooling) start with poor measuring or missing tools.

This checklist is everything I wish I’d known before cutting into drywall for the first time — a simple, Savvy-approved guide to measuring, planning, and prepping your wall before your unit ever comes out of the box.

📏 Step 1: Know Your Wall (and What’s Inside It)

Before you even think about sawing, take time to understand your wall’s structure and depth.

Most modern homes use 2x4 stud framing with drywall, but older homes or basements may have brick, plaster, or concrete walls. The type of wall determines what kind of saw, sleeve, and anchors you’ll need.

🔍 Here’s what I do first:

Find the studs.
Use a stud finder to mark vertical framing members. You want your AC between them — not through them.
Check for wires and pipes.
Always assume something could be behind the wall. I use my small inspection hole trick: cut a 3x3-inch square to peek inside before the main cut.
Measure wall depth.
The Amana unit’s wall sleeve requires a minimum wall thickness of around 8 inches. Measure from inside drywall to exterior siding or brick.

🔧 Savvy Tool Pick:

👉 Laser Distance Measurer
It’s faster and more accurate than tape. I measure depth, height, and width in seconds — no math errors, no second guesses.

Reference: U.S. Department of Energy — Room AC Install Basics.

🔢 Step 2: The Sizing Formula — BTUs That Fit the Room

Getting the right BTU rating is where comfort begins. An oversized unit short-cycles and wastes energy. An undersized one runs endlessly, fighting a losing battle.

Here’s my go-to BTU formula for through-the-wall systems:

BTUs = (Length × Width × Height ÷ 500) × Adjustment Factors

Let’s do my actual living room as an example:

22 ft (L) × 16 ft (W) × 9 ft (H) = 3,168 cubic feet
Divide by 500 = 6.3
Add 30% for open layout, high ceiling, and west-facing windows

6.3 × 1.3 = 8.19 → ~8,200 BTUs base need

For humid climates or bright rooms, I add another 10–15%. That’s why the Amana 11,900 BTU unit hits my perfect target — it’s slightly above the base requirement, ensuring consistent, quiet comfort.

If you’re unsure, the Energy Star sizing guide provides room-to-BTU charts to double-check your math.

🧰 Step 3: The Complete Pre-Install Toolkit

Cutting into your wall without the right gear is like baking without measuring cups. You might get something close, but not precise.

I’ve organized my essentials into four tool categories:

🧮 Measuring & Layout Tools

Tool	Why It Matters
Laser Distance Measurer	Accurate, fast, and reliable room and wall depth measurement
Stud Finder	Keeps you from hitting framing members
Carpenter’s Square	Ensures your sleeve cutout stays perfectly level
Painter’s Tape	Safe for marking cut lines on painted surfaces
Pencil or Chalk Line	For permanent layout marks

💡 Tip: Tape out your unit’s outline on the wall before cutting. Stand back and visualize airflow — you’ll instantly know if it’s too high or too close to furniture.*

🪚 Cutting & Framing Tools

Tool	Why It Matters
Oscillating Multi-Tool	Clean, controlled cuts through drywall or paneling
Drill with Masonry Bit	For brick or concrete walls
Level	Keeps the sleeve from sloping unevenly
Screwdriver & Anchor Kit	Secure sleeve without vibration

If you’re working on concrete, consider renting a rotary hammer drill. Through-the-wall ACs demand precision mounting — the sleeve can’t wobble.

🔩 Mounting & Sealant Essentials

Part	Use
Wall Sleeve (compatible with Amana model)	Structural support & weatherproof frame
Foam Gasket Kit	Reduces vibration & noise
Silicone Caulk	Seals around sleeve to block moisture
Mounting Screws & Anchors	Secure sleeve in various wall materials

Never skip the wall sleeve — it’s the difference between a 10-year install and a 10-month mistake.

Reference: Amana Installation & Sleeve Compatibility Guide .

🦺 Safety Gear

Tool	Use
Goggles	Protect from drywall dust
Gloves	Prevent cuts and burns
Dust Mask	Keeps insulation and sawdust out of your lungs
Drop Cloth	Protects flooring from debris

“A clean install starts with clean safety habits.”

🧱 Step 4: Understanding the Wall Sleeve — Your System’s Backbone

If you’re new to wall ACs, here’s the rule: the sleeve goes in first. Always.

It supports the entire unit, seals against air leaks, and absorbs vibration. Without it, your AC can rattle, leak condensation, or even shift out of place.

When choosing a sleeve:

Match it exactly to your Amana model.
Check sleeve depth against your wall.
Verify the rear drain holes are angled slightly downward (for condensation runoff).

If you’re replacing an older AC, resist the urge to reuse the old sleeve unless it’s the same brand and dimensions. Even a half-inch difference can cause efficiency loss or leaks.

⚡ Step 5: Power Prep — Electricity Before Airflow

Wall ACs are more powerful than window units — they need dedicated circuits.

The Amana 11,900 BTU model uses a 230/208V plug, not a standard 115V household outlet. That means:

It must be connected to a dedicated breaker.
Extension cords are never allowed.
The outlet should sit within 4 feet of the install location.

If you’re not comfortable handling wiring, hire a licensed electrician. It’s a one-time job that guarantees years of safe, efficient operation.

Reference: National Electrical Code Overview .

⚡ Pro Tip: Confirm voltage before purchasing. Many DIYers accidentally buy 115V units, then discover their wall circuit can’t handle the upgrade.*

🌬️ Step 6: Airflow Planning — Think Like Air

Most people overlook this step — and it’s the one that makes or breaks performance.

Your Amana wall unit should be installed:

3–5 feet from the floor (for balanced air circulation)
At least 12 inches from corners or other walls
Away from direct sunlight or curtains

Use painter’s tape to “map out” the airflow zone. Sit where you’ll actually spend time (sofa, desk, bed) and ensure airflow reaches you, not the wall behind you.

Reference: Energy Star – Optimal Placement Tips.

💬 “If air hits your furniture, it never hits you.”

🔧 Step 7: The Pilot Cut Trick

Before committing to a full cutout, I always start small. I cut a pilot square (about 4x4 inches) where the center of my sleeve will go.

Then I shine a flashlight in and check for:

Wiring
Plumbing
Stud placement
Insulation type

This five-minute step has saved me hundreds of dollars in patching jobs.

Once confirmed, I use a level and chalk line to extend the full sleeve outline before cutting completely through.

🧩 Step 8: The “Dry Run” — Mock Installation

One of the best parts about through-the-wall ACs is that you can test fit everything before committing.

My Dry Run Process:

Place the sleeve inside the outline (without mounting).
Check for levelness — add shims if necessary.
Confirm the downward tilt (about ¼ inch) for condensation drainage.
Make sure the power outlet aligns properly.
Note any gaps or uneven edges.

If all looks good, remove the sleeve, clean up, and make the final cut.

🧊 Step 9: Post-Cut Cleanup & Seal Prep

After cutting the wall opening:

Vacuum debris immediately.
Inspect edges for splinters or insulation damage.
Insert foam insulation between sleeve and wall cavity to prevent air leaks.
Apply silicone sealant around sleeve perimeter before final screw mounting.

This step ensures your installation looks polished and performs efficiently for years.

“The invisible details — insulation, slope, seal — are what make your system feel premium.”

🧠 Step 10: Confidence Before Commitment

Take a deep breath. Step back. Check your measurements one last time.

Does your sleeve sit level?
Is your outlet within reach?
Are your studs clear and airflow optimized?

Then, and only then, it’s time to cut.

Once the Amana unit slides into place, you’ll instantly see why prep matters — it fits flush, runs quietly, and looks like it was built into your home, not forced into it.