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What’s the Best Spot in the Wall? Height, Placement & Airflow Tips from Mike

When it comes to installing a through-the-wall air conditioner like the GE AJEQ12DWJ, most homeowners think the brand, BTUs, and features matter the most. But I’ll tell you something almost no one talks about: placement is just as important as the unit you choose.

Put a great AC in the wrong spot and you’ll get:

uneven cooling
noisy operation
poor airflow
hot and cold spots
higher power bills
premature wear on the compressor

Put an average AC in the right spot and it’ll feel like you upgraded to a premium model. Placement makes that much of a difference.

Today I’m going to walk you through exact wall height, ideal room position, airflow angles, how far the air should travel, and the mistakes I see homeowners make constantly. This is the stuff technicians learn through years of installing units in real homes—bedrooms, offices, apartments, workshops, and everything in between.

1. The #1 Rule: Don’t Just “Pick a Wall”—Pick the Right Wall

Homeowners tend to install through-the-wall ACs where it’s easiest:

shortest distance to the outside
closest to an electrical outlet
spot where an old unit existed

But the right location considers:

airflow direction
heat load in the room
furniture layout
ceiling height
window sunlight
doorways and vents
noise levels for sleeping areas

Your AC shouldn’t work around your furniture.
Your furniture should work around your AC.

Let’s break it down.

2. Ideal Height for Installing a Through-the-Wall AC

Most wall units land between 18 and 48 inches off the floor, but the sweet spot is very specific.

Mike’s Ideal Height: 24–36 inches from the floor

Why?

This height gives the best balance of airflow spread across the room.
Cool air naturally sinks → you don’t want the unit too low.
Heat from the electric coil distributes more evenly when it's not installed near the ceiling.
It reduces noise transfer as the unit doesn’t blast right at head level when you're sitting or sleeping.

Reference: HVAC Air Distribution and Comfort Standards

Why Not Higher? (Above 48”)

If the unit is too high:

cool air dumps down the wall instead of projecting forward
airflow circulation suffers
thermostat misreads room temperature
heat gets trapped up near the ceiling

You end up with a system that short cycles, freezes up, or constantly runs on high because the thermostat thinks the room is warmer than it is.

Why Not Lower? (Below 18”)

If installed too low:

cool air immediately pools at the floor
hot air remains high and unconditioned
your energy use jumps
the unit works harder, louder, longer

Most rooms cool unevenly with a low wall unit.

3. The Best Wall in the Room (And the Worst)

I’ve installed enough wall ACs to say this confidently:

Best Spot: The Longest Unbroken Wall in the Room

This gives:

maximum air throw
balanced circulation
stable airflow without hitting corners
minimal turbulence

Reference: Residential Airflow Optimization Principles

Worst Spot: A Narrow Wall or Corner Wall

Here’s what happens:

airflow hits the adjacent corner → bounces back
creates turbulence and “dead spots”
increases sound
reduces effective cooling

Avoid corner walls at all costs.

4. Where Should the Air Blow? (Direction Matters More Than Most People Realize)

Most homeowners don’t think about where the cold air is going—but this is one of the biggest factors in comfort.

Ideal Airflow Target: Across the Longest Direction of the Room

So if your room is:

12 ft × 18 ft → point air toward the 18 ft side
10 ft × 14 ft → aim toward the 14 ft side

Long-throw airflow cools the entire space evenly.

Never Blow Directly Toward:

your bed
your couch
your dining table
your workstation

Why?

Because it feels like a cold draft, not cooling.
You end up raising the temperature — which defeats the whole purpose.

Avoid Blowing Air at:

curtains
plants
tall cabinets
wall corners

These deflect air and cause loud airflow noise.

Reference: Indoor Climate Zoning and Load Distribution Practices

5. Sunlight Exposure: Install Opposite the Hot Wall

Every home has one “trouble wall” — the one that gets hammered by afternoon sun. You never want to install the AC directly under that sun-load because the AC will constantly fight the heat pouring in.