What to Know Before Installing a Through-the-Wall Air Conditioner

🧊 Introduction: Planning for a Smooth Installation

Installing a through-the-wall air conditioner like the GE 12,000 BTU AKEQ12DCJ is not just about cutting a hole and sliding the unit in. Done right, it provides years of reliable, efficient comfort without blocking your windows. Done wrong, it can lead to drafts, water damage, electrical issues, and expensive repairs.

Tony, our trusted HVAC expert, says:

“Measure twice, cut once, and always check your electrical before starting.”

This guide will walk you through:

• Measuring and sizing your wall space

• Electrical requirements

• Wall sleeve installation

• Drainage planning

• Insulation and sealing

• Safety considerations

📏 Measuring and Sizing Your Space

Before you start: ✅ Measure the width and height of your unit, including clearance recommendations from the manufacturer. ✅ Check wall thickness; most through-the-wall ACs fit walls 5–8 inches thick. ✅ Mark the area on the wall, ensuring clearance from studs and electrical wiring.

Tip: Use a stud finder to avoid cutting into structural supports. If you must cut a stud, a header and support framing will be required.

Reference: Family Handyman Wall Framing

⚡ Electrical Requirements

Many through-the-wall ACs, including the GE 12,000 BTU, require 208/230V power and a dedicated 15–20A circuit.

✅ Verify your panel has available capacity. ✅ Check for an accessible location to install a new circuit if needed. ✅ Hire a licensed electrician if you’re not experienced with high-voltage installations.

Reference: Home Electrical Load Guide

🪟 Wall Sleeve Installation

A wall sleeve supports your unit, insulates the cutout, and helps prevent moisture intrusion.

Steps:

1. Cut the wall opening to sleeve size.

2. Insert the sleeve, ensuring it slopes slightly downward outside for drainage.

3. Secure the sleeve with fasteners according to the manufacturer.

4. Seal gaps around the sleeve with foam insulation and exterior-grade sealant.

Tip: Purchase the sleeve model recommended by your AC manufacturer to ensure a secure fit.

💧 Drainage and Moisture Control

Through-the-wall ACs produce condensate that needs proper drainage:

✅ Ensure your sleeve slopes outward.

✅ Confirm your installation area has exterior drainage clear of obstructions.

✅ Use drip deflectors if needed to protect siding.

Water buildup can damage interior walls and insulation if drainage is not correctly planned.

🧰 Insulation and Sealing

Proper sealing around your AC prevents:

• Hot air infiltration

• Cold air leaks in winter

• Higher energy bills

✅ Use closed-cell foam or weatherstripping around the sleeve.

✅ Apply exterior caulking to prevent rainwater entry.

✅ Check seals annually for wear.

🔊 Noise Considerations

Through-the-wall ACs are quieter than many window units, but placement matters:

• Avoid placing the unit near beds or desks if noise sensitivity is a concern.

• Use vibration pads if needed during installation to reduce noise transfer.

🛠️ Professional vs. DIY Installation

DIY Installation is feasible if:

• You are comfortable with cutting and framing walls.

• Electrical needs are already met.

• You have helper support for heavy lifting.

Hire a professional if:

• You need a new 208/230V circuit.

• You are unsure about cutting structural studs.

• Your home’s siding or wall type complicates installation.

Reference: Energy Star AC Installation

🏠 Permitting and HOA Considerations

✅ Check with your city building department for permit requirements. ✅ Confirm HOA guidelines if applicable for exterior modifications. ✅ Some jurisdictions may require inspections for electrical or structural changes.

🔧 Maintenance Access

Ensure your AC is installed in a location that allows:

• Easy filter removal and cleaning

• Access for coil cleaning

• Drain pan inspection

Avoid installations near tight corners where future maintenance is difficult.

Reference: Family Handyman AC Maintenance

🛡️ Safety Precautions

• Wear safety glasses and gloves when cutting walls.

• Use a dust mask to avoid insulation inhalation.

• Turn off power at the panel before electrical work.

• Ensure ladder safety when working on higher floors.

✅ Conclusion: Is a Through-the-Wall AC Installation Right for You?

If you are looking for a clean, permanent, and efficient cooling solution, a through-the-wall AC is a great choice for your small space.

Before starting:

✅ Confirm your electrical capacity.

✅ Measure carefully.

✅ Plan drainage. 

✅ Use proper insulation and sealing.

✅ Follow safety protocols.

Tony’s Final Tip:

“Take your time, plan ahead, and don’t skip the sealing step if you want to avoid drafts and water issues.”

In the next topic we will know more about: Energy Efficiency and Cost to Run a 12,000 BTU Through-the-Wall AC