Introduction
Hey, Jake Lawson here. If you’re shopping for a through-the-wall air conditioner, chances are you want two things above all else: a quiet unit and one that doesn’t blow up your electric bill.
But here’s the catch — sometimes noise and energy efficiency pull in opposite directions. Powerful compressors and fans keep you cool but can make noise. Meanwhile, quieter units sometimes sacrifice energy efficiency or cooling power.
So, how do you pick the right model that keeps you comfortable, saves money, and doesn’t sound like a jet engine?
In this guide, I’ll break down how noise is measured, what to look for in energy efficiency, and the best ways to find through-the-wall AC units that balance both like a pro.
Why Noise Matters in Through-the-Wall ACs
Unlike central AC or window units that can sit away from living spaces, through-the-wall air conditioners are mounted directly in your room’s wall. That means noise travels directly into your living space, making quiet operation critical — especially in bedrooms or offices.
What Causes Noise?
The main sources of noise in through-the-wall ACs are:
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Compressor noise: The compressor pressurizes refrigerant to cool the air, and it’s the noisiest mechanical part.
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Fan noise: Both indoor and outdoor fans move air through the system, and higher fan speeds usually mean more noise.
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Vibration: If the unit or wall sleeve isn’t installed securely or isn’t balanced, it can cause rattling or humming sounds.
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Airflow noise: Sometimes the air moving through the vents can whistle or buzz if airflow is restricted.
Decibels (dB): Understanding Noise Ratings
AC noise is measured in decibels (dB). The lower the dB number, the quieter the unit. To put it in perspective:
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A quiet library is about 40 dB.
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Normal conversation is around 60 dB.
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A lawn mower runs about 90 dB.
Most through-the-wall units run between 50 and 70 dB. If noise is a big concern, aim for units rated 55 dB or lower.
Tips to Reduce Noise Impact
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Proper installation is key. A poorly sealed sleeve or loose mounting increases vibration noise.
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Look for units with noise-reducing insulation inside the cabinet.
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Choose models with variable fan speeds — running on lower speeds can cut noise dramatically.
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Sound barriers or seals around the unit’s exterior can reduce noise leaks.
The Importance of Energy Efficiency
Energy efficiency is the other side of the coin. A more efficient unit uses less electricity to cool your space, saving you money and reducing your carbon footprint.
What’s SEER and EER?
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SEER (Seasonal Energy Efficiency Ratio) measures cooling efficiency over an entire cooling season, considering changes in temperature and usage. Higher SEER means better efficiency.
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EER (Energy Efficiency Ratio) measures efficiency at a single outdoor temperature, often 95°F. This is useful for comparing units in peak heat.
For through-the-wall units, the EER rating is often more relevant since these units typically run in hot conditions.
ENERGY STAR® Certification
The ENERGY STAR® program sets minimum efficiency standards for room air conditioners, including through-the-wall units. ENERGY STAR-certified models use about 10% less energy than standard models.
Look for the ENERGY STAR® label when shopping — it’s a reliable sign of both energy savings and performance (source: ENERGY STAR Room AC Guide).
What Affects Energy Efficiency?
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Compressor technology: Newer inverter compressors modulate speed to match cooling demand, saving energy and reducing noise.
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Thermostat accuracy: Precise temperature control avoids unnecessary run times.
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Fan design: Efficient fans move more air with less power.
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Insulation and sealing: Preventing air leaks means the AC doesn’t have to work as hard.
Balancing Noise and Efficiency: What to Look For
Variable Speed Compressors and Fans
Models with variable-speed compressors and fans can run slower when less cooling is needed, which means they’re quieter and use less electricity.
Sound Ratings and Reviews
Don’t just trust the specs — look at customer reviews and professional test results for noise performance. People often report if a unit is “too loud” or pleasantly quiet.
Installation Matters
Noise and efficiency go hand-in-hand with proper installation. Poor installation can cause vibration and air leaks that hurt efficiency and increase noise.
Hiring a pro for installation or following manufacturer instructions carefully can make a big difference (source: Family Handyman AC Installation Tips).
Features That Help Noise and Efficiency
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Sleep mode or quiet mode lowers fan speed and compressor activity at night.
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Programmable timers and smart thermostats prevent overcooling and waste.
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Well-insulated cabinets reduce sound transmission.
My Top Quiet and Efficient Through-the-Wall AC Recommendations
Here at The Furnace Outlet, we carefully select models that perform well in noise and efficiency. Here are some standout features to look for:
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SEER ratings above 13 or 14 (for best efficiency)
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EER ratings above 11
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Noise levels under 55 dB
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ENERGY STAR certification
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Variable speed compressor and fan
Installation Tips to Keep Noise Down and Efficiency Up
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Make sure the wall sleeve is installed level and securely.
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Use foam insulation and caulk to seal around the sleeve.
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Check that the drainage slope is correct to prevent water noise.
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Use anti-vibration pads if possible.
Why R-32 Refrigerant Matters for Efficiency
Many new through-the-wall units now use R-32 refrigerant — a next-generation refrigerant that’s more energy efficient and has a lower global warming potential than older types.
Switching to R-32 means your AC will run cleaner, greener, and more efficiently over its lifetime (source: EPA Refrigerant Transition Resources).
Conclusion
Finding the perfect through-the-wall air conditioner comes down to balancing noise levels and energy efficiency for your unique space.
Pay attention to decibel ratings, look for ENERGY STAR certification, and consider advanced features like variable-speed compressors. And remember — proper installation is just as important as the unit itself.
If you want a stress-free buying experience, browse our top-rated, quiet, energy-efficient models on the Through-the-Wall Air Conditioners pillar page — all chosen with Jake Lawson’s expert seal of approval.
Stay cool and quiet!
