Through the wall air conditioners with heat offer a powerful, space-saving solution for year-round climate control, combining efficient cooling and heating in one sleek unit. Ideal for apartments, offices, and rooms without windows, these systems provide reliable performance, easy installation, and energy-saving features—making them a smart upgrade for consistent comfort in any season.

Key Takeaways

• Choose dual-function units: Opt for models with both cooling and heating for year-round comfort.
• Check BTU ratings: Match BTU capacity to room size for efficient performance.
• Prioritize energy efficiency: Look for high EER/SEER ratings to reduce utility costs.
• Ensure proper installation: Use a professional for secure, weatherproof fitting and optimal operation.
• Consider noise levels: Select low-decibel models for quiet, undisturbed use.
• Verify thermostat compatibility: Confirm integration with smart thermostats for automated climate control.

Why Through the Wall Air Conditioners with Heat Are a Game-Changer

If you’ve ever lived in a space without central HVAC, you know the struggle. You’re sweating through summer nights, then bundling up in blankets when winter hits. I’ve been there—my first apartment had a tiny window AC unit that barely cooled the room, and a space heater that tripped the circuit breaker if I dared run it for more than an hour. It was a constant battle of discomfort. That’s why I fell in love with through the wall air conditioners with heat. These units are the unsung heroes of year-round comfort, offering both cooling and heating in one sleek, built-in package. They’re not just convenient—they’re a total lifestyle upgrade.

Unlike portable units that hog floor space or window ACs that block your view, through-the-wall units are installed directly into the wall, leaving your windows free and your room looking clean. They’re perfect for apartments, condos, sunrooms, or even small homes where ductwork isn’t an option. And with modern features like smart thermostats, energy-efficient modes, and quiet operation, they’re far from the clunky, loud units of the past. Whether you’re a renter, homeowner, or just someone tired of seasonal HVAC chaos, this guide will walk you through everything you need to know to choose, install, and love your through-the-wall unit.

How Through the Wall Air Conditioners with Heat Work

The Dual-Purpose Design

At their core, these units are heat pumps. That means they use the same technology to cool in summer and heat in winter. Here’s how it works: in cooling mode, the unit pulls warm air from your room, passes it over cold refrigerant coils, and expels the heat outside. In heating mode, it reverses the process—pulling heat from the outside air (even when it’s cold!) and bringing it indoors. This makes them far more efficient than electric resistance heaters, which simply convert electricity into heat.

For example, a 12,000 BTU unit might have an EER (Energy Efficiency Ratio) of 10.5 for cooling and an HSPF (Heating Seasonal Performance Factor) of 9.5 for heating. That means for every 1 watt of electricity used, you get 9.5 watts of heat—a huge win over baseboard heaters, which offer a 1:1 ratio.

Components That Matter

• Compressor: The heart of the unit. Modern units use rotary compressors for quieter, longer-lasting performance.
• Reversing Valve: Switches between heating and cooling modes. Look for units with a “defrost cycle” to prevent ice buildup in cold weather.
• Fan Motors: Dual motors (one for indoor, one for outdoor) ensure balanced airflow. Brushless DC motors are quieter and more efficient.
• Thermostat: Built-in sensors monitor room temperature. Some units even have remote controls or Wi-Fi apps for precise adjustments.

Pro Tip: Units with “auto-switch” mode automatically shift between heating and cooling based on the room’s temperature. I use this in my sunroom—it keeps the space cozy at 72°F year-round without me lifting a finger.

Key Benefits of Through the Wall Units

Space-Saving and Aesthetic Appeal

Let’s face it: window ACs are clunky, and portable units are eyesores. Through-the-wall units sit flush with your wall, giving you back your window and floor space. I installed one in my home office, and the difference was night and day. No more tripping over cords or blocking sunlight. Plus, many units have sleek front panels (some even with customizable colors) that blend into your decor. One friend put hers in a basement apartment with a brick wall—it looks like a built-in appliance, not an afterthought.

Energy Efficiency and Cost Savings

Because they’re heat pumps, these units are far more efficient than electric heaters. For example, if you pay $0.15/kWh, a 12,000 BTU unit with an HSPF of 9.5 will cost about $0.16/hour to heat. A 1,500-watt space heater? $0.23/hour for less heat. Over a winter, that’s hundreds of dollars saved. Plus, many units have Energy Star ratings and “eco” modes that adjust output to avoid energy waste.

Year-Round Comfort in One Unit

No more storing bulky heaters in summer or lugging ACs out of the attic in spring. Everything you need is in one place. I once helped a neighbor install a through-the-wall unit in her tiny beach cottage. She went from using a noisy window AC and a kerosene heater to a single, quiet unit that handled both seasons effortlessly. The best part? Her electric bill dropped by 30%.

Quiet Operation

Modern units are whisper-quiet. Look for models with decibel ratings under 55 dB (about as loud as a conversation). My current unit runs at 48 dB—I can’t hear it over my TV, even when the compressor kicks in.

Top Features to Look for When Buying

BTU Rating and Room Size

Matching your unit to your room size is critical. Too small, and it’ll struggle; too large, and it’ll cycle on/off too much, wasting energy. Here’s a quick guide:

Room Size (sq ft)	BTU (Cooling)	BTU (Heating)
100-250	6,000-8,000	7,000-9,000
250-400	10,000-12,000	11,000-13,000
400-600	14,000-18,000	15,000-20,000

Note: For sunrooms or kitchens (which generate extra heat), add 2,000-3,000 BTUs. For shaded rooms, subtract 10%.

Energy Efficiency Ratings

• EER (Cooling): Aim for 10.0 or higher. The higher the number, the less electricity you use.
• HSPF (Heating): Look for 8.5+ for cold climates. In milder areas, 7.5+ is fine.
• Energy Star: Ensures the unit meets strict efficiency standards. Saves ~15% on energy bills.

I once bought a unit with a low HSPF to save money upfront. Big mistake—it cost me $200 more in heating bills that winter. Learn from my error: efficiency pays off.

Smart Features and Controls

Today’s best units come with:

• Wi-Fi/App Control: Adjust temps from your phone. Perfect for pre-cooling a room before you get home.
• Programmable Thermostats: Set schedules (e.g., 68°F at night, 72°F during the day).
• Auto-Restart: Resumes settings after a power outage—no more waking up to a freezing room.
• Remote Sensors: Some units come with wireless sensors to monitor temps in multiple areas.

Noise Level and Installation Type

Check the unit’s decibel rating (dB) and installation type:

• Slide-Out Chassis: Easier to clean and maintain. Just slide the unit out from inside.
• Fixed Chassis: Harder to service but often cheaper.
• Through-the-Wall vs. Wall Sleeve: Most units require a wall sleeve (a metal frame installed in the wall). If your building has one, you can swap units easily.

Installation: DIY or Hire a Pro?

When to DIY

If you’re handy, installing a through-the-wall unit is doable. You’ll need:

• A wall sleeve (if one isn’t already installed).
• A hole in the wall (typically 14”H x 26”W for standard units).
• Electrical work: Most units require a 20-amp, 115V circuit (some larger units need 230V).

I DIYed my first unit using a YouTube tutorial and a borrowed hole saw. Took 3 hours, cost $150 (vs. $500 for a pro). But I’m not afraid of power tools or basic wiring.

When to Hire a Pro

Call a pro if:

• You’re dealing with brick, concrete, or stucco walls (drilling through these is tough).
• Your building requires permits (common in apartments).
• You need to run a new electrical line (this should only be done by a licensed electrician).
• You’re installing in a historic or protected building (check local codes first).

Pro Tip: If you’re renting, get written permission from your landlord. Some buildings prohibit wall modifications.

Installation Steps (Simplified)

1. Measure and mark the wall opening.
2. Cut the hole (use a reciprocating saw or hole saw).
3. Install the wall sleeve (secure with screws and seal with caulk).
4. Connect the electrical (follow the manual’s wiring diagram).
5. Slide in the unit, seal gaps with foam, and test.

Safety First: Always turn off the circuit breaker before working with electricity. Use a voltage tester to confirm it’s off.

Maintenance and Troubleshooting

Monthly Maintenance

Keep your unit running smoothly with these simple tasks:

• Clean the air filter (every 2-4 weeks). Just rinse it with water and let it dry. A dirty filter reduces efficiency by up to 15%.
• Wipe the exterior with a damp cloth. Avoid harsh cleaners.
• Check the outdoor side for debris (leaves, dirt). Clear any blockages.

I keep a calendar reminder to clean my filter on the 1st of every month. It takes 5 minutes and makes a huge difference.

Seasonal Checks

• Spring: Inspect the condensate drain for clogs. A blocked drain can cause water damage.
• Fall: Check the outdoor coil for ice buildup (in heating mode). If it’s iced up, the unit might need a defrost cycle.
• Yearly: Hire a pro to inspect refrigerant levels and electrical connections.

Common Issues and Fixes

• Unit won’t turn on: Check the circuit breaker and thermostat settings. Reset the unit (unplug for 5 minutes).
• Not cooling/heating enough: Clean the filter, check for airflow obstructions, or call a pro if refrigerant is low.
• Strange noises: Rattling? Tighten loose screws. Grinding? The motor might be failing.
• Leaking water: Clear the drain line with a wet/dry vac or pipe cleaner.

I once had a unit that kept shutting off. Turns out, the filter was so clogged it was overheating. A $10 filter saved me a $200 repair bill.

Real-World Examples: Who Benefits Most?

Through the wall air conditioners with heat aren’t one-size-fits-all, but they shine in these scenarios:

Apartments and Condos

Renters often can’t install central HVAC, but many buildings allow through-the-wall units (with approval). A friend in a 500 sq ft studio installed a 12,000 BTU unit. Now she has central-like comfort without breaking her lease terms.

Sunrooms and Additions

These spaces are hard to heat/cool with ductwork. A 14,000 BTU unit in my sunroom handles 100°F summers and 30°F winters effortlessly.

Small Homes and Cabins

No ductwork? No problem. A couple in a 1,200 sq ft cabin uses two units (one in the living room, one in the bedroom) for whole-home comfort. Their electric bill is half of what it was with space heaters.

Offices and Workspaces

Freelancers and small businesses love these units. One coworking space uses them to let members control their own climate—no more arguments over the thermostat!

Remember: Always check your building’s rules and local codes. Some areas restrict wall modifications or require permits. But for most people, these units are a smart, efficient choice.

Choosing a through the wall air conditioner with heat isn’t just about buying a gadget—it’s about reclaiming control over your comfort. Whether you’re escaping summer heat, battling winter chills, or just tired of seasonal HVAC chaos, these units deliver reliable, quiet, and efficient performance. They’re not perfect (installation can be tricky, and upfront costs are higher than portable units), but the long-term savings and convenience are worth it. From energy-efficient heat pumps to smart controls, today’s models are smarter, quieter, and more user-friendly than ever. So take the leap: measure your room, pick a unit that fits your needs, and enjoy a space that’s always just the right temperature. After all, comfort shouldn’t be a seasonal luxury—it should be a year-round guarantee.

Frequently Asked Questions

What is a through the wall air conditioner with heat?

A through the wall air conditioner with heat is a self-contained HVAC unit installed directly into an exterior wall, offering both cooling and heating functions. Unlike window units, they provide a permanent, built-in solution with better insulation and aesthetics. These are ideal for rooms without windows or where window units aren’t feasible.

How does a through the wall AC with heat work?

These units pull in outside air, condition it (cool or heat), and circulate it indoors via a sealed wall sleeve. Heating is typically provided by an electric resistance coil or heat pump, making them energy-efficient for moderate climates. The sealed design reduces drafts and improves efficiency.

Are through the wall air conditioners with heat energy efficient?

Yes, many models feature high Energy Efficiency Ratio (EER) ratings and programmable thermostats to minimize energy use. Look for ENERGY STAR® certified units for optimal savings, especially in regions with long heating or cooling seasons. Proper installation and insulation further boost efficiency.

Can I install a through the wall AC with heat myself?

While possible, professional installation is recommended to ensure proper wall sleeve fit, electrical wiring, and weatherproofing. DIY risks include air leaks, electrical hazards, or voiding warranties. Always follow local building codes and manufacturer guidelines.

What size through the wall air conditioner with heat do I need?

Unit size depends on room square footage, insulation, and climate. For example, a 10,000 BTU unit suits ~450 sq ft. Consult a sizing chart or HVAC professional to balance power and efficiency for your space.

Do through the wall ACs with heat require maintenance?

Yes, clean or replace filters monthly during peak use, and annually check coils, fan blades, and drainage channels. Regular maintenance ensures longevity and prevents mold or performance issues. Some units include washable filters for convenience.