By Jake Lawson
One of the questions homeowners ask me most often isn't about replacing their entire HVAC system. Instead, it's something much more specific.
"Jake, I've converted a spare bedroom into a home office."
"Our sunroom is freezing in winter and unbearably hot in summer."
"We added a family room, but the central HVAC just doesn't keep up."
Those are exactly the situations where homeowners begin exploring through-the-wall heat pumps.
Over the years I have seen many homes where the primary heating and cooling system works fine for the bulk of the home, but one or two rooms are uncomfortable regardless of what the thermostat is set to. Broken HVAC equipment isn’t necessarily the problem. It’s just that the room has different heating and cool requirements than the rest of the house.
These are exactly the kinds of challenges that through-the-wall heat pumps were designed to solve. They provide you with independent heating and cooling where you need it, rather than relying on the central HVAC system for all of it. That flexibility can make them attractive as a solution for home offices, enclosed patios, finished garages, room additions, workshops, guest suites and many other spaces that don’t always get balanced airflow from the primary HVAC system.
Amana PBH093J35AA 9,300 BTU 208/230V Through-the-Wall Air Conditioner with Heat Pump & Remote Control
That doesn’t necessarily mean they’re the best choice for every situation. Like any HVAC solution, they bring with them advantages and disadvantages, installation prerequisites and operating issues of which home owners should be aware before investing.
In this guide, I’ll discuss where through-the-wall heat pumps excel, where they may not be the best choice, and what questions I recommend asking before deciding if one is the right fit for your home.
Why Certain Rooms Are More Difficult to Heat and Cool
One thing that homeowners sometimes forget is that not every room in a house acts the same. While they share the same roof and walls, individual rooms can have entirely different heating and cooling loads.
Consider a home office, for instance. Years ago a spare bedroom may have seen little use during the day. Today’s office may include multiple computer monitors, printers, networking equipment, lights, and a person working eight to ten hours per weekday. All that electronic stuff generates heat.
A sunroom is a whole different animal. Large areas of glass provide beautiful natural light, but they also provide significant solar heat gain in the summer, and lose heat more rapidly on cold winter nights.
Another problem is the extension of rooms. Many additions connect into the existing ductwork of the home, but the original HVAC system may not have been designed to accommodate the added square footage. This causes air flow to be redirected to rooms that the equipment was not designed to serve.
I have seen houses where the addition was five or six degrees warmer all summer, but the living room was comfortable. The central system was not damaged, it simply had more area to condition than it was built to handle.
The first step in selecting the right comfort solution is often knowing these unique room characteristics.
🏠 Why These Rooms Need Different HVAC Solutions
Different spaces often create different heating and cooling demands because of:
- ☀ Large glass areas
- 💻 Computers and office equipment
- 🚪 Frequent door openings
- 📏 Additional square footage
- 🌡 Poor duct airflow
- 🏡 Separation from the main living space
Recognising these differences helps explain why one thermostat doesn't always provide equal comfort everywhere in the home.
What Is a Through-the-Wall Heat Pump?
Before we get into the details of individual rooms, it helps to know what a through-the-wall heat pump is in the first place. Unlike portable air conditioners or traditional window units, through-the-wall systems are permanently installed inside a dedicated wall sleeve that is built into an exterior wall. It’s part of the structure of the home, not just something that’s put in a window opening temporarily. These systems, like all heat pumps, do two jobs year round. The air conditioning removes the excess humidity in the space and takes the heat from inside the room and dumps it outside.
In winter the refrigeration cycle is reversed. Rather than rejecting heat outside, the system collects available heat energy from the outside air and transfers it inside the room. Modern heat pumps can do this with surprising efficiency, even when it’s fairly cold outside.
What I especially like is that each room has its own through-the-wall heat pump, providing independent temperature control. Rather than having to change the entire house because one room is uncomfortable, homeowners have the ability to control that space without impacting the rest of the home.”
The U.S. Department of Energy explains that heat pumps move heat rather than generate it directly, allowing them to provide efficient heating and cooling from the same equipment.
Learn more:
🌎 U.S. Department of Energy – Energy Saver
https://www.energy.gov/energysaver
Home Offices May Be One of the Best Applications
If there’s one room where I’ve seen through-the-wall heat pumps make an instant impact, it’s the modern home office. Many homes are being used differently because of home working. The rooms that were built for guest bedrooms are now full-time work spaces with computers, monitors, printers, internet equipment, video conferencing lights and several people in them during the day.
All those devices generate more heat than was ever considered in the original design of the home's central HVAC system. I've had homeowners who would turn down the thermostat for the entire house just to cool down one office. Meanwhile the rest of the house was too cold, everyone else in the house complained.
The problem is solved by a through-the-wall heat pump, which allows the office to maintain its own temperature without affecting the other rooms. A third benefit that homeowners like is quieter operation. Many of the through-the-wall heat pumps available today are designed with improved fan technology and sound insulation to help keep operating noise down. That quieter environment can be surprisingly useful in video meetings, on phone calls, or when you’re focusing on work.
Rather than cooling the entire house during the day, you’re cooling the room that is actually occupied. That combination of comfort, independence of control, and efficiency often makes great sense for remote workers.
💻 Why Home Offices Benefit
A dedicated heat pump can provide:
- ✅ Independent temperature control
- ✅ Reduced energy use
- ✅ Improved comfort during long workdays
- ✅ Better humidity management
- ✅ Quieter operation
- ✅ Comfort without changing the whole-house thermostat
Those advantages have become increasingly important as more people continue working from home.
Sunrooms Present Unique Comfort Challenges
Sunrooms are nice spaces. And they’re some of the hardest rooms in the whole house to heat and cool from an HVAC perspective; Large windows are great for natural light, but glass is a very different heat conductor than insulated walls. In summer, multi-window sunlight can heat up the inside temperature higher than other rooms in a few minutes. In winter, those same windows are allowing heat to escape much faster after sunset.
I have been in homes where the thermostat in the main living space was set at 72 degrees, while the attached sun room was almost 85 degrees on a sunny afternoon. Homeowners assume the central HVAC system isn't working right, of course. It is most of the time. The room just has much higher heating and cooling loads than the rest of the house.
A through-the-wall heat pump makes that room nearly its own climate zone. Rather than having the home’s entire HVAC system compensate for the sunroom’s unique conditions, the dedicated unit responds directly to that space. Modern heat pumps also provide heating during the cooler months, so many homeowners can enjoy their sunrooms much more of the year, not just during spring and autumn.
The ENERGY STAR® program notes that properly selected high-efficiency heat pumps can provide efficient heating and cooling while reducing overall energy consumption.
Learn more:
🌎 ENERGY STAR Heat Pumps
https://www.energystar.gov
Room Additions Can Overload Existing HVAC Systems
Another situation I encounter regularly involves room additions.
Families grow.
Needs change.
A playroom becomes a dining room. A patio is a family room. Garage turned into a home gym. All additions are constructed onto existing homes. The thing is that the existing HVAC system wasn't necessarily designed FOR those extra rooms. Many homeowners simply extend existing ductwork into the addition, assuming the original equipment can handle the added load. Sometimes it works pretty well.
Other times the airflow becomes stretched too thin.
I have seen additions that were much warmer in the summer and cooler in the winter simply because the central system was already running at or near design capacity before the addition was built.
A through-the-wall heat pump is an efficient alternative to replacing the whole home's HVAC system (which can be a big investment) to condition just the new space. That method also allows for flexibility. It can have its own comfort settings without constantly impacting the temperatures in the rest of the house.
📊 Central HVAC vs Through-the-Wall Heat Pump
| Feature | Central HVAC | Through-the-Wall Heat Pump |
|---|---|---|
| Individual room control | ❌ Limited | ✅ Yes |
| Great for additions | ⚠ Sometimes | ✅ Excellent |
| Home office comfort | ⚠ Whole-house adjustment | ✅ Independent |
| Sunroom temperature control | ⚠ Often difficult | ✅ Dedicated comfort |
| Heating & cooling | ✅ Yes | ✅ Yes |
| Room-by-room flexibility | ❌ Limited | ✅ Excellent |
Each solution has strengths. The right choice depends on how the space is used and whether independent comfort is important.
Energy Efficiency Can Be Better Than You Might Expect
I hear a lot of people assume that having another HVAC system will magically increase your utility bills. The answer really depends on how the equipment is being used. Imagine being in one office working from home all day with the rest of the house empty. If you’re turning down the thermostat for the whole house just to get one room comfortable, you’re asking your central HVAC system to condition hundreds or thousands of square feet that no one is occupying.
A through-the-wall heat pump gives you another option.
You can stay comfortable right where you spend your time, rather than heating or cooling the entire house. The occupied room receives the precise temperature it requires, while the central HVAC system can maintain a more moderate setting.
That's why a lot of homeowners find out they use less energy after they have heating and cooling solutions put in for each room. Naturally, every home is different, and actual savings depend on insulation, climate, occupancy, equipment efficiency, and thermostat settings. The good news is that there’s often more sense in conditioning just the occupied spaces than to have to condition the whole darn house.
The U.S. Department of Energy explains that zoning and conditioning occupied spaces more effectively can improve overall energy efficiency when properly applied.
Learn more:
🌎 U.S. Department of Energy – Energy Saver
https://www.energy.gov/energysaver
Independent Temperature Control Is One of the Biggest Benefits
If I had to choose the single feature homeowners appreciate most after installation, it would probably be independent temperature control.
Every family experiences comfort differently.
One person working in a home office may want 70°F while another family member relaxing in the living room is comfortable at 75°F. For example, a sunroom with afternoon sun may need cooling, while the shaded side of the home is perfectly comfortable with no conditioning at all. A through the wall heat pump allows each room to be controlled to its own conditions, instead of being controlled by one thermostat located somewhere else in the house.This flexibility can be especially useful in a home where family members have different schedules. Guest rooms don’t need to be heated all winter long if no one is sleeping in them. A workshop doesn’t need cooling until it is occupied. Rather than a thermostat attempting to satisfy all rooms equally you can have each major space governed independently.
🌡 Benefits of Independent Room Control
A dedicated heat pump allows you to:
- ✅ Adjust temperatures room by room
- ✅ Improve personal comfort
- ✅ Reduce unnecessary heating and cooling
- ✅ Control occupied spaces only
- ✅ Improve comfort for guests
- ✅ Reduce thermostat disagreements
For many families, that flexibility alone makes the investment worthwhile.
Installation Still Matters
One thing I always try to remind homeowners, even the best equipment won’t work right if it isn’t installed properly. For through-the-wall heat pumps, it takes more than just cutting a hole in an exterior wall. Properly sized wall sleeve to the equipment. Electrical service must be as specified by the manufacturer. Air sealing and insulation around the sleeve reduces drafts and unwanted heat transfer. Outdoor units require adequate clearance for airflow. Condensate drainage must safely remove water from the building.
I've seen excellent equipment struggle because shortcuts were taken during installation.
That's one reason I recommend working with contractors who have experience specifically installing through-the-wall systems rather than assuming every HVAC installation follows the same process. Organizations such as AHRI and ASHRAE continue to emphasize that proper installation is fundamental to achieving expected equipment performance and longevity.
Learn more:
🌎 AHRI Consumer Resources
https://www.ahrinet.org
🌎 ASHRAE
https://www.ashrae.org
Noise Levels Often Surprise Homeowners
Another concern I hear frequently involves operating noise.
People naturally assume that having an HVAC system located directly inside the room will be louder than central air conditioning.
Sometimes older equipment earned that reputation.
Many modern through-the-wall heat pumps, however, have benefited from years of improvements in fan blade design, compressor insulation, cabinet construction, and electronic motor controls. While every manufacturer and model differs, today's equipment is often considerably quieter than many homeowners expect.
For home offices, this matters.
HVAC noise background can be a major distraction during video calls, phone calls or when you are trying to focus on your work. In the middle of the night, bedrooms and guest rooms also operate more quietly during heating and cooling. I always encourage homeowners to compare published sound ratings when considering different models. The best performing unit may not be the quietest, but quieter is definitely more comfortable all around.
When a Through-the-Wall Heat Pump May Not Be the Best Choice
While I often recommend through-the-wall heat pumps, they aren’t always the right choice for every home. If your existing central HVAC system already provides great comfort throughout the house, the cost of adding separate equipment may not be worth it. Homeowners contemplating large-scale, whole-house HVAC replacements may also discover that upgrading their central system, improving ductwork or installing zoning controls is a better solution to comfort issues.
Older homes, condos or buildings with architectural controls or homeowners’ associations may have installation restrictions as well. The objective is not to just mount yet another piece of equipment.It's about choosing the solution that works for the home and what the homeowner wants to achieve in the future.And that's why I'm telling folks to look at the whole picture, and not just the temperature in one room right now.
📊 When a Through-the-Wall Heat Pump Makes Sense
| Excellent Choice ✅ | May Need Another Solution ⚠️ |
|---|---|
| Home office | Whole-home comfort already balanced |
| Sunroom | Historic building restrictions |
| Room addition | HOA exterior limitations |
| Finished garage | Whole-house HVAC replacement planned |
| Guest suite | Major remodeling underway |
| Workshop | Duct zoning may solve the issue |
Every home is unique, and selecting the right solution begins with understanding how the space is actually used.
Looking Beyond the Purchase Price
One of the biggest mistakes I tell homeowners to avoid is comparing HVAC equipment based on just today’s purchase price. But think of the total value over ten, fifteen years from now.That includes installation quality, operating costs, comfort improvements, maintenance requirements, equipment longevity and how often the room is used in reality.
However, for someone who works from home five days a week, the comfort and productivity benefits can outweigh the value of energy savings alone. Likewise, homeowners who finally make their sunroom comfortable year round often gain an entire new living space without building an addition.In the long run, many homeowners decide that they are investing not only in the HVAC equipment but in how they use their home every day.
🏠 Homeowner Buying Checklist
Before purchasing a through-the-wall heat pump, ask yourself:
- ✔ Is this room consistently uncomfortable?
- ✔ Does the central HVAC struggle to maintain temperature here?
- ✔ Will this room be occupied regularly?
- ✔ Is independent temperature control important?
- ✔ Can the exterior wall accommodate installation?
- ✔ Is professional installation available?
- ✔ Have I compared heating and cooling costs?
- ✔ Have I selected the correct capacity for the room?
- ✔ Have I reviewed manufacturer warranty coverage?
- ✔ Will this improve long-term comfort in my home?
The more confidently you answer "yes," the more likely a through-the-wall heat pump deserves serious consideration.
Final Thoughts from Jake
One thing I’ve learned over the years is that homeowners don’t generally complain about their whole HVAC system not working. More often they’re frustrated that no room *ever* feels comfortable. This might be a bright home office where computers are adding heat, a beautiful sunroom that is uncomfortable in very hot or very cold weather, or a room addition that doesn't really fit in with the rest of the house. Those spaces require solutions tailored to their particular needs.
A through-the-wall heat pump isn’t the best choice for every home, but it can be a great option when independent comfort, heating and cooling for the whole year, and temperature control in each room are priorities. When sized correctly, installed professionally and maintained regularly, these systems give dependable performance and let homeowners enjoy spaces that might have been uncomfortable for much of the year.
If someone asks me whether a through-the-wall heat pump is a good investment, I tell them not to think so much about the equipment itself but how they intend to use the room. When a dedicated comfort solution helps you work more comfortably, enjoy your sunroom through the seasons or make a new addition feel like it has always been part of the home, that’s value you will appreciate every day.
Jake Lawson
HVAC Insights Specialist
The Furnace Outlet
Next Blog: Why Through-the-Wall Air Conditioners Last Longer Than Window Units in Many Homes
