Best Through-the-Wall Air Conditioners Reviewed: AC Guide

What to Look For In a Quality Wall Unit Air Conditioner

Cooling Area (Room Size – Sq. ft.)

Calculating the square footage, or area, of a room is easier than you might think. You simply measure the length and width of the room and multiply the two to get the area. For triangular shapes, multiply the length and width as though it is a rectangle but then divide the product by 2.

If you have a circular room, multiply the radius by itself and then by 3.14. (The radius is half of the length across the circle.) In many cases, however, a room is irregular in its dimensions. If so, just divide the room into measurable subparts as best you can, find the areas, and add them together.

British Thermal Units (BTU)

A BTU is an amount of thermal energy (heat) required to raise the temperature of 1 lb. of water by 1⁰ F. (Note that, many times in reference to AC units, BTU numbers are short for BTUs/hour.)

According to Consumer Reports, you generally need an AC with about 20 BTUs of cooling for every sq. ft. It is important to realize, too, that buildings with high ceilings, many heat-producing machines, or multiple people, require more cooling.

For buildings that house more than two people, add about 600 BTU for each additional person. A kitchen may require an additional 4000 BTU. Similarly, increase or decrease the total BTUs by 10% for especially sunny or shady locations.

Noise Levels (dB)

Loudness, or sound intensity, is usually measured in decibels (dB). Air conditioner dB levels are reported in the model’s description; most wall air conditioners create between 50 and 60 dB of sound.

All air conditioners, including through-the-wall, make some noise, but most people favour those that are quieter, especially when the unit is in the house—especially in the bedroom. (However, if you want your wall AC to double as a noise-maker to block other sounds, you might want it on the louder side.)

To learn more about decibel levels and how they can affect humans, you can visit this article and learn more.

Energy Efficiency (EER Rating)

The EER rating is a standard efficiency rating for all air conditioners. It is calculated by taking the cooling capacity per hour (in BTU) and dividing it by the energy needed per hour (in kW). Ultimately, it tells you just how much energy you have to pay for to get a given amount of cooling.

Most users want a high EER (more cooling for less), but highly efficient units are often more costly. However, a good-quality unit will eventually give back the extra cost (and possibly more) in savings. The estimated yearly energy cost of a unit is calculated based on an electric energy cost of 13 cents/kW, 8 hours/day, 3 months/year.

Size (dimensions of unit)

Wall AC units are not restricted by the size of your windows, as are window units. However, you do have to already have, or create, a hole all the way through your wall that will at least roughly fit your desired unit’s wall sleeve. Fortunately many units of similar cooling power will fit in the same openings. Most units are about 15 inches high, 25 inches wide, and 20 inches deep.

Voltage

Want to work out the Watts your window AC uses? The standard electric outlet in the US is 115V (actually a range of 114-126V), so if your wall AC unit is made to work in this voltage class, you can just plug it in. However, some units require a 230V (actually 220-240V) outlet, in which case you either must already have a special 230V outlet in your location of choice, or you must get an electrician to create one for you.

Sleeve (Size & Installation)

Normally, the wall sleeve is a separate purchase from the AC unit. The sleeve for a wall air conditioner is really just a thin metal box open on two faces (outside and inside).

You insert it into an opening in your wall and insert the AC unit in the sleeve. For an excellent sleeve option, consider the Koldfront WTCSLV Through-the-Wall Air Conditioner Sleeve.

This durable steel sleeve can fit the Koldfront line of wall ACs, and even fits most other wall-mounted AC brands—with its dimensions of 15.25’’ (height) x 25.5’’ (width) x 17.5’’ (depth).

Heating Options

Some wall AC units can double as heaters. This makes sense, because air conditioners are essentially reverse heat pumps. It is the same mechanism, but in reverse. Some elements do not reverse the cycle; instead they have an electrical heating element. However, note that unless you are in a very small space, most wall units are not sufficient to be the sole heat source, but they make excellent supplemental heat sources for a single room or a way to keep a garage warm.

Dehumidification Levels

All AC units dehumidify to some extent—usually a few pints of water/hour—since lower temperature air does not hold water as well. Units release extracted humidity as water out the back (exterior face) of the unit, normally by dripping. However, with many units, the water tends to just re-evaporate once it is heated by the warm exhaust of the AC and the warm outside air. Dehumidification is enhanced when fans blow air slowly over the cooling coils, allowing more water vapour to condense. This is generally what the dry mode on an AC does.

Extra Features for Convenience

Most good-quality wall AC units have multiple convenience features. Some allow you to operate the device from your smartphone or to set a timer so that the unit turns on and off when you want it to, even if you are not at home.

Many have a sleep mode that allows the room temperature to rise bit by bit throughout the night (usually for 6 hours) before returning to the set temperature, saving energy and keeping you from waking up cold.

Most brands also have an energy-saver mode that runs the fan by itself every 10 minutes or so, and only turns the AC back on if the temperature is rising above the set temperature. Most at least have a remote control, which sometimes has a temperature sensor that acts as a thermostat for the unit.

There is a high-quality thread on Quora that discusses these 2 options in detail.

Warranty

Wall AC units normally have at least 1-year limited warranties, and many times, warranties are only for the AC parts themselves, not the electrics, sleeves, covers, etc. Most companies have a warranty statement that lists what is covered and what is not. Damages and breakages that are not directly related to the unit’s manufacture are usually not covered: this includes electrical issues, problems with the wall the unit is installed in, and malfunction from accidental abuse.

5 Tips on Keeping Noise to a Minimum

1. Use an appropriately sized unit for your space: An overly powerful unit will be triggered to turn on and off a lot, which is annoying to many; a unit with insufficient cooling power will be triggered to run constantly.
2. Keep your unit clean with weekly checks, including filter cleans and dusting (if needed). Also check the back (exterior) face periodically. A unit with residue or other obstructions on its grills will have to run more to transfer heat.
3. Seek a unit that is relatively quiet. Look at the reported loudness (in dB) of a unit, if you can find it. Look at any noise-related reviews about it, too. Take into account your own preferences: some people actually like more ambient noise; others are sensitive to it.
4. Meticulous insulation between the unit and the sleeve not only makes the unit more efficient—so it runs less—but it also dampens a portion of the noise. Also, be sure the unit is correctly installed (everything is screwed in place)—if not, there may be rattling as it runs.
5. Use operation modes and convenience features strategically: sleep mode automatically reduces noise both as the exterior temperature usually drops at night and as the unit allows the interior temperature to rise a little bit; a timer or smartphone connection allows you to get the unit on ahead of time so it does not have blast to catch up later.

Comparing Different Types of ACs

A central AC unit is a large AC mechanism (almost always located just outside the building) that pipes the cool air it produces into the building’s interior via a system of insulated ducts. Window ACs and AC wall units are mostly similar in structure and ideal for cooling single rooms or apartment-sized dwellings.

For something that has both the room-by-room flexibility and the energy efficiency of a wall/window unit, but also the capacity to cool an entire building like a central AC unit, consider split system AC units. A split system has the hot-air-producing half of the unit outside and the cool-air-producing elements located on the interior.

A portable air conditioner is generally the least energy-efficient option, but it allows you to move the AC system anywhere you are, and it might be altogether sufficient for single rooms.

People Also Ask (FAQs)

Can I install one of these mounted units by myself?

It depends on how much you have to do—is there already an appropriately sized hole in the wall? Is a wall sleeve already there?—and how much expertise you have. If the sleeve is already in, you can probably just lift the unit up and slide it in, ideally with the help of another person. If you need to alter the wall opening or the electrics, then you might need specialized help.

How do you install a ‘through the wall’ air conditioner sleeve?

How much handiwork you have to do to install a through-the-wall AC unit depends on where in the process you are starting: in many instances, an appropriately sized opening is already there and you just have to be sure you get a sleeve that fits or do some minor adjustments so that the sleeve you have will fit. A good rule of thumb that many through-the-wall AC installers discover is: Use your common sense.

However, at some point, all of these steps must be done:

1. Find wall space. Try your best to avoid an area with plumbing, electrical, or any other household wires or ducts.
2. Mark an outline of the rectangular hole to be cut. Take note of wall studs.
3. Cut the opening from the inside, and take out intruding wall studs. Install a wooden support frame about the perimeter of the opening.
4. Drill guide holes in exterior and proceed to cutaway opening.
5. Use a leveller to be sure the opening is level, and make fine adjustments if it is not.
6. Put the sleeve in. Affix the sleeve to the opening by following the installation instructions and using the hardware, both of which usually come with the purchase of the sleeve or AC unit itself.
7. Insert the air filter and put the front grill on. Apply any insulation (this usually comes with the AC unit), and finally, if desired, a finishing frame to the wall surrounding the AC.

The ehowathomechannel, P.C. Richard, and Dazzling Dave provide straightforward tips about wall AC installation.

What else should I consider when installing a mounted wall AC?

First of all, if a unit is already in place, unplug it before removing it. If you are installing a unit anew, do not plug it in until you are done with installation and try to make a good location choice. Consider: Is the unit away from doors or other elements that could whack into it?

Also, consider installing at a height that reduces the chances of children tampering with the unit or people being in some way impeded by its presence. Realize that cold air tends to sink and warm air tends to rise—this is yet another reason to put the unit up higher. However, if you want to be able to control it directly (without remote control), you must put it at a level you can reach.

How do I seal one of these units to the wall?

Wall ACs often come with foam inserts that can be used to create a weathertight seal. If needed, you can also purchase extra foam and/or weathertight sealing for this purpose.

One user voluntarily promoted the product Great Stuff spray foam, made by Dow, as an easy-to-use insulating product. For finer sealing, you might even want to caulk around the unit, including the space above it. The ehowathomechannel thoroughly discusses how to seal AC units.

How do I clean a wall air conditioner without removing it?

Ideally, you should check/clean your filter about once every 2 weeks, especially if you live in a location with a lot of dust, pollen, or other fine particles in the air. Inspect the exposed front of the unit for dust as you are doing this. Start by turning the unit off. If you anticipate doing more than just slipping the air filter out, unplug the unit for safety. Furthermore, it is a good idea to lay some sort of cover on the floor below to catch any debris that falls. To check the filter:

1. Take the front grill off. Usually, this requires no unscrewing—you just gently flip it up/down or snap it off.
2. Slip out the air filter and clean, or change, if needed. Most units have filters that you can clean and reuse. Simply wipe it with a damp paper towel (according to the Consumer Reports video below) and, if needed, bath it in soap (dish or hand) and water, and let it dry.
3. If there is dust on the exposed front (behind the filter) of the AC unit, then brush this off. If there is a more serious residue, use a vacuum cleaner and/or small brush (potentially a toothbrush) to clean the exposed front of the unit. VideoJoeKnows is another great YouTube channel for wall AC unit cleaning advice.

Are wall air conditioners more powerful than window or portable models?

Not inherently so. Portable models are generally not as energy efficient, but they can have equal cooling power. Window and wall models are essentially the same device—in fact, many can double as either one. Look at the BTU label—this is what really indicates the cooling power.

Can I sleep comfortably with these types of Wall ACs?

Generally, yes. However, you have to consider how much noise you like as you are sleeping. Also, be sure you have a unit with appropriate cooling capacity for the room size so that it does not cut on and off a lot—aside from the fact that this diminishes the dehumidifying effects of the AC, some might find it annoying.

Conclusion

A through-the-wall AC with heating is an excellent way provide climate control to a garage. The Koldfront WTC12001W 12,000BTU 208/230V Through-the-Wall Air Conditioner—this article’s #1 wall-mounted air conditioner—gives you this and so much more. Its energy-, money-, and time-saving features make it great for almost any office or residential situation.