What is a Window Air Conditioner? A window air conditioner is an air conditioning device that is fitted into a window opening inside a room and used to cool or heat the air in that room. They are most commonly found installed in single or multiple rooms in large homes and hotels, allowing each room with such a device to be cooled or heated individually according to its occupant’s wishes.
Window air conditioners are stand-alone air conditioning devices; they are not part of a distributed central air conditioning system that runs throughout a building. While these devices provide maximum flexibility for controlling the air temperature in rooms individually, if an air conditioning solution is needed for a large number of rooms, for power consumption reasons it is usually less expensive in the long run to have a central air conditioning system installed in a building.
Window air conditioners are very similar to wall air conditioners, the primary difference being that the former is fitted into a window opening while the latter is fitted into a wall opening. The two types of air conditioner together are often referred to as room air conditioners.
Room air conditioners come in two varieties: unitary systems and PTAC (Packaged Terminal Air Conditioning) systems. In unitary systems, the more common of the two, interior air is cooled as a fan blows it over the evaporator. On the exterior the air is heated as a second fan blows it over the condenser. By this process heat is drawn from the room and discharged to the surrounding environment.
PTAC systems are also known as wall split air conditioning systems or ductless systems. These systems have two separate units: an evaporative unit on the interior and a condensing unit on the exterior, with tubing passing through a wall and connecting them.
Window air conditioners are not difficult to install. Some of them are fitted into a window opening with special brackets that must be attached to the window frame. Other designs feature extendable edges that slide outwards until they touch the edges of the window opening and hold the air conditioner in place.
Choosing a Window Air Conditioner by BTU
Window air conditioner models come in different sizes with different power consumptions. Which model is right for you depends on the size of the room or space that you want to apply the air conditioning to. You need to measure the square area of that space and use the result to calculate how large and powerful a window air conditioner you need to buy.
To do this, simply multiply the length times the width of the room or space you want to cool. Then, multiply the resulting figure by 25 BTU. This allows for ample air conditioning, whether it is a rainy, moist day or a hot, humid day. So if we have a room that’s twelve feet in width and fifteen feet in length, we perform the calculation: 12×15=180 square feet. Then we multiply the 180 sq. ft. by the 25 BTU and we identify the approximate BTU air conditioner we should buy: 180×25=4500 BTU. So we have determined that a cooling capacity of around 4500 BTU is needed from our window air conditioner.
You may wonder whether a smaller, cheaper air conditioner will suffice or whether a larger, more powerful unit might do a better job.
An air conditioner with a significantly lower BTU will need to be run continuously in order to adequately cool the space. This will increase your electric bill and cost you more money in the long term.
An air conditioner with a significantly higher BTU might be overkill. To dispute the misconception that bigger is better, an air conditioner that is too large will cool a space more quickly, but this may impede the reason for operating the air conditioner in the first place. You see, along with cooling the air in a space, an air conditioner also extracts the moisture from the air (humidity) in that space that makes people feel hot and sticky. Although the air may be cooler, if the device doesn’t run for a longer period of time than was necessary for it to cool the space (which would be more expensive in terms of energy bills because), the moisture will not be extracted from the air properly and there will still be an element of humidity in the space.
Your best bet is to get a window air conditioner that conforms relatively closely to the BTU requirements of the room or space you want to cool.
10 Best Window Air Conditioner Reviews
1. Frigidaire FFRE0533S1 5000 BTU Window-Mounted Mini Compact Room Air Conditioner
The Frigidaire FFRE0533S1 is Energy Star compliant so it reduces energy cost while cooling down a room. With 5,000 BTU, the unit is designed for rooms up to 150 sq ft and comes complete with a 2-speed fan, antibacterial mesh filter, and full-featured remote controls and a 24-hour timer.
Energy Efficiency Ratio: 12.2
2. Frigidaire FFRA0511R1 5000 BTU 115V Window-Mounted Mini-Compact Air Conditioner
The FFRA0511R1 is also designed for rooms up to 150 sq ft and is notable for its top of the line rotary controls. In addition to cooling air quickly, the FFRA0511R1 is also equipped with an antimicrobial filter that minimizes room odor, bacteria and other unhealthy particles that might be in the room.
Energy Efficiency Ratio: 11.1
3. LG LW8016HR Window Air Conditioner
This LG LW8016HR 7500 BTU AC unit is capable of cooling down rooms up to 320 square feet, and its dehumidifier is good for up to 2.1 pints per hour. There are three cooling speeds, perfect if you want the process to reach a certain level, and the fan has 2-speed options as well. In addition, this small window air conditioner has a four-way air deflection that points cool air where it has to go. Though the unit has a lot of functions, it’s still simple to learn and use.
Energy Efficiency Ratio: 11.2
4. Frigidaire FFRE0833S1 8000 BTU Window-Mounted Mini-Compact Air Conditioner
The Frigidaire FFRE0833S1 is an 8000 BTU is good for rooms up to 350 square feet, and one of the things you’ll notice immediately is how quiet it is. A common problem with most air conditioning systems is they’re too noisy and keep you up at night, but the FFRE0833S1 doesn’t. With its Ready-Select controls, you can choose the level you’re comfortable at. The unit also comes with a temperature readout which you can easily read.
Energy Efficiency Ratio: 12.0
5. Frigidaire FFRA0511U1 5000 BTU Window-Mounted Room Air Conditioner
This 5,000 BTU is a window-mounted air conditioning unit that offers a convenient way of removing warm air from any room and replacing it with something cooler. The FFRA0511U1 also has quality rotary controls as well as 3 fan and 3 cool speeds. Though the FFRA0511U1 is one of the more affordable AC units available, it’s also one of the most durable and can be used on a regular basis without any worry of the system breaking down. Like the other AC units featured on this list, the FFRA0511U1 is eco-friendly and has energy saving features built in.
Energy Efficiency Ratio: 11.1
6. LG LW1015ER 10000 BTU Window Air Conditioner
The LW1015ER 10,000 BTU comes with a remote control that allows you to access and change the several functions on the unit. With the LW1015ER you can cool the temperature in rooms up to 450 sq ft, and the package comes with a mounting kit so installation is straightforward.
Energy Efficiency Ratio: 11.3
The LW1015ER also comes with full-featured electronic controls, and its dehumidification is good for up to 3 pints per hour. The remote control moreover, gives you full control over the unit and how it works. Finally, the unit comes with an Energy Saver mode, a “clean filter” alert and a 24 hour on/off timer.
7. Quirky + GE Aros Smart Window Air Conditioner
Despite the name, there’s nothing quirky about the way this casement window air conditioner works. As the name makes clear, this is a “smart” AC that learns your habits and patterns so it runs accordingly.
The system has many of the same features as the other units on this list, but what makes this different is it learns your habits, budget, and usage so even if you don’t mess with the controls, the Aros makes the proper adjustments and savings. If that’s not enough, you can use the Wink app to control the unit from your mobile device. Another good smart window air conditioner Frigidaire: FGRC0844S1
Energy Efficiency Ratio: 10.9
8. Haier HWE10XCR 10000 BTU Room Air Conditioner
The HWE10XCR is Energy Star rated so whenever it’s running you’re assured that it’s not wasting energy. Apart from that, the AC has full electronic controls as well as a remote control so from across the room you can change the cooling and speed settings. There’s also a temperature display if you want to be specific about the numbers, and the time is displayed as well. You can also let the Auto Cool run on its own, but if you want to make manual adjustments, you can do so with the 3 fan speeds and 3 cooling speeds.
Energy Efficiency Ratio: 11.3
9. Friedrich Chill CP06G10B 6000 BTU Window Air Conditioner
This Friedrich window air conditioner isn’t just stylish and sleek, as it is also durable and built according to the rigid Friedrich standards. This Friedrich Chill CP06G10B Energy Star compliant AC has 6000 BTU and can cool rooms up to 250 sq ft.
Energy Efficiency Ratio: 12.2
The unit also has 3 cooling speeds and options for using a fan as well. Regardless of which setting you choose, the Friedrich runs quietly and won’t keep you awake at night. In addition, the unit uses the proprietary Auto Air Sweep that allows air to be distributed more evenly, and with its digital remote control, accessing the unit is always convenient.
10. GE AEM08LX 8000 BTU Window Air Conditioner
The AEM08LX is powered by 8000 BTUs and is perfect for rooms up to 300 sq. ft, and with the kind of power the GE AEM08LX has, it’s the ideal solution for those long summer days and nights. Once the unit is up and running you can pretty much leave it to work without any maintenance. But if you want to make adjustments to this unit, you can do so via its multiple cooling and fan speed options.
Energy Efficiency Ratio: 12.1
How to Install a Window Air Conditioner
Before you begin, you should arrange for a friend or family member to be present to assist you with the installation. Window air conditioners are large and heavy objects that can sometimes be difficult for one person to hold in place; you don’t want your expensive new appliance falling out of the window opening and smashing on the ground outside.
The following are general instructions just to give you the main idea of how to install a window air conditioner. Always thoroughly read the installation guide section of the instruction manual provided with your device in case of any model-specific requirements. If for any reason you do not have an instruction manual available for your device, you may be able to view a copy on its manufacturer’s website.
Some of these devices are fitted into a window opening with special brackets that need to be attached to the window frame. Others use extendable edges that slide outwards until they grip the sides of the window opening and hold the air conditioner in place.
If you’re dealing with a window air conditioner that uses special brackets, you will need to attach those to the window opening before doing anything with the air conditioner. If screws are needed for this, they will almost certainly be included with the brackets in the packaging, sometimes along with a small screwdriver.
If your window air conditioner uses extensions that slide out of the device to make it fit the window frame, then these will either be already integrated into the device or you will need to manually assemble and attach them to it yourself before you install the air conditioner. As with those devices that utilize holding brackets, any screws and other equipment needed to attach the slide out extensions should be included in the packaging.
When you’re ready to proceed, raise the window’s lower pane and have your helper place the device on the windowsill. Fit the device onto the holding brackets or slide out the extensions to fill the empty window space on either side, whichever is applicable (some models utilize both of these positioning methods). Lower the upper window pane onto the air conditioner to hold it in place. Most models will require you to secure the upper window pane in this position to prevent any movement.
Most window air conditioners will tip very slightly to the outside to allow them to drain condensation, but some units are not designed to do this. Set your device up in the window opening exactly as directed in the instruction manual and it will be immediately clear which of the two you have. Never try to force a tipping unit to lie straight or a straight lying unit to tip.
At this point, you’re ready to plug in the air conditioner and turn it on. These devices can use a lot of energy, however, so keep that in mind when connecting it to a circuit. If the circuit in question powers other high energy appliances such as refrigerators, washing machines, dryers or vacuum cleaners, consider plugging the air conditioner in elsewhere.
Window Air Conditioner Maintenance Guide
Window air conditioners are very useful appliances but are also intricate devices that require maintenance in order to continuously operate at maximum efficiency. Follow these simple tips to keep your window air conditioner properly maintained.
1) Start out by unplugging your device and removing it from its mounting frame within the window opening. Now take it outside and gently remove the access covers on the front and/or back.
2) Slowly vacuum out the condenser coils with a soft brush attachment. You can also hose off the coils from the inside out but you must take great care not to get the electronics or the motor wet. It’s probably more advisable to clean the coils with a watering can or a shower attachment or something that allows you more control of the water flow than a hose. Do not get those electronics or that motor wet!
3) Now check the condenser coil for bent cooling fins. You should use a coil fin comb to straighten the bent fins. The trick is to find a comb with a tooth count that matches the “fins per inch” of the condenser coil. Carefully draw the comb across the bent coil fins to straighten them out.
4) Examine the foam air filter for any signs of damage. If it is ripped or damaged, replace it. If it is dirty, wash it with dish soap and water, leave it until completely dry and then replace it.
5) Finally, reattach the front and/or back covers of the device, place it back in its mounting frame within the window opening and plug it back in.
Perform the above process at least twice a year to keep your window air conditioner running at its best. This not only ensures the smooth operation of the device but also maintains maximum possible energy efficiency and saves you money.
Window Air Conditioner Energy Usage Explained
There are two metrics used to rate the energy efficiency of central air conditioners: the Energy Efficiency Ratio (EER) and the Seasonal Energy Efficiency Ratio (SEER). The unit for both metrics is BTU/W•h.
EER is the cooling capacity of the unit (in BTU/h) at an outdoor temperature of 95°F divided by the current power draw of the unit in watts.
SEER is the total cooling output (in BTU) over the cooling season divided by the total electrical power input (in watt-hours) over the cooling season. With typical home air conditioners, EER is equivalent to about 0.875 SEER, but this ratio varies somewhat between different air conditioner models.
Air conditioning systems can be classified as being of one of two types: central air conditioning and room air conditioning. Window air conditioners fall into the room air conditioning category. Central air conditioners’ energy efficiency is rated by both EER and SEER, while window air conditioners’ and other room air conditioners’ energy efficiency is rated only by EER.
As we’re concerned with window air conditioners here, we’ll look at how to judge the energy efficiency of a window air conditioner by its EER.
Window and other room air conditioners that draw at least 10% less energy than the U.S. federal standard are awarded something called an “Energy Star” label. Energy Star is a government scheme to identify and highlight energy efficient consumer products that allow people to save money on utility bills for their homes and workplaces. When shopping for a window air conditioner, look for a model with an Energy Star label and an EER of 10.7 or more.
As a side note, if you find yourself shopping for a central air conditioning solution instead of a window or other room air conditioner, understand that the purpose of the SEER rating which applies only to central air conditioners is to allow consumers to compare the seasonal efficiency of central air conditioning systems rather than their peak efficiency. Look for a central air conditioner with the Energy Star award label, a SEER of at least 14.5, and an EER of at least 11.