Is Window Air Conditioner a Good Choice for You?
While window air conditioners provide you maximum cooling flexibility (you are able to cool each room separately), their cooling capability is limited to single room. If you are thinking or cooling a larger house or building, you will need several such units, which will probably cost you more than installing central air conditioning system.
How Window Air Conditioners Works?
Window ACs use the same concept to cool thing down as refrigerators. There are three main parts of AC: a compressor, evaporator and condenser; compressor and condenser are located outside, while evaporator is located inside the room. Besides these parts, a window air conditioner contains two fans, a hot and cold coil, expansion valve and a control unit.
The compressor pressurizes and heats the refrigerant (most commonly Freon), which provides the cooling. When Freon becomes liquid, it runs through the coils to dissipate the heat. Afterwards the liquid runs through the expansion valve and becomes bold Freon gas, which further runs through the set of cold coils to cool the other side of the window. The same motor provides power to both fans, which are necessary to blow the coils to dissipate the air; one is blowing the hot coil from inside out, while the other is blowing the cool air inside.
Selecting Appropriate Window Air Conditioner
The most important criteria for selecting the right among available window ACs is required cooling capacity, which depends on the size of the room being cooled. Window ACs generally range between 5,000 and 14,000 BTUs.
You have to be aware that bigger unit does not necessary mean a better choice. If the AC unit is to large, according to the room being cooled, it will operate uniformly and a smaller unit running at extended period could be a more effective choice. Large units are also less efficient at dehumidifying, if they are frequently turning on/off.
By the rule of thumb, a window air conditioner needs 20 BTUs for each square foot of living space, if we take only the size of the room into the consideration. However, there are other important factors to consider, like height of the room, local climate, shading and window size.
In case you have a narrow long room or if you plan to mount your AC near the corner of the room, you should look for the unit that can direct its airflow in the desired direction and has the power function to send the cooled air further into the room.
You can plug smaller window AC into any 15 or 20-amp, 115-volt household circuit, while larger room air conditioners need their own dedicated 115-volt circuit. The largest models require even 230-vole circuit. You should verify that your home’s electrical system meets your air conditioner power requirements.
Efficiency of window ACs is measured by energy efficiency ratio (EER), which is representing the cooling capacity in British thermal units per hour to the power input in watts. Higher ratio means better air conditioner.
National appliance standards require ACs to have the EER of 8 or greater since 1990, but when buying today, about 10 is what you should look for. By the rule of thumb, if you double the EER of your air conditioner, you can expect to cut your air conditioning energy cost to half. You should definitely look for air conditioners labeled as Energy Star ACs.
Other Features to Look for
Among other features to watch when buying a new window AC, you should look for:
- Possibilities of cleaning the filter (it should slide out for easy cleaning);
- Logically arranged controls;
- Built-in timer is a very useful function also.
Installing and Operating Window Air Conditioners
You should plan the installation of your AC very carefully, to avoid some extra time and costs. Here are some installation and operating tips:
- You should level the AC unit in order to function properly and efficiently.
- If possible, do not place the unit on the sunshine spot of your home, look for north or east side. Direct sunshine lowers AC efficiency by 10%.
- Placement of the unit must take care of not blocking the unit’s airflow, so do not block it.
- Place the AC thermostat where no other heating devices like lamps or TV will surround it, otherwise it will run longer than necessary and your electric bill will be higher.
- Set the thermostat as high as possible in the summer, since the heat goes up and you will cool the room more efficiently than you normally would.
- Do not exaggerate with cooling settings when turning on your air conditioner. It will not help you to cool your room any faster, but it will influence your energy bill.
- In times of low humidity, you should set your fans on high and vice versa. In times of high humidity, you should rather set the fan speed to low for more comfort. Slower air movement on humid days cools your room better and removes more moisture from the air.
- Think of using interior fan in combination with your window air conditioner to speed the cooled air through the home, without greatly increasing the electric bill.