If you've got one or more air-conditioning units in your apartment, have you looked at the settings? Chances are, your units have more than just an on-off switch. Settings such as fan speed, auto, and timer can help cool your apartment more efficiently, which means lower electricity bills. Take a moment to familiarize yourself with the settings on your air-conditioning units. Even if you're missing the instruction manual for a unit, its controls should be self-explanatory.
Check the Fan Options
Many units offer three fan settings: high, medium, and low. High is usually most effective for cooling during normal warm weather. However, when it's very humid, it's better to keep the fan on low. This cools most effectively because it circulates the humid air slowly and steadily through the air conditioner, allowing it to dehumidify the air more efficiently.
Redirect the Vents
If the vents are pointed all the way toward one side, move them to face the center of the room. This helps direct the cool air outward into the room. If air conditioner has an oscillating setting, use oscillation only if every fan position serves the general area of the room. If the air is directed toward the back of the couch or into curtains, much of its cooling power is wasted.
Use the Auto, Energy-Saver, or Smart Fan Function
The standard way to set air-conditioning units is to adjust the temperature (using either a warm-to-cold dial or a digital temperature display) and the fan setting to your liking. But modern units offer ways to cool your home effectively while using less energy. Look for buttons that read "auto," "energy saver," or "smart fan," and experiment with these settings to see if the air-conditioning still meets your needs. If so, you'll probably save energy using these functions.
Inspect the Filter
If your unit's filter is dusty or dirty, the unit won't operate as efficiently as it should, meaning you'll spend the same amount of money for less air-conditioning. You'll probably also get less cooling, and the extra wear and tear on your unit may damage it. Many modern units have an indicator light that goes on when it's time to clean the filter. But if you think your unit isn't working well, a visual inspection of your unit's filter should tell you whether it's the culprit. As a rule of thumb, check your filter before the start of the summer season and at least once a month during periods of regular use.
Set the Timer
When it's hot outside, there's nothing better than returning home to an apartment that's well air-conditioned. But if you're gone all day, it may seem like overkill (not to mention a waste of money) to run the air-conditioning while you're out. Look for a timer or hours button and set it for the amount of time you want to pass before the unit turns on.
For example, say you leave your apartment at 8:15 a.m. each day and get home at 5:45 p.m. Before you leave, set the timer for nine hours. This way, your air-conditioner will stay off while you're at work but will automatically turn on during your commute at 5:15 p.m., cooling your apartment in time for your return. Don't have a timer? Don't sweat it. If you feel you must keep your air-conditioning running while you're gone, try raising the temperature setting on your unit five or so degrees, and lower the fan settings while you're away.
Got pets? Even if you have a timer, if you have pets in your apartment, leaving the air-conditioning off all day might leave your place too hot for their comfort. If you decide you need to keep your units running because of pets, don't use your timer. Instead, consider raising the temperature setting and lowering the fan settings a bit, as appropriate, to save money while still accommodating your pets' needs.
How Low Should You Go?
The US Department of Energy recommends setting air-conditioning at 78 F when you are home and setting it higher when you are away from home. If this temperature is too high for your comfort, you can supplement the cooling in individual rooms with ceiling fans. Fans can make your body feel 4 degrees F cooler and use relatively little electricity.