How can I tell which air conditioner uses the least electricity?

Question

i am looking at window air conditioners and it's a little confusing. I am asking this in the green section since the folks here seem to know their electricity usage.

Does a 115 volt unit use less energy than a 230 volt?

I know i might seem obvious, but when I look at Amps and Watts, sometimes the 230 volt is less. Then they have the EER(energy efficiency rating), these numbers are confusing too. Some items are Energy Star but have higher maximum watts and amps than others that use less. Do different units use that wattage more efficiently? How can I tell which unit will use the least amount of electricity? Should I be looking at voltage, amps, watts? I am looking for a 12,000-18000 unit. Some are 115v, while others are 230v. Some say 12 amps, some say 8. Maximum watts on one is 1308, while 1780 on another. Some have lower watts with a higher amp number, but a higher watt will have a lower amp than the other. This is all so confusing, please help. Thanks.

Answer 1

115 volts

Answer 2

I'd say, first calculate the BTU's you really need.  Looks like you have that narrowed down.

Then, just look for lowest kWh per year rating, which should be on the yellow tag.  That reflects how much energy the A/C will actually use to cool your room.  The winner will be an EnergyStar unit.

Ignore volts and amps, except to get the voltage that you need.  Watts are somewhat helpful, but a low-wattage unit could be running all day and night, while a higher-wattage unit, because of efficiency, could only need a short spurt to do the same job.

Answer 3

Watts are equal to volts times amps so you will see the electrical consumption is the same. The bigger the unit, the more sq. footage it covers. The real question is why you need air conditioning?

Air conditioning is a nice trade name, it is in fact refrigeration and the same as leaving your fridge door open to cool the home. Do you have heating in your home? If you told an engineer you had refrigeration and heating in the same application, he would tell you that you have a design problem.

Buildings are designed, insulated and insured with your regional temperature extremes, the bad part is that no one could see the temperatures or solar impact. The entire building industry designs for the temperatures in a calculator and academia teaches us the same so we can calculate with utmost accuracy. We do not want to generate heat atmospherically or it changes weather.

Thermografix Consulting Corporation completed several seasons using the most advanced thermal imaging in the world to qualify building energy use and solar impact on buildings. The results contradicted the educations of their own professionals because solar radiation including the same UV that burns our skin is burning building exteriors. It was never thought or taught that buildings and development could generate extreme heat.

Go to the following link and see accurate temperature images of the effect of solar radiation. You will see solar exposed building finishes generating extreme heat the building isn't designed or insulated for. That changes the entire energy consumption formula, fire separations, mold, investment and health. You will see the effect of shade(no electrical required) and paint, etc. Look at the images and then look at the solar exposed sides of your building so you can address the problem instead of treating the symptoms with air conditioning. the air conditioning loads are knocking California off the electrical gris and they are not addressing their heat generation that is changing weather. http://www.thermoguy.com/globalwarming-h...

Follow this link to see how the mercury associated with generating electricity for air conditioning is contributing to polluted newborns. Babies had mercury inside them before they took their first breath. http://www.thermoguy.com and scroll down to the picture of the fetus where you can link to the study on polluted newborns.

Answer 4

The units of EER are Btu/watt-hour.  So a 10,000 BTU A/C with an EER of 12 will use 825 (10,000/12) watt-hours for every hour it runs (less when it is cycling).

Get the highest EER you can in the size appropriate for the area you want to cool.  Voltage doesn't matter.

DK