I live an an 580sq ft apartment, & I know some of the other tenants have 220 volt A/C, & some have 110 volt A/C. Which is better & Why??


:confused:

Are we talking window units? Or mini split systems?

240 is better (believe it or not) because it will use less energy.

Mygirlsdad:

Let's get rid of that myth. If I had a 120 Watt load. At 120 Volt it would draw 1 Amp and at 240 V it would draw 0.5 amps

P = V * I or (240)*(0.5) or 120 * 1

At which voltage does the 120 Watt load use less electricity?

If we neglect 3 phase and concentrate on single phase, the primary reason is that there is less copper at 240 V. Copper is expensive. Thick copper wire doesn't flex as well.

In the limit it may use less electricity because of less eddy current losses, less current, less voltage drops, but these are not the primary reasons.

The primary reason is less copper. It may be less expensive to wire. It may not. There will not be that much difference in operating cost. Reliability, probably yes.
Install costs maybe.

15-20 A 120 V circuits are easy to deal with, but we are not going to have a 120 v whole house stove or water heater.

A 5 HP motor at 120 V isn't likely. A 1 HP at 120 V, probably. A 1 HP at 240 volts probably.

So, it's economics.

With 3 phase motors, its an entirely different playing field.

Wall Mount

Quote:

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Originally Posted by mygirlsdad77

240 is better (believe it or not) because it will use less energy.

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I've been told you use more electric with 220v, not 110v

You only need 8000 btus so I would go with 110 volt

Great explanation Kiss. Josh, I agree that with a unit this small, the asker would be best off with a 110v unit.

Remember you pay for Kilowatts not Volts. Double the voltage gives you half the Kw. The 220 unit will always be less expensive to run. It will be more expensive to buy and more expensive to run the wiring.
e=i*r
1800W = 120V X 15A (this is why some hair dryers blow 15 Amp circuits)
With this example you are paying for 1.8 KW per hour.

If you live like I do in the Philippines and MOST foreign countries you use 220V
The same unit in 220 uses half the electricity.
1800W/220V = 8.2A
or what actually happens is that the Wattage is way lower on electric appliances.

Max voltage hair dryer is 1000W here. My Refrigerator is only 750W and my Air Conditioner is only 713W.

They only reason the USA uses the 110V standard is because that is what house holds started with when electricity started A/C delivery. I believe that was the Niagara Falls Generation Plant. It was cheap back then and by the 1950's all the appliances were 110V. It was too late to change. The rest of the world followed but in a much smarter way by using 220V. There are very few places in the world that use 110V. If America switched over we could use about 1/2 the copper in our motors and pay half the electricity costs. Too late for America to change. What a shame. I'm a Brooklyn, NY boy and when I was younger, many of the plants used DC but you had to be near a power station. The electricity did not travel as far as DC load Vs. AC. This is also why our Dryers and Stoves are 220V. It would be prohibitively expensive to run these 110V and you could not generate the heat needed with out everything being made with #4 wire.

So I was correct. 240v uses less energy than 120v. Thanks for the explanation Lancasterpa.