231 posts, read 669,106 times 1,955 posts, read 7,530,185 times 8,309 posts, read 28,190,502 times Originally Posted by Narfcake Exactly what I was thinking. As a kid I used to call that the "angry" plug. My house was built before central A/C was a consideration and the bedrooms were all retrofitted for window units. At the time window units were usually 240V systems. If this plug is near a window, that's very likely to be why someone would put such a thing in the wall. Switching to 120V probably isn't going to be very difficult or time consuming and if you know much about wiring and applicable codes, you could probably DIY. I'm guessing, however, by the subject of this thread that you would be smart to hire this job out. If the stars are aligned your electrician may be able to leave your existing wires in place, cap one leg of the 240V at the panel and in the wall box and replace the breaker with a 15A. You may get off as lightly as $25 in materials and an hour or two labor.

*EDIT* I just realized that you were renting. Your landlord probably has people he would want to use, have you talked to him or her about this? 8,293 posts, read 18,846,880 times Originally Posted by jmax I can't say for sure, but I'd bet my big fat butt that it's a 220V outlet, and you have a 110V window unit. If my hunch is correct, the bottom line is that you simply can't plug your AC into that outlet. Get an acceptable (heavy) extension cord and run to a different outlet. Bigger window AC units used to be 220V. Imagine how THAT would make your electric meter spin! 26,348 posts, read 69,637,911 times Originally Posted by Omaha Rocks Maybe not much more if the current draw was half as much. 13,975 posts, read 39,423,209 times 10,205 posts, read 33,380,249 times Take a look at the standard wall outlet and figure out if it has a 15 or 20 A breaker, then look at the data plate on your air conditioner - if it draws less than 15 amps, you should be able to use the outlet nearby.

Get a heavy-duty extension cord, 14 gauge wire or better, no longer than needed (don't stretch it tight, but the longer it is the more resistance) If your A/C draws more than 15 but less than 20A, you can use that recepticle *if* it's on a 20A breaker. This might require changing over to a 20A type 110 outlet. This is rare but I am mentioning it to be complete. I agree that the existing outlet is probably a 220/240 type outlet. Actually you can get some good high-efficiency 220 A/C units anymore, or heat pumps. home ac unit optionsElectrical billing is by watts, so it does not matter if you use 10A at 110 or 5A at 220 - same price. many ton ac unit do needSame power, actually the 220 is a bit superior as there is less "IR" loss in the cabling and the device itself.what is the cost of an ac unit