You can run your window air conditioner from an inverter. The most common way to use an inverter is when changing from alternating current, or AC, when going off the grid. By going off the grid, you will be using direct current, or DC electricity, from a sustainable energy source like solar, windmills or water. The inverter converts the DC current into AC current so that regular household appliances can be run from typical household sockets. The Electrical Basics An inverter is part of a 12-volt DC system. For practical purposes, it takes 11 amps of DC power to successfully run a 1-amp AC powered device. If you have a 5-amp window air conditioner, you will need 55 amps of DC power to run the unit continuously. However, all electrical appliances have a starting surge that gets the motor running. This is generally five times the continuous electrical load, which means that, in this instance, you will need 275 amps of DC power to start the 5-amp air conditioning unit and then a continuous 55 amps to keep it running.

The Air-Conditioning Unit The smallest window air conditioners that are designed for a single room, usually in the 5,000 BTU range, use about 4 to 5 amps of power when running. A larger whole house unit that puts out 12,000 BTU will use about 11 amps of power when running. The surge on an 11-amp unit will be about 360 DC amps while the surge on a 4-amp unit will be about 130 amps. In this case, using the smallest air conditioning unit possible will enable you to use a smaller and less expensive inverter. The Power Source In real terms, all the inverter does is to transfer a specified amount of power to operate any given AC electrical unit, including air conditioners. Although the inverter must be rated to accept the high amperage rating that an air conditioner will pull through it, all inverters get their power from a power source like storage batteries or direct hook-ups to solar panels, windmills or hydropower. These power sources must be capable of providing the needed surge power as well as the continuous energy needed to keep the air conditioner running.

Charging In most cases, storage batteries will be used as the power source to run the air conditioner. These batteries will need to be charged on a regular basis. Alternate forms of sustainable power are almost always used to charge the batteries, including solar panels and windmills, among others. However, unless you are using hydropower, which guarantees a continuous source of sustainable power day or night, wind or no wind, a back-up AC grid hook-up can be used to charge the batteries on days when there is no sun or wind. why does my ac unit keeps running/Getty Images Suggest a Correctionac unit does not stopIn April 2009, Mayor Bloomberg signed a bill giving NYC the toughest laws against vehicular idling, with stiff fines for repeat offenders. types of ac unit

Three months later, AP reporters caught the mayor repeatedly flouting the law, with his chauffeur and security detail sometimes leaving their engines running for an hour while waiting for the mayor. Bloomberg had to apologize, but ever since he's presumably had a team of engineers working around the clock to come up with a solution to keep his SUV cool when he's not in it. Well, they finally had a major breakthrough, and yesterday they did some beta-testing! As you can see from these photos obtained by the NY Post, they're experimenting with a high-tech solution that will enable the mayor to step into a pre-chilled, hypocrisy-free SUV. To be honest, the science at work here is beyond our primitive understanding, but to put it in layman's terms, it seems engineers have connected what appears to be a standard residential A.C. unit onto the rear window of Bloomberg's SUV. Then, using a complicated series of "extension cords" and—no doubt—some sort of nuclear fusion, the A.C. unit will be "plugged in" to an electrical power source.

At press time, it was unclear how many miles of extension cord the mayor will need to conduct official business within the five boroughs, but clearly this innovation will be an enormous boon for New York's troubled extension cord industry. (Rumors that Bloomberg was sourcing the extension cords from Malaysian sweatshops could not be confirmed.) Speaking to the Post, Bloomberg's spokesman said yesterday was just an experiment, adding that "there is far less emissions corresponding to the power of a single air conditioner on the grid than idling a V-8 engine." And by attaching colorful plastic ribbons to the AC's vents, Bloomberg's backseat is bound to be far more festive!1758 All liquid evaporation has a cooling effect. Benjamin "I invented everything" Franklin and Cambridge University professor John Hadley discover that evaporation of alcohol and other volatile liquids, which evaporate faster than water, can cool down an object enough to freeze water.1820 Inventor Michael Faraday makes the same discovery in England when he compresses and liquifies ammonia.1830s At the Florida hospital where he works, Dr. John Gorrie builds an ice-making machine that uses compression to make buckets of ice and then blows air over them.

He patents the idea in 1851, imagining his invention cooling buildings all over the world. But without any financial backing, his dream melts away.1881 After an assassin shoots President James Garfield on July 2, naval engineers build a boxy makeshift cooling unit to keep him cool and comfortable. The device is filled with water-soaked cloth and a fan blows hot air overhead and keeps cool air closer to the ground. The good news: This device can lower room temperature by up to 20 F. The bad news: It uses a half-million pounds of ice in two months… and President Garfield still dies.More: Crown Molding Cutting & Installation Guide1902 Willis Carrier invents the Apparatus for Treating Air for the Sackett-Wilhelms Lithographing and Publishing Co. in Brooklyn, N.Y. The machine blows air over cold coils to control room temperature and humidity, keeping paper from wrinkling and ink aligned. Finding that other factories want to get in on the cooling action, Carrier establishes the Carrier Air Conditioning Company of America.1906 Stuart Cramer, a textile mill engineer in North Carolina, creates a ventilating device that adds water vapor to the air of textile plants.

The humidity makes yarn easier to spin and less likely to break. He's the first to call this process "air conditioning."1914 Air conditioning comes home for the first time. The unit in the Minneapolis mansion of Charles Gates is approximately 7 feet high, 6 feet wide, 20 feet long and possibly never used because no one ever lived in the house.1931 H.H. Schultz and J.Q. Sherman invent an individual room air conditioner that sits on a window ledge—a design that's been ubiquitous in apartment buildings ever since. The units are available for purchase a year later and are only enjoyed by the people least likely to work up a sweat—the wealthy. (The large cooling systems cost between $10,000 and $50,000. That's equivalent to $120,000 to $600,000 today.)1939 Packard invents the coolest ride in town: the first air-conditioned car. Dashboard controls for the a/c, however, come later. Should the Packard's passengers get chilly, the driver must stop the engine, pop open the hood, and disconnect a compressor belt.

More: Ceiling Tiles Installed Easily & Step By Step1942 The United States builds its first "summer peaking" power plant made to handle the growing electrical load of air conditioning.1947 British scholar S.F. Markham writes, "The greatest contribution to civilization in this century may well be air-conditioning—and America leads the way." Yet somehow people still say a brilliant new idea is "the best thing since sliced bread."1950s In the post-World War II economic boom, residential air conditioning becomes just another way to keep up with the Joneses. More than 1 million units are sold in 1953 alone.1970s Window units lose cool points as central air comes along. The units consist of a condenser, coils, and a fan. Air gets drawn, passed over coils, and blasted through a home's ventilation system. R-12, commonly known as Freon-12, is used as the refrigerant.1994 Freon is linked to ozone depletion and banned in several countries. Auto manufacturers are required to switch to the less harmful refrigerant R134a by 1996.