A window air conditioner unit implements a complete air conditioner in a small space. The units are made small enough to fit into a standard window frame. You close the window down on the unit, plug it in and turn it on to get cool air. If you take the cover off of an unplugged window unit, you'll find that it contains: The fans blow air over the coils to improve their ability to dissipate heat (to the outside air) and cold (to the room being cooled). When you get into larger air-conditioning applications, its time to start looking at split-system units. A split-system air conditioner splits the hot side from the cold side of the system, as in the diagram below. The cold side, consisting of the expansion valve and the cold coil, is generally placed into a furnace or some other air handler. The air handler blows air through the coil and routes the air throughout the building using a series of ducts. The hot side, known as the condensing unit, lives outside the building.

The unit consists of a long, spiral coil shaped like a cylinder. Inside the coil is a fan, to blow air through the coil, along with a weather-resistant compressor and some control logic. This approach has evolved over the years because it's low-cost, and also because it normally results in reduced noise inside the house (at the expense of increased noise outside the house). Other than the fact that the hot and cold sides are split apart and the capacity is higher (making the coils and compressor larger), there's no difference between a split-system and a window air conditioner. In warehouses, large business offices, malls, big department stores and other sizeable buildings, the condensing unit normally lives on the roof and can be quite massive. Alternatively, there may be many smaller units on the roof, each attached inside to a small air handler that cools a specific zone in the building. In larger buildings and particularly in multi-story buildings, the split-system approach begins to run into problems.

Either running the pipe between the condenser and the air handler exceeds distance limitations (runs that are too long start to cause lubrication difficulties in the compressor), or the amount of duct work and the length of ducts becomes unmanageable. At this point, it's time to think about a chilled-water system.How Room Air Conditioners Work Window and room air conditioners use refrigeration principles to extract heat and moisture from room air, cooling and dehumidifying the air. The basic components inside the unit include a blower and/or fans for moving cooled air into the room and exhausting warm air, and refrigerant components for extracting heat from the air. Those components include a compressor, evaporator coil, refrigerant-filled tubing, and condenser coil. Most window and room air conditioners have thermostatic controls. How Does a Window or Room Air Conditioner Work? Room temperature reaches the thermostat’s set point, turning on the room or window air conditioner’s blower.

This draws room air through the air inlet grille and a filter that removes airborne dust and particles. Refrigerant is pumped through tubing in the unit, initiating the refrigeration process. ac package unit for saleThis refrigerant takes on and gives off heat as it raises and lowers in temperature, changing from liquid to gas and then back to liquid.how much does it cost to get a new ac unit When the refrigerant begins to circulate through the indoor coil, it is very cold. how to repair your home acAs the blower pushes warm air across the coil, the refrigerant absorbs heat and turns into vapor. The vapor travels to a compressor that pressurizes it and moves it through the condenser coil, where it gives off heat, which is expelled outside.

The refrigerant then moves through an expansion device that converts it to a low-pressure, cool liquid again, which then returns to the evaporator coil.All the while, the blower pushes air past the cold coil to chill the air and blow it back into the room. The tado° Smart AC Control makes your air conditoner smart to maximize your comfort. Works with almost all remote-controlled air conditioners Split / wall-hanging AC Be a pioneer in a new age of intelligent air conditioner control Automatically adjusts the air conditioner: cool before you get home, saving when you're away. With the tado° app on your phone you can always check and change the settings while on the move. Save up to 40% on your AC costs. tado° can pay for itself in less than a year. Works with almost all remote-controlled ACs tado° controls your AC via infrared. How Geolocation controls your AC See how your home is cooled down before you arrive Save up to 40% on your AC’s energy bill

Monitor your individual savings Control your AC from anywhere Check the temperature at home and change settings Setup your air conditioner See how the Smart AC Control replaces your simple remote ... and many more tado° makes it easy to be green Together tado° customers save the energy of 52 wind turbines per year.Send your question to Umbra! We are in the midst of a heat wave. I have a window unit air conditioner in my tiny apartment. There is an “energy saver” option that shuts down once the temp reaches the desired setting (generally 79 degrees), then starts back up again when the mercury rises. It’s been so hot that it seems to only take a few minutes till it fires back up. Is this really saving energy? With hope, the heat will have broken by the time you read this. But we all know it will rise again, and we’ll have plenty more days when we can hear the entire country lean back in its chair, wipe its brow, and mumble, “Hot enough for ya?”

Except here in Seattle, where we get approximately one hot day a year, usually the third Tuesday in September. Before we get to your question, a few eye-opening facts about America’s love of indoor climate control: In the late 1970s, 23 percent of American homes had some form of air conditioning; today, 87 percent do. We have become so addicted that 9 out of 10 new homes are built with central air. We spend $40 billion a year air-conditioning our buildings, says the EPA, and cooling our homes accounts for 17 percent of household energy use. In return, we get — well, I’ll let author Stan Cox say it: “Air-conditioning buildings and cars in the U.S. has the climate impact of half a billion metric tons of carbon dioxide a year. That exceeds the total annual carbon dioxide emissions of any one of these nations: Australia, France, Brazil, or Indonesia.” Wait, you mean the thing we use to get through the record heat is … helping to cause the record heat? I believe that is what the kids call ironic.

So my first piece of advice is, when you can stand to go without the AC, please do. Keep your blinds closed against the sun, use a fan, unplug appliances that generate heat, eat popsicles, drink water, place wet washcloths upon your fevered brow, sleep naked. When you use the AC, please set it at a reasonable temperature (your 79 is very civilized) and do not — do not — crank it all day while you are gone, people. Your dining room set does not need to be comfortable. Emily, you’ve perhaps passed out while waiting for me to get to your actual question. I have experienced “energy-saving” mode, and I’ll admit I find it rather annoying. The mechanical hum stops. Your brain adjusts to the quiet. And then — ga-glunk — it starts up again. It can’t seem to decide. Here’s what is actually happening: Air conditioners remove heat and moisture from your air by passing it over coils filled with refrigerants. In a window unit, a compressor moves the refrigerants through the coils, and fans move the air where it needs to go.

In energy-saver mode, the compressor shuts off when, as you say, the desired temperature is achieved. The fans turn off too, but they come back on every so often to check in on you, see whether you need any lemonade, etc. When the fans find air that’s too warm, the compressor comes back on. So what you might be hearing every few minutes is the fans turning on and off, while the compressor is laying low. According to the EPA, this mode uses about 10 percent less energy than the conventional “cool”mode, so that saves you a little money. I’ve had trouble getting more detail than that from several manufacturers I contacted, none of whom could provide specifics on power savings by my deadline. Some even seemed a bit stymied. Generally I can count on geeky online chats to yield at least one insanely detailed calculation in these situations, but here, too, they all just shrug and say, “Eh, doesn’t save you much.” I guess even the geeks are feeling hot. If I do get more details, I’ll add an update here.