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. how to change car ac air filterDashboard controls for the a/c, however, come later. thru the wall ac unitShould the Packard's passengers get chilly, the driver must stop the engine, pop open the hood, and disconnect a compressor belt.air conditioner units for trucksMore: 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. Brands like Honeywell and Carrier develop coolants that are more environmentally friendly.2003 In "Hey Ya," Andre 3000 raps, "What's cooler than being cool? They aren't talking about air conditioning.More: 10 Best Swimming Pools in the World - Must See!How Much Does it Cost to Install Solar on an Average US House?

A new report has revealed which cars cost most when their air-conditioning systems go wrong. An estimated half-a-million air-conditioning systems fail each year and - with an average repair cost of £445.60 - it means that fixing the systems costs an annual £220 million. The car that costs the most to put right, according to the survey by Warranty Direct, is the Volkswagen Sharan S TDI, which costs, on average, £1,578.93 when its air-conditioning fails. Second most expensive to repair is the Honda FR-V Sport, at £1,348.26, followed by the Toyota Land Cruiser at £1,294.27 and the Porsche Boxster S at £1,285.38, said Warranty Direct. Seat's Alhambra and the old-model Ford Galaxy are also among the dearest to repair, although the top 10 also includes executive models and sports cars, all of which produced garage bills topping £1,000. "Air-conditioning units are one of the most expensive parts of a car to fix, because the systems are often very complex," says Warranty Direct's Duncan McClure Fisher.

"It's not just the cost of parts that motorists have to shell out when things go wrong; the labour costs can be very high simply because it's not easy to get to a car's air-con system to fix it." Air-conditioning failures represent 1.65 per cent of all breakdowns recorded by Warranty Direct. MAKE / MODEL / AVERAGE REPAIR COST Volkswagen Sharan S £1,578.93 Honda FR-V Sport £1,348.26 Toyota Land Cruiser £1,294.27 Porsche Boxster S £1,285.38 Seat Alhambra £1,278.59 Mercedes CLK 430 £1,100.54 Volkswagen Golf GTI £1,050.22 Ford Galaxy £1,044.63 Audi A6 £1,044.57 Mercedes ML270 £1,014.97 *All examples were between three and six years old at the time of breakdown.If you start the installation in the morning, you’ll be enjoying cold air byA ceiling fan helps circulate the air and eliminate hot spots, but if the A/C unit keeps you cool enough, you can skip the fan. how to pick the right size unit for your garage and how to install it in the wall. In a hot garage, the

heat and humidity slow you down, make you grumpy and increase your garage solves those problems and doesn’t cost a fortune. You can buy a TTW (through-the-wall) unit for aboutWindow units cost a bit less, so consider going that route if you have a units are the same except for installation. A window unit comes with hardware and sealing gear for mounting it in a window, while a TTW unit requires a separate sleeve that fits into a wall opening that you frame into the wall. If you plan to use your garage A/C only occasionally, you don’t have to installIt’ll just take longer to lower the temperature to a comfortable level and the A/C compressor will run for longer periods, costing you more in electric bills. dramatically speed up the cool-down time and increase cooling effectiveness by hanging drywall on the ceiling. That reduces the size of the area to be cooled and helps the cool air circulate.

Install a vapor barrier first, in case you decide to add attic insulation later on. But if you plan to frequently use the garage A/C, it’s well worth insulating and finishing the entire space. Then size the A/C unit Measure the area of your garage (length times width) to determine the total square footage, then consult theApply the adjusting factors at the bottom of the chart. shop around for the best price on the A/C unit and a matching through-the- wall sleeve (an additional $100 to the cost of a window unit). Pick a location and cut the opening A/C units have weak circulating fans, so don’t locate one on the end wall of a locate it in the middle of the longest wall and aim the airflow toward theIf you’re installing a window unit and it’s located on the end wall of a rectangular garage, plan to install circulating fans to help move the cold air to the other end.

Next, check the sleeve installation instructions for the rough openingSome manufacturers want a 1-in. clearance on the sides and top of thePlus, the distance from the ceilingDon’t place the opening directly below the top wall plate.That’ll result in rapid compressor cycling and inefficient cooling. the top of the sleeve opening about 24 in. down from the ceiling (or as shown in the sleeve installation instructions). Then remove drywall (if any) in that location to expose the studs. center stud to allow for the thickness of the new top and sill plates. task is reworking the siding. most cases it’s best to remove as much siding as needed before cutting the opening in the sheathing and then to trim and re-side around the opening. Follow the manufacturer’s instructions to mount and secure the sleeve Run electrical cable to the location and install the receptacle. units require a dedicated receptacle on

either a 15- or 20-amp circuit breaker (no extension cords allowed). sized from 9,000 to 12,000 Btu will typically run on a 20-amp, 120-volt circuit. But you’ll have to install a 220-volt circuit Other A/C options for your garage We didn’t cover portable A/C units in thisThey’re an option but not a veryPortable units use cold air from the room to cool the condensing coil and then exhaust that air to the outdoors. negative pressure this creates inside the garage draws in an equal amount of hot humid “make-up” air from outside. portable unit then has to cool that makeup air and the cycle repeats over and over, wasting 30 to 50 percent of the rated capacity of the unit. units don’t come close to the efficiency of a window unit or a TTW unit. If you want the very best cooling option and are willing to dig deep (expect to pay about $4,000), contact an HVAC company and get quotes on a split system.