Air conditioners and the field of air conditioning are getting better over time. This is due, in large part, to HVAC technology. Here’s what you need to know about the history of air conditioning, as well as modern HVAC and how it keeps you comfortable.
In The Beginning
In the beginning, air conditioning units were loud, expensive, but also necessary. Prior to air conditioning, you would have had to rely on fans, and other inventive methods, to stay cool. Despite the fact that it’s been in American homes since the 1930s, most people are still largely ignorant about its history.
Old systems that were installed 20 years ago, used about 6,000 watts of electricity per hour to cool an average house. Today, the same sized home can be cooled with just 1,710 watts per hour. That’s a 250 percent increase in efficiency. But, how did it all start?
Air conditioning can be traced all the way back to 1851, when Dr John Gorrie designed the first machine that created ice using a compressor which was powered by a horse, water, wind-driven sails, or steam engine. He was able to show that the machine worked in 1848 and was awarded a patent for it in 1851.
But, it was Willis Carrier that designed the first modern cooling unit powered by electricity in 1902. He did it not for its cooling abilities but for its dehumidifying properties – to cool a moisture problem for a publishing company. The St Louis World’s Fair played home to one of the first public demonstrations of air conditioning, when the Missouri State Building was cooled using mechanical refrigeration.
In 1906, Stuart W. Cramer, a North Carolina textile mill owner, coins the term “air conditioning” with a patent he filed for his unique technique for controlling humidity in his textile mills. In 1922, Carrier invested the centrifugal chiller to improve on the performance of earlier air conditioning models. The new units have fewer moving parts and less compressor stages.
Then, in 1928, Thomas Midgley, Albert Henne and Robert McNary of General Motors discover a chemical that will change the way we think about air conditioning. They discover chlorofluorocarbon (CFC) can be synthesized, and they go to work creating a blueprint for Frigidaire’s air conditioning systems. Up until recently, these chemicals were used in nearly every air conditioner. And, air conditioning service often required skilled technicians to recharge and discharge systems as part of the regular maintenance of the system.
But, it was eventually discovered that CFCs contribute to ozone depletion. In 1929, room cooling systems hit the market, and in 1931, in-window air conditioning units were commercialized. It wasn’t until 1947 that low cost air conditioning units became widely available. Between 1975 and 1978, National Laboratory research developed what would become the modern heat pump design to advance the efficiency of air conditioning systems.
Today’s Systems and What To Look For
Today’s air conditioning systems are efficient and powerful, and even a small window unit can cool several rooms at a time, depending on the unit’s rating and cooling power. Central air conditioning easily cools an entire home, and reduces humidity – reducing or eliminating the risk of mold growth in humid climates, while also keeping you comfortable.
Most systems are two-part systems for cooling indoor air. The first part is a condenser that sits outside the home. You’re probably familiar with this. It’s that large metal box with a fan unit on top. If you have an older unit, it’s probably noisy – especially if you haven’t cleaned it in a while. The second part of the system is an evaporator inside the house.
As refrigerant circulates inside a closed loop, between the evaporator and the condenser, it captures heat from the house and carries it outside. A fan then blows it away. New systems do this exceptionally well.
If you’re in the market for a new air conditioning system, look for a SEER rating of 13 or higher. SEER stands for “seasonal energy-efficiency ratio.” Think of it like a “miles per gallon” rating but for your air conditioning. SEER tells you how efficient your system is. 13 happens to be the minimum rating for what’s considered a high-efficiency unit.
By law, the minimum SEER rating must be 10. These systems will set you back between $2,000 and $4,000, and will cool a 2,000 square foot home. Make sure you get someone to size the system for you though. Bigger is not better. With air conditioning, part of its cooling power comes from the fact that the unit needs to pull moisture out of the air. If an air conditioning system is too powerful, it will cool the room too quickly, leaving the air damp and cold. Undersized systems overwork the condenser and clog it with frost.
Rod emigrated to Australia in 2006 with his wife Tanya and two Staffordshire bull terriers, Honey and Jake. Once a keen golfer, 5 handicap, he wonders if he’ll ever lose the kilos he needs to in order to swing a club in anger again! He purchased Peninsula Air Conditioning in 2007 and has successfully transformed it into a leading installation company within the Sydney Metro area.