Air Conditioning Has Changed Homeowners’ Lives : Lifestyle: It ranks as one of America’s great inventions, but there’s more to it than just flipping a switch.
It is an event that ranks up there with the Louisiana Purchase, the Battle of Vicksburg, and the development of the atomic bomb.
At least it does according to Life magazine, which in 1975 listed the invention of air conditioning among the 100 events that most shaped America.
Introduced in 1902 as a way to control humidity in a Brooklyn printing plant, air conditioning was the brainchild of Willis Carrier, a Cornell University graduate who went on to refine his invention into a compact, practical device capable of cooling everything from movie theaters to passenger trains.
Air conditioning changed America forever.
It tamed the hottest climates, making possible the economic and population booms of the South and Southwest, and sped the growth of a host of new industries dependent on precise climate control.
Hospitals, skyscrapers and shopping malls would be unthinkable without it.
Perhaps nowhere, however, has air conditioning made so personal an impact upon American life than in the home.
In the 15 years since Life published its list of American milestones, residential air conditioning has gone from a luxury item to an expected part of daily life.
In Orange County, air conditioning for the home took off with the residential building boom of the 1970s. Industry sources estimate that 75% of the homes here are equipped with some form of refrigerated cooling device.
And yet for large numbers of homeowners, air conditioning remains something of a mystery to be misunderstood and misused--when it isn’t being taken for granted, which is most of the time.
Air conditioning, whether a central system or self-contained window unit, is basically a refrigerator turned extrovert. It uses the same components (compressor, condenser, evaporator, fan and working fluid) to cool air, but on a much larger scale.
A few basic physical laws are at work. Namely, that as the working fluid (usually the chlorofluorocarbon Freon) is compressed, it gets hotter, and with the release of pressure, it evaporates into a gas and gets cooler. At the same time, hot Freon liquid releases heat to its surroundings; cool Freon gas absorbs it.
In an air conditioner, the cool gaseous Freon passes through coils in the evaporator inside the house where it absorbs heat from the warm interior air. It then passes through transfer lines to the compressor-condenser outside. Here the gas is compressed into a hot (200 degrees Fahrenheit) liquid and pumped through the condenser coils. The liquid, now being much hotter than the outside air, releases heat to its surroundings before passing back to the evaporator. As pressure is released, the liquid Freon turns once more into a cool gas, ready to begin another cycle of heat absorption and release. Put simply, an air conditioner is like a man bailing out a boat--except in this case the boat is your house, the water is heat, and the bucket is the Freon.
Many people believe that an air conditioner somehow “makes” cold air. Scientifically, however, there is no such thing as cold, only varying degrees of more or less heat. The cool breeze coming from the fan of an air conditioner is air that has lost something--about 20 degrees of heat.
As far as comfort goes, it is as important for an air conditioner to remove moisture from the air as it is to cool that air. This moisture removal is possible because the colder air becomes, the less water it can hold. As indoor air reaches its saturation point during the cooling process, the moisture it contains collects on fins inside the air conditioner and drains away. Think of how a glass of ice water “sweats” as warm air cools on contact and gives up its moisture. An air conditioner works much the same way.
The failure to understand this process of dehumidification can lead a homeowner to choose the wrong air conditioner.
Most people think bigger is better, says Mike Karsten, co-owner of Benchmark Air Systems Inc. in Anaheim. But an oversize system cools so rapidly that airborne moisture has little chance to condense on collection fins.
“People I run across in residential sales think choosing air conditioning is like buying a race car. If 200 horsepower is good, then 400 horsepower is great. That isn’t the case with air conditioning. Too much cooling, too fast, and what you get is very cold damp air,” Karsten says.
Most new homeowners don’t have to worry about picking the right air conditioner. Builders do it for them.
“Up until the mid-1970s, (residential) air conditioning was optional,” Karsten says. “Builders didn’t prepare homes for it the way they do now, and often the homeowners had to buy and install their own systems.”
During the “optional period” of the last 20 years, air conditioning proved popular and tens of thousands of units were installed. These are the systems that have distributors, installers and manufacturers anticipating a surge in residential sales as tired units are replaced by new, more efficient models.
Ralph Luciano, sales representative for Trane, a large manufacturer of air conditioners, says units today are nearly twice as efficient as they were in the mid-1970s.
“Energy conservation is very big today,” he says. “Fifteen years ago, air conditioners probably ran at (an Energy Efficiency Rating of) five or six. Today the average is nine, and by 1992 federal law mandates a level of at least 10.”
EER is the acronym of the moment in air-conditioning circles. Basically, it is the measure of the amount of heat a unit can remove per watt-hour of electricity consumed. Its cousin, SEER, or Seasonal Energy Efficiency Rating, is used to estimate the cost of running an air conditioner over an average cooling season. Federal law requires that every air-conditioning unit carry these ratings, which are expressed in BTUs, or British thermal units.
(A BTU is a measure of cooling capacity. For example, 12,000 BTUs equal one ton of refrigeration capacity, or the capacity needed to melt 2,000 pounds of ice during a 24-hour period. A typical central air-conditioning system for a two-bedroom house may equal three to 3 1/2 tons of cooling capacity, or 36,000 to 42,000 BTUs.)
Central air conditioners with EERs of 16 or more are gaining popularity with residential customers who want to get the most cooling bang for their energy buck, according to Luciano.
To help spur the move to save electricity, Southern California Edison offers rebates on high-efficiency residential air-conditioning equipment. Edison spokesman Kevin Kelley says customers also get billing discounts if they enroll in a “cycling” program that will automatically shut off selected residential air conditioners by radio remote control during peak demand times.
“These shutdowns last from one hour to no more than six hours,” Kelley says. “They can take place no more than 15 days a year, usually in the afternoons, and never on weekends. Most people who join up aren’t even home during the times the shutdowns might occur.”
Customers who join the program are rewarded with automatic credits for six months on their electric bills, regardless of whether shutdowns take place.
The introduction of split systems that use more than one air conditioner to cool several areas in the same house has also helped cut operating costs for homeowners by making it possible to shut down one of the units when its area is not in use. In addition, multi-thermostats can control cooling room by room, and timers can turn systems on and off according to a predetermined and, it is hoped, a more energy efficient schedule.
For those homeowners planning to replace their old central air-conditioning units, care must be taken. Chances are, if a unit dates back much before 1980, the piping contains asbestos.
“The EPA estimates that there are 300,000 homes here in Orange County with asbestos piping,” says Tony Grupensperger, Karsten’s partner at Benchmark. “As long as it isn’t smashed or damaged, it’s OK. But if a (homeowner) starts tearing it apart and handling it improperly, he’ll have major problems.”
Major as in money . . . or worse. Once piping that contains asbestos is damaged, it must be removed and replaced. And only a licensed asbestos remover can do the job.
“Most distributors and installers can’t touch it,” Grupensperger says. “It’s the law and it’s punishable by imprisonment, and that includes the homeowner who tries to fool with it.”
Indoor air quality is a growing concern to homeowners, especially if a family member suffers from serious allergies. Dust, lint, smoke, pollen and bacteria circulate through air-conditioning systems, traveling to all parts of a house unless intercepted by a filter.
Throwaway fiber filters remove large airborne particles such as dust, but more advanced--and more expensive--electrostatic and electronic filters are needed to trap various microscopic debris that may include animal dander, fungi and even dead skin, according to the Air Conditioning and Refrigeration Institute.
The ACRI also points out that a dirty filter isn’t much good for anything except cutting air flow to your system. It is recommended that filters be replaced or cleaned at least once a month during steady use.
Keeping your cool by installing central air in a typical two-bedroom home can run $3,000 to $4,000, according to Grupensperger. And for homes without existing duct work, sheet metal and labor costs can add another $500 to $1,000 to the total.
For those who want to beat the heat on a budget, there is the economy-class alternative to central cooling, the room air conditioner. Although still noisy despite many manufacturers’ claims to the contrary, new models can be surprisingly effective at cooling smaller areas.
Prices range from about $300 to $500 for machines with load capacities of 5,000 to 7,000 BTUs that will adequately cool and dehumidify areas the size of a medium bedroom.
Installation of room units is usually a do-it-yourself job, although you will need help during positioning because the units are heavy (from 50 to 90 pounds) and awkward. People living on upper floors need to ensure the installation is secure. Two years ago, an air conditioner slipped from a seventh-floor window in New York City and plunged to the sidewalk, killing a pedestrian.
Of far more global concern than the errant air conditioner dropping from the sky is the use of chlorofluorocarbons that can escape and pose a threat to the ozone layer.
Researchers have been experimenting with various approaches to air conditioning--both old and new--that would eliminate the need for CFCs.
One promising device based on old technology cools air by blowing it through a water mist while at the same time managing the neat trick of removing humidity. It accomplishes this by adding a desiccant, lithium bromide, to the water to “dry” the air as it passes through the spray.
Researchers are also working to find environmentally safe refrigerates to replace CFCs. If effective substitutes can be found, the millions of residential and commercial air conditioners now in use could be made ozone-friendly with a simple recharge of the new cooling agents.
