The Journey to Modern Day Air Conditioning

Although residents of the Southern United States benefit from air conditioning, it was not always easy to stay cool. Cooling systems underwent multiple changes over the years to become the central air system that we know today. Over time, modern air conditioning changed the ways in which we interact, socialize, and live. To understand these changes, let’s ex plore some early forms of air conditioning. Keeping Cool Before A/C Back in the third century, Roman emperor Elagabalus built his own personal mound of snow to keep cool. Imported via donkeys, th e snow stayed in the emperor’s garden villa during the summer. While this system was convenient for him, he couldn’t possibly provide e nough snow to cool his citizens. Instead, wealthy Roman citizens relied on water from local aqueducts to cool their homes through wall-c irculation systems. Unfortunately, aqueducts were only available to a select few individuals. Less wealthy residents needed to work with their environme nt to beat the heat. For example, many people later built their windows to face away from the sun, and they planted trees on the East a nd West to shade their homes. Eventually, architects referred to such tactics as passive solar design. Aside from these early attempts at air cooling, architects and homeowners found additional ways to keep comfortable. Below are so me of the most common ways people kept cool before the advent of air conditioning:

  • Underground buildings and homes
  • Brick and other insulating building materials
  • High ceilings to let heat rise
  • Front porches for hot night socializing
  • Outdoor summer sleeping arrangements
  • Underwear in the icebox

Many of these tactics still work today, but few people employ them because it’s easier to turn on the air conditioning. However, that’ s quite a leap in time between refrigerating skivvies and turning down the thermostat. Keep reading to find out which discoveries eventu ally lead to central air as we know it. Modern Timeline of Air Conditioning Air conditioning wasn’t invented overnight. Instead, it took multiple inventions over an extended time period to achieve the cooling method we enjoy now. 1758 – Professor John Hadley and Benjamin Franklin discover that evaporating volatile liquids cools objects eno ugh to freeze them. 1830 – Dr. John Gorrie builds an ice-making machine. He patents the idea, but he fails to popularize his inventio n due to a lack in financial backing. 1902 – Willis Carrier creates an air treatment apparatus. As it blows air over cold coils, the apparatus regulates h umidity levels and temperatures. He later establishes his own air conditioning company. 1906 – Stuart Cramer of North Carolina uses a water vapor device to humidify the air at textile plants. He wante d to create an environment where yarn was more workable and less brittle. He first coins the phrase “air conditioning.” 1931 – The wealthy implement individual room air conditioning units costing up to $50,000 (about $600,000 b y today’s standards). 1939 – A car with air conditioning comes to the market. However, if you wanted to turn it on or off while driving , you’d need to pull over-the controls were under the hood. 1942 – The United States builds its first power plant to combat growing energy demand from air conditioning.< /p> 1950 – During the post WWII economic boom, more and more middle-class Americans purchase an air conditio ning unit. In 1953 alone, Americans purchased over a million units. What used to be a luxury for the rich is more available than ever. 1970 – Air conditioning companies perfect and market central air. They initially relied on Freon as a refrigerant, b ut a mandated switch in 1994 required companies to use more environment-friendly coolants. Today, central cooling currently remains the most popular source of air conditioning for American businesses and homeowners. Beca use of this, modern air conditioning has changed daily habits, social interactions, and even our way of life. Effects on Modern Life You might not think about it, but air conditioning affects how we socialize on a regular basis. For example, front porches used to be a place where friends and family gathered. These gatherings in the cool of the evening yielde d social interaction and entertainment. But the widespread use of the television, the automobile, and air conditioning changed that. Now , families and friends often gather indoors throughout the year because they can socialize in the comfort of conditioned air. Air conditioning also changed how we use fire escapes. In the past, many city dwellers slept on the fire escape during hot nights. To day, you can enjoy a cool night indoors with modern day cooling technologies. Many homes now house central air systems, so fire escap es are more for escaping fires than for sleeping. These are just two small examples of how modern day air conditioning has changed our social interactions and habits. If you take th e time to appreciate air conditioning, you’ll realize that it has a significant impact on how and where you spend your time. However, if your furnace or air conditioning is on the fritz, call your friendly neighborhood HVAC experts. You don’t have to s pend another night outdoors to stay comfortable.

How Does an Air Conditioner Work?

Unless you’re an HVAC specialist, you probably don’t think about your central air conditioning system on a regular basis. However, w hen your air conditioner stops working and the temperature of your home is unbearable, AC is all you can think about. During these tim es of reflection as you wait for the HVAC repair service to arrive, you may ask yourself the question, “How does my air conditioner work i n the first place?” To answer that question, here is a simple explanation of the different components in your air conditioner and how they work togeth er to cool your home: Air Conditioner Basics Your air conditioner cools your home using a basic physical law: when a liquid converts to a gas, it absorbs heat. Your AC unit uses t his principle to take heat from the air in your home and send it outside. To do this, it uses various components, starting with refrigerants . Refrigerants Refrigerants are substances that are easy to convert between liquid and gaseous states. This allows them to absorb heat while they are in a cool liquid state, convert quickly to a gas to carry the heat outside, then cool back into a liquid to start the cycle over again. Refri gerants, like their name suggests, do most of the actual cooling in your AC system. Evaporator The air conditioning cycle begins inside your home in an apparatus called an evaporator. An evaporator consists of a series of metal coils that contain cool, liquid refrigerant. As the warm air in your home comes in contact with these coils, the liquid refrigerant in the coils absorbs the heat, causing the surrounding air to cool. To aid in this process, your AC system has a series of fans called blowers. These blowers move the warm air in your home over the e vaporator coils. This speeds up the heat transfer toward the refrigerant and spreads the cooled air into your home. As this process continues and the refrigerant continues to heat up, it vaporizes into a low-pressure gas. This change from liquid to g as causes the refrigerant to absorb the maximum amount of heat from the surrounding air. Then, because the refrigerant can’t absorb a dditional heat, it flows through a hose to the next component of the air conditioning cycle, called the compressor. Compressor A compressor, as per its name, takes in the heated gas from the evaporator and compresses it. This raises both the pressure and te mperature of the gaseous refrigerant. Because heat transfers from a hotter substance to a colder substance, the gaseous refrigerant mus t be hotter than the air outside to be able to dissipate the heat it collected from inside your home. After it is compressed, the hot, high-pressure refrigerant leaves your home through a tube to a device called a condenser. Condenser A condenser unit located outside of your home performs the exact opposite function of the evaporator in your home. It uses a serie s of coils, metal fins, and fans to dissipate heat away from the refrigerant and convert it back into liquid. The heat from the refrigerant st ays outside your home and the cooled refrigerant heads back toward the evaporator to begin the cycle again. Before it reaches the evap orator, however, it travels through an expansion valve. Expansion Valve An expansion valve is a device that regulates the flow of the cooled liquid refrigerant back into the evaporator coils. This helps the ev aporator maintain the correct level of refrigerant so that it can easily convert it into a gas again. Additional Air Conditioner Functions In addition to cooling your home, your AC system performs a few other important tasks to make the air in your home safer and mo re comfortable. Dehumidify Properties Interestingly, the design for the modern AC system was not invented as a means of cooling a building, but rather to remove excess humidity. As warm air passes over the evaporator, moisture condenses on the coils. This is the same effect you can observe on the outsi de of a cold glass of water on a humid day. This also explains why water tends to pool around your AC unit on a humid day. The result i n both cases is that it removes moisture from the air, leaving the room feeling more pleasant. Air Filtering Your AC system also includes a filter to remove pollutants and allergens from your home’s air. Most AC systems use a mechanical air filter located near the blowers to clean the air before it circulates it back into your home. Keep this information in mind next time you schedule a repair for your AC system. Now that you are well-versed in the basic parts of your air conditioning system, you can impress your HVAC repair person. More importantly, you will be able to understand which parts of your system he or she is fixing, what those parts do, and why it is important.