Residential Air Conditioning Installation & Repair Services

Though modern air conditioning only began its journey in the mid-19th century, the reality is humans have sought ways to make the air around them cooler and more comfortable for thousands of years.

For example, it’s easy to call many forms of evaporative cooling found in history the forerunners of today’s AC.

For most of human history, we used passive cooling techniques to lower the temperature in our homes. Passive cooling works in two different ways: heat gain prevention, which involves using insulation to keep heat from entering the building, and natural cooling designs that allow heat to escape the home while keeping the cold air inside. These techniques worked fairly well for thousands of years and are coming back in style as a method of fighting climate change. However, they’re not nearly as effective as active cooling and air conditioning, which date back to the 18th and 19th centuries.

Did you know that Benjamin Franklin was not only a founding father of the United States but also of air conditioning technology? In 1758, Franklin and a Cambridge professor of chemistry named John Hadley conducted an experiment that established one of the foundations of modern air conditioners: evaporative cooling. First, Franklin and Hadley took an ordinary mercury thermometer and dipped the bulb in alcohol. Then, they used a bellows to quickly evaporate the alcohol from the thermometer. The result was an enormous transfer of heat away from the bulb of the thermometer. Although the ambient temperature of the room was about 65 degrees Fahrenheit, they were able to lower the temperature of the thermometer to about 7 degrees. Franklin would conclude that “from this experiment, one may see the possibility of freezing a man to death on a warm summer’s day,” although we’ve found a much more positive use for the principle he discovered.

In 1820, the English inventor Michael Faraday discovered that he could chill ambient air by compressing, liquefying, and finally evaporating ammonia. His experiments formed the basis for the refrigerant used in modern air conditioners. This technology was soon put to use as a way to make ice and keep food from spoiling while it was being shipped.

Finally, in 1901, an inventor named Willis H. Carrier created the first mechanical air conditioner using the compression and evaporation technology pioneered by Faraday. The AC manufacturing company he created, Carrier Engineering, still exists today as Carrier Global. The US embraced residential air conditioning wholeheartedly over the next few decades, and today it’s hard to find a house or apartment that doesn’t have at least some kind of AC.

What Is Evaporative Cooling?

Numerous inventors and scientists, including Michael Faraday discovered that compressing a liquid and then allowing it to evaporate could achieve a cooling effect. Early compressor systems were difficult to power, inefficient, and mostly put to the purpose of making ice. However, it laid important groundwork.

Michael Faraday

Early Compressor System
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That groundwork was built upon by Willis Carrier in the early 20th century who pioneered electrical cooling – the process we know today. These developments ultimately led to the first split-system designs suitable for homes, and the development of evermore efficient refrigerant chemicals to undergo the compression and expansion process. Ultimately, ductwork became a standard part of many homes, and central air conditioners took their place in our daily lives.

Willis Carrier

Modern Air Conditioner
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The evaporative process, described above, is relatively easy to understand. In this day and age, nearly all air conditioners, from central air to window-mounted units use the compression and evaporation of a refrigerant to cool the air inside your home.

The process works like this.

• Your thermostat detects, through mechanical or digital means, that the indoor air temperature is higher than your preferred temperature setting.
• The thermostat sends a command to the AC to switch on its compressor and to power the internal blower fans.
• The compressor forces refrigerant into the system at very high pressure so that it remains a liquid.
• Refrigerant enters your home and expands into an evaporating coil: here, a strong fan blows air pulled from the home’s intake over the condenser.
• Within the coil, the refrigerant evaporates to its gaseous state, pulling heat energy out of the air in the process.
• The now-cool air re-circulates into the home due to the blower fan.
• The refrigerant returns outside, where it enters a condenser to return it to a liquid before being re-compressed and sent back through the system.

This process is how almost all modern cooling systems work. Ductless systems work on a room by room basis, but still require an external unit for moving refrigerant.

Today’s air conditioners work using the same principles discovered by Franklin, Hadley, and Faraday all those years ago. These days, however, it all starts with the thermostat. Any air conditioner, even the smallest window units, is connected to a sensor that constantly tests the temperature of the air inside. When the thermostat detects that the temperature is warmer than your preferred settings, it sends a signal to the air conditioner.

 

The signal from the thermostat turns on two different mechanical parts inside the AC – the compressor, and the blower fan. The compressor pushes a working fluid called a refrigerant through a line, using pressure to force it into a liquid state. The liquid refrigerant then passes into a metal coil called the evaporator, which reduces the pressure. The lower pressure allows the liquid refrigerant to evaporate into a gaseous state, which also lowers the temperature of the coil – just like the thermometer bulb in Franklin and Hadley’s experiment. The blower fan pushes all the newly-cooled air out into the ducts or straight into the room, lowering the temperature in your house. Finally, the gaseous refrigerant passes through another line into the condenser coil, which re-compresses it back into a liquid and starts the cycle over again.

 

Most modern-day residential air conditioners are split-system ACs, which means the parts mentioned in the previous paragraph are split into two separate units. The outside unit holds the condenser coil and the compressor, and the inside unit holds the evaporator coil and the blower fan. Two refrigerant lines pass through the wall of your house and connect the two units. While it’s not important to know every little detail of how your AC works, knowing the general function of the four main parts – compressor, condenser coil, evaporator coil, and blower fan – can go a long way to help you diagnose potential problems when they arise. It’ll also come in handy when you’re speaking to an HVAC technician since you’ll have the knowledge and vocabulary to explain what the concern is. Just by reading this one section, you already know more than most people!

There are several different ways one might choose to install an air conditioner in a residential property. The right choice often depends on the space to be cooled, how often it will run, and how much work is necessary for installation. Here are the big three that most homeowners will consider at some point.

Split System

The traditional, most well-known type of air conditioner, also known as “central air.” Requires ductwork throughout the home to be able to transport cooled air. Typically more energy intensive and suitable for whole-house cooling.

Ductless Mini Split

For homes without ductwork, or for extensions for which adding ductwork would be too costly or difficult. A mini-split still uses an outdoor compressor, but the condenser and blower are packaged into one unit, usually installed above a doorway. Ideal for cooling smaller spaces and individual rooms, multiple mini-split units can run off the same compressor.

Through Wall

In cases where a mini-split won’t work, “window shakers” and units installed directly into a wall are an option. These all-in-one packages are best suited for small spaces or homes where cooling is not frequently needed. Though less common, there are still many use cases for this installation type.

 

When people think about air conditioning, they typically picture a split-system central air AC. A central air system uses the ductwork to deliver cool air throughout every part of the building, which makes it ideal for most homeowners. However, the ducts do lower the efficiency of the whole system. Air gets caught in corners or escapes through tiny holes in the ductwork, and suddenly you’re losing energy. Ductwork also forces your air conditioner to work pretty hard since it needs to push air into every part of your house simultaneously. On the one hand, it’s often nice to have every room be the same temperature, but it can be a little wasteful if you’re going to be staying in one area for a while.

 

If you have a smaller home or a house without any ductwork, you might also consider looking into a ductless mini-split system. Mini-splits use outdoor compressors like regular split-system AC does, but they package the condenser, evaporator, and blower into a single unit that can be mounted on your wall. One compressor unit can provide refrigerant to multiple indoor units, each one blowing cold air directly into a single room. Mini-splits can be pretty expensive to purchase and install, but they’re significantly more energy efficient than central air systems, and they also allow you to set different temperatures for different rooms.

 

Finally, you can always use a window unit or an air conditioner installed directly into the wall. These air conditioners package every part into a single unit and are ideal for small spaces that rarely require cooling. They’re popular in places like New York where living spaces are small and cooling is only necessary during heat waves.