A brief history of HVAC systems shows exactly how much the industry has evolved over the years.
Many people ask when air conditioning was first invented. Most histories of HVAC start in the early 1900s. And others start centuries before that. As early as the 1500s, basic ventilation machines were being used to provide air to miners. These machines had little resemblance to today’s HVAC systems. They were simple blades that fanned fresh air into mines.
But when was modern air conditioning invented?
One answer is that air conditioning was invented in 1902, when Willis Carrier published the first drawings of air conditioning systems. He was looking for a way to cool the printing plant he worked at, where overheating was damaging the books they were printing. In danger of losing one of their biggest clients, the plant put Willis Carrier in charge of finding a solution.
His solution was brilliantly simple: by circulating chilled water instead of hot water through a heater’s coils, he was able to chill the air that passed over it.
Over the next fifty years, air conditioners were improved dramatically. Refrigerants replaced cold water in air conditioning systems, leading to significantly more cooling ability. The size of air conditioners changed, too. At first, the venting and piping that was required for an air conditioner to function took up large rooms. As more efficient coolants were used, air conditioning systems shrank considerably. The first residential air conditioner was installed just ten years later.
Individual room air conditioners, which set the design for today’s portable air conditioners, were invented in 1931. These units sat on a window ledge, much like today’s window units. Although people could purchase them by 1932, they weren’t yet widely adopted.
That’s because a window unit cost between $10,000 and $50,000, or between $120,000 and $600,000 in today’s currency. Air conditioning was a luxury only the wealthy could afford. But by the 1950s, air conditioners are both affordable and widely available.
The technical specifications for air conditioners changed dramatically, too. By the middle of the last century, HVAC systems had come a long way from their large industrial predecessors. Air conditioners for cars, busses, and theaters were all invented. Air conditioners were even adapted to work in astronauts’ suits.
With all these changes, it’s no surprise that the history of HVAC systems focuses on the early half of the 1900s. But what’s happened since then?
In the past half century, there have been enormous technical advances in air conditioning technology and the HVAC industry. Since the 1970s, billions of dollars have been spent researching how to improve air conditioning and refrigeration systems. From internet connections to sustainability, today’s HVAC systems owe a lot to the developments of the past 50 years.
Read on for a timeline of major advancements in the last fifty years.
History of Air Conditioning
1970s: Ductless air conditioning systems are first invented. They’re offered as an alternative to standard portable air conditioners, which usually attach to windows. The new system allows air conditioners to be located in places other than windows, including ceilings and walls. Although they don’t gain widespread use in the U.S. for a few years, they’re critical for the adoption of air conditioning in densely populated cities in Asia.
1970s: New inventions by Exxon reduce the cost of solar production from $100 per Watt to $20 per Watt. The lower cost means that solar power becomes a viable power source for a variety of applications, including HVAC.
1975: The federal government makes its first investments into HVAC research and technology in the late 1970s. Their interest is driven by the energy crisis of the late 1970s, when the cost of fuel spiked and the country faced energy shortages. National standards for appliances are first adopted.
1978: The Heat Pump Design Model is invented at the Oak Ridge National Laboratory. It’s an air-to-air heat pump that’s used in both heating and air conditioning systems. With its invention, significant improvements in air conditioners became possible.
1987: The United Nations Montreal Protocol is established to protect the ozone layer. It’s an international treaty that requires participating countries to phase out their use of ozone depleting chemicals. At this point, most air conditioners use a coolant called Freon.
1987: SEER (Seasonal Energy Efficiency Ratio) 10 is adopted as the measure of energy efficiency for HVAC systems. It’s the first national standard for HVAC energy efficiency. SEER standards are still used today, although the current requirements for energy efficiency are higher than in 1987.
1994: Freon is linked to ozone depletion, leading to its ban in many countries. This kicks off a search for more environmentally friendly coolants. Over the next decade, the federal government will invest millions of dollars into research on air conditioning and refrigeration improvements.
1994: Carrier introduces a chlorine free HVAC system with no ozone depleting chemicals. It’s introduced two years earlier than other environmentally friendly models.
1996: All HVAC manufacturers a required to switch to the more environmentally friendly coolant R134a. A few companies, like Honeywell and Carrier, decide to go further in their search for environmentally friendly coolants.
2000s: R410a replaces other coolants as the most environmentally friendly coolant on the market. This change is led in part by Honeywell, who demonstrates the efficiency of R410a with the Heat Pump Design Model.
2005: New technology and refrigerants have dramatically improved energy efficiency in HVAC systems. Since 1993, energy efficiency in residential HVAC systems has improved by 30 percent.
2006: The US Department of Energy sets new standards for energy efficiency for HVAC systems. The new standards are expected to prevent the emission of more than 369 million metric tons of carbon dioxide.
2007: Eighty six percent of American homes now have air conditioning. This is up from just ten percent in 1965.
2010s: HVAC first connects to the Internet of Things. The Internet of Things refers to the wide variety of physical objects that are connected to the Internet. The term is first used in 1999, but gains widespread popularity over the next decade. HVAC systems, where sensors have been widely used for years, is an ideal industry for this connections. A variety of software startups have been experimenting with connecting HVAC to the Internet of things through the early 2000s.
2011: The Copeland Scroll Variable Speed Compressor is released by Emerson. Variable speed compressors reduce energy use in HVAC systems by 25 to 35 percent. Over the next few years, the Copeland Scroll compressor becomes critical to other energy efficiency advancements.
2011: Nest introduces the Nest Thermostat, making it easy to connect home HVAC systems to the Internet. Other startups, as well as utility companies, follow suit. Consumers can now monitor their energy usage and adjust their HVAC systems directly from their phones. It’s success leads to a $3.2 billion acquisition by Google just a few years later.
Industrial HVAC begins to make use of the Internet of Things just a few years later. Companies like Concirrus, Vickers Energy, and Thermocable design internet-connected monitoring systems that allow HVAC professionals to monitor and diagnose air conditioner issues remotely .
2015: The US Department of Energy begins to fund research into non-vapor compression technologies for HVAC systems. This technology won’t rely on coolants to chill air. It’s estimated that this could reduce energy use by more than 50 percent.
What’s Next for the HVAC Industry?
Many of these new HVAC technologies haven’t been used to their full potential. Internet connectivity, smart home technology, and widespread adoption of solar power are all relatively new developments. That means that they may have major implications for the HVAC industry in the future.
Some of the developments that we may see in the future include:
Replacing Vapor Compression HVAC systems with non-vapor compression technologies
A number of companies have been working on inventions in this market, and considerable funding is going into research and development in this area. Two of the most viable alternatives are thermoelastic cooling systems and membrane heat pumps, according to a 2014 study.
Current HVAC systems use vapor compression technology, a model that’s been used in air conditioning for over a hundred years. Air conditioning systems that use vapor compression rely on a closed loop system of refrigerants that heat or chill the air. Most refrigerants today are hydrofluorocarbons that produce significant greenhouse gasses.
If these new systems are viable, HVAC systems would no longer depend on coolants to heat and chill the air. Instead, thermoelastic systems would have metal alloys that absorb heat from the air. Membrane heat pumps, on the other hand, use a vacuum to pump air through a series of membranes, which add moisture to the air and reduce heat.
Improved HVAC processing chips and Internet connections
The development of new processing chips for HVAC systems may be one critical advancement we see occurring over the next few years. A big step in this direction was made just recently, when Echelon released their IzoT platform. Many HVAC manufacturers use Echelon technology for connectivity, so this new IP enabled chip could mean new ways to monitor, connect, and use HVAC systems.
Developments in processors will be particularly critical for industrial HVAC manufacturers. That’s because industrial HVAC systems tend to be used for longer, and are replaced less frequently than consumer systems. Right now, connecting with industrial HVAC systems means shoehorning new technology into talking to old systems. Better processing chips could have a big impact on industrial HVAC management, monitoring, and maintenance.
Connected vents that allow consumers to control HVAC airflow
Technology that allows consumers to control vents is another new development. Central air conditioning, the dominant form of air conditioning in many homes and businesses, relies on vents to to direct air conditioning to the rooms it’s needed in. Today, most vents are manually controlled. If a consumer wants to shut off air flow to a room, they need to physically close the vent to do so. But because this takes more effort, HVAC systems tend to waste energy conditioning unused rooms.
Startups like Keen Home Smart Vent and Ecovent are both designing connectivity-enabled smart vents that can be opened and closed via an app. If these inventions take off, they’ll dramatically reduce air conditioning consumption in unoccupied rooms.
Increased integration with other smart home technologies
Third party smart home systems like Nest, Hive, Heil, and Lennox have made rapid advancements into HVAC controls. In 2015, the smart home market grew by 123 percent. HVAC manufacturers like Honeywell, Emerson, Fujitsu, and GE have all been developing HVAC systems that integrate more thoroughly with this growing market.
Currently, much of the smart home market is fragmented. Consumers need different apps to manage their HVAC system, doors, lighting, and security system. The next trend to affect smart HVAC systems may be more integrated smart home systems.
More interaction with utility companies
HVAC monitoring systems create a wealth of data on when air conditioning is used, where it’s used, and how to make it more efficient. Utility companies have already taken notice of this data. Some utilities have already begun to make use of it as a tool for smart grid energy stabilization.
Although the energy efficiency of HVAC systems has improved dramatically in recent years, HVAC systems use a larger share of energy than ever before. This is in large part due to their widespread adoption throughout the US. Record heat in recent years has also played a big role. As utility companies find ways to use HVAC data to predict and stabilize energy usage, it’s possible that HVAC manufacturers and technicians will interact more with utility companies and their regulations.