Before air conditioning existed, people used various creative ways to combat the heatwave. The houses were thick-walled, constructed with stones, and the ceilings were high to reflect the heat away. People would build water fountains and front porches where they can take a breezy nap under a shady tree. With the constant evolution of technology, humans have revolutionalized the way we cool our surroundings today. HVAC technology played a major role in the development of the Modern Air Conditioner
The credit for the first modern air conditioner goes to Willis Haviland Carrier, a skilled engineer, who began experimenting with the laws of humidity control in 1902, to solve an application obstacle at a printing mill in Brooklyn. Later, Carrier’s technology was implemented to enhance productivity in the workplace.
In 1915, Willis started Carrier Corporation, to meet the rising demand around his invention. The company specializes in the manufacture and distribution of heating, ventilation, and air conditioning (HVAC) systems. Over a course, air conditioning was used to provide comfort in homes and automobiles as well.
Later in 1933, the company designed an air conditioner using a belt-driven condensing unit and associated blower, mechanical controls, and an evaporator coil. This device became the idolized model in the growing economy and marketplace for air-cooling systems.
Today’s air conditioners, while operating on the same fundamental science as Carrier’s 1933 system, incorporate improvements in numerous aspects.
In 1945, Robert Sherman invented a portable, Window Air Conditioner. His prototype AC could cool, heat, humidify, dehumidify and filter the air. The temperature controls were an integrated part of the air conditioner.
Air conditioners soon, became more affordable than ever, attributing to the increase in demand, which in turn led to an increase in production and thus availability. Soon enough, air conditioning, which was earlier thought of luxury appliance became a necessity in many parts of the world.
With technological advancement, when the first Split Air Conditioners came out, the thermostat became the most important part of the control system. Basic electrical components, fans, and compressors needed for air conditioning were now mounted inside the air conditioner.
The Split air conditioner is a combination of an outdoor unit and an indoor unit. The outdoor unit has the compressor, expansion valve, and condenser. It passes air through a tube to the indoor unit containing the evaporator, cooling fan, and cooling coil.
With the evolution, the split AC’s are now available with a multi-split option. It connects up to five indoor units to a single outdoor unit, which enables individual control of room temperature settings. Users can install a complete air conditioning system to multiple zone interior spaces with no need for ductwork.
Putting a single unit in every room of a huge development would be very expensive. Therefore, the simplest solution proposed was to install central air conditioning. This system uses a large compressor with tons of air conditioning capacity. Its feasible setup for malls or very large enterprises.
Evolution of Air Conditioner: Thermostat Controls
The first thermostats provided basic functionality, such as on/off, set point temperature, operation mode, and fan speed, utilizing simple buttons, toggles, and control disks.
The more advanced programmable thermostat gives users precise control over the comfort levels in their homes. These models allow different settings for each day of the week. They are programmed to accommodate varying schedules and provide precision displays. These programmable thermostats are equipped with security features that prevent unauthorized occupants from changing the settings.
Today’s Smart Thermostats can be controlled using digital devices or Wi-Fi apps. The user input could be transferred to the HVAC unit through IR, Wired remote, Wireless (non-IR): Wi-Fi, Bluetooth, Zigbee, etc.
The feature enables you to avoid wasting energy in heating and cooling an empty home. Users can also turn on the AC when they head home so that they don’t have to walk into a heated room. Some Thermostats can even adjust the set temperature automatically.
Evolution of Air Conditioner: Compressor
AC compressors have evolved significantly these days. In the beginning, they had only one mode that was either on or off.
Following that, compressors started coming with two-stages. These compressors gave users two speeds to choose from, so it provides the advantage of running at a slower speed when users needed less cooling. It uses less energy and ultimately gives the consumer a better control over the room’s temperature.
As the technology advanced, variable speed compressors arrived that offered three or more speed options, letting users easily make minute adjustments to their home cooling.
Later, the increasing demand for energy-saving technology led to the development of an inverter-based compressor. This technology allows compressors to regulate the amount of refrigerant in the HVAC system.
It aggregates all the information from the different data points, temperature, and pressure data from the built-in sensors, outdoor temperature, user input, and based on that, it determines how the HVAC system should work to meet those requirements.
Evolution of Air Conditioner: Refrigerant
For many years, people preferred R-22 refrigerant for their air conditioning systems. However, they discovered that the gas was doing irreparable damage to the ozone layer. Therefore brands introduced a new system that relies on more eco-friendly R-410A refrigerant.
However, the issue remains the same, the drastic effect of these gases kept accelerating, which was corrupting the environment while contributing to global warming.
Keeping that in mind, now all the Air Conditioners use R-32 the most environment-friendly refrigerant available to our disposal. R-32 offers superior performance as compare to any other refrigerant.
Evolution of Air Conditioner: Design
The earliest domestic air conditioners were piano-sized, which took a lot of home space. However, as technology evolved, the size of the air conditioner also shrank exponentially. Firstly they got to the size wherein users can mount the AC to the window and now in recent years, ACs have gone portable. Recently, Sony launched a wearable AC, which is smaller than a smartphone and weighs only 85g.
Evolution of Air Conditioner: Latest Technologies
As we have witnessed the rise of technology and its demand, there are some serious, noteworthy HVAC innovations.
Ubiquitous Sensor Network For Smart Cooling:
Most of the top AC brands use sensor technologies to impart smart cooling. Hitachi uses revolutionary iSee technology, which comes with an intelligent image sensor technology detects the number of people in the room, their location, their activity, etc., and then cools accordingly to ensure maximum cooling comfort. It also recognizes the shape and size of the room and then regulates its swing angle with a special smart swing feature in a bid to optimize cooling. Another important feature is it also recognizes human absence in the room for a specified time and switches the AC off automatically to avoid cooling wastage.
Similarly, modern Carrier ACs come with a Follow Me feature. When this feature is enabled, the main room sensor inside the unit takes the back seat, and the specialized sensor inside the remote gets activated.
Conventional ACs come with a 2-way (up and down) swing blade to distribute cool air within the room. However, most of the new ACs come with the 4D swing function (up-down + right-left) which blows the cool air in varied directions to ensure precise cooling inside the room.
Fast Cooling Technologies:
Manufacturers are always striving to incorporate various techniques and designs to cool the room in a flash.
New models from LG come with Himalaya Cool technology. LG offers a dedicated button on the remote to enable this mode and the button is labeled as HCOOL. When enabled, AC would throw cool air at a super-high-speed for around 30 minutes, until the temperature of the room is brought down to a comfortably cool level. With the Himalaya Cool technology, LG ACs deliver faster cooling without compromising on the energy-saving aspect.
Daikin comes with a Power Chill mode with dual flap flattening to quickly cool the room within 20 minutes. Whirlpool AC uses 3D Cool Extreme and dual fan compressor to deliver what they call Turbo Cool.
Most of the new AC models from reputed brands come with dehumidification or dry mode to keep the humidity under control.
Hitachi is one step ahead of its competitor in this department. Apart from the dry mode, high-end models of Hitachi ACs come with Auto Humid Control technology wherein the temperature and humidity profile of over 100 cities is fed inside its processor. Based on the data it adjusts the air conditioning and when it detects the high humidity, the refrigerant cycle is expedited to extract humidity out of the room.
An air filter is one of the crucial battlegrounds for the AC brands to innovate in. The simple reason being the rising level of air impurity. According to WHO levels of air pollution have tremendously increased in the developing economies. Brands have started using multi-layer filters to control the rising levels of air impurity.
Initially, Whirlpool came with PM 2.5 filter to filter out impurities from the room air which are of the size two and a half microns in width. Now, LG offers PM 1 filters that offer filtration of particles of size 10,000 microns or less.
Some ACs come with an anti-VOC filter for the removal of volatile organic compounds (VOC). Anti-VOC filter used in split ACs eliminates toxic VOCs like formaldehyde to ensure air is debarred of such impurities.
Premium ACs from top-rated brands come with an auto-clean functionality wherein AC cleans its filter using various techniques and methods.
Read Also: Sony’s Wearable Air Conditioner Released