A few inventions have significantly raised the standard of living for humans throughout history. Air conditioning is one among them.
Since humans discovered fire and hearths around 2 million years ago, which allowed them to relocate to colder areas, heating has never been much of a problem. But cooling has always been difficult.
A Snippet of Modern Air Conditioning History
Evaporative cooling and air circulation (fans) were the primary methods of cooling off until the late 1800s. An engineer by the name of Willis Carrier set out to find a solution to the excessive humidity issue that was negatively affecting a Buffalo (New York) printing plant’s paper rolls, ink, and equipment in 1902. Carrier came to the realization that air may be dried by passing it through cool water to create condensation while gazing at the mist on a foggy day. Within a year, he created a device that used electricity to dry out indoor air, which also had the effect of lowering the temperature. Modern air conditioning had its beginnings in this manner.
The numerous ways in which Carrier’s invention radically altered how we work and live were beyond his ability to foresee. Mechanical cooling improved the operation of printing presses as well as the production of food, drink, pharmaceuticals, and petrochemicals. The ability to regulate temperature and humidity was advantageous for hospitals, shops, theaters, and the transportation sector, particularly air travel. Air conditioning has made high-tech computers and the internet possible by cooling server rooms and data centers. In other words, the development of air conditioning contributed to the development of the world economy in addition to making hot weather bearable in stores, homes, workplaces, and places of worship. It makes sense why Carrier was listed as one of the 100 Most Influential People of the 20th Century by TIME magazine.
HVAC Systems For Homes, Businesses, And Industries
Depending on the area that has to be cooled, there are numerous types of air conditioning systems in varying sizes and with diverse technologies and capacities, more than a century after Carrier’s original patent. Residential systems are obviously different from commercial and industrial systems because of the differing spaces and user needs.
Central Air Conditioning
Standalone window units, which normally only cool one room, are a welcome respite during periods of extreme heat and humidity for older homes and structures. In US homes, central air conditioning spread like wildfire starting around 1970. It has the advantage of being silent, discrete, and efficient in cooling a whole house. Forced air systems are less expensive than modern technologies and can run on electricity or natural gas. The drawback is that they necessitate a network of ducts, which is difficult and costly to fix in older construction or to extend for room extensions. Such retrofitting is unpleasant or possibly impossible in old buildings.
Mini-splits are a great substitute for central air because they don’t need ductwork or vents. The “mini” in their name refers to the wall-mounted, low-profile indoor evaporator unit(s), which only need a few small holes for the many lines carrying electricity, condensation drain, and refrigerant. The term “split” describes how the outdoor condenser unit is distinct from the indoor unit (s). Due to their smaller size and higher cost, mini-split systems are less expensive to operate than forced air systems even if they have a lower capacity. Ductless mini-split systems are widely used in the construction of new homes and buildings in Europe and Asia because they allow for individual temperature control in each room and double as heaters.
Variable Refrigerant Flow
Variable refrigerant flow, or VRF, was developed in 1982 by the Japanese business Daikin, but it wasn’t until the early 2000s that this technology became widely used in the US. Its name refers to the inverter compressors and fans on the outdoor unit, which change their speed by varying the power source. The amount of refrigerant that the compressors deliver depends on the changing rate. In that it is ductless, contains indoor/outdoor units, and has the ability to both heat and cool, VRF is similar to mini-splits. The primary distinction is that VRF units have a significantly bigger capacity, making VRF an excellent option for commercial buildings, industrial facilities, and warehouses. Additionally, it is adaptable: a single system may simultaneously heat or cool several building zones.
Packaged Rooftop Unit (RTU)
A packaged rooftop unit (RTU) is a common feature of commercial buildings in the US and Canada for cooling and occasionally heating. As suggested by the name, the entire HVAC system for the refrigerant (and heating) cycle is housed inside a sizable metal box. In fact, this may be viewed as the enormous relative of the common window unit! In order to send cooled air to the building below and receive hot air, ductwork is directly connected to the bottom of the RTU. RTUs began as constant air volume (CAV) systems, which means they had one fixed airflow rate tailored for one specific zone. (Packaged units can also have horizontal connections, for example, if positioned next to a structure.) However, this constant flow rate occasionally resulted in unequal cooling in certain areas of the structure and excessive air circulation in other areas. These issues are resolved by variable air volume (VAV) systems, which also improve comfort and energy efficiency.
Chilled Water System
Water functions as a refrigerant and a thermal fluid. Hot water or steam radiates heat into enclosed rooms in a conventional boiler system, which is used in both residential and commercial buildings. A chilled water system, on the other hand, absorbs heat while piping beneath floors, inside walls, and on ceilings transports water that has been cooled to about 45°F (7°C). This technique can be used to cool a single building, a chiller plant, a number of structures, or even an entire high-density area (district cooling).
Geothermal Heating And Geocooling
The temperature in the air varies greatly, yet 10 feet (3 meters) below the surface, it is a comfortable 55°F (13°C) all year round. Although geothermal heating and cooling are pricey up front, interest in them is growing as people and businesses look for ways to cut back on energy use. These systems basically consist of a loop of underground pipes that transport water. When it comes back above ground, a heat pump raises the water to the proper temperature and circulates it through the building’s pipes. In cold weather, air-temperature water is transported below to warm. The mechanism operates under the same theory in hot temperatures, but in reverse. Geothermal systems are relatively quiet and attractive without exterior or rooftop equipment. But more than that, alternative HVAC options like geothermal play a significant role in the LEED (Leadership in Energy and Environmental Design) certification that more commercial developers are seeking for for their projects.
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