User:Lee3629/Air conditioning

Essay sections from citations in biblio:
After World War II, air conditioning systems’ affordability led to widespread adoption, improving living conditions and boosting productivity in industries and urban areas.

history: During the beginning of the Han Dynasty, Ding Huan, a Chinese inventor, developed a manual fan machine that was recorded to cool an entire hallway.

Health effects
In hot weather, air conditioning can prevent heat stroke, dehydration from excessive perspiration, fluid and electrolyte disorders, renal failure , and other problems related to hyperthermia. Heat waves are the most lethal type of weather phenomenon in the United States. A 2020 study found that areas with lower use of air conditioning correlated with higher rates of heat-related mortality and hospitalizations. The August 2003 France heatwave resulted in approximately 15,000 deaths, where 80% of the victims were over 75 years old. In response, the French government required all retirement homes to have at least an air-conditioned room at 25°C (77°F) per floor during heatwaves.

Air conditioning (including filtration, humidification, cooling and disinfection) can be used to provide a clean, safe, hypoallergenic atmosphere in hospital operating rooms and other environments where proper atmosphere is critical to patient safety and well-being. It is sometimes recommended for home use by people with allergies, especially mold. However, poorly maintained water cooling towers can promote the growth and spread of microorganisms such as Legionella pneumophila, the infectious agent responsible for Legionnaires' disease. As long as the cooling tower is kept clean (usually by means of a chlorine treatment), these health hazards can be avoided or reduced. The state of New York has codified requirements for registration, maintenance, and testing of cooling towers to protect against Legionella.

Environmental impacts[edit]
Refrigerants have caused and continue to cause serious environmental issues, including ozone depletion and climate change, as several countries have not yet ratified the Kigali Amendment to reduce the consumption and production of hydrofluorocarbons.

Current air conditioning accounts for 20% of energy consumption in buildings globally, and the expected growth of the usage of air conditioning due to climate change and technology uptake will drive significant energy demand growth.

It is projected that by 2050, with the progress currently seen, greenhouse gas emissions attributable to space cooling will double: 1,135 million tons (2016) to 2,070 million tons. There is some push to increase the energy efficiency of air conditioners. United Nations Environment Programme (UNEP) and the IEA found that if air conditioners could be twice as effective as now, 460 billion tons of GHG could be cut over 40 years. The UNEP and IEA also recommended legislation to decrease the use of hydrofluorocarbons, better building insulation, and more sustainable temperature-controlled food supply chains going forward.

Alternatives to continual air conditioning include passive cooling, passive solar cooling, natural ventilation, operating shades to reduce solar gain, using trees, architectural shades, windows (and using window coatings) to reduce solar gain.[citation needed]

Economic effects[edit]
First designed to benefit targeted industries such as the press as well as large factories, the invention quickly spread to public agencies and administrations with studies with claims of increased productivity close to 24% in places equipped with air conditioning.

Air conditioning caused various shifts in demography, notably that of the United States starting from the 1970s. In the US the birth rate was lower in the spring than during other seasons until the 1970s but this difference then declined since then. As of 2007, the Sun Belt contains 30% of the total US population while it was inhabited by 24% of Americans at the beginning of the 20th century.

The spread of the use of AC acts as a main driver for the growth of global demand of electricity. According to a 2018 report from the International Energy Agency (IEA), it was revealed that the energy consumption for cooling in the United States, involving 328 million Americans, surpasses the combined energy consumption of 4.4 billion people in Africa, Latin America, the Middle East, and Asia (excluding China). A 2020 survey found that an estimated 88% of all US households use AC, increasing to 93% when solely looking at homes built between 2010 and 2020. A 2018 report by the IEA projected that by 2025, the international demand for electricity generation will soon grow to 395%.

Social Disparities
The increased temperatures leading to more extreme heat waves disproportionately affect those in low socioeconomic groups as they already lack access to cooling units.

The cost of having air conditioning in one's residence includes the unit and the high installation, maintenance, and energy consumption. This often leads to disparities in access to cooling, exacerbating inequalities during extreme heat waves. The lack of cooling can be hazardous, as areas with lower use of air conditioning correlate with higher rates of heat-related mortality and hospitalizations. Premature mortality in NYC is projected to grow between 47% and 95% in 30 years, with lower-income and vulnerable populations most at risk. Studies on the correlation between heat-related mortality and hospitalizations and living in low socioeconomic locations can be traced in Phoenix, Arizona, Hong Kong , China , Japan , and Italy. Additionally, costs concerning health care can act as another barrier, as the lack of private health insurance during a 2009 heat wave in Australia, was associated with heat-related hospitalization.

Access to AC for marginalized ethnic/racial groups can depend on many factors but is overall linked to one's socioeconomic group and neighborhood. This connection stems from systemic racism, which has led to the association of specific marginalized communities with lower economic status, poorer health, residing in hotter neighborhoods, engaging in physically demanding labor, and experiencing limited access to cooling technologies such as air conditioning. A study overlooking Chicago, Illinois, Detroit, and Michigan found that black households were half as likely to have central AC units when compared to their white counterparts. Especially in cities, Redlining creates heat islands, increasing temperatures in certain parts of the city. This is due to materials heat-absorbing building materials and pavements and lack of vegetation and shade coverage.[7]

There have been initiatives that provide energy-efficient cooling solutions to low-income communities or support inclusive design practices can help bridge gaps and reduce inequalities. For instance, public cooling spaces [3]