document_title: Temporary Assistance for Needy Families

question_text: where does the money for tanf come from

question_tokens: where does the money for tanf come from

text: Temporary Assistance for Needy Families

text: Background[edit]

text: Prior to TANF, Aid to Families with Dependent Children was a major federal assistance program that was coming under heavy criticism. Some argued that such programs were ineffective, promoted dependency on the government, and encouraged behaviors detrimental to escaping from poverty.[5] Some people also argued that TANF is detrimental to its recipients because using these programs have a stigma attached to them, which makes the people that use them less likely to participate politically to defend this program, and thus the programs have been subsequently weakened. Beginning with President Ronald Reagan’s administration and continuing through the first few years of the Clinton administration, growing dissatisfaction with AFDC, particularly the rise in welfare caseloads, led an increasing number of states to seek waivers from AFDC rules to allow states to more stringently enforce work requirements for welfare recipients. The 27 percent increase in caseloads between 1990 and 1994 accelerated the push by states to implement more radical welfare reform.[6]

text: States that were granted waivers from AFDC program rules to run mandatory welfare-to-work programs were also required to rigorously evaluate the success of their programs. As a result, many types of mandatory welfare-to-work programs were evaluated in the early 1990s. While reviews of such programs found that almost all programs led to significant increases in employment and reductions in welfare rolls, there was little evidence that income among former welfare recipients had increased. In effect, increases in earnings from jobs were offset by losses in public income, leading many to conclude that these programs had no anti-poverty effects.[7] However, the findings that welfare-to-work programs did have some effect in reducing dependence on government increased support among policymakers for moving welfare recipients into employment.[8]

text: While liberals and conservatives agreed on the importance of transitioning families from government assistance to jobs, they disagreed on how to accomplish this goal. Liberals thought that welfare reform should expand opportunities for welfare mothers to receive training and work experience that would help them raise their families' living standards by working more and at higher wages.[8] Conservatives emphasized work requirements and time limits, paying little attention to whether or not families' incomes increased. More specifically, conservatives wanted to impose a five-year lifetime limit on welfare benefits and provide block grants for states to fund programs for poor families.[9] Conservatives argued that welfare to work reform would be beneficial by creating role models out of mothers, promoting maternal self-esteem and sense of control, and introducing productive daily routines into family life. Furthermore, they argued that reforms would eliminate welfare dependence by sending a powerful message to teens and young women to postpone childbearing. Liberals responded that the reform sought by conservatives would overwhelm severely stressed parents, deepen the poverty of many families, and force young children into unsafe and unstimulating child care situations. In addition, they asserted that welfare reform would reduce parents' ability to monitor the behaviors of their children, leading to problems in child and adolescent functioning.[10]

text: In 1992, as a presidential candidate, Bill Clinton pledged to "end welfare as we know it" by requiring families receiving welfare to work after two years. As president, Clinton was attracted to welfare expert and Harvard University Professor David Ellwood’s proposal on welfare reform and thus Clinton eventually appointed Ellwood to co-chair his welfare task force. Ellwood supported converting welfare into a transitional system. He advocated providing assistance to families for a limited time, after which recipients would be required to earn wages from a regular job or a work opportunity program.[8] Low wages would be supplemented by expanded tax credits, access to subsidized childcare and health insurance, and guaranteed child support.

text: In 1994, Clinton introduced a welfare reform proposal that would provide job training coupled with time limits and subsidized jobs for those having difficulty finding work, but it was defeated.[9] Later that year, when Republicans attained a Congressional majority in November 1994, the focus shifted toward the Republican proposal to end entitlements to assistance, repeal AFDC and instead provide states with blocks grants.[11] The debates in Congress about welfare reform centered around five themes:[11]

text:
Reforming Welfare to Promote Work and Time Limits: The welfare reform discussions were dominated by the perception that the then-existing cash assistance program, AFDC, did not do enough to encourage and require employment, and instead incentivized non-work. Supporters of welfare reform also argued that AFDC fostered divorce and out-of-wedlock birth, and created a culture of dependency on government assistance. Both President Clinton and Congressional Republicans emphasized the need to transform the cash assistance system into a work-focused, time-limited program.
Reducing Projected Spending: Republicans argued that projected federal spending for low-income families needed to be reduced because it was too high and that this reduction was necessary to reduce federal spending.

text:
Promoting Parental Responsibility: There was broad agreement among politicians that both parents should support their children. For custodial parents, this meant an emphasis on work and cooperation with child support enforcement. For non-custodial parents, it meant a set of initiatives to strengthen the effectiveness of the child support enforcement.
Addressing Out-of-Wedlock Birth: Republicans argued that out of wedlock birth was presenting an increasingly serious social problem and that the federal government should work to reduce out-of-wedlock births.
Promoting Devolution: A common theme in the debates was that the federal government had failed and that states were more successful in providing for the needy, and thus reform needed to provide more power and authority to states to shape such policy.

text: Clinton twice vetoed the welfare reform bill put forward by Newt Gingrich and Bob Dole. Then just before the Democratic Convention he signed a third version after the Senate voted 74-24[12] and the House voted 256-170[13] in favor of welfare reform legislation, formally known as the Personal Responsibility and Work Opportunity Reconciliation Act of 1996 (PRWORA). Clinton signed the bill into law on August 22, 1996. PRWORA replaced AFDC with TANF and dramatically changed the way the federal government and states determine eligibility and provide aid for needy families.

text: Before 1997, the federal government designed the overall program requirements and guidelines, while states administered the program and determined eligibility for benefits. Since 1997, states have been given block grants and both design and administer their own programs. Access to welfare and amount of assistance varied quite a bit by state and locality under AFDC, both because of the differences in state standards of need and considerable subjectivity in caseworker evaluation of qualifying "suitable homes".[14] However, welfare recipients under TANF are actually in completely different programs depending on their state of residence, with different social services available to them and different requirements for maintaining aid.[15]

text: State implementations[edit]

text: States have large amounts of latitude in how they implement TANF programs.[16][17] [18] [18] [19]

text: California: CalWORKs

text: Funding and eligibility[edit]

text: PRWORA replaced AFDC with TANF and ended entitlement to cash assistance for low-income families, meaning that some families may be denied aid even if they are eligible. Under TANF, states have broad discretion to determine who is eligible for benefits and services. In general, states must use funds to serve families with children, with the only exceptions related to efforts to reduce non-marital childbearing and promote marriage. States cannot use TANF funds to assist most legal immigrants until they have been in the country for at least five years. TANF sets forth the following work requirements in order to qualify for benefits:[21]

text:
Recipients (with few exceptions) must work as soon as they are job ready or no later than two years after coming on assistance.
Single parents are required to participate in work activities for at least 30 hours per week. Two-parent families must participate in work activities 35 or 55 hours a week, depending upon circumstance.
Failure to participate in work requirements can result in a reduction or termination of benefits to the family.
States, in fiscal year 2004, have to ensure that 50 percent of all families and 90 percent of two-parent families are participating in work activities. If a state meets these goals without restricting eligibility, it can receive a caseload reduction credit. This credit reduces the minimum participation rates the state must achieve to continue receiving federal funding.

tag: ol

text: While states are given more flexibility in the design and implementation of public assistance, they must do so within various provisions of the law:[22]

text:
Provide assistance to needy families so that children may be cared for in their own homes or in the homes of relatives;
end the dependence of needy parents on government benefits by promoting job preparation, work, and marriage;
prevent and reduce the incidence of out-of-wedlock pregnancies and establish annual numerical goals for preventing and reducing the incidence of these pregnancies;
and encourage the formation and maintenance of two-parent families.

text: Since these four goals are deeply general, "states can use TANF funds much more broadly than the core welfare reform areas of providing a safety net and connecting families to work; some states use a substantial share of funding for these other services and program".[23]

text: Funding for TANF underwent several changes from its predecessor, AFDC. Under AFDC, states provided cash assistance to families with children, and the federal government paid half or more of all program costs.[11] Federal spending was provided to states on an open-ended basis, meaning that funding was tied to the number of caseloads. Federal law mandated that states provide some level of cash assistance to eligible poor families but states had broad discretion in setting the benefit levels. Under TANF, states qualify for block grants. The funding for these block grants are fixed and the amount each state receives is based on the level of federal contributions to the state for the AFDC program in 1994[24] States are required to maintain their spending for welfare programs at 80 percent of their 1994 spending levels, with a reduction to 75 percent if states meet other work-participation requirements. States have greater flexibility in deciding how they spend funds as long as they meet the provisions of TANF described above.

text: In July 2012, the Department of Health and Human Services released a memo notifying states that they are able to apply for a waiver for the work requirements of the TANF program. Critics claim the waiver would allow states to provide assistance without having to enforce the work component of the program.[25] The administration has stipulated that any waivers that weaken the work requirement will be rejected.[26] The DHHS granted the waivers after several Governors requested more state control.[27] The DHHS agreed to the waivers on the stipulation that they continue to meet all Federal requirements.[28] States were given the right to submit their own plans and reporting methods only if they continued to meet Federal requirements and if the state programs proved to be more effective.

text: Impact[edit]

text: Discussions about the effectiveness of TANF by policymakers and proponents of welfare reform has centered on the rapid decline in the number of families on welfare since TANF went into effect. Indeed, if measured by the reduction in welfare caseloads, TANF has been a success. Between 1996 and 2000, the number of welfare recipients plunged by 6.5 million, or 53% nationally. Furthermore, the number of caseloads was lower in 2000 than at any time since 1969, and the percentages of persons receiving public assistance income (less than 3%) was the lowest on record.[29]

text: Since the implementation of TANF occurred during a period of strong economic growth, there are questions about how much of the decline in caseloads is attributable to TANF program requirements. First, the number of caseloads began declining after 1994, the year with the highest number of caseloads, well before the enactment of TANF, suggesting that TANF was not solely responsible for the caseload decline.[6] Research suggests that both changes in welfare policy and economic growth played a substantial role in this decline, and that no larger than one-third of the decline in caseloads is attributable to TANF[29][30]

text: While declining caseloads dominates discussion about TANF’s effect, declining caseloads are an incomplete and misleading indicator of TANF’s success. Caseload reductions indicate less reliance on government assistance, but they do not account for the well-being of poor families and children. As such, other factors have been taken into account in assessing the impact of TANF: work, earnings, and poverty of former welfare-recipients; marriage and fertility of mothers; well-being of mothers; and child well-being.

text: Work, earnings, and poverty[edit]

text: One of the major goals of TANF was to increase work among welfare recipients. During the post-welfare reform period, employment did increase among single mothers. Single mothers with children showed little changes in their labor force participation rates throughout the 1980s and into the mid-1990s, but between 1994-1999, their labor force participation rose by 10%.[6] Among welfare recipients, the percentage that reported earnings from employment increased from 6.7% in 1990 to 28.1% by 1999.[6] While employment of TANF recipients increased in the early years of reform, it declined in the later period after reform, particularly after 2000. From 2000-2005, employment among TANF recipients declined by 6.5%.[31] Among welfare leavers, it was estimated that close to two-thirds worked at a future point in time[32][33] About 20 percent of welfare leavers are not working, without a spouse, and without any public assistance.[31] Leavers who left welfare because of sanctions (time limits or failure to meet program requirements) fared comparably worse than those who left welfare voluntarily. Sanctioned welfare recipients have employment rates that are, on average, 20 percent below those who left for reasons other than sanctions.[34]

text: While the participation of many low-income single parents in the labor market has increased, their earnings and wages remained low, and their employment was concentrated in low-wage occupations and industries. Over three quarters (78 percent) of employed low-income single parents were concentrated in 4 typically low-wage occupations: service; administrative support and clerical; operators, fabricators, and laborers; and sales and related jobs.[35] While the average income among TANF recipients increased over the early years of reform, it has become stagnant in the later period; for welfare leavers, their average income remained steady or declined in the later years.[31] Studies that compared household income (includes welfare benefits) before and after leaving welfare find that between one-third and one-half of welfare leavers had decreased income after leaving welfare.[30][36]

text: During the 1990s, poverty among single-mother and their families declined rapidly from 35.4% in 1992 to 24.7% in 2000, a new historic low.[6] However, due to the fact that low-income mothers who left welfare are likely to be concentrated in low-wage occupations, the decline in public assistance caseloads has not translated easily into reduction in poverty. The number of poor female-headed families with children dropped from 3.8 million to 3.1 million between 1994 and 1999, a 22% decline compared to a 48% decline in caseloads.[29] As a result, the share of working poor in the U.S. population rose, as some women left public assistance for employment but remained poor.[6] Most studies have found that poverty is quite high among welfare leavers. Depending on the source of the data, estimates of poverty among leavers vary from about 48% to 74%.[32][37]

text: TANF requirements have led to massive drops in the number of people receiving cash benefits since 1996,[38] but there has been little change in the national poverty rate during this time. [39] The table below shows these figures along with the annual unemployment rate.[40][41][42]

text:
Average monthly TANF recipients, percent of U.S. families in poverty and unemployment rate

Year
Average monthly TANF recipients
Poverty rate (%)
Annual unemployment rate (%)

1996
12,320,970 (see note)
11.0
5.4

1997
10,375,993
10.3
4.9

1998
8,347,136
10.0
4.5

1999
6,824,347
9.3
4.2

2000
5,778,034
8.7
4.0

2001
5,359,180
9.2
4.7

2002
5,069,010
9.6
5.8

2003
4,928,878
10.0
6.0

2004
4,748,115
10.2
5.5

2005
4,471,393
9.9
5.1

2006
4,166,659
9.8
4.6

2007
3,895,407
9.8
4.5

2008
3,795,007
10.3
5.4

2009
4,154,366
11.1
8.1

2010
4,375,022
11.7
8.6

text: Note: 1996 was the last year for the AFDC program, and is shown for comparison. All figures are for calendar years. The poverty rate for families differs from the official poverty rate.

text: Marriage and fertility[edit]

text: A major impetus for welfare reform was concern about increases in out-of-wedlock births and declining marriage rates, especially among low-income women. The major goals of the 1996 legislation included reducing out-of-wedlock births and increasing rates and stability of marriages.[6]

text: Studies have produced only modest or inconsistent evidence that marital and cohabitation decisions are influenced by welfare program policies. Schoeni and Blank (2003) found that pre-1996 welfare waivers were associated with modest increases in probabilities of marriage.[43] However, a similar analysis of post-TANF effect revealed less consistent results. Nationally, only 0.4% of closed cases gave marriage as the reason for leaving welfare.[29] Using data on marriage and divorces from 1989-2000 to examine the role of welfare reform on marriage and divorce, Bitler (2004) found that both state waivers and TANF program requirements were associated with reductions in transitions into marriage and reductions from marriage to divorce.[44] In other words, individuals who were not married were more likely to stay unmarried, and those who were married were more likely to stay married. Her explanation behind this, which is consistent with other studies, is that after reform single women were required to work more, increasing their income and reducing their incentive to give up independence for marriage, whereas for married women, post-reform there was potentially a significant increase in the amount of hours they would have to work when single, discouraging divorce.[45][46]

text: In addition to marriage and divorce, welfare reform was also concerned about unwed childbearing. Specific provisions in TANF were aimed at reducing unwed childbearing. For example, TANF provided cash bonuses to states with the largest reductions in unwed childbearing that are not accompanied by more abortions. States were also required to eliminate cash benefits to unwed teens under age 18 who did not reside with their parents. TANF allowed states to impose family caps on the receipt of additional cash benefits from unwed childbearing. Between 1994 and 1999, unwed childbearing among teenagers declined 20 percent among 15- to 17-year-olds and 10 percent among 18- and 19-year-olds.[29] In a comprehensive cross-state comparison, Horvath-Rose & Peters (2002) studied nonmarital birth ratios with and without family cap waivers over the 1986-1996 period, and they found that family caps reduced nonmarital ratios. [47] Any fears that family caps would lead to more abortions was allayed by declining numbers and rates of abortion during this period.[48]

text: Child well-being[edit]

text: Proponents of welfare reform argued that encouraging maternal employment will enhance children’s cognitive and emotional development. A working mother, proponents assert, provides a positive role model for her children. Opponents, on the other hand, argued that requiring women to work at low pay puts additional stress on mothers, reduces the quality time spent with children, and diverts income to work-related expenses such as transportation and childcare.[29] Evidence is mixed on the impact of TANF on child welfare. Duncan & Chase-Lansdale (2001) found that the impact of welfare reform varied by age of the children, with generally positive effects on school achievement among elementary-school age children and negative effects on adolescents, especially with regards to risky or problematic behaviors.[49] Another study found large and significant effects of welfare reform on educational achievement and aspirations, and on social behavior (i.e. teacher assessment of compliance and self-control, competence and sensitivity). The positive effects were largely due to the quality of childcare arrangement and afterschool programs that accompanied the move from welfare to work for these recipients.[50] Yet another study found that substitution from maternal care to other informal care had caused a significant drop in performance of young children.[51] In a program with less generous benefits, Kalili et al. (2002) found that maternal work (measured in months and hours per week) had little overall effect on children’s antisocial behavior, anxious/depressed behavior or positive behavior. They find no evidence that children were harmed by such transitions; if anything, their mothers report that their children are better behaved and have better mental health.[52]

text: Synthesizing findings from an extensive selection of publications, Golden (2005) reached the conclusion that children's outcomes were largely unchanged when examining children's developmental risk, including health status, behavior or emotional problems, suspensions from school, and lack of participation in extracurricular activities.[53] She argues that contrary to the fears of many, welfare reform and an increase in parental work did not seem to have reduced children's well-being overall. More abused and neglected children had not entered the child welfare system. However, at the same time, improvement in parental earnings and reductions in child poverty had not consistently improved outcomes for children.

text: Maternal well-being[edit]

text: While the material and economic well-being of welfare mothers after the enactment of TANF has been the subject of countless studies, their mental and physical well-being has received little attention. Research on the latter has found that welfare recipients face mental and physical problems at rates that are higher than the general population.[54] Such problems which include depression, anxiety disorder, post-traumatic stress disorder, and domestic violence mean that welfare recipients face many more barriers to employment and are more at risk of welfare sanctions due to noncompliance with work requirements and other TANF regulations[29] Research on the health status of welfare leavers have indicated positive results. Findings from the Women’s Employment Study, a longitudinal survey of welfare recipients in Michigan, indicated that women on welfare but not working are more likely to have mental health and other problems than are former welfare recipients now working.[54][55] Similarly, interviews with now employed welfare recipients find that partly as a result of their increased material resources from working, the women felt that work has led to higher self-esteem, new opportunities to expand their social support networks, and increased feelings of self-efficacy.[56] Furthermore, they became less socially isolated and potentially less prone to depression. At the same time, however, many women were experiencing stress and exhaustion from trying to balance work and family responsibilities.

text: Reauthorization[edit]

text: Enacted in July 1997, TANF was set for reauthorization in Congress in 2002. However, Congress was unable to reach an agreement for the next several years, and as a result, several extensions were granted to continue funding the program. TANF was finally reauthorized under the Deficit Reduction ACT (DRA) of 2005. DRA included several changes to the original TANF program. It raised work participation rates, increased the share of welfare recipients subject to work requirements, limited the activities that could be counted as work, prescribed hours that could be spent doing certain work activities, and required states to verify activities for each adult beneficiary.[57]

text: In February 2009, as part of the American Recovery and Reinvestment Act of 2009 (ARRA), Congress created a new TANF Emergency Fund (TANF EF), funded at $5 billion and available to states, territories, and tribes for federal fiscal years 2009 and 2010. The original TANF law provided for a Contingency Fund (CF) funded at $2 billion which allows states meeting economic triggers to draw additional funds based upon high levels of state MOE spending. This fund was expected to (and did) run out in FY 2010. The TANF Emergency Fund provided states 80 percent of the funding for spending increases in three categories of TANF-related expenditures in FYs 2009 or 2010 over FYs 2007 or 2008. The three categories of expenditures that could be claimed were basic assistance, non-recurrent short-term benefits, and subsidized employment.[58] The third category listed, subsidized employment, made national headlines[59] as states created nearly 250,000 adult and youth jobs through the funding.[60] The program however expired on September 30, 2010, on schedule with states drawing down the entire $5 billion allocated by ARRA.[61]

text: TANF was scheduled for reauthorization again in 2010. However, Congress did not work on legislation to reauthorize the program and instead they extended the TANF block grant through September 30, 2011, as part of the Claims Resolution Act.[62] During this period Congress once again did not reauthorize the program but passed a three-month extension through December 31, 2011.

text: Exiting The TANF Program[edit]

text: When transitioning out of the TANF program, individuals find themselves in one of three situations that constitute the reasons for exiting:[63]

text:
The first situation involves work related TANF exit, in which individuals no longer qualify for TANF assistance due to acquired employment.
The second type of situation is non- work TANF related exit in which the recipient no longer qualifies for assistance due to reaching the maximum time allowed to be enrolled in the assistance program. Once their time limit has been reached, individuals are removed from receiving assistance.
The third type of situation is continued TANF receipt in which employed recipients earning a wage that does not help cover expenses continue receiving assistance.

text: It has been observed that certain situations of TANF exit are more prominent depending on the geographic area which recipients live in. Focusing the comparison between metropolitan (urban) areas and non-metropolitan (rural) areas, the number of recipients experiencing non work TANF related exit is highest among rural areas (rural areas in the South experience the highest cases of this type of exiting the program).[63]

text: Information asymmetry or lack of knowledge among recipients on the various TANF work incentive programs is a contributor to recipients experiencing non work related TANF exits. Not being aware of the offered programs impacts their use and creates misconceptions that influence the responsiveness of those who qualify for such programs, resulting in longer time periods requiring TANF services.[64] Recipients who exit TANF due to work are also affected by information asymmetry due to lack of awareness on the “transitional support” programs available to facilitate their transitioning into the work field. Programs such as childcare, food stamps, and Medicaid are meant increase work incentive but many TANF recipients transitioning into work do not know they are eligible.[65] It has been shown that TANF-exiting working women who use and maintain the transitional incentive services described above are less likely to return to receiving assistance and are more likely to experience long term employment.[66]


document_title: Charlie's Angels (film)

question_text: who played charlie in the charlie's angels movie

question_tokens: who played charlie in the charlie 's angels movie

root

text: Charlie's Angels (film)

text: Plot[edit]

text: Natalie Cook (Cameron Diaz), Dylan Sanders (Drew Barrymore) and Alex Munday (Lucy Liu) are the "Angels", three talented, tough, attractive women who work as private investigators together for an unseen millionaire named Charlie (voiced by John Forsythe). Charlie uses a speaker in his offices to communicate with the Angels, and his assistant Bosley (Bill Murray) works with them directly when needed.

tag: p

text: Charlie assigns the Angels to find Eric Knox (Sam Rockwell), a software genius who created a revolutionary voice-recognition system and heads his own company, Knox Enterprises. Knox is believed to have been kidnapped by Roger Corwin (Tim Curry), who runs a communications-satellite company called Redstar. The Angels infiltrate a party held by Corwin and spot the Creepy Thin Man (Crispin Glover) who was seen on the surveillance videos during Knox's kidnapping. They chase and fight the Creepy Thin Man.

text: After the Angels reunite Knox with his business partner Vivian Wood (Kelly Lynch), Charlie explains that they must determine whether the Creepy Thin Man has stolen Knox's voice-recognition software. The Angels infiltrate Redstar headquarters, fool the security system, and plant a device in the central computer that will enable them to explore it remotely. They retire for the night after giving Bosley the laptop computer that communicates with the Redstar computer. Dylan takes up Knox's offer to spend the night with him, end up in having sex but he betrays her later that night, explaining that he faked the kidnapping with help from Vivian and the Creepy Thin Man. He has kidnapped Bosley, and, with access to Redstar's central computer, he intends to use his voice software with the Redstar satellite network to find and kill Charlie, who he believes had killed his father in the Vietnam War.

text: Knox shoots at Dylan, seemingly killing her, but she escapes unharmed. Natalie and Alex are also attacked, and Corwin is murdered by the Creepy Thin Man. When the Angels regroup together, all uninjured, Charlie's offices are blown up. A radio receiver survives in the rubble, and Natalie deduces Bosley's location as he speaks to the Angels using a radio transmitter implanted in his teeth, explaining how to spot his location where he is being held captive.

text: With help from Dylan's current boyfriend Chad (Tom Green), the Angels approach the abandoned lighthouse where Knox is holding Bosley prisoner. The Angels rescue Bosley and defeat Vivian, the Creepy Thin Man, and some henchmen before Knox blows up the lighthouse, but Knox uses his software and the Redstar satellite network to locate Charlie when he telephones Bosley. When Knox programs a helicopter with a missile towards Charlie's house, Bosley helps the Angels board the helicopter, and Alex reprograms the missile to have it shoot backwards, which blows up the helicopter and kills Knox while all of the Angels land safely together on the beach.

text: Seeing the opportunity to finally meet Charlie in person, they enter the beach house that Knox had targeted the missile at, but Charlie has already left. He remotely congratulates the Angels on a job well done through another speaker, and treats them and Bosley to a vacation. Charlie tells them that Knox's father was undercover; however, he was discovered and he was killed by someone else but not Charlie. When he speaks to the Angels unseen again by telephone on the beach, they ask if they could ever meet him in person. Dylan then suspects that she might be seeing him nearby talking into a cell phone, but she doesn't tell the group.

text: Cast[edit]

text:
Cameron Diaz as Natalie Cook
Drew Barrymore as Dylan Sanders
Lucy Liu as Alex Munday
Bill Murray as John Bosley
John Forsythe as Charles "Charlie" Townsend (Voice)
Sam Rockwell as Eric Knox
Kelly Lynch as Vivian Wood
Crispin Glover as the Thin Man
Tim Curry as Roger Corwin
Matt LeBlanc as Jason Gibbons
Luke Wilson as Peter Kominsky
Tom Green as Chad
LL Cool J as Mr. Jones
Alex Trebek as Himself
Karen McDougal as Roger Corwin's girlfriend
Melissa McCarthy as Doris

tag: ul

text: Soundtrack[edit]

text: Released October 24, 2000.

text:
"Independent Women Part I" by Destiny's Child
"Heaven Must Be Missing an Angel" by The Tavares
"You Make Me Feel Like Dancing" by Leo Sayer
"True" by Spandau Ballet
"Dot" by Destiny's Child
"Baby Got Back" by Sir Mix-A-Lot
"Angel's Eye" by Aerosmith
"Barracuda" by Heart
"Turning Japanese" by The Vapors
"Brandy (You're a Fine Girl)" by Looking Glass
"Got to Give It Up (Part 1)" by Marvin Gaye
"Ya Mama" by Fatboy Slim
"Groove Is in the Heart" by Deee-Lite
"Charlie's Angels 2000" by Apollo 440
"Tangerine Speedo" by Caviar

Other songs used in the film

"Blind" by Korn
"Live Wire" by Mötley Crüe
"Wake Me Up Before You Go Go" by Wham!
"Money (That's What I Want)" by The Flying Lizards
"I Love Rock 'n' Roll" by Joan Jett and the Blackhearts
"Angel of the Morning" by Juice Newton
"Undercover Angel" by Alan O'Day
"Principles of Lust" by Enigma
"Twiggy Twiggy" by Pizzicato Five
"Sukiyaki" by Kyu Sakamoto
"Zendeko Hachijo" by Zenshuji Zendeko
"Smack My Bitch Up" by The Prodigy
"Another Town" by Transister
"Belly" by Nomad
"When Angels Yodel" written and arranged by Frank Marocco
"The Humpty Dance" by Digital Underground
"Miami Vice Theme" by Jan Hammer
"Simon Says" by Pharoahe Monch
"Leave You Far Behind" by Lunatic Calm
"Skullsplitter" by Hednoize
"Song 2" by Blur
"Billie Jean" by Michael Jackson
"Angel" by Rod Stewart
"All the Small Things" by Blink-182
"A Girl Like You" by Edwyn Collins

tag: table

text: Reception[edit]

text: Box office[edit]

text: Charlie's Angels grossed $125.3 million domestically and $148.8 million in other territories, for a worldwide gross of $264.1 million, becoming the 12th highest-grossing of 2000. Against a budget of $93 million, the film was a box office success.

text: North America[edit]

text: Domestically, the film opened in November 3, 2000, earning $13.7 million in its opening day, debuting at the top of the box office. For its first weekend, the film grossed $40.1 million dethroning Meet the Parents, which had stayed at number-one for four weeks. Eventually, Charlie's Angels grossed a total of $125,305,545 domestically.

text: Critical reception[edit]

text: Charlie's Angels received generally positive reviews from critics, some action scenes, the humor of the film and the performances of Diaz and Murray were highly praised. On Rotten Tomatoes, the film has a 67% "Fresh" rating based on 141 reviews, despite the lower 45% audience rating. At Metacritic, which assigns a normalized rating out of 100 to reviews from film critics, it has a rating score of 52, indicating "mixed or average reviews".

text: During the making of Blade II, Guillermo del Toro commented that while films like Charlie's Angels had helped to popularize the wire fu style of fighting choreography in Western films, they also served as a "nail in the coffin" and prompted many filmmakers to want to get back to more "hard-hitting" action.[2] "The moment you see Cameron Diaz flying in the air, and you know that she is incapable of flying in the air and kicking five guys... you realize that it is done using wires. [...] I mean, Charlie's Angels was great, but it[s fighting style] was almost satirical."[2]

text: Home media[edit]

text: Charlie's Angels was released on both VHS and DVD on 27 March 2001.

text: Sequel[edit]

text: A sequel called Charlie's Angels: Full Throttle released in 2003. Cameron Diaz, Drew Barrymore and Lucy Liu reprised their roles, as did John Forsythe as the voice of Charlie in his last film role. Bernie Mac replaced Bill Murray as Bosley, Demi Moore had a major role, and Jaclyn Smith reprised her role of Kelly Garrett from the original television series.

text: Reboot[edit]

text: On September 15, 2015, The Hollywood Reporter has reported that Sony are rebooting the film with Elizabeth Banks both producing with her producing partner and husband Max Handelman and the studio are in negotiations with her to direct the film.[3] On April 13, 2016, Sony has confirmed that Banks will direct the reboot.[4] On May 23, 2017, the reboot was scheduled for a June 7, 2019 release.


document_title: Cast Away

question_text: what is the name of the ball in cast away

text: Cast Away

text: Plot[edit]

text: In December 1995, Chuck Noland is a time-obsessed systems engineer, who travels worldwide resolving productivity problems at FedEx depots. He is in a long-term relationship with Kelly Frears, with whom he lives in Memphis, Tennessee. Although the couple wants to get married, Chuck's busy schedule interferes with their relationship. A Christmas with relatives is interrupted when Chuck is summoned to resolve a problem in Malaysia. While flying through a violent storm, his plane crashes into the Pacific Ocean. Chuck escapes the sinking plane and is saved by an inflatable life raft, but loses the emergency locator transmitter. He clings to the life raft, loses consciousness, and floats all night before washing up on an island. After he awakens, he explores the island and soon discovers that it is uninhabited.

text: Several FedEx packages from the crashed plane also wash up on the shore, as well as the corpse of one of the pilots, which he buries. He initially tries to signal for rescue and makes an escape attempt with the remnants of his life raft, but cannot pass the powerful surf and the coral reefs surrounding the island. He searches for food, water, and shelter, and opens the packages, finding a number of useful items. He leaves one package, which has a pair of angel wings stenciled on it, unopened. During a first attempt to make fire, Chuck receives a deep wound to his hand. In anger and pain, he throws several objects, including a Wilson volleyball from one of the packages. A short time later he draws a face in the bloody hand print on the ball, names it Wilson, and begins talking to it. One night, Chuck calculates that in order for the rescue workers to find the site of the plane crash, they will have to search an area twice the size of Texas, making him doubtful he will ever be found.

text: Four years later, Chuck has adapted to the island’s meager living conditions, having become adept at spearing fish and making fires. He also has regular conversations and arguments with Wilson, his only means of socialization. A large section of a portable toilet washes up on the island; Chuck uses it as a sail in the construction of a raft. After spending some time building and stocking the raft and deciding when weather conditions will be optimal (using an analemma he has created in his cave to monitor the time of year), he launches, using the sail to overcome the powerful surf. After some time on the ocean, a storm nearly tears his raft apart. The following day, as Chuck sleeps, Wilson becomes untethered and floats away from the raft. Chuck is wakened by the spray of a sounding whale, sees Wilson, and swims after him, but Wilson has gone too far to safely retrieve. Chuck returns to the raft and collapses in tears. Later, a passing cargo ship finds him, drifting.

text: Upon returning to civilization, Chuck learns that he has long been given up for dead; his family and acquaintances have held a funeral, and Kelly has since married Chuck's onetime dentist and has a daughter. After reuniting, the pair profess their love for each other but, realizing they cannot be together because of her commitment to her new family, they sadly part. Kelly gives Chuck the car they once shared.

text: Some time later, after buying a new volleyball, Chuck travels to Canadian, Texas, to return the unopened FedEx package with the angel wings to its sender, a woman named Bettina Peterson. No one is home, so he leaves the package at the door with a note saying that the package saved his life. He departs and stops at a remote crossroads. A friendly woman passing by in a pickup truck stops to explain where each road leads. As she drives away, Chuck notices the angel wings on the back of her truck are identical to those on the parcel. As Chuck is left standing at the crossroads he looks down each road, then smiles faintly as he looks in the direction of the woman's truck.

text: Cast[edit]

text:
Tom Hanks as Chuck Noland
Helen Hunt as Kelly Frears
Nick Searcy as Stan
Jenifer Lewis as Becca Twig
Chris Noth as Jerry Lovett
Lari White as Bettina Peterson
Vince Martin as Albert "Al" Miller
Geoffrey Blake as Maynard Graham
Michael Forest as Jack
Jay Acovone as Petrov

text: Production[edit]

text: Development[edit]

text: Tom Hanks once stated in an Actor Roundtable with The Hollywood Reporter that "...I wanted to examine the concept of four years of hopelessness, in which you have none of the requirements for living — food, water, shelter, fire and company". But it took six years to put together the alliance that would actually examine that. [Hanks] only had a third of [the story], and [screenwriter] Bill Broyles only had a third of it, [director] Bob Zemeckis came along and provided that other third. Hanks also went on to say "I had that original idea. I was reading an article about FedEx, and I realized that 747s filled with packages fly across the Pacific three times a day. And I just thought, "What happens if that goes down?"[3]

text: Filming[edit]

text: The film's shooting occurred between 1998 and 2000, but was not shot consecutively. Hanks gained 50 pounds (23 kg) during pre-production, for the purpose of making his transformation more dramatic. After a majority of the film was shot, production was halted for a year so that he could lose the weight and grow his hair and beard to look like he had been living on the island for years. During the year-long hiatus, Zemeckis used the same film crew to make another film, What Lies Beneath.[2]

text: Cast Away was filmed on Monuriki, one of the Mamanuca Islands in Fiji.[4] It is in a subgroup of the Mamanuca archipelago, which is sited off the coast of Viti Levu, Fiji's largest island. The island became a tourist attraction following the film's release. After Chuck's return, it is identified by Kelly as being "about 600 miles south of the Cook Islands," but there is actually no land between the southernmost Cook Islands of Mangaia and Antarctica.

text: The film essentially begins and ends in the same location, on the Arrington Ranch in the Texas Panhandle south of the city of Canadian, Texas.[5]

text: Music[edit]

text: The film's minimal score was composed by Alan Silvestri for which he won a Grammy Award in 2002. The film's soundtrack is most notable for its lack of score and creature sound effects (such as bird song or insect sounds) while Chuck is on the island, which is intended to reinforce the feeling of isolation.[6] Cast Away contains no original musical score until Chuck escapes the island. However, there is a Russian choral piece heard near the start of the film that was not composed or even recorded by Silvestri, so it does not appear on the film's soundtrack list. It is a traditional Russian song written by Lev Knipper called "Oh, My Field" ("Polyushko, Polye") and it is available on various collections of Red Army hymns. The tracks in Silvestri's score are as follows:

text:
"Cast Away" – 3:44
"Wilson, I'm Sorry" – 1:39
"Drive to Kelly's" – 3:54
"Love of My Life" – 1:47
"What the Tide Could Bring" – 3:39
"Crossroads" – 2:08
"End Credits" – 7:29

text: The official soundtrack CD is an anthology of musical pieces from all films up to that point directed by Zemeckis and scored by Silvestri. The only track from Cast Away itself is the theme from the end credits.[7]

text: FedEx[edit]

text: FedEx provided access to their facilities (Memphis, Los Angeles, and Moscow) as well as airplanes, trucks, uniforms, and logistical support. A team of FedEx marketers oversaw production through more than two years of filming.[8] FedEx CEO Fred Smith made an appearance as himself for the scene where Chuck is welcomed back, which was filmed on location at FedEx's home facilities in Memphis, Tennessee. The idea of a story based on a FedEx plane crashing gave the company "a heart attack at first," but the overall story was seen as positive. FedEx, which paid no money for product placement in the film,[9] saw an increase in brand awareness in Asia and Europe following the film's release.[10]

text: Wilson the volleyball[edit]

text: In the film, Wilson the volleyball serves as Chuck Noland's personified friend and only companion during the four years that Noland spends alone on a deserted island.[11][12][13] Named after the volleyball's manufacturer, Wilson Sporting Goods, the character was created by screenwriter William Broyles, Jr.. While researching for the film, he consulted with professional survival experts, and then chose to deliberately strand himself for one week on an isolated beach in the Gulf of California, to force himself to search for water and food, and obtain his own shelter. During this time, a volleyball washed up on shore. This was the inspiration for the film's inanimate companion. From a screenwriting point of view, Wilson also serves to realistically allow dialogue in a one-person-only situation.[14][15]

text: One of the original volleyball props was sold at auction for $18,500 to the ex-CEO of FedEx Office, Ken May. At the time of the film's release, Wilson launched its own joint promotion centered on the fact that one of its products was "co-starring" with Tom Hanks. Wilson manufactured a volleyball with a reproduction of the bloodied handprint face on one side. It was sold for a limited time during the film's initial release and continues to be offered on the company's website.[16]

text: Reception[edit]

text: On Rotten Tomatoes, Cast Away has an approval rating of 90% based on 154 reviews, with an average rating of 7.4/10. The site's critical consensus reads, "Flawed but fascinating, Cast Away offers an intelligent script, some of Robert Zemeckis' most mature directing, and a showcase performance from Tom Hanks."[17] On Metacritic the film has a score of 73 out of 100, based on 32 critics, indicating "generally favorable reviews".[18]

text: Cast Away opened in 2,774 theaters in North America and grossed $28,883,406 with an average of $10,412 per theater on its opening weekend.[19] For the four-day Christmas long holiday weekend, it took in a total of $39,852,075.[20] The film kept performing well and ended up earning $233,632,142 domestically and $196,000,000 internationally for a total of $429,632,142, well above its production budget of $90 million.[1]

text: Accolades[edit]

text:
Award
Category
Recipients and nominees
Result

73rd Academy Awards[21]
Best Actor
Tom Hanks
Nominated

Best Sound
Randy Thom, Tom Johnson, Dennis S. Sands and William B. Kaplan
Nominated

54th British Academy Film Awards[22]
Best Actor
Tom Hanks
Nominated

6th Critics' Choice Awards[23]
Best Inanimate Object
Wilson
Won

58th Golden Globe Awards[24]
Best Actor – Motion Picture Drama
Tom Hanks
Won

2001 MTV Movie Awards
Best Action Sequence
Plane crash
Nominated

Best Kiss
Tom Hanks and Helen Hunt
Nominated

Best Male Performance
Tom Hanks
Nominated

Best On-Screen Duo
Tom Hanks and Wilson
Nominated

7th Screen Actors Guild Awards[25]
Outstanding Performance by a Male Actor in a Leading Role
Tom Hanks
Nominated

text: In popular culture[edit]

text: A FedEx commercial during the 2003 Super Bowl parodied the final scene of the film, in which Chuck returns a package to its sender. In this version, the woman answers the door, and when Chuck asks what was in the box, the woman replies: "Just a satellite phone, GPS locator, fishing rod, water purifier, and some seeds. Just silly stuff."[26]

text: Media executive Lloyd Braun of ABC Studios first suggested the idea of a Cast Away–type television series at a dinner party in 2003.[27] Thom Sherman later pitched the idea for Cast Away – The Series, but never developed the idea.[27] The concept was later developed and pitched with the title Nowhere, which later turned into the ABC show Lost.[27]


document_title: Air conditioning

question_text: who is widely regarded as the inventer of air conditioner

question_tokens: who is widely regarded as the inventer of air conditioner

text: Air conditioning

text: History[edit]

text: Evaporative cooling[edit]

text: Since prehistoric times, snow and ice were used for cooling. The business of harvesting ice during winter and storing for use in summer became popular towards the late 17th century.[3] This practice was replaced by mechanical ice-making machines.

text: The basic concept behind air conditioning is said to have been applied in ancient Egypt, where reeds were hung in windows and were moistened with trickling water. The evaporation of water cooled the air blowing through the window. This process also made the air more humid, which can be beneficial in a dry desert climate. In Ancient Rome, water from aqueducts was circulated through the walls of certain houses to cool them. Other techniques in medieval Persia involved the use of cisterns and wind towers to cool buildings during the hot season.[4]

text: The 2nd-century Chinese mechanical engineer and inventor Ding Huan of the Han Dynasty invented a rotary fan for air conditioning, with seven wheels 3 m (10 ft) in diameter and manually powered by prisoners of the time.[5] In 747, Emperor Xuanzong (r. 712–762) of the Tang Dynasty (618–907) had the Cool Hall (Liang Tian) built in the imperial palace, which the Tang Yulin describes as having water-powered fan wheels for air conditioning as well as rising jet streams of water from fountains. During the subsequent Song Dynasty (960–1279), written sources mentioned the air conditioning rotary fan as even more widely used.[6]

text: In the 17th century, the Dutch inventor Cornelis Drebbel demonstrated "Turning Summer into Winter" as an early form of modern air conditioning for James I of England by adding salt to water.[7]

text: Development of mechanical cooling[edit]

text: Modern air conditioning emerged from advances in chemistry during the 19th century, and the first large-scale electrical air conditioning was invented and used in 1902 by American inventor Willis Carrier. The introduction of residential air conditioning in the 1920s helped enable the great migration to the Sun Belt in the United States.[citation needed]

text: In 1758, Benjamin Franklin and John Hadley, a chemistry professor at Cambridge University, conducted an experiment to explore the principle of evaporation as a means to rapidly cool an object. Franklin and Hadley confirmed that evaporation of highly volatile liquids (such as alcohol and ether) could be used to drive down the temperature of an object past the freezing point of water. They conducted their experiment with the bulb of a mercury thermometer as their object and with a bellows used to speed up the evaporation. They lowered the temperature of the thermometer bulb down to −14 °C (7 °F) while the ambient temperature was 18 °C (64 °F). Franklin noted that, soon after they passed the freezing point of water 0 °C (32 °F), a thin film of ice formed on the surface of the thermometer's bulb and that the ice mass was about 6 mm (1⁄4 in) thick when they stopped the experiment upon reaching −14 °C (7 °F). Franklin concluded: "From this experiment one may see the possibility of freezing a man to death on a warm summer's day"[8]

text: In 1820, English scientist and inventor Michael Faraday discovered that compressing and liquefying ammonia could chill air when the liquefied ammonia was allowed to evaporate. In 1842, Florida physician John Gorrie used compressor technology to create ice, which he used to cool air for his patients in his hospital in Apalachicola, Florida. He hoped to eventually use his ice-making machine to regulate the temperature of buildings. He even envisioned centralized air conditioning that could cool entire cities. Though his prototype leaked and performed irregularly, Gorrie was granted a patent in 1851 for his ice-making machine. Though his process improved the artificial production of ice, his hopes for its success vanished soon afterwards when his chief financial backer died and Gorrie did not get the money he needed to develop the machine. According to his biographer, Vivian M. Sherlock, he blamed the "Ice King", Frederic Tudor, for his failure, suspecting that Tudor had launched a smear campaign against his invention. Dr. Gorrie died impoverished in 1855, and the dream of commonplace air conditioning went away for 50 years.[citation needed]

text: James Harrison's first mechanical ice-making machine began operation in 1851 on the banks of the Barwon River at Rocky Point in Geelong (Australia). His first commercial ice-making machine followed in 1853, and his patent for an ether vapor compression refrigeration system was granted in 1855. This novel system used a compressor to force the refrigeration gas to pass through a condenser, where it cooled down and liquefied. The liquefied gas then circulated through the refrigeration coils and vaporized again, cooling down the surrounding system. The machine produced 3,000 kilograms of ice per day.[citation needed]

text: Though Harrison had commercial success establishing a second ice company back in Sydney in 1860, he later entered the debate over how to compete against the American advantage of ice refrigerated beef sales to the United Kingdom. He wrote: "Fresh meat frozen and packed as if for a voyage, so that the refrigerating process may be continued for any required period", and in 1873 prepared the sailing ship Norfolk for an experimental beef shipment to the United Kingdom. His choice of a cold room system instead of installing a refrigeration system upon the ship itself proved disastrous when the ice was consumed faster than expected.[citation needed]

text: Electrical air conditioning[edit]

text: In 1902, the first modern electrical air conditioning unit was invented by Willis Carrier in Buffalo, New York. After graduating from Cornell University, Carrier found a job at the Buffalo Forge Company. While there, he began experimenting with air conditioning as a way to solve an application problem for the Sackett-Wilhelms Lithographing and Publishing Company in Brooklyn, New York. The first air conditioner, designed and built in Buffalo by Carrier, began working on 17 July 1902.[citation needed]

text: Designed to improve manufacturing process control in a printing plant, Carrier's invention controlled not only temperature but also humidity. Carrier used his knowledge of the heating of objects with steam and reversed the process. Instead of sending air through hot coils, he sent it through cold coils (filled with cold water). The air was cooled, and thereby the amount of moisture in the air could be controlled, which in turn made the humidity in the room controllable. The controlled temperature and humidity helped maintain consistent paper dimensions and ink alignment. Later, Carrier's technology was applied to increase productivity in the workplace, and The Carrier Air Conditioning Company of America was formed to meet rising demand. Over time, air conditioning came to be used to improve comfort in homes and automobiles as well. Residential sales expanded dramatically in the 1950s.[citation needed]

text: In 1906, Stuart W. Cramer of Charlotte was exploring ways to add moisture to the air in his textile mill. Cramer coined the term "air conditioning", using it in a patent claim he filed that year as an analogue to "water conditioning", then a well-known process for making textiles easier to process. He combined moisture with ventilation to "condition" and change the air in the factories, controlling the humidity so necessary in textile plants. Willis Carrier adopted the term and incorporated it into the name of his company.[9]

text: Shortly thereafter, the first private home to have air conditioning was built in Minneapolis in 1914, owned by Charles Gates.[10] Realizing that air conditioning would one day be a standard feature of private homes, particularly in regions with warmer climate, David St. Pierre DuBose (1898-1994) designed a network of ductwork and vents for his home Meadowmont, all disguised behind intricate and attractive Georgian-style open moldings.[when?] This building is believed to be one of the first private homes in the United States equipped for central air conditioning.[11]

text: In 1945, Robert Sherman of Lynn, Massachusetts invented a portable, in-window air conditioner that cooled, heated, humidified, dehumidified, and filtered the air.[12]

text: Refrigerant development[edit]

text: The first air conditioners and refrigerators employed toxic or flammable gases, such as ammonia, methyl chloride, or propane, that could result in fatal accidents when they leaked. Thomas Midgley, Jr. created the first non-flammable, non-toxic chlorofluorocarbon gas, Freon, in 1928. The name is a trademark name owned by DuPont for any chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), or hydrofluorocarbon (HFC) refrigerant. The refrigerant names include a number indicating the molecular composition (e.g., R-11, R-12, R-22, R-134A). The blend most used in direct-expansion home and building comfort cooling is an HCFC known as chlorodifluoromethane (R-22).

text: Dichlorodifluoromethane (R-12) was the most common blend used in automobiles in the US until 1994, when most designs changed to R-134A due to the ozone-depleting potential of R-12. R-11 and R-12 are no longer manufactured in the US for this type of application, so the only source for air-conditioning repair purposes is the cleaned and purified gas recovered from other air conditioner systems. Several non-ozone-depleting refrigerants have been developed as alternatives, including R-410A. It was first commercially used by Carrier Corp. under the brand name Puron.[citation needed]

text: Modern refrigerants have been developed to be more environmentally safe than many of the early chlorofluorocarbon-based refrigerants used in the early- and mid-twentieth century. These include HCFCs (R-22, as used in most U.S. homes even before 2011) and HFCs (R-134a, used in most cars) have replaced most CFC use. HCFCs, in turn, are supposed to have been in the process of being phased out under the Montreal Protocol and replaced by HFCs such as R-410A, which lack chlorine.[13] HFCs, however, contribute to climate change problems. Moreover, policy and political influence by corporate executives resisted change.[14][15] Corporations insisted that no alternatives to HFCs existed. The environmental organization Greenpeace solicited a European laboratory to research an alternative ozone- and climate-safe refrigerant in 1992, gained patent rights to a hydrocarbon mix of isopentane and isobutane, but then left the technology as open access.[16][17] Their activist marketing first in Germany led to companies like Whirlpool, Bosch, and later LG and others to incorporate the technology throughout Europe, then Asia, although the corporate executives resisted in Latin America, so that it arrived in Argentina produced by a domestic firm in 2003, and then finally with giant Bosch's production in Brazil by 2004.[18][19]

text: In 1995, Germany made CFC refrigerators illegal.[20] DuPont and other companies blocked the refrigerant in the U.S. with the U.S. E.P.A., disparaging the approach as "that German technology."[19][21] Nevertheless, in 2004, Greenpeace worked with multinational corporations like Coca-Cola and Unilever, and later Pepsico and others, to create a corporate coalition called Refrigerants Naturally!.[20][22] Then, four years later, Ben & Jerry's of Unilever and General Electric began to take steps to support production and use in the U.S.[23] Only in 2011 did the E.P.A. finally decide in favor of the ozone- and climate-safe refrigerant for U.S. manufacture.[16][24][25]

text: Operating principles[edit]

text: This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2016) (Learn how and when to remove this template message)

text: Refrigeration cycle[edit]

text: In the refrigeration cycle, heat is transported from a colder location to a hotter area. As heat would naturally flow in the opposite direction, work is required to achieve this. A refrigerator is an example of such a system, as it transports the heat out of the interior and into its environment. The refrigerant is used as the medium which absorbs and removes heat from the space to be cooled and subsequently ejects that heat elsewhere.

text: Circulating refrigerant vapor enters the compressor, where its pressure and temperature are increased. The hot, compressed refrigerant vapor is now at a temperature and pressure at which it can be condensed and is routed through a condenser. Here it is cooled by air flowing across the condenser coils and condensed into a liquid. Thus, the circulating refrigerant removes heat from the system and the heat is carried away by the air. The removal of this heat can be greatly augmented by pouring water over the condenser coils, making it much cooler when it hits the expansion valve.

text: The condensed, pressurized, and still usually somewhat hot liquid refrigerant is next routed through an expansion valve (often nothing more than a pinhole in the system's copper tubing) where it undergoes an abrupt reduction in pressure. That pressure reduction results in flash evaporation of a part of the liquid refrigerant, greatly lowering its temperature. Aircraft air conditioners use turbines for cooling, more efficient but more complex. The cold refrigerant is then routed through the evaporator. A fan blows the interior warm air (which is to be cooled) across the evaporator, causing the liquid part of the cold refrigerant mixture to evaporate as well, further lowering the temperature. The warm air is therefore cooled and is pumped by an exhaust fan/ blower into the room. To complete the refrigeration cycle, the refrigerant vapor is routed back into the compressor. In order for the process to have any efficiency, the cooling/evaporative portion of the system must be separated by some kind of physical barrier from the heating/condensing portion, and each portion must have its own fan to circulate its own "kind" of air (either the hot air or the cool air).

text: Modern air conditioning systems are not designed to draw air into the room from the outside, they only recirculate the increasingly cool air on the inside. Because this inside air always has some amount of moisture suspended in it, the cooling portion of the process always causes ambient warm water vapor to condense on the cooling coils and to drip from them down onto a catch tray at the bottom of the unit from which it must then be routed outside, usually through a drain hole. As this moisture has no dissolved minerals in it, it will not cause mineral buildup on the coils. This will happen even if the ambient humidity level is low. If ice begins to form on the evaporative fins, it will reduce circulation efficiency and cause the development of more ice, etc. A clean and strong circulatory fan can help prevent this, as will raising the target cool temperature of the unit's thermostat to a point that the compressor is allowed to turn off occasionally. A failing thermistor may also cause this problem. Refrigerators without a defrost cycle may have this same issue. Dust can also cause the fins to begin blocking air flow with the same undesirable result: ice.

text: By running an air conditioner's compressor in the opposite direction, the overall effect can be completely reversed and the indoor compartment will become heated instead of cooled (see heat pump). The engineering of physical and thermodynamic properties of gas–vapor mixtures is called psychrometrics.

text: Heat pump unit[edit]

text: A heat pump is an air conditioner in which the refrigeration cycle can be reversed, producing heating instead of cooling in the indoor environment. They are also commonly referred to as a "reverse cycle air conditioner". The heat pump is significantly more energy efficient than electric resistance heating. Some homeowners elect to have a heat pump system installed as a feature of a central air conditioner. When the heat pump is in heating mode, the indoor evaporator coil switches roles and becomes the condenser coil, producing heat. The outdoor condenser unit also switches roles to serve as the evaporator, and discharges cold air (colder than the ambient outdoor air).

text: Air-source heat pumps are more popular in milder winter climates where the temperature is frequently in the range of 40–55 °F (4–13 °C), because heat pumps become inefficient in more extreme cold. This is because ice forms on the outdoor unit's heat exchanger coil, which blocks air flow over the coil. To compensate for this, the heat pump system must temporarily switch back into the regular air conditioning mode to switch the outdoor evaporator coil back to being the condenser coil, so that it can heat up and defrost. A heat pump system will therefore have a form of electric resistance heating in the indoor air path that is activated only in this mode in order to compensate for the temporary indoor air cooling, which would otherwise be uncomfortable in the winter.

text: The icing problem becomes much more severe with lower outdoor temperatures, so heat pumps are commonly installed in tandem with a more conventional form of heating, such as a natural gas or oil furnace, which is used instead of the heat pump during harsher winter temperatures. In this case, the heat pump is used efficiently during the milder temperatures, and the system is switched to the conventional heat source when the outdoor temperature is lower.

text: Absorption heat pumps are a kind of air-source heat pump, but they do not depend on electricity to power them. Instead, gas, solar power, or heated water is used as a main power source. An absorption pump dissolves ammonia gas in water, which gives off heat. Next, the water and ammonia mixture is depressurized to induce boiling, and the ammonia is boiled off, which absorbs heat from the outdoor air.[citation needed]

text: Some more expensive fixed window air conditioning units have a true heat pump function. However, a window unit may only have an electric resistance heater.

text: Evaporative cooling[edit]

text: In very dry climates, evaporative coolers, sometimes referred to as swamp coolers or desert coolers, are popular for improving coolness during hot weather. An evaporative cooler is a device that draws outside air through a wet pad, such as a large sponge soaked with water. The sensible heat of the incoming air, as measured by a dry bulb thermometer, is reduced. The temperature of the incoming air is reduced, but it is also more humid, so the total heat (sensible heat plus latent heat) is unchanged. Some of the sensible heat of the entering air is converted to latent heat by the evaporation of water in the wet cooler pads. If the entering air is dry enough, the results can be quite substantial.

text: Evaporative coolers tend to feel as if they are not working during times of high humidity, when there is not much dry air with which the coolers can work to make the air as cool as possible for dwelling occupants. Unlike other types of air conditioners, evaporative coolers rely on the outside air to be channeled through cooler pads that cool the air before it reaches the inside of a house through its air duct system; this cooled outside air must be allowed to push the warmer air within the house out through an exhaust opening such as an open door or window.[26] These coolers cost less and are mechanically simple to understand and maintain.

text: Free cooling[edit]

text: Air conditioning can also be provided by a process called free cooling which uses pumps to circulate a coolant (typically water or a glycol mix) from a cold source, which in turn acts as a heat sink for the energy that is removed from the cooled space. Common storage media are deep aquifers or a natural underground rock mass accessed via a cluster of small-diameter boreholes, equipped with heat exchanger. Some systems with small storage capacity are hybrid systems, using free cooling early in the cooling season, and later employing a heat pump to chill the circulation coming from the storage. The heat pump is added because the temperature of the storage gradually increases during the cooling season, thereby declining its effectiveness.

text: Free cooling systems can have very high efficiencies, and are sometimes combined with seasonal thermal energy storage (STES) so the cold of winter can be used for summer air conditioning. Free cooling and hybrid systems are mature technology.[27]

text: Humidity control[edit]

text: This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2016) (Learn how and when to remove this template message)

text: Since humans perspire to provide natural cooling by the evaporation of perspiration from the skin, drier air (up to a point) improves the comfort provided. The comfort air conditioner is designed to create a 50% to 60% relative humidity in the occupied space.[citation needed]

text: Dehumidification and cooling[edit]

text: Refrigeration air conditioning equipment usually reduces the absolute humidity of the air processed by the system. The relatively cold (below the dewpoint) evaporator coil condenses water vapor from the processed air, much like an ice-cold drink will condense water on the outside of a glass. Therefore, water vapor is removed from the cooled air and the relative humidity in the room is lowered. The water is usually sent to a drain or may simply drip onto the ground outdoors. The heat is rejected by the condenser which is located outside of room to be cooled.

text: Dehumidification Program[edit]

text: On most modern Air-conditioning systems there is a dehumidification cycle; the compressor is on and the fan is slowed as much as possible (lowest speed under normal conditions).[citation needed] This reduces the evaporator temperature and therefore condenses more water than if it were to have a high fan speed. To help mitigate temperature drops when the temperature falls below a threshold, both the fan and compressor turn off,[clarification needed] this stops moisture on the evaporator being blown back into the room.[citation needed] When the temperature rises[clarification needed] again the compressor comes and the fan goes back to low speed. However occasionally the fan will stay on and compressor go off to thaw any ice produced (hence why the program doesn't work in cool conditions).

text: Inverter type Air Conditioners use the inside coil temperature sensor (typically used for heat pump operation where it regulates fan speed according to how warm the evaporator is) to adjust compressor speed to keep the evaporator as cold as possible, when the evaporator is too cold[clarification needed] the compressor is slowed or stopped with the indoor fan running.

text: Dehumidifier[edit]

text: A specialized air conditioner that is used only for dehumidifying is called a dehumidifier. It also uses a refrigeration cycle, but differs from a standard air conditioner in that both the evaporator and the condenser are placed in the same air path. A standard air conditioner transfers heat energy out of the room because its condenser coil releases heat outside. However, since all components of the dehumidifier are in the same room, no heat energy is removed. Instead, the electric power consumed by the dehumidifier remains in the room as heat, so the room is actually heated, just as by an electric heater that draws the same amount of power.

text: In addition, if water is condensed in the room, the amount of heat previously needed to evaporate that water also is re-released in the room (the latent heat of vaporization). The dehumidification process is the inverse of adding water to the room with an evaporative cooler, and instead releases heat. Therefore, an in-room dehumidifier always will warm the room and reduce the relative humidity indirectly, as well as reducing the humidity directly by condensing and removing water.

text: Inside the unit, the air passes over the evaporator coil first, and is cooled and dehumidified. The now dehumidified, cold air then passes over the condenser coil where it is warmed up again. Then the air is released back into the room. The unit produces warm, dehumidified air and can usually be placed freely in the environment (room) that is to be conditioned.

text: Dehumidifiers are commonly used in cold, damp climates to prevent mold growth indoors, especially in basements. They are also used to protect sensitive equipment from the adverse effects of excessive humidity in tropical countries.

text: Energy transfer[edit]

text: In a thermodynamically closed system, any power dissipated into the system that is being maintained at a set temperature (which is a standard mode of operation for modern air conditioners) requires that the rate of energy removal by the air conditioner increase. This increase has the effect that, for each unit of energy input into the system (say to power a light bulb in the closed system), the air conditioner removes that energy.[28] In order to do so, the air conditioner must increase its power consumption by the inverse of its "efficiency" (coefficient of performance) times the amount of power dissipated into the system. As an example, assume that inside the closed system a 100 W heating element is activated, and the air conditioner has an coefficient of performance of 200%. The air conditioner's power consumption will increase by 50 W to compensate for this, thus making the 100 W heating element cost a total of 150 W of power.

text: It is typical for air conditioners to operate at "efficiencies" of significantly greater than 100%.[29] However, it may be noted that the input electrical energy is of higher thermodynamic quality (lower entropy) than the output thermal energy (heat energy).

text: Air conditioner equipment power in the U.S. is often described in terms of "tons of refrigeration". A ton of refrigeration is approximately equal to the cooling power of one short ton (2000 pounds or 907 kilograms) of ice melting in a 24-hour period. The value is defined as 12,000 BTU per hour, or 3517 watts.[30] Residential central air systems are usually from 1 to 5 tons (3 to 20 kilowatts (kW)) in capacity.

text: Seasonal energy efficiency ratio[edit]

text: For residential homes, some countries set minimum requirements for energy efficiency. In the United States, the efficiency of air conditioners is often (but not always) rated by the seasonal energy efficiency ratio (SEER). The higher the SEER rating, the more energy efficient is the air conditioner. The SEER rating is the BTU of cooling output during its normal annual usage divided by the total electric energy input in watt hours (W·h) during the same period.[31]

text: this can also be rewritten as:

text: For example, a 5000 BTU/h air-conditioning unit, with a SEER of 10, would consume 5000/10 = 500 Watts of power on average.

text: The electrical energy consumed per year can be calculated as the average power multiplied by the annual operating time:

text: Assuming 1000 hours of operation during a typical cooling season (i.e., 8 hours per day for 125 days per year).

text: Another method that yields the same result, is to calculate the total annual cooling output:

text: Then, for a SEER of 10, the annual electrical energy usage would be:

text: SEER is related to the coefficient of performance (COP) commonly used in thermodynamics and also to the Energy Efficiency Ratio (EER). The EER is the efficiency rating for the equipment at a particular pair of external and internal temperatures, while SEER is calculated over a whole range of external temperatures (i.e., the temperature distribution for the geographical location of the SEER test). SEER is unusual in that it is composed of an Imperial unit divided by an SI unit. The COP is a ratio with the same metric units of energy (joules) in both the numerator and denominator. They cancel out, leaving a dimensionless quantity. Formulas for the approximate conversion between SEER and EER or COP are available from the Pacific Gas and Electric Company:[32]

text: From equation (2) above, a SEER of 13 is equivalent to a COP of 3.43, which means that 3.43 units of heat energy are pumped per unit of work energy.

text: The United States now requires that residential systems manufactured in 2006 have a minimum SEER rating of 13 (although window-box systems are exempt from this law, so their SEER is still around 10).

text: Installation types[edit]

text: Window unit and packaged terminal[edit]

text: Window unit air conditioners are installed in an open window. The interior air is cooled as a fan blows it over the evaporator. On the exterior the heat drawn from the interior is dissipated into the environment as a second fan blows outside air over the condenser. A large house or building may have several such units, allowing each room to be cooled separately.

text: In 1971, General Electric introduced the first portable in-window air conditioner designed for convenience and portability.[33]

text: Packaged terminal air conditioner (PTAC) systems are also known as wall-split air conditioning systems.[34] They are ductless systems. PTACs, which are frequently used in hotels, have two separate units (terminal packages), the evaporative unit on the interior and the condensing unit on the exterior, with an opening passing through the wall and connecting them. This minimizes the interior system footprint and allows each room to be adjusted independently. PTAC systems may be adapted to provide heating in cold weather, either directly by using an electric strip, gas, or other heater, or by reversing the refrigerant flow to heat the interior and draw heat from the exterior air, converting the air conditioner into a heat pump. While room air conditioning provides maximum flexibility, when used to cool many rooms at a time it is generally more expensive than central air conditioning.

text: The first practical through-the-wall air conditioning unit was invented by engineers at Chrysler Motors and offered for sale starting in 1935.[35]

text: Split systems[edit]

text: Split-system air conditioners come in two forms: mini-split and central systems. In both types, the inside-environment (evaporative) heat exchanger is separated by some distance from the outside-environment (condensing unit) heat exchanger.

text: Mini-split (ductless) system[edit]

text: A mini-split system typically supplies air conditioned and heated air to a single or a few rooms of a building.[36] Multi-zone systems are a common application of ductless systems and allow up to 8 rooms (zones) to be conditioned from a single outdoor unit. Multi-zone systems typically offer a variety of indoor unit styles including wall-mounted, ceiling-mounted, ceiling recessed, and horizontal ducted. Mini-split systems typically produce 9,000 to 36,000 Btu (9,500–38,000 kJ) per hour of cooling. Multi-zone systems provide extended cooling and heating capacity up to 60,000 Btu's.

text: Advantages of the ductless system include smaller size and flexibility for zoning or heating and cooling individual rooms. The inside wall space required is significantly reduced. Also, the compressor and heat exchanger can be located farther away from the inside space, rather than merely on the other side of the same unit as in a PTAC or window air conditioner. Flexible exterior hoses lead from the outside unit to the interior one(s); these are often enclosed with metal to look like common drainpipes from the roof. In addition, ductless systems offer higher efficiency, reaching above 30 SEER.[37]

text: The primary disadvantage of ductless air conditioners is their cost. Such systems cost about US$1,500 to US$2,000 per ton (12,000 BTU per hour) of cooling capacity. This is about 30% more than central systems (not including ductwork) and may cost more than twice as much as window units of similar capacity."[38]

text: An additional possible disadvantage that the cost of installing mini splits can be higher than some systems, although lower operating costs and rebates or other financial incentives—offered in some areas—can help offset the initial expense.[39]

text: Central (ducted) air conditioning[edit]

text: Central (ducted) air conditioning offers whole-house or large-commercial-space cooling, and often offers moderate multi-zone temperature control capability by the addition of air-louver-control boxes.

text: In central air conditioning, the inside heat-exchanger is typically placed inside the central furnace/AC unit of the forced air heating system which is then used in the summer to distribute chilled air throughout a residence or commercial building.

text: Portable units[edit]

text: A portable air conditioner can be easily transported inside a home or office. They are currently available with capacities of about 5,000–60,000 BTU/h (1,500–18,000 W) and with or without electric-resistance heaters. Portable air conditioners are either evaporative or refrigerative.

text: The compressor-based refrigerant systems are air-cooled, meaning they use air to exchange heat, in the same way as a car radiator or typical household air conditioner does. Such a system dehumidifies the air as it cools it. It collects water condensed from the cooled air and produces hot air which must be vented outside the cooled area; doing so transfers heat from the air in the cooled area to the outside air.

text: Portable split system[edit]

text: A portable system has an indoor unit on wheels connected to an outdoor unit via flexible pipes, similar to a permanently fixed installed unit.

text: Portable hose system[edit]

text: Hose systems, which can be monoblock or air-to-air, are vented to the outside via air ducts. The monoblock type collects the water in a bucket or tray and stops when full. The air-to-air type re-evaporates the water and discharges it through the ducted hose and can run continuously.

text: A single-hose unit uses air from within the room to cool its condenser, and then vents it outside. This air is replaced by hot air from outside or other rooms (due to the negative pressure inside the room), thus reducing the unit's overall efficiency.[40]

text: Modern units might have a coefficient of performance of approximately 3 (i.e., 1 kW of electricity will produce 3 kW of cooling). A dual-hose unit draws air to cool its condenser from outside instead of from inside the room, and thus is more effective than most single-hose units. These units create no negative pressure in the room.

text: Portable evaporative system[edit]

text: Evaporative coolers, sometimes called "swamp coolers", do not have a compressor or condenser. Liquid water is evaporated on the cooling fins, releasing the vapor into the cooled area. Evaporating water absorbs a significant amount of heat, the latent heat of vaporisation, cooling the air. Humans and animals use the same mechanism to cool themselves by sweating.

text: Evaporative coolers have the advantage of needing no hoses to vent heat outside the cooled area, making them truly portable. They are also very cheap to install and use less energy than refrigerative air conditioners.

text: Uses[edit]

text: Air-conditioning engineers broadly divide air conditioning applications into comfort and process applications.

text: Comfort applications[edit]

text: Comfort applications aim to provide a building indoor environment that remains relatively constant despite changes in external weather conditions or in internal heat loads.

text: Air conditioning makes deep plan buildings feasible, for otherwise they would have to be built narrower or with light wells so that inner spaces received sufficient outdoor air via natural ventilation. Air conditioning also allows buildings to be taller, since wind speed increases significantly with altitude making natural ventilation impractical for very tall buildings.[citation needed] Comfort applications are quite different for various building types and may be categorized as:

text:
Commercial buildings, which are built for commerce, including offices, malls, shopping centers, restaurants, etc.
High-rise residential buildings, such as tall dormitories and apartment blocks
Industrial spaces where thermal comfort of workers is desired
Cars, aircraft, boats, which transport passenger or fresh goods
Institutional buildings, which includes government buildings, hospitals, schools, etc.
Low-rise residential buildings, including single-family houses, duplexes, and small apartment buildings
Sports stadiums, such as the University of Phoenix Stadium[41] and in Qatar for the 2022 FIFA World Cup.[42]

text: Women have, on average, a significantly lower resting metabolic rate than men.[43] Using inaccurate metabolic rate guidelines for air conditioning sizing can result in oversized and less efficient equipment,[43] and setting system operating setpoints too cold can result in reduced worker productivity.[44]

text: In addition to buildings, air conditioning can be used for many types of transportation, including automobiles, buses and other land vehicles, trains, ships, aircraft, and spacecraft.

text: Domestic usage[edit]

text: Air conditioning is common in the US, with 88% of new single-family homes constructed in 2011 including air conditioning, ranging from 99% in the South to 62% in the West.[45] In Canada, air conditioning use varies by province. In 2013, 55% of Canadian households reported having an air conditioner, with high use in Manitoba (80%), Ontario (78%), Saskatchewan (67%), and Quebec (54%) and lower use in Prince Edward Island (23%), British Columbia (21%), and Newfoundland and Labrador (9%).[46] In Europe, home air conditioning is generally less common. Southern European countries such as Greece have seen a wide proliferation of home air-conditioning units in recent years.[47] In another southern European country, Malta, it is estimated that around 55% of households have an air conditioner installed.[48] In India AC sales have dropped by 40% [clarification needed] due to higher costs and stricter energy efficiency regulations.[49]

text: Process applications[edit]

text: Process applications aim to provide a suitable environment for a process being carried out, regardless of internal heat and humidity loads and external weather conditions. It is the needs of the process that determine conditions, not human preference. Process applications include these:

text:
Chemical and biological laboratories
Cleanrooms for the production of integrated circuits, pharmaceuticals, and the like, in which very high levels of air cleanliness and control of temperature and humidity are required for the success of the process.
Environmental control of data centers
Facilities for breeding laboratory animals. Since many animals normally reproduce only in spring, holding them in rooms in which conditions mirror those of spring all year can cause them to reproduce year-round.
Food cooking and processing areas
Hospital operating theatres, in which air is filtered to high levels to reduce infection risk and the humidity controlled to limit patient dehydration. Although temperatures are often in the comfort range, some specialist procedures, such as open heart surgery, require low temperatures (about 18 °C, 64 °F) and others, such as neonatal, relatively high temperatures (about 28 °C, 82 °F).
Industrial environments
Mining
Nuclear power facilities
Physical testing facilities
Plants and farm growing areas
Textile manufacturing

text: In both comfort and process applications, the objective may be to not only control temperature, but also humidity, air quality, and air movement from space to space.

text: Health effects[edit]

text: Air-conditioning systems can promote the growth and spread of microorganisms,[50] such as Legionella pneumophila, the infectious agent responsible for Legionnaires' disease, or thermophilic actinomycetes; however, this is only prevalent in poorly maintained water cooling towers. As long as the cooling tower is kept clean (usually by means of a chlorine treatment), these health hazards can be avoided or reduced.

text: Conversely, 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. Excessive air conditioning can have a negative effect on skin, causing it to dry out, and can also cause dehydration.[citation needed]

text: Environmental impacts[edit]

text: Power consumption[edit]

text: Innovation in air conditioning technologies continues, with much recent emphasis placed on energy efficiency. Production of the electricity used to operate air conditioners has an environmental impact, including the release of greenhouse gases.

text: Cylinder unloaders are a method of load control used mainly in commercial air conditioning systems. [51] On a semi-hermetic (or open) compressor, the heads can be fitted with unloaders which remove a portion of the load from the compressor so that it can run better when full cooling is not needed. Unloaders can be electrical or mechanical.

text: Use of programmable thermostats[edit]

text: In the United States, 87 percent of the homes use air conditioning and 65 percent of those homes having central air conditioning. Most of the homes with central air conditioning have programmable thermostats, but approximately two-thirds of the homes with central air do not use the features of them to make their homes more energy efficient.[52]

text: Automobile power consumption[edit]

text: In an automobile, the A/C system will use around 4 horsepower (3 kW) of the engine's power, thus increasing fuel consumption of the vehicle.[53]

text: Refrigerants[edit]

text: Most refrigerants used for air conditioning contribute to global warming, and many also deplete the ozone layer.[54] CFCs, HCFCs, and HFCs are potent greenhouse gases when leaked to the atmosphere.

text: The use of CFC as a refrigerant was once common, including the refrigerants R-11 and R-12 (sold under the brand name Freon-12). Freon refrigerants were commonly used during the 20th century in air conditioners due to their superior stability and safety properties. When they are released accidentally or deliberately, these chlorine-bearing refrigerants eventually reach the upper atmosphere.[55] Once the refrigerant reaches the stratosphere, UV radiation from the Sun homolytically cleaves the chlorine-carbon bond, yielding a chlorine radical. These chlorine radicals catalyze the breakdown of ozone into diatomic oxygen, depleting the ozone layer that shields the Earth's surface from strong UV radiation. Each chlorine radical remains active as a catalyst until it binds with another radical, forming a stable molecule and quenching the chain reaction.

text: Prior to 1994, most automotive air conditioning systems used R-12 as a refrigerant. It was replaced with R-134a refrigerant, which has no ozone depletion potential. Old R-12 systems can be retrofitted to R-134a by a complete flush and filter/dryer replacement to remove the mineral oil, which is not compatible with R-134a.

text: R22 (also known as HCFC-22) has a global warming potential about 1,800 times higher than CO2.[56] It was phased out for use in new equipment by 2010, and is to be completely discontinued by 2020. Although these gasses can be recycled when air conditioning units are disposed of, uncontrolled dumping and leaking can release gas directly into the atmosphere.

text: In the UK, the Ozone Regulations[57] came into force in 2000 and banned the use of ozone depleting HCFC refrigerants such as R22 in new systems. The Regulation banned the use of R22 as a "top-up" fluid for maintenance between 2010 (for virgin fluid) and 2015 (for recycled fluid). This means that equipment that uses R22 can still operate, as long as it does not leak. Although R22 is now banned, units that use the refrigerant can still be serviced and maintained.[58]

text: The manufacture and use of CFCs has been banned or severely restricted due to concerns about ozone depletion (see also Montreal Protocol).[59][60] In light of these environmental concerns, beginning on November 14, 1994, the U.S. Environmental Protection Agency has restricted the sale, possession and use of refrigerant to only licensed technicians, per rules under sections 608 and 609 of the Clean Air Act.[61]

text: As an alternative to conventional refrigerants, other gases, such as CO2 (R-744), have been proposed.[62] R-744 is being adopted as a refrigerant in Europe and Japan. It is an effective refrigerant with a global warming potential of 1, but it must use higher compression to produce an equivalent cooling effect.[citation needed]

text: In 1992, a non-governmental organization, Greenpeace, was spurred by corporate executive policies and requested that a European lab find substitute refrigerants. This led to two alternatives, one a blend of propane (R290) and isobutane (R600a), and one of pure isobutane.[17][20] Industry resisted change in Europe until 1993, and in the U.S. until 2011, despite some supportive steps in 2004 and 2008 (see Refrigerant Development above).[25][63]