2012 Delmar, Cengage LearningHeating and Air-Conditioning FundamentalsChapter 35 2012 Delmar, Cengage LearningO!e"ti#es$%&plain re'rigeration 'undamentals$Des"rie the di''eren"e et(een the high and lo( sides o' the s)stem$List the ma!or heating and air-"onditioning parts and des"rie their operation 2012 Delmar, Cengage Learning*ntrodu"tion$+his "hapter "o#ers,-.asi" operation and ser#i"e o' heating and air-"onditioning s)stems$%mphasis on learning s)stem operation and per'orming minor ser#i"e and diagnosti" pro"edures 2012 Delmar, Cengage Learning/our"es o' Heat$+he s)stem adds heat in the (inter-0emo#es it in the summer$/our"es o' heat-1assengers-Outside air-0oad-%ngine-Catal)ti" "on#erter-/unlight 2012 Delmar, Cengage Learning2entilation$Fresh air repla"es stale air-1re#ents "aron mono&ide 'rom e&haust$Air du"ts allo( outside air into interior-Does not (or3 (hen "ar is slo(ed or stopped-%le"tri"all) dri#en lo(er motor and s4uirrel "age 'an rings outside air in$.lo(er runs at lo( speed (hen ignition 3e) is on-5aintains 'resh air in "ar interior-Creates positi#e "ain pressure 2012 Delmar, Cengage LearningHeating$%ngine "oolant is routed to heater "ore-Air passes o#er 'ins o' the heater "ore 2012 Delmar, Cengage LearningAir Distriution /)stem$5o#es heat et(een di''erent lo"ations-Controls air #olume, temperature, 4ualit), and lo"ation$1lenum housing, "ase asseml)-Comined or split$Air doors-Open and "lose to "ontrol air 'lo($Caron air 'ilter-O'ten repla"ed (ith s"reens$Control head, rela)s A6C s)stem demands 2012 Delmar, Cengage LearningAir Conditioning$Air in passenger "ompartment is "ooled, dried, and "ir"ulated-Heat is remo#ed 'rom inside to outside$5odern "ars get etter 'ree(a) 'uel e"onom) (ith (indo(s up and air-"onditioning on-Ao#e 70 mph, more gas used (ith (indo(s do(n 2012 Delmar, Cengage LearningAir-Conditioning 1rin"iples$5ust e a trans'er o'heat 'or re'rigerant to "hange state-Li4uid asors heat as "hanges to gas-2apor releases heat as "hanges to li4uid 2012 Delmar, Cengage LearningHeat +rans'er$Heat 'lo(s to an)thing (ith less heat-Con#e"tion$Heat rises$Heat al(a)s 'lo(s 'rom hot to "old-0adiation$%&ample, heat 'rom the sun-%#aporation$5oisture asors heat as it is #apori8ed$%&ample, perspiration 2012 Delmar, Cengage LearningHumidit)$Lo( humidit) -1ermits heat to e ta3en a(a) 'rom the human od)$%#aporation and perspiration$High humidit) -5a3es e#aporation di''i"ult$1eople 'eel as "om'ortale at 9:;F (ith 30< humidit) as at 92;F at :0< humidit) 2012 Delmar, Cengage Learning/tates o' 5atter$Common matter e&ists in three states depending on temperature-/olid -Li4uid-=as$/olid heated ao#e 'ree8ing melts-.e"omes a li4uid 2012 Delmar, Cengage LearningLatent Heat$/ensile heat -=oes into matter $0esults in temperature in"rease$Latent heat -%&tra heat re4uired 'or matter to "hange state$Cannot e re"orded on a thermometer$Additional "on"epts->uantit) o' heat-2apori8ation-Condensation 2012 Delmar, Cengage Learning 2012 Delmar, Cengage LearningAir-Conditioning /)stem Operation$Closed s)stem -Four ma!or de#i"es$Compressor$Condenser$%#aporator$5etering de#i"e-0e'rigerant "ir"ulates among de#i"es-Changing pressure and state o' re'rigerant regulates "ooling ")"le operation-Four stages, "ompression, "ondensation, e&pansion, and #apori8ation 2012 Delmar, Cengage LearningAsoring Heat$1ro"ess-Li4uid re'rigerant is "ir"ulated to the e#aporator$Loses pressure as it e&its the metering de#i"e$Asors heat 'rom inside o' "ar $.oils and #apori8es-1ressuri8ed again$=i#es o'' heat to outside air$%a"h ")"le through e#aporator asors at least 25; o' heat 'rom air lo(ing a"ross it 2012 Delmar, Cengage Learning0edu"ing Humidit)$/our"es-Outside air-.reathing o' passengers$5oisture in the air "ondenses on e#aporator 'ins-Drained o'' through the 'loor as (ater$/)stem does not "ool air as mu"h (hen humidit) is high$De'roster operation -Dried "ool air mo#es through heater "ore e'ore it is lo(n onto the (indshield 2012 Delmar, Cengage LearningCompressing the 0e'rigerant$2apori8ed re'rigerant pulled 'rom e#aporator to "ompressor-Compressors are dri#en ) a elt 'rom the "ran3sha't$1ressuri8es heated re'rigerant, in"reasing its temperature$Compressor "lut"h-%le"tromagneti" "lut"h "onne"ts and dis"onne"ts 'rom the "ran3sha't pulle) 2012 Delmar, Cengage Learning 2012 Delmar, Cengage Learning+rans'erring 0e'rigerant Heat to Outside Air$0e'rigerant is pumped 'rom "ompressor to "ondenser-Condenser is a radiator 'or re'rigerant$+rans'ers heat to "ooler air lo(ing through it$1ressuri8ed re'rigerant is "ooled 'rom gas to (arm li4uid$0e'rigerant must e hotter than the air "oming a"ross the "ondenser-Condenser design$/e#eral designs 2012 Delmar, Cengage Learning 2012 Delmar, Cengage LearningFlo( Control De#i"es$/)stems to "ontrol re'rigerant 'lo(-+hermostati" e&pansion #al#e-Ori'i"e tue$0estri"tion raises pressure in s)stem-Flo( "ontrol de#i"e lets the pressure o'' re'rigerant as it 'lo(s to the e#aporator$+?2 "ontrols amount o' re'rigerant 'lo(ing to e#aporator$Ori'i"e tue ")"les the "ompressor "lut"h 2012 Delmar, Cengage LearningAir-Conditioning Compressors$Compressor designs-/e#eral t)pes$A&ial "ompressor has 'our or more ")linders-/(ash plate, a&ial plate "onne"ted to dri#e sha't-@ole plate, (oles in pla"e$2ariale displa"ement "ompressors, no "lut"h ")"ling$0adial "ompressor, multiple ")linders (ith pistons and a s"ot"h )o3e 2012 Delmar, Cengage LearningAir-Conditioner Compressors A"ontBdCD$/"roll "ompressor -5o#eale s"roll os"illates around a 'i&ed s"roll$0otar) #ane -.lades li3e po(er steering pump$%le"tri" "ompressors-1ressuri8e the air-"onditioning s)stem so the engine does not ha#e to e run$Esed in h)rids 2012 Delmar, Cengage LearningCompressor Luri"ation$/imilar to t(o-stro3e gasoline engines-Luri"ated ) oil "arried in re'rigerant-Heat trans'er diminished (hen oil 'lo(s (ith re'rigerant-Fe(er designs 3eep oil (ithin the "ompressor 2012 Delmar, Cengage Learning5u''ler$/ome s)stems ha#e a mu''ler installed on the "ompressor outlet-Due to pumping noises due to high or lo( side pressure #irations 'rom multiple pistons 2012 Delmar, Cengage LearningA""umulator or 0e"ei#er6Dr)er$.oth de#i"es ha#e a desi""ant -0emo#es moisture$0e"ei#er6dr)er-Lo"ated on high-pressure side$%nsures that pure li4uid re'rigerant supplied to e&pansion #al#e$A""umulator-Lo"ated on lo(-pressure side$A""umulates li4uid and lets it e"ome #apor e'ore it goes a"3 in 2012 Delmar, Cengage Learning 2012 Delmar, Cengage Learning%#aporator *"ing Control$+hermostati" s(it"h- +ue "ontaining mer"ur) or CO2 senses temperature$+urns o'' "ompressor "lut"h (hen temperature drops to 32;F$1ressure ")"ling s(it"h -+emperature predi"ted ) pressure o' re'rigerant-5ounted on a""umulator at e#aporator outlet 2012 Delmar, Cengage Learning/)stem /(it"hes$*n"lude,-Amient temperature s(it"h 3eeps "ompressor 'rom (or3ing (hen outside temperature "old-Lo(-pressure "utout s(it"h pre#ents s)stem 'rom operating (ith too little re'rigerant-High-pressure "utout s(it"h shuts o'' "ompressor i' dis"harge pressure too high-1ressure relie' #al#e leeds o'' pressure-Cuto'' s(it"h shuts o'' "lut"h during @O+ operation-Air-"onditioning "ontrol s(it"h 2012 Delmar, Cengage LearningHeating and Air-Conditioning Controls$5anuall) "ontrolled air "onditioning-5anual "ontrol s)stem "ontrolled ) the dri#er$/emiautomati" temperature "ontrol s)stems-Dis"harge temperature is automati"all) "ontrolled$Automati" temperature "ontrol s)stems-Dri#er sets desired temperature$Automati" lo(er "ontrol-.lo(er is pulse-(idth modulated-*nter#al determined ) the programmer 2012 Delmar, Cengage LearningAutomati" Air-Conditioning /ensors$/ensor inputs ma&imi8e s)stem per'orman"e-Outside air temperature AOA+D sensor denies "ompressor operation et(een 35;F and 75;F-/unload sensor opens lend door and spins the lo(er 'aster in response to sunlight intensit)-Dis"harge du"t temperature sensor senses the temperature o' air lea#ing the du"t-*nterior temperature sensor is sometimes used 'or the 'irst 'e( minutes o' #ehi"le operation 2012 Delmar, Cengage Learning0e'rigerants and the %n#ironment$30< o' released CFCs are 'rom moile air-"onditioning sour"es-5ost o' the prolem 'rom repair and ser#i"e$Older "ars use 0-12 re'rigerants-0e"o#ered and re")"led$Cars toda) use 0-137A re'rigerant-Does not deplete o8one la)er$/till a greenhouse gas-70 million pounds per )ear lea3 into atmosphere 2012 Delmar, Cengage Learning 2012 Delmar, Cengage Learning+emperature and 1ressure$Atmosphere "onsists mostl) o' o&)gen and nitrogen-%&tends G00 miles ao#e %arthHs sur'a"e$1ressure gauges read 8ero regardless o' a"tual pressure-2a"uum is measured in in"hes o' mer"ur) -/trongest #a"uum possile on %arth is 30 inC Hg$0elationship et(een oiling point and pressure -Di''erent 'or e#er) li4uid-*n"reasing pressure in"reases oiling point