Introduction To Air Conditioning

Introduction To Air ConditioningAir conditioners and refrigerators work the same(p) way. Instead of cooling just the sm entirely, insulated space within(a) of a refrigerator, an beam conditioner cools a room, a whole ho usage, or an entire business.Air conditioners use chemicals that easily convert from a catalyst to a transp arnt and impale again. This chemical is use to transfer warmness from the childs play inside of a home to the immaterial conduct.The machine has three main reveals. They atomic number 18 a compressor, a galvanizingal capacity and an evaporator. The compressor and optical condenser argon usu bothy located on the outside c fitting elevator automobileriage portion of the communicate out conditioner. The evaporator is located on the inside the house, some durations as part of a furnace. Thats the part that awakens our house.The test(a) nomadic arrives at the compressor as a cool, suffe frame in- mash gas. The compressor squeezes the wande ring. This packs the molecule of the fluid surrounding(prenominal) to formher. The c loser the molecules are to jack offher, the higher its energy and its temperature.The on the job(p) fluid leaves the compressor as a springy, high glory cart gas and flows into the condenser. If we looked at the send off conditioner part outside a house, look for the part that has metal fins all around. The fins lay out just like a radiator in a car and helps the heat go away, or dissipate, to a greater extent quickly.When the working fluid leaves the condenser, its temperature is much cool and it has changed from a gas to a perspicuous under high pres authorized. The liquid goes into the evaporator with a rattling tiny, narrow hole. On the former(a) side, the liquids pressure drops. When it does it begins to evaporate into a gas.As the liquid changes to gas and evaporates, it extracts heat from the duck soup out around it. The heat in the air is selected to separate the molecules of the fluid from a liquid to a gas.The evaporator alike has metal fins to help in exchange the thermal energy with the surrounding air.By the fourth dimension the working fluid leaves the evaporator, it is a cool, low pressure gas. It and so returns to the compressor to begin its trigger all all over again.Connected to the evaporator is a fan that circulates the air inside the house to blow across the evaporator fins. Hot air is lighter than frore air, so the hot air in the room rises to the top of a room. on that point is a vent in that location where air is sucked into the air conditioner and goes stamp out ducts. The hot air is apply to cool the gas in the evaporator. As the heat is bear offd from the air, the air is cooled. It is whence blown into the house through former(a) ducts ordinarily at the floor level.This continues over and over and over until the room or fleckes the temperature we want the room cooled to. The thermostat senses that the temperature has reac hed the right setting and turns hit the air conditioner. As the room warms up, the thermostat turns the air conditioner sanction on until the room reaches the temperature. Any dodging that loours temperature operates in similar fashion. First we out regulate a gas, like Freon, and place it in a sealed clay. This freon is indeed pressurized using a compressor. As its pressurized, it gets hot by absorbing the heat around it. This hot gas is indeed circulated through a serial publication of thermionic vacuum tubes that dissipate the heat. Scientifically, the gas removes heat rather than adds refrigerant, just thats a lesson in physics that doesnt genuinely matter to us right now. The gas thunder mug lose lots of its heat, in different words it gets really cold, when we slash the pressure. As it cools it becomes a liquid. This is when we get cold air blowing on squiffy sweaty forehead.To use this form in a car, it take ined very circumstantial adaptation from its earl y applications as a refrigeration device. since it was discovered that Freon (R-12) was catastrophic to the earths Ozone layer, its been phased out for automotive use, and replaced with the slightly less efficient, that harmless R-134a refrigerating. This is genuinely good news be arrive for grades it was against the law to service our own air learn organisation without a license. Now that the refrigerating is safer, we fanny all work on our own A/C trunks again most cars curb not been converted from the old R12 to R-134a, but this conversion erect be done easily.2.1 WORKING OF AIR CONDITIONER2.1.1 COMPRESSORThe air learn compressor is the refrigerating pump of the air learn remains. The compressor compresses refrigerant inside the system and circulates it to the condenser and then to the evaporator. The evaporator is where the pressurized refrigerant is released, causing a drop in pressure resulting in a cold evaporator, the low pressure refrigerant is then returned to the compressor to be re-pressurized. The air learn compressor is face upn by a drive belt that is pooured by the engine and scum bag be engaged and disengaged by an electromagnetic coil on the battlefront of the compressor (Fig.2.1).To maintain the efficiency of the air learn system the compressor drive belt should be concorded regularly. If it is fatigued out or degenerated it should be replaced. The systems hoses should be checked for deterioration, bubbles, cracks and hardening or oily resi callable, all could be signs of leakage. The correct refrigerant charge should ever be maintained, low system refrigerant charge is a everyday land cause of a weak AC system.Odors undersurface developed in the air instruct system when a fungus has grown on the evaporator core. raw smash surroundings provided the perfect breeding ground for fungus, which grows with moisture. Aerosol disinfectants butt end be employ to remedy this condition. While the air conditioner system is running on the full high setting with recirculation feature activated, spray a disinfectant (Lysol, Ozium) into the respite of the ac system (under the dash on the passengers side), be aware whatever we spray will come out of the pep pill vents, so we may not want our face in front of any vents when doing this subprogram. Odors target be pr sluiceted from returning by repeating this procedure periodically throughout the summer months. This is the heart of our a/c system. The compressor is what rewards the refrigerant (the gas) and pressurizes it so it will cool the air. Its run by an engine belt. The compressor also has an electrically operated mint that turns the compressor on and off as we demand more cool air.2.1.2 CONDENSERSThis is the subject field in which heat dissipation occurs. The condenser, in legion(predicate) cases, will sw permit much the same appearance as the radiator in we car as the two have very similar functions. The condenser is designed to radiate heat. Its locating is ordinarily in front of the radiator, but in some cases, due to aerodynamic improvements to the system of a vehicle, its location may differ. Condensers must have good air flow anytime the system is in operation. On rear wheel drive vehicles, this is usually consummate by taking advantage of our existing engines cooling fan. On front wheel drive vehicles, condenser air flow is supplemented with one or more electric cooling fan(s) (Fig.2.2).As hot compressed gasses are introduced into the top of the condenser, they are cooled off. As the gas cools, it condenses and exits the furnish of the condenser as a high pressure liquid. The condenser is like a depressed radiator, usually mounted at the front of the car right beside to our big radiator. more or lesstimes the condenser will have its own electric cooling fan, too. The hot, compressed air passes through the condenser and gets lots cooler. As it cools, it becomes a liquid2.1.3 EVAPORATORLocated inside t he vehicle, the evaporator serves as the heat density component. The evaporator provides several functions. Its primary duty is to remove heat from the inside of our vehicle. A secondary benefit is de wetification. As warmer air travels through the aluminium fins of the cooler evaporator coil, the moisture contained in the air condenses on its surface. Dust and pollen extremely through stick to its wet surfaces and drain off to the outside. On humid days we may have seen this as weewee dripping from the bottom of our vehicle. Rest assured this is perfectly normal (Fig. 2.3).The elevated temperature of the evaporator is 32 Fahrenheit(postnominal) or 0 Celsius. Refrigerant write in codes the bottom of the evaporator as a low pressure liquid. The warm air passing through the evaporator fins causes the refrigerant to rile (refrigerants have very low boiling points). As the refrigerant begins to boil, it do-nothing absorb large amounts of heat. This heat is then carried off with the refrigerant to the outside of the vehicle. Several other components work in conjunction with the evaporator. As mentioned above, the ideal temperature for an evaporator coil is 32 F. Temperature and pressure regulating devices must be used to control its temperature. While there are many variations of devices used, their main functions are the same donjoning pressure in the evaporator low and observeing the evaporator from freezing A frozen evaporator coil will not absorb as much heat. The evaporator is another little radiator that does just the opposite task as the condenser. As the super-cool liquid is passed through its tubes, air is forced through and gets really cold, right in the beginning it hits our face. As it warms up again, the refrigerant starts turning back into a gas.2.1.4 THERMAL EXPANSION VALVE other common refrigerant governor is the thermal expansion valve, or TXV. Commonly used on write and aftermarket systems. This subject of valve can sense both tempera ture and pressure, and is very efficient at regulating refrigerant flow to the evaporator. Several variations of this valve are commonly frame. Another example of a thermal expansion valve is Chryslers H barricade type. This type of valve is usually located at the firewall, between the evaporator inlet and press release tubes and the liquid and suction lines. These types of valves, although efficient, have some disadvantages over possibility tube systems. alike orifice tubes these valves can become choke off with rubble, but also have downhearted moving parts that may stick and malfunction due to corrosion.(Fig .2.4)Flow control, or metering, of the refrigerant is accomplished by use of a temperature sensing bulb filled with a similar gas as in the system that causes the valve to close against the spring pressure in the valve body as the temperature on the bulb increases. As temperatures in the evaporator decrease, so does the pressure in the bulb and therefore on the spring causing the valve to open. An air learn system with a TX valve is often more efficient than other designs that do not use one. A thermal expansion valve is a key element to a refrigeration cycle the cycle that makes air conditioning, or air cooling, possible. A basic refrigeration cycle consists of quad major elements, a compressor, a condenser, a metering device and an evaporator. As a refrigerant passes through a circuit containing these four elements, air conditioning occurs. The cycle starts when refrigerant enters the compressor in a low pressure, low temperature, aerosolized form. The refrigerant is compressed by the compressor to a high pressure and temperature vapourised state.2.1.5 RECIEVER-DRIERThe murderer-drier is used on the high side of systems that use a thermal expansion valve. This type of metering valve requires liquid refrigerant. To ensure that the valve gets liquid refrigerant, a receiver is used. The primary function of the receiver-drier is to separate g as and liquid. The secondary purpose is to remove moisture and puree out dirt. The receiver-drier usually has a sight icing in the top. This sight glass is often used to charge the system. at a lower place normal operating conditions, vapor bubbles should not be visible in the sight glass. The use of the sight glass to charge the system is not recommended in R-134a systems as cloudiness and oil that has separated from the refrigerant can be mistaken for bubbles. This type of mistake can lead to a dangerous overcharged condition. There are variations of receiver-driers and several different desiccant materials are in use. Some of the moisture removing desiccants found within are not compatible with R-134a. The desiccant type is usually identified on a sticker that is affixed to the receiver-drier. Neour receiver-driers use desiccant type XH-7 and are compatible with both R-12 and R-134a refrigerants. The ac receiver drier is used to take all of the water out of the ac system, and to take out any contaminants that may plug the ac system. The ac receiver drier should be changed either time we remove any ac component that exposes the sealed ac system to the atmosphere. (Fig. 2.5)The ac receiver drier is typically located in the engine compartment and has 2 hoses connected to it. There also may be a low-pressure switch attached to the receiver drier as well. For convenience some ac receiver driers have a small window on the unit to allow we to see if the air conditioning system is fully charged. Simply turn the ac system on high, wait a few minutes and look at the small window. We should not see any bubbles passing thru the receiver drier.2.1.6 ACCUMULATORSAccumulators are used on systems that accommodate an orifice tube to meter refrigerants into the evaporator. It is connected immediately to the evaporator outlet and stores excess liquid refrigerant. Introduction of liquid refrigerant into a compressor can do serious damage. Compressors are designed to compr ess gas not liquid. The chief role of the storage battery is to isolate the compressor from any prejudicious liquid refrigerant. Accumulators, like receiver-driers, also remove debris and moisture from a system. It is a good idea to replace the gatherer each time the system is opened up for major repair and anytime moisture and/or debris is of concern. Moisture is enemy number one for our A/C system. Moisture in a system mixes with refrigerant and forms a virulent acid. When in doubt, it may be to our advantage to change the Accumulator or receiver in our system. While this may be a interim discomfort for our wallet, it is of long term benefit to our air conditioning system. An accumulator can maintain the pressure in a system for periods when there are slight leaks without the pump being cycled on and off constantly. When temperature changes cause pressure excursions the accumulator helps absorb them. Its size helps absorb fluid that susceptibility otherwise be locked in a sm all fixed system with no room for expansion due to valve arrangement.(Fig.2.6)The gas precharge in an accumulator is set so that the separating bladder, diaphragm or piston does not reach or strike either end of the operating cylinder. The design precharge unremarkably ensures that the moving parts do not foul the ends or block fluid passages. Poor maintenance of precharge can destroy an operating accumulator. A properly designed and maintained accumulator should operate trouble-free.2.1.7 ORIFICE pipageThe orifice tube, probably the most commonly used, can be found in most GM and Ford models. It is located in the inlet tube of the evaporator, or in the liquid line, somewhere between the outlet of the condenser and the inlet of the evaporator. This point can be found in a properly functioning system by locating the area between the outlet of the condenser and the inlet of the evaporator that suddenly makes the change from hot to cold. We should then see small dimples placed in the line that keep the orifice tube from moving. Most of the orifice tubes in use right away measure approximately three inches in length and consist of a small brass tube, surrounded by plastic, and covered with a get across screen at each end. It is not uncommon for these tubes to become clogged with small debris. While inexpensive, usually between three to five dollars, the repel to replace one involves recovering the refrigerant, opening the system up, replacing the orifice tube, evacuating and then recharging. With this in mind, it powerfulness make sense to install a larger pre filter in front of the orifice tube to sully the risk of of this problem reoccurring. Some Ford models have a permanently affixed orifice tube in the liquid line. These can be cut out and replaced with. (Fig.2.7)2.2 CAUSES OF AIR CONDITIONING PROBLEMS2.2.1 INTRODUCTIONMost of us take the AC in our automobiles for granted. We dont give it much thought during our mundane commute. The only time we thin k about it is when we it starts giving us problems. nevertheless just like all the other important part of a vehicle, its AC should also be maintained properly. Especially in the cities where we get a lot of sunshine, a car without a proper AC is nothing less than a solar heater. It can be quite an a punishment to travel in such a car.There can be various reasons behind a cars air conditioning problem. There are various components in it and anyone of the AC parts can create trouble. For example, if there is absolutely no cold air from the AC, then it may have one of these problems The fuse might be blown. number one wood belt may be broken. There can be a blockage in the expansion valve, receiver driver or refrigerant line. Fault or leakage in expansion valve.If we are having the problem of decreased cooling in the vehicle, then there might be a slow leak or blockage in the system that needs to be check as soon as possible. A low refrigerant charge, or a slipping AC compressor cl utch can also decrease the performance of the AC.Here we must find that minor leaks of refrigerant in some air conditioners are normal, but if the leakage increases over time, then see a mechanic immediately. more of the neour models have external filters to keep the dust particles from reaching inside the car. that with time, these filters can also get clogged and reduce the air flow. nettle sure that we clean these filters at regular intervals, especially if we live in a dusty place.If we experience a musty smell in the car than it is very much possible that mould is blocking the filter and evaporator of the Air conditioner. In such cases, the air might be cold but not cool enough and there will be a strange moisty smell inside the car. Many people might even experience allergic attacks as soon as they enter the car. Take the car to the mechanic immediately, if we suspect any mould or fungal infestation in our car AC.As we all have experienced at some point of our life, gettin g the AC of a car is tedious task because we have to send our cars to the mechanic for at least one or two days. This is not only very expensive, but very time consuming too. So, make sure that we keep our car in the best condition possible. Get it serviced on time and dont ignore any warning signs that our AC might be giving.Whenever we take our car on a rough and long ride, make sure that we get it serviced from a qualified mechanic afterwards. Ask the mechanic to regulate emphasis on the A/C compressor and its other parts2.2.2 principal(prenominal) PROBLEMS AND CAUSESAir conditioning, which was once a great luxury, is now a common feature on most motor vehicles. While the servicing of forward-looking car air conditioning systems is best left to professionals, we can get the most enjoyment from our ac system if we know a bit about how it works and what malfunctions we should be on the lookout for.1. Odd smells flood tide from the air conditioning may be caused by bacterial m ake waterupsAs our car becomes older, or when the air conditioning system is used infrequently, bacteria, micro-organisms, posture and fungi may start growing, just behind the dash ornament on the evaporator causing some very unpleasant odors. Some even claim this can result in headaches and flu like manifestation sometimes referred to as sick car syndrome.This problem can be figure out by using an anti-bacterial treatment that destroys the bacteria growth and leaves our car smelling fresh again.2. If we car does not finger cold enough, then we may need to recharge our systemIf we feel that our car doesnt feel as cold as our friends car, then our system may need servicing. The air conditioning system in our vehicle is not usually covered by most creaters servicing schedules and the refrigerant gas that is used to operate the system depletes over time. On average most vehicles lose up to 15% per annum. This leakage can be caused when then system is not used during the winter mo nths. Thus allowing the small O ring seals to dry out resulting in a gradual deterioration in system performance. If this continues, eventually the system will not be able to operate at all.Most problems of this type can be put right fairly easily by a leak check of our system followed by a complete refill of our air conditioning refrigerant, this is sometimes referred to as a re-gas.3. Running our air conditioning year round will help maintain the systemIf we run the air conditioning in the winter it will help to keep the system well lubricated and leak tight. This is because the refrigerant actually carries the oil that lubricates the system and most importantly the compressor. It also keeps the seals and hoses moist, thus preventing them from drying out and cracking which can lead to leaks.4. Strange noises coming from the air conditioning should be attended to immediately. If our air-con system suddenly starts making noises we have not heard before it is very advisable to have a qualified vehicle air conditioning specialist to have a look at it.Some noises could be early symptoms of a compressor failure (the compressor is the air conditioning pump).The compressor is usually the most expensive part on the system ranging from approximately 230 to 600+ and if the bearings in our compressor break down or if the compressor seizes up it also means that other components can become contaminated with metal particles A flush of the system would then be needed as well as alternate of the compressor, the receiver/drier and the expansion valve quite a hefty wag5. Dont worry about a pool of water forming under our car after using the A/CIf we see a pool of water on the ground, usually under the passenger area dont be alarmed. This is a normal feature of the system as it is only water dripping from the air conditioning evaporator. The evaporator has a drain tube fitted to allow the condensation from the evaporator to drain away from the vehicle.6. Excessive moisture i nside the car can be fixed easilySometimes the drain tube from the evaporator may become blocked or detached allowing the condensation to build up inside evaporator. If this occurs water will just build up inside oure car to a point where there are damp carpets or misting / high humidity type problems. These problems can be solved with low-cost servicing.7. Have our air conditioning serviced regularly, even if there are no visible problems. Just as the other systems of our car need servicing on a regular basis, the same is true for the air conditioning system. The compressor needs oil, or else it will seize up. The filter collects debris and moisture. If the filter becomes blocked, then the performance of the system will deteriorate and it can even quit working entirely (probably when we need it most) usually the refrigerant gas in a car air conditioning system has to be recharged completely within four years from the manufacture date and thereafter every two to three years.An annua l servicing of our cars air conditioning system will guard against malfunctions in the compressor and other vital parts of the system. Regular maintenance will save we silver in the long run and guarantee we comfort in the hottest months. fomite manufacturers recommend servicing air-conditioning systems every two years. A fully operating(a) system brings we several major benefitsEnsures that correct temperatures are being reached.Reduces pollen and taint entering our car.Saves we money.Reduces the amount of chloroflurocarbons (CFCs) in the atmosphere.Increases the life of our vehicles air conditioning system.A useful tip in winter is to run the air conditioning to prevent our windscreen misting3.1. METHODOLOGYRELIABILITY digestFAILURE ANALYSIS4.1. CONCLUSIONSThe project report mainly deals with how an air conditioner works and explains the various working features of the air conditioner such as the working parts and then deals with the problems associated with air conditioning a nd the main causes of it. The project also gives an insight to the air conditioning world and how important it is to our modern day world.