"Are You Getting the Most Out of Your Car Air Conditioning?"
"Air Conditioning Aldershot ( 750+ words)"
[ "                        Are You Getting the Most Out of Your Car Air Conditioning?Your car's air conditioning system is designed to keep you and your passengers comfortable for an extended period. This means that it has to produce enough cool air to overcome the heat generated by all your occupants, plus any luggage or freight in the trunk or back seat. It also needs maximum engine power (which means that the air conditioner compressor cycles off when not required), and it can't cycle on and off too often (which might cause problems with frozen coils)R-12 was used in most vehicle Air Conditioning Aldershot systems from 1954 through 1995. It has a higher boiling point than R-134a, so it works at much lower temperatures--as low as -15 degrees F vs. -26 degrees F for 134a. However, its specific heat is only half as great as 134a's, which means that less heat can be absorbed by each pound of refrigerant when cooling brakes are applied. Even though R-134a is much less effective at low temperatures, it's still about twice as good as R-12 when normal operating temperatures are reached.Another significant difference between the two is that R-134a doesn't need to be mixed with oil before adding it to the system, making R-134a much cheaper than R-12 since you don't have to recover and recharge systems after they're opened (and fixed ones never had this problem). It also means there's less chance of oil contamination if a vehicle leaks 134a into its high-pressure line, which can happen easily because 134a has a lower boiling point than R-12 (which can leave oily deposits in the condenser).R-12 is currently available in the U.S. because of pre-1995 OE stocks, so it's still used in some European cars since they originally came with R-12 systems (and many other countries still require its use). But even though 134a has been used for years around the world, most auto manufacturers are now specifying only 134a refrigerant because of its advantages over 12--especially in newer vehicles.To get the most out of your system:First, make sure it's charged up with R-12 Freon, and you don't have a leak (which requires evacuation and recharging).Clean the condenser every spring before summer driving begins since dirt builds up on the fins during winter storage.Remove any window tinting where the air conditioning lines pass through a window since this restricts airflow and reduces system performance.Check that flexible ducts are not crushed or kinked, restricting airflow and reducing system performance.Don't place objects over or near an air conditioning line or coil, since this could damage them if they overheat. Any object that blocks airflow may also cause compressor motor windings to burn out prematurely (which is ok with R-134a systems).What's so important about checking refrigerant levels?Without refrigerant in it, the car's air conditioning system won't work at all. Once you add refrigerant, the system holds a specific amount and doesn't allow it to escape.That's what differentiates an automotive Air Conditioning Aldershot system from many other types of refrigeration systems, such as home window air conditioners walk-in coolers, and freezers. Home AC units can be left unchanged for a year or more with no problems because they don't operate unless the compressor motor is energized by opening up a start/run contactor--and that only happens when someone turns on the cooling controls. Automotive air conditioners work all the time, whether you're using them or not, so they have to hold their charge forever (or at least as long as your car stays in service) without leaking out.Why do some cars have a belt-driven compressor and others don't?Most car manufacturers switched from belt-drive to other compressors because belts aren't very reliable. They slip, break and stretch, so they wear out quickly. However, some European manufacturers such as Mercedes Benz and Peugeot still use them because they feel that the improved fuel economy you get with belt drive offsets the higher cost and lower reliabilityA belt-driven air conditioning compressor can save weight (and maybe even space) since it's part of the powertrain instead of being mounted separately under the hood. Belt-driven compressors make more noise than other types because they're not mounted solidly and rely on fluid bearings to support the rotating assembly (instead of a solid housing like other compressors). The clutch that engages and disengages the compressor also makes noise." ]