A Cars HVAC SystemWritten by Kevin Schappell
Not only do we depend on our cars to get us where we want to go, we also depend on them to get us there without discomfort. We expect heater to keep us warm when it's cold outside, and air conditioning system to keep us cool when it's hot. We get heat from heater core, sort of a secondary radiator, which is part of car's cooling system. We get air conditioning from car's elaborate air conditioning system. Despite its relatively small size, cooling system has to deal with an enormous amount of heat to protect engine from friction and heat of combustion. The cooling system has to remove about 6,000 BTU of heat per minute. This is a lot more heat than we need to heat a large home in cold weather. It's good to know that some of this heat can be put to useful purpose of keeping us warm. Air conditioning makes driving much more comfortable in hot weather. Your car's air conditioner cleans and dehumidifies (removes excess moisture), outside air entering your car. It also has task of keeping air at temperature you select. These are all big jobs. How do our cars keep our "riding environment" way we like it? Most people think air conditioning system's job is to add "cold" air to interior of car. Actually, there is no such thing as "cold," just an absence of heat, or less heat than our bodies are comfortable with. The job of air conditioning system is really to “remove” heat that makes us uncomfortable, and returns air to car's interior in a "un-heated" condition. Air conditioning, or cooling, is really a process of removing heat from an object (like air). A compressor circulates a liquid refrigerant called Refrigerant-12 (we tend to call it "Freon," a trade name, way we call copy machines "Xerox" machines). The compressor moves Refrigerant-12 from an evaporator, through a condenser and expansion valve, right back to evaporator. The evaporator is right in front of a fan that pulls hot, humid air out of car's interior. The refrigerant makes hot air's moisture condense into drops of water, removing heat from air. Once water is removed, "cool" air is sent back into car's interior. Aaaaaah! Much better. Newer cars have R-134 as refrigerant, but work in same way as R-12.
| | Winter Car CareWritten by Kevin Schappell
As weather turns colder, it is time to think about your car for a second. A little preparation can go a long way to making your winter travels a lot safer. Here is a checklist to get you started. 1.Check antifreeze. The freezing point can be checked with a simple tool available at any auto parts store. Make sure you check antifreeze when it's cool. Opening a hot radiator can be a dangerous thing. 2.Check air pressure in your tires. As air gets cooler pressure drops in your tires. Maintaining your tire pressures will reward you with higher gas mileage and longer tire life. 3.Make sure you have following items in your car. - Ice Scraper
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