Heating & Air Condition Repairs at West Coast Tire and Service

AUTOMOTIVE SERVICES

• Car Repairs
• Diagnosis
• Maintenance
• Oil Change
• Tune Up
• Wheel Alignment

The heating, ventilation, and air conditioning (HVAC) system is designed to help keep the interior of your vehicle nice and cool on hot summer days and toasty warm in the winter. There are two parts to this system, one for heating and one for cooling. A variable speed fan is used to circulate the temperature-controlled air into the passenger compartment. The knobs and vents on your dashboard help you determine how much air is released into the cabin and where you want it directed.

The heating system uses hot coolant from the engine to warm the air discharged from the heating ducts. Hot coolant flows through the heater core and warms it up. When the air moves past the hot heater core, it is warmed before being distributed out of the vents on your dashboard.



All AC (refrigeration) systems-in your car, your office, and even your refrigerator-use the same thermodynamic principles. When gas expands, it absorbs heat. When heat is dissipated from a hot gas it condenses to its liquid state. AC refrigerant is a chemical that can change from a gas to a liquid and back again at moderate temperatures and pressures. As the refrigerant transitions between liquid and gaseous forms, heat is removed from the passenger compartment and released to the outside air, which helps to cool the cabin.

There are two different types of refrigerant used in automotive AC systems:

• R12 (Freon) was invented in 1928 and discontinued in the early 1990s after it was found to have significant ozone layer-depletion properties
• R134a is a more environmentally friendly option to R12 that is used in modern cars and to recharge AC systems in older cars.

The AC system consists of five components:

• The compressor, the heart of the system, is a belt driven, or electrically operated pump. Here, warm, gaseous refrigerant is compressed into a hot gas before traveling to the condenser.
• The condenser is where the heat dissipation occurs. The air moving past the condenser absorbs heat from the refrigerant flowing through it. As the gaseous refrigerant cools, it changes to its liquid state.
• The receiver/dryer functions as a refrigerant filter, removing moisture and most contaminants.
• The orifice tube/expansion valve is a device that regulates how much refrigerant is released into the evaporator. As liquid refrigerant passes through the orifice tube/expansion valve, it expands and becomes partly vaporized, which cools it off rapidly.
• The evaporator removes heat from the air inside the vehicle. As refrigerant enters the bottom of the evaporator, it continues its vaporization, which cools the entire evaporator. The cooled evaporator then absorbs heat from the air moving past it. The cool air is released into the passenger compartment via the vents on the dashboard while the heat is carried off with the gaseous refrigerant and sucked back into the compressor, so the cycle can begin again.

Using the AC system places extra load on the engine. If your vehicle begins to overheat, turn off the AC. If the engine continues to overheat, turn the heater on high-its small radiator will help cool the engine. If the engine does not cool down, immediately pull over to a safe location and turn off the engine. Overheating can severely damage your engine.