Presentation on automobile hvac system

This presentation will introduce the reader about the automobile HVAC system which will very effectively further lay down foundation for his/her further understanding on this topic.Things are explained in logical way so that it is easy to understand and memorise also.

1. Presentation on Automobile hvac system Submitted by:-Kartik Bhardwaj 16162039 6 th sem (B.tech mechanical engg.) Submitted to :-Mr. Paramjit lamba sir Mechanical deptt . GJUS&T,Hisar

2. So what does HVAC stands for? HEATING VENTILATION & AIR CONDITIONING

3. Basic intro of an automotive hvac system “Your HVAC system is nothing more than a heat exchanger.” Heating, ventilation, and air conditioning (HVAC) systems are responsible for providing thermal comfort and fresh air to building occupants. Air conditioning like it says 'conditions' the air. It not only cools it down, but also reduces the moisture content, or humidity. All air conditioners work the same way whether they are installed in a building, or in a car. The fridge or freezer is in a way an air conditioner as well. It consists of refrigerant which circulates within the HVAC system and with the help of condenser and evaporator all the conditioning of cabin air is done.

4. A BRIEF HISTORY ABOUT HVAC Now that you know have basic intro about HVAC let’s know about some history of HVAC. Even early civilizations created ways for their citizens to enjoy conditioned air. Ancient Rome:- Rome was one of the first cities to influence the air within buildings. Rome’s hypocaust system was primarily used to heat the public bathhouses and saunas. A hypocaust would push heated air through a system of air ducts and under raised floors to heat a room. Ancient China:- The Han Dynasty introduce the mechanized rotary fan. A single person could manually cool an entire room using large wheels which engaged a series of interconnected fans. Early America :-Wood burning stoves helped warm early American homes beginning in the mid-1600s. In 1744, Benjamin Franklin created his own version of the cast iron stove. This new stove was more efficient than its predecessor and spread across America as settlers moved west. Advances in HVAC technology continued to improve the way we use conditioned air, and as the years passed, these developments have increased exponentially

5. IMAGE OF HVAC SYSTEM IN AN AUTOMOBILE

6. Components of an automobile hvac system A basic HVAC system of a automobile consists of various components like compressor, evaporator etc with each component having their respective position on the basis of their job. But they can be divided mainly into two types for:- Onboard components Outboard components

7. 0NBOARD COMPONENTS So basically onboard components include those HVAC system component which are located inside of the cabin of an automobile. Those are:- CABIN AIR FILTER BLOWER MOTOR AND FAN EVAPORATOR HEATER CORE

8. IMAGE OF ONBOARD COMPONENTS

9. OUTBOARD COMPONENTS Continuing on that outboard components include those HVAC system component which are located outside of the cabin of an automobile. Those are:- AC COMPRESSOR CONDENSOR ORIFICE/EXPANSION VALVE RECEIVER DRYER/ACCUMULATOR

10. IMAGE OF OUTBOARD COMPONENTS

11. ABOUT EACH COMPONENTS OF HVAC SYSTEM

12. ONBOARD Components :- Blower motor and fan:- A blower motor is the component within a car’s HVAC system. The motor blows heated air through vents when the heating system is in use. Conversely, some blower motors blow cold air when the air conditioning system is in use. There are two main types of blower motors: single-speed motors and variable-speed motors. Single-speed blower motors blow air at one speed. Variable-speed motors adjust their speed to blow air at varying speed levels. A properly functioning blower motor remains a critical component of your home’s HVAC system. The blow motor is vital in maintaining a comfortable temperature within your car. Cabin air filter:- The primary purpose of cabin air filters, located on most vehicles since 2000, is keeping the air inside your vehicle’s cabin clean. It’s typically located behind the glove compartment. Its job is to filter all of the air that comes through the car’s HVAC system to prevent pollutants, such as dust, pollen, smog from entering.

13. Evaporator coils:- The  A/C evaporator , or evaporator core, works as a heat exchange within a vehicle's engine.Evaporators are usually made of aluminum . They look like, and in fact are, similar to radiators, only thicker and smaller in overall size. Like radiators, evaporators consist of a series of internal tubes or “flow paths” with fins attached to them. Air can pass freely through the fins, just like a radiator. But unlike a radiator, where the internal tubes carry moving engine coolant, the passages in the evaporator carry moving refrigerant. Heater core:- A heater core is a  radiator -like device used in heating the cabin of a  vehicle . Hot  coolant  from the vehicle's  engine  is passed through a winding tube of the core, a heat exchanger between coolant and cabin air. Fins attached to the core tubes serve to increase surface for heat transfer to air that is forced past them, by a fan, thereby heating the passenger compartment.

14. Compressor:- Commonly referred to as the heart of the system, the Compressor is typically a belt driven pump that is fastened to the engine or motor. It is responsible for compressing and transferring refrigerant gas. The A/C system is split into two sides, a High pressure side and a Low pressure side; defined as Discharge and Suction. Since the Compressor is basically a pump, it must have an intake side and a discharge side. They are mainly of three types:- Reciprocating Rotary Scroll Condenser:- It is another heat exchanger. The air-conditioning condenser is a radiator positioned between the car’s grille and the engine-cooling radiator in which the gaseous refrigerant sheds heat and returns to a liquid state. The liquid refrigerant flows to the evaporator inside the dashboard, where it cools the cabin.

15. ORIFICE/EXPANSION VALVE:- An expansion valve is an AC component that is commonly found on many road going vehicles. It is usually installed at the evaporator inlet and works together with the orifice tube to regulate the flow of refrigerant through the vehicle’s AC system. Too much refrigerant flow and the evaporator core will freeze over; too little and the evaporator core will overheat and compromise the efficiency of the AC system. The expansion valve meters refrigerant flow according to evaporator temperature and the load and cooling demand of the AC system.  RECEIVER DRYER/ACCUMULATOR:- The receiver-drier’s primary function is to receive and store some liquid refrigerant from the condenser. The liquid refrigerant enters at the top of the receiver and falls to the bottom. A pickup tube with a filter screen extends to the bottom of the receiver-drier. This pickup tube draws liquid refrigerant from the bottom of the receiver-drier. The liquid refrigerant then passes on to the inlet of the thermostatic expansion valve.

16. What about the refrigerant use? Vehicle manufacturers have used two different refrigerants in automotive A/C systems. Most pre-1994 model year vehicles used CFC-12 (also called R-12; most people know it by its most popular brand name,  Freon™ ). It is not the type of refrigerant used in most cars today. You should use the term  refrigerant   not the brand name  when referring to this gas. 1995 and up model year vehicles use HFC-134a  refrigerant , also referred to as R-134a. Many (but not all) older systems that were designed to operate with CFC-12 can be retrofitted to use HFC-134a.

17. IMAGE OF refrigerant CONTAINER

18. THANKYOU! ANY QUESTIONS?