CHAPTER 5 Refrigerants and the Environment

CHAPTER 5Refrigerants and the Environment

Automotive Heating and Air Conditioning, 6/e

By Thomas S. Birch

Copyright © 2012, 2010, 2006, 2001, 1997, 1991 Pearson Education

Upper Saddle River, NJ 07458 • All rights reserved.2

KEY TERMS• Blend • Clean Air Act • Drop in • EPA (Environmental Protection Agency) • Fractionation • Glide • Global warming • Global warming potential (GWP)• Greenhouse effect• Greenhouse gases (GHGs) • Heel • Ozone • Ozone depletion potential (ODP)

• Recovery • Recycling • SAE (Society of Automotive Engineers) • Section 609 • Small can• SNAP (Significant New Alternatives Policy) • Stratosphere• Topping off • Vent • Zeotrope


By Thomas S. Birch



After studying Chapter 5, the reader will be able to:1. Discuss the ozone layer and the adverse effects

of a CFC on it. 2. Discuss global warming and the effect of

greenhouse gases. 3. Explain the effects of the Montreal and Kyoto

Protocols on automotive A/C servicing. 4. Understand what refrigerants are and the

important safety concerns related to them.5. Describe what the next generation of HVAC

systems might be.

OBJECTIVES

Objectives (1 of 2)

• Define the term air conditioning.• Discuss the historic developments of modern

refrigeration.• Discuss the advantages of air conditioning in the

automotive industry.• Explain the importance of the ozone layer.• Discuss what the automotive industry is doing about

the ozone depletion problem.• Discuss what the government is doing about the

ozone depletion problem.• Describe how ozone is created.• Describe how ozone is destroyed.

Objectives (2 of 2)

• Discuss the Clean Air Act• Discuss Ozone Protection Regulations• Describe Technician Certification• Explain Special Safety Precautions• Discuss the types of antifreeze/coolant used• Discuss hazardous materials used.• Describe toxic gases


By Thomas S. Birch



R134A

• Combustible at high pressures if mixed with air.• Air Should not used to flush system due to fire or

explosion.


By Thomas S. Birch



INTRODUCTION

• OZONE DEPLETION• GLOBAL WARMING AND GREENHOUSE

GASES


By Thomas S. Birch



Ozone Layer

• Blocks out ultraviolet wavelengths of light generated by the sun

• Ultraviolet light causes skin cancer and cataracts in eyes and damage to immune system

• Damage to plants and vegetables• Plankton and larvae in the sea• Why is it gone? Man made chemicals (Chlorine)

from R-12• Chlorinated fluorocarbon (CFC)


By Thomas S. Birch



Greenhouse gases

• Gas layer traps heat at earth atmosphere• Increasing the temperature of our living area


By Thomas S. Birch



LEGISLATION

• At a conference in Montreal, Canada, in 1987, the United States, along with 22 other countries, agreed to limit the production of ozone-depleting chemicals. • This agreement is referred to as the Montreal

Protocol. • In 1990, President Bush (senior) signed the Clean

Air Act , which phased out the production of CFCs in the United States by the year 2000. • In 1993, the phaseout of CFC-12 was moved

forward; R-12 production in the United States ceased at the end of 1995.


By Thomas S. Birch



LEGISLATION

• Section 609 is a portion of the Clean Air Act that places certain requirements on the mobile vehicle air conditioning (MVAC) service field.• EUROPEAN R-134A PHASEOUT• http://www.macsw.org/AM/Template.cfm?Sectio

n=Section_609

http://www.macsw.org/AM/Template.cfm?Section=Section_609

http://www.macsw.org/AM/Template.cfm?Section=Section_609


By Thomas S. Birch



TECH TIP

• New SAE standards J2788 and J2791 have improved refrigerant recovery/recycling/recharging machine and electronic leak detector performance, which should reduce refrigerant emissions as well as improve HVAC system service.


By Thomas S. Birch



RECOVERY AND RECYCLING

• RECOVERING CONTAMINATED REFRIGERANT• Recovery container should be gray with yellow

top labeled mixed, junk, dirty. Then sent off to firms that specialize in disposal and recovery of mixtures.

• Recovery container recertified every 5 yrs. • Failure to recertify is 25K fine • Air powered recovery for flammables or unknown

mixtures


By Thomas S. Birch



REFRIGERANTS

• ALTERNATE REFRIGERANTS FOR R-12• ALTERNATE REFRIGERANTS, R-134A• COUNTERFEIT AND BOOTLEG

REFRIGERANTS• FUTURE REFRIGERANTS AND SYSTEMS

• R1234yf, R-152A, Co2, HC• REFRIGERANT SAFETY PRECAUTIONS• Europeans will begin ban on R134A in 2011


By Thomas S. Birch



TECH TIP

• A crude but effective way to tell how much refrigerant or, with barbecue grills, propane is in a container is to pour hot water over the container. The heat will warm the top of the container, cause some of the liquid to boil, and increase container pressure, and if you feel along the container, the liquid will cool the lower part. The liquid fills the container to the point of temperature change.


By Thomas S. Birch



SAFETY NOTE

• A wise technician wears safety goggles or a clear face shield and protective clothing (gloves) when working with refrigerants. If refrigerant splashes into your eyes, blindness can occur. If refrigerant splashes into your eye or onto your skin, do not rub that body part; flush it with cool, clean water to restore the temperature. Place sterile gauze over the eye to keep it clean and get professional medical attention immediately.


By Thomas S. Birch



Air Conditioning Defined

• The process by which air is: – Cooled – Heated– Cleaned or filtered– Humidified or Dehumidified– Circulated or Recirculated

Historic developments of modern refrigeration

• 10,000 B.C.– Bleeding water through

pores in barrel• 1910

– First domestic refrigeration• 1940

– Packard uses the first automotive cooling system

• 1960– Cadillac first modern

automotive air conditioning system

Advantages of air conditioning in the automotive industry

• Keeps people fresh and alert for business meetings and personal business

• Reduces allergic reactions• Lowers tension• Meet customer demands for comfort

What Is Ozone?

• Ozone is a molecule of three oxygen atoms bound together (O3).

• It is unstable and highly reactive.• Ozone is used as a bleach, a deodorizing

agent, and a sterilization agent for air and drinking water.

• At low concentrations, it is toxic.

Ozone• Protective ozone lies in

the stratosphere– 9-22 miles (15-35 km)

above the earth• Reduces ultraviolet

(UV) radiation • Created by oxygen and

UV radiation• Destroyed by chlorine

– 1 molecule kills 100,000 molecules of ozone

– Chlorofluorocarbons (CFC)

• freon, halons

Where is Ozone Found? (1 of 2)

• Ozone is found naturally in small concentrations in the stratosphere, a layer of Earth's upper atmosphere. – In this upper atmosphere, ozone is made when UV

light from the sun splits an oxygen molecule, forming two single oxygen atoms.

• Each single oxygen atom then binds to an oxygen molecule to form ozone.

• Stratospheric ozone is considered “good” ozone because it protects the Earth's surface from dangerous ultraviolet light.

Where is Ozone Found? (2 of 2)

• Ozone is also found in the troposphere.– The troposphere is the lowest layer of the earth’s

atmosphere, where we live and breathe every day.• Ozone that exists in the troposphere is often

referred to as bad ozone.– It is the result of air pollution from power plants and

internal combustion engines.

The Ozone Layer Hole

• Over Antarctica

Ozone hole over Antarctica January 2008 Courtesy of NASA

How Does CFC reach the Stratosphere?

• Even though CFC molecules are heavier than air they are swept up to the stratosphere by the earths winds.

• This process can take as long as ten years.

How is Ozone in the Stratosphere Being Destroyed?

• Chlorine gas– Enters the

stratosphere as CFC– May linger in the

stratosphere for 100 years or more

Why does CFC break down in the stratosphere?

• Sunlight causes CFC to release its chlorine atom.

• 1 chlorine molecule kills 100,000 molecules of ozone

• This chlorine atom reacts with ozone to produce chlorine monoxide and free oxygen.– For each 1 percent

reduction in ozone, 1.5 to 2 percent more UV radiation reaches the surface of the earth.

Effects of Loss of Ozone on Human Health and Plant Life

• Increased levels of UV radiation

• Effects on humans– Increased risk of all

types of skin cancer– Increased risk of

cataracts, which can lead to blindness

Effects of Loss of Ozone on Human Health and Plant Life

• Effects on plant life– Plankton in the sea and some species of larvae

may be killed off by increasing levels of UV radiation.

– The corrosive nature of ozone can damage plants and trees.

– High levels of ozone in the troposphere can destroy agricultural crops and forest vegetation.

Regulation of Chlorine (1 of 2)

• Clean Air Act (CAA)– November 15, 1990, President George H. W.

Bush signed into law sweeping revisions of the Clean Air Act (CAA).

– Title V• EPA (Environmental Protection Agency)

– A federal agency

Regulation of Chlorine (2 of 2)

• Montreal Protocol– International– Require meetings on ozone depletion– Phase out of all CFC production by 2000– CFC-12 (R-12)– Because ozone-depleting gases typically last 40

to 100 years in the atmosphere, full recovery is not expected to be reached before 2070.

Global Warming and the Greenhouse Effect (1 of 2)

• Solar radiation passes through the clear atmosphere.

• Most of the radiation is absorbed by the earth’s surface to warm it.

• Some of the solar radiation is reflected by the earth and the atmosphere.

Global Warming and the Greenhouse Effect (2 of 2)

• Some of the infrared radiation that passed through the atmosphere is absorbed and readmitted in all directions by greenhouse gas molecules. The effect of this is to warm the lower atmosphere.– Greenhouse gases, in

effect, work like a blanket, warming the lower atmosphere.

Two Common Automotive Refrigerants

• R-134a (HFC-134a)• R-12 (CFC-12) on pre-1994 vehicles• HFO-1234yf

– http://reviews.cnet.com/8301-13746_7-20038449-48.html

http://reviews.cnet.com/8301-13746_7-20038449-48.html

http://reviews.cnet.com/8301-13746_7-20038449-48.html

Refrigerant Cylinders• R-134a (HFC-134a)

refrigerant containers are Sky Blue in color.

• R-12 (CFC-12) refrigerant containers are White in color.

• DOT-approved Refrigerant containers may be non-refillable disposable containers or refillable containers

Refillable Refrigerant Cylinders• Refillable refrigerant

containers must be inspected and recertified every 5 years.– Refer to the date code

stamped on the rim of the cylinder to determine the last date of inspection.

– Cylinder should never be filled beyond 80% of its rated capacity.

– Cylinder should never be exposed to temperatures above 125°F (52°C)

Certifications• EPA Certification

– Under the Clean Air Act (CAA) a technician servicing a motor vehicle air conditioning (MVAC) system must be EPA 609-certified.

– This is an open book test• Certification is available through organizations such as

Automotive Service Excellence (ASE) and Mobile Air Conditioning Society (MACS), to name a few.

• A.S.E. Certification– A.S.E. is a voluntary certification system– A.S.E. A7- Auto Heating and Air Conditioning test is

not a substitute for EPA 609-certified.

Injuries as a Result of High Pressure

• One of the basic characteristics of automotive HVAC systems is the use of fluids, which may be in either the gas or liquid state.

• In addition these fluids are often under varying pressures.

• These fluids when contained in a confined chamber exert Hydrostatic pressure.– Extreme care must be taken not to overfill or

overheat a confined fluid.

Special Safely Precautions• Always wear eye protection when working in shop areas or when

servicing mechanical equipment in any setting.

• Eye Damage - If refrigerant enters the eyes:– Do Not rub eyes– Rinse eyes with cool water– Call 911– Tape sterile dressing over the eye to prevent further exposure to unsanitary

conditions and to protect eyes. Do not apply salves or ointments unless directed to by emergency response (911).

– Bring victim immediately to a medical facility (i.e. hospital emergency room)

• Skin Damage - Refrigerant exposure to the skin can cause series frost bit.

• Asphyxiation - Refrigerant is heavier than air and can displace oxygen in a confined space causing drowsiness or unconsciousness – even death. Always work in a well ventilated space.


By Thomas S. Birch



SUMMARY

1. Refrigerants escaping into the atmosphere can have detrimental effects on the ozone layer and also increase climate change and global warming.

2. The Clean Air Act places requirements for technicians to follow when servicing mobile A/C systems.

3. Before doing work that could release refrigerant from a system, a technician must recover the refrigerant from that system.

4. Recycled refrigerant must meet the same standards as new, virgin refrigerant.

5. The SNAP rule limits which refrigerants can be used in a system.

6. Safety precautions should be followed when handling refrigerants.

Documents

CHAPTER 5 Refrigerants and the Environment