# HOW HVAC WORKS. How HVAC. Works PAGE 1

Size: px
Start display at page:

## Transcription

1 How HVAC Works PAGE 1

2 Heat - What is it? Heat is more than a physical concept - it is a feeling. Heat is taught to us at a very young age as a danger to be avoided. Yet, have you ever stopped and thought about what heat really is? How does it move? What are some of the ways we can move it? Heat, commonly described in degrees of temperature, such as Fahrenheit ( F) or Celsius ( C), describes the random motion or vibration of molecules. When a substance becomes hotter, its molecules move faster. How fast these molecules move determines whether the substance is a solid, a liquid, or a gas. In a solid, molecules are locked together in position. In a liquid, molecules move and share a loose relationship with each other. Molecules in a gas, share no relationship with each other because they move very fast. Heat and temperature do not describe the same thing. Heat is an absolute quantity measured in British Thermal Units (BTU s), much like one cube describes a quantity of sugar. Temperature (measured in degrees Fahrenheit or Celsius) is a relative measurement similar to how sweetness describes one cube of sugar dissolved in a cup of coffee. Both one cube and sweetness are describing a quantity of sugar, but sweetness is describing the sugar relative to the coffee. If I added more coffee to the cup, the amount of sugar would be the same, but the sweetness would decrease. SOLID: Molecules are rigidly bound and do not move. LIQUID: Molecules are loosely bound, they vibrate and move around. GAS: Molecules are not bound and move freely, really bouncing off the walls! PAGE 2

3 Heat on the Move Heat is always on the move. Since heat is a measure of the molecule s speed, hot molecules move faster than colder, slower molecules. Speed = heat. 1 When a fast, hot molecule collides with a slower, colder molecule, like a fast car colliding with a slow car the slower molecule speeds up (it becomes hotter) like the cars, but never as fast as the car that hit it, and it cools the faster car, too! 2 Heat always goes from hot to cold because a slow molecule cannot make a fast molecule go faster! Have you ever heard of a car going 15 mph catching up to and hitting a car going 30 mph? 30 mph 15 mph 15 mph 30 mph PAGE 3

4 Cab Environment Understanding the three ways heat moves helps you consider all the heat sources that an air conditioner contends with. Conduction is when heat is transferred through a solid such as the metal fins of an evaporator. Convection is when a colder gas displaces a warmer gas causing them to move around and circulate. Radiant heat is when the sun s rays hit a solid surface causing it to heat up. For example, understanding radiant heat will help you consider how the sun places an additional load on an air conditioner. Truck cabs and off-road machinery cabs are hard to heat and cool. They have large glass areas and are not always well insulated. Hot and cold weather directly affect the temperature inside the cab. This means that any air conditioner system must have the capacity to do a lot of heating and cooling. The purpose of an AC system is to keep the driver comfortable (which sometimes seems to be an impossibility). Most people feel comfortable in the 70 F to 80 F range. Because truck drivers and heavy duty vehicle operators are in their cabs for long periods of time, the cab temperature is very important for their comfort. The ideal cab environment has a modest humidity level and should reach and remain at a temperature of 70 F to 80 F within several minutes of operation. Most air conditioners cycle on and off by the action of a thermostat or a low pressure switch. This switch cycles the compressor clutch and regulates the evaporator core temperature. This cycling action maintains a comfortable temperature range for the driver and any passengers. PAGE 4

5 How do we remove heat? Removing heat is simple. Since heat always goes towards a colder object, all we have to do is give heat a cold thing to flow into. A good example of this is a iced drink. To cool the drink down, we put in ice cubes. Since ice cubes are colder than the warm liquid, the heat will flow into the ice cubes. The ice cubes absorb the heat and melt, removing the heat from the liquid. Now the drink is much more enjoyable. Another simple way to remove heat is to use water. If you go the beach on a hot day, you may notice that folks who sunbathe frequently spray themselves with water to keep their skin cool. When they spray water on their skin, the heat from their bodies speeds up the water molecules and causes them to boil. When the water molecules boil, they change to a gas and escape into the air taking the heat with it. Overall, the water gets hot, the skin gets cool. We call this process evaporation. H H H Water Molecule Skin Surface H H H H One of the main reasons for developing refrigeration systems was to produce beer. Beer yeast must ferment at temperatures around 45 o F. Because of this cold ferment temperature, brewers were forced to make beer in Milwaukee because of the longer cold season. With refrigeration, brewers can now brew beer as far south as Florida s Busch Gardens. PAGE 5

6 Introduction to Pressure Under pressure Gases and liquids exert a force on the sides of whatever container they are in. This force is known as pressure. Have you ever noticed how a can of soda will spray all over the place when you shake it up and open it? It was pressure that caused that mess. The energy from the shaking started moving the molecules around inside the can. When the can opened, the pressure was released. Pressure can also effect temperatures and the boiling points of liquids. Let s take a look... Everything in the atmosphere is under pressure because of millions of tiny collisions. The force of these crashes add up to a terrific force called pressure. For example, if a car hits a wall, the wall reacts and crumbles in the direction of the crash. If we reduce the scale of the crash to the size of molecules and add millions more, the wall will react the same as before. This reaction is known as pressure. Pressure and heat are very similar but heat is the speed of a molecule and pressure is the reaction of what the molecule runs into (such as a wall). Heat and pressure are also related to each other, or one will cause the other and vice versa. We ll discuss that next. Force of Car Many Small Collisions Reaction of Wall Equals Pressure PAGE 6

7 Compression Heating When we described heat, we said that heat is transferred from a fast moving or hot molecule to a slow moving or cold molecule. When a gas is compressed, the pressure caused by a moving object (like a piston) can speed up molecules and make them hotter. Have you ever wondered why a diesel engine doesn t need a spark plug? Diesel engines ignite their fuel-air mixtures by using compression. The force of the diesel engine s piston raises the pressure so much that the fuel-air mixture gets hot enough to explode. In AC systems, the compressor takes in cool low pressure gas and discharges hot, high pressure gas. At work is the compressor piston, crashing into millions of gas molecules causing them to speed up and get hot. Remember, an increase in pressure means an increase in temperature. PAGE 7

8 Boiling Over Boiling is the process of rapid evaporation, where liquid molecules escape as vapor and take heat away. Engines frequently operate at temperatures well over the boiling point of water (212 F). If an engine is at 220 F, why doesn t it boil over? The reason is simple, the water cooling system in the engine is under pressure because it is capped off. When pressure is placed on a substance, it is harder for it to boil. If more pressure makes it harder for a substance to evaporate or boil, what happens when we decrease pressure? Less pressure makes it easier for substances to boil or evaporate because High Pressure forces water to boil at a higher temperature Molecules Cap Pressure Relief Valve Low pressure allows water to boil at a lower temperature Molecules there is less force keeping the molecules together as a liquid. For example, if you boil water high in the mountains, it would take up to 28 F less heat because there is less air pressure at high altitudes. Pressure is a valuable concept in our AC system. With it, we can create boiling and evaporation at very low temperatures and create condensation (changing from a gas to a liquid) at very high temperatures. These principles are what makes AC possible. RADIATOR CORE Water molecules are not allowed to expand into vapor because of the counter-pressure applied by the radiator cap. So water can be heated above it's normal 212 F boiling point. At sea level, water boils at 212 F At 11,500 feet, water boils at 184 F Counter-pressure is applied by the radiator cap spring. If the radiator was totally sealed it could explode at some point from the constant increase in pressure. The function of the radiator cap is to provide a relief-valve that is set for a certain level of pressure. Reducing atmospheric pressure lowers the boiling point PAGE 8

9 Expansion Valve System Accumulator System HOW HVAC WORKS Introduction to A/C Operation AC Systems are much like a mother, who uses a sponge to soak up milk from a spilled glass. She soaks it up and then wrings the milk out of the sponge and into the sink. Similarly, an AC system soaks up heat in the cab using evaporation and then squeezes the heat into the outside air using condensation. Let s take a closer look. Air conditioners have two basic layouts: the expansion valve system and the accumulator system. Red Dot primarily uses the expansion valve system. With five basic components 1. Expansion device: A restriction in the liquid line of the system, purposely designed to cause a pressure drop. 2. Evaporator: A device that removes heat from the cab air by exchanging it into boiling refrigerant. 3. Compressor: Provides the mechanical energy to move refrigerant and manipulate pressures. This is the heart of the system. 4. Condenser: Designed to exchange heat from the refrigerant to the outside air. Similar to the evaporator. 5. Drier Filter Device: A storage container for extra refrigerant that usually contains a drying agent called desiccant and a filter to screen out contaminants. PAGE 9

10 Expansion Valve System Compressor PSI 300 PSI #10 Hose Cold Low Pressure Gaseous State WARM INLET AIR Expansion Valve #10 Hose Low Pressure Gaseous State (Suction Side) #8 Hose Hot (200 ) High Pressure Gaseous State COOL AIR TO THE CAB Thermostat Evaporator #8 Hose Metered Refrigerant Gaseous State #6 Hose Liquid State Receiver Drier #6 Hose High Pressure Liquid State 135 Condenser HEATED OUTSIDE AIR FLOW COOL OUTSIDE AIR FLOW LOW SIDE HIGH SIDE PAGE 10

11 Accumulator System Orifice Tube High-Pressure Liquid to the Low Side COOL AIR TO THE CAB LOW SIDE #10 Hose Cold Low Pressure Gaseous State Evaporator WARM INLET AIR #10 Hose Low Pressure Gaseous State (Suction Side) #6 Hose High Pressure Liquid State 135 Accumulator Compressor PSI HIGH SIDE Condenser HEATED OUTSIDE AIR FLOW 300 PSI #8 Hose Hot (200 ) High Pressure Gaseous State COOL OUTSIDE AIR FLOW Thermostat PAGE 11

12 Low-Side Operation Since the low side has a very low pressure, the refrigerant can begin to boil off into a gas. When the refrigerant changes from liquid to gas it gathers heat from the cab air. The pressure difference is created by an expansion device. Pressure-Temperature Drop There are two types of expansion device is the component that begins the evaporation process: 1. Thermostatic Expansion Valve (TXV) (left) 2. Orifice Tube (right) The expansion device creates a pressure drop by restricting the flow of refrigerant around the system. Slowing down the flow of refrigerant causes the compressor to partially evacuate one side of the system. This low pressure void is called the Suction side or the Low side of the system. Expansion Valve Internal Equalization Passage Discharge from Evaporator When Operating Pin pushes ball seat, refrigerant bleeds into Evaporator Outlet to Evaporator Low Pressure Flow from Evaporator Low Pressure Flow to Evaporator Valve Diaphragm The refrigerant inside of an air-conditioner is essentially a heat sponge. It very similar to taking a dry sponge and dunking it into a bucket of water. As the water fills the sponge, the sponge expands and becomes heavy with water. Then, when you want to remove the water, you simply squeeze the sponge with your hands and the water comes out. Low Pressure Flow to Compressor High Pressure Flow from Condensor Outlet to Compressor Sealed Sensing Bulb Operating Pin Inlet from Receiver Drier High Pressure Liquid Metering Orifice Valve Spring Orifice Tube Out Low Pressure Flow to Evaporator Orifice Tube (Small tube) O-Ring High Pressure Flow from Condensor PAGE 12

13 Expansion Cooling Low-Side Operation Cold refrigerant absorbs heat from the cab air while the refrigerant circulates inside the evaporator coil. Heat from the cab air passes through the metal of the evaporator and cause the refrigerant to expand by boiling off into a vapor. This boiling is possible because refrigerants used in AC systems have a boiling point of about one pound per square inch per 1 F. For example, the boiling point of refrigerant is approximately 20 F at 20 psi. As the refrigerant expands by boiling into a vapor, it takes massive amounts of heat with it. Refrigerant mist is sprayed into evaporator Thermostat COOL AIR TO THE CAB Evaporator WARM INLET AIR Expansion valve (TXV) LOW SIDE Refrigerant boils into vapor, collecting heat from cab air HIGH SIDE Refrigerant is forced thru orifice into low-pressure void Heated gas runs thru TXV to help valve meter flow Gas goes on to the compressor Dense, hot high pressure liquid hits restriction An air conditioner uses similar principles. It uses refrigerant like a sponge to soak up heat (just like a sponge soaks up water). When the refrigerant enters into the thermal expansion valve (TXV) it is essentially a dry sponge. When it passes through the small orifice of the TXV it sprays into the evaporator. As the refrigerant heats up in the evaporator, it expands collecting large amounts of heat, like a sponge expands with water. PAGE 13

14 High-Side Operation So far, we have learned that the low pressures attract heat into the system by expanding refrigerant. The part of the system that rejects heat into the outside air is known as the high side. It rejects heat by condensing hot vapor into warm liquid and through this process, squeezes heat out of the system. Heat rejection is accomplished using very high pressures (up to 350 psi) and large volumes of air. COMPRESSION HEATING Remember that raising the refrigerant pressure is necessary to begin the process of rejecting heat into the outside air. On its downstroke (#1 at right), the compressor piston collects the expanded refrigerant inside the compressor. On its up-stroke (#2) the piston forces the refrigerant molecules closer together. The refrigerant vapor is raised in pressure, temperature and boiling point before being forced out of the valve plate assembly. The temperature of the vapor is normally two and a half times higher than the temperature of the outside air. Since heat always flows from hot to cold, the refrigerant must be much hotter than the outside air to be able to move heat out of the system. 1 2 Piston on Downstroke Low pressure coming in. On downstroke piston sucks refrigerant gas through open valve. Piston on Upstroke High pressure going out. On upstroke the valve is forced open and hot refrigerant gas is forced into high side of system. PAGE 14

15 High-Side Operation Subcooling The hot, high pressure vapor makes its next stop at the condensing coil. The condenser is just like the evaporator it is a heat exchanger. It looks a little different from the evaporator because it is more flat and a little larger (an evaporator must fit under the dash). Inside the condensing coil, the gas starts its way from the top to the bottom, cooling down a little with each pass. By the time the refrigerant reaches the lower third of the coil, it cools down enough to change back into a liquid. As a liquid, it continues to cool F below its boiling point in a process called subcooling. Subcooling is an important concept to understand because it will tell what is wrong with the high side of the system. The next modules four, five and six will cover Troubleshooting, Inspection and AC Performance with more detail on subcooling and other topics. Hot high pressure gas from Compressor HEATED OUTSIDE AIR FLOW Condenser When the expanded refrigerant enters into the compressor, the mechanical force of the piston forces the expanded refrigerant molecules closer together, increasing the pressure (just like when you squeeze a sponge full of water). When the high pressure refrigerant enters into the condenser, the heat is squeezed out into the outside air. PAGE 15

16 P.O.Box Seattle, WA

### Refrigeration Basics 101. By: Eric Nelson

Refrigeration Basics 101 By: Eric Nelson Basics Refrigeration is the removal of heat from a material or space, so that it s temperature is lower than that of it s surroundings. When refrigerant absorbs

### Heavy-Duty Air Conditioning And Heater Service

A i r C o n d i t i o n i n g S y s t e m Red Dot HVAC Training Manual Heavy-Duty Air Conditioning And Heater Service Heavy Duty Air Conditioning and Heating Service Training Manual Go to Table of Contents

### Rusty Walker, Corporate Trainer Hill PHOENIX

Refrigeration 101 Rusty Walker, Corporate Trainer Hill PHOENIX Compressor Basic Refrigeration Cycle Evaporator Condenser / Receiver Expansion Device Vapor Compression Cycle Cooling by the removal of heat

### HVAC-02, Air Conditioning Troubleshooting and Repair

HVAC-02, Air Conditioning Troubleshooting and Introduction Since I'm constantly receiving questions on 944 air conditioning systems, I figured it's time to come up with come helpful troubleshooting tips.

### Automobile Air Conditioning Primer

Automobile Air Conditioning Primer An air conditioner is basically a refrigerator without the insulated box. It uses the evaporation of a refrigerant, like Freon, to provide cooling. The mechanics of the

### Air Conditioning 101. STN Presentation AC101

Air Conditioning 101 What is Refrigeration? Refrigeration is Cooling by the Removal of Heat Heat is Measured In BTU s A BTU is a British Thermal Unit It is the Amount of Heat to Raise One Pound of Water,

### Characteristics of Evaporators

Characteristics of Evaporators Roger D. Holder, CM, MSME 10-28-2003 Heat or Energy In this paper, we will discuss the characteristics of an evaporator coil. The variance of the operational condenses of

### Any Service Technician Can Fix It A Good Service Technician Can Figure Out What s Wrong With It.

I Dave s Statement If the thermostat calls for cooling, and the furnace fan is running properly, and the coil airflow is adequate, and the condenser fan is running properly, and the condenser airflow is

### How does solar air conditioning work?

How does solar air conditioning work? In a conventional air conditioning system; The working fluid arrives at the compressor as a cool, low-pressure gas. The compressor is powered by electricity to squeeze

### A brief explanation on how air conditioning works and what terms mean

A brief explanation on how air conditioning works and what terms mean -presented by- Before we begin, let s explain the air conditioning process. In the most basic of terms, air conditioning simply takes

### 01-3 6820-11 6820-11 AIR CONDITIONER GENERAL 1. SPECIFICATIONS AIR CONDITIONER REXTON 2010.01

682011 013 GENERAL 1. SPECIFICATIONS 682011 014 682011 2. REPAIR INSTRUCTIONS 1) Precautions for Working with R134a R12 refrigerant and R134a refrigerant are not compatible. These refrigerants must never

### UNDERSTANDING REFRIGERANT TABLES

Refrigeration Service Engineers Society 1666 Rand Road Des Plaines, Illinois 60016 UNDERSTANDING REFRIGERANT TABLES INTRODUCTION A Mollier diagram is a graphical representation of the properties of a refrigerant,

### Glossary of Heating, Ventilation and Air Conditioning Terms

Glossary of Heating, Ventilation and Air Conditioning Terms Air Change: Unlike re-circulated air, this is the total air required to completely replace the air in a room or building. Air Conditioner: Equipment

### SECTION 5 COMMERCIAL REFRIGERATION UNIT 21 EVAPORATORS AND THE REFRIGERATION SYSTEM

SECTION 5 COMMERCIAL REFRIGERATION UNIT 21 EVAPORATORS AND THE REFRIGERATION SYSTEM UNIT OBJECTIVES After studying this unit, the reader should be able to Define high-, medium-, and low-temperature refrigeration.

### TEACHER BACKGROUND INFORMATION THERMAL ENERGY

TEACHER BACKGROUND INFORMATION THERMAL ENERGY In general, when an object performs work on another object, it does not transfer all of its energy to that object. Some of the energy is lost as heat due to

### A/C refrigerant system, overview

Page 1 of 19 87-18 A/C refrigerant system, overview A/C refrigerant system, identification Typical A/C refrigerant system with expansion valve and receiver drier 1 - Evaporator 2 - Expansion valve 3 -

### Heat Transfer: Conduction, Convection, and Radiation

Heat Transfer: Conduction, Convection, and Radiation Introduction We have learned that heat is the energy that makes molecules move. Molecules with more heat energy move faster, and molecules with less

### Troubleshooting an Air Conditioning system. R D Holder Eng. Roger D Holder MSME

Troubleshooting an Air Conditioning system R D Holder Eng. Roger D Holder MSME Troubleshooting of an air conditioning system is a step by step procedure. I have found that a 4 step procedure is the best

### Chapter 4: Transfer of Thermal Energy

Chapter 4: Transfer of Thermal Energy Goals of Period 4 Section 4.1: To define temperature and thermal energy Section 4.2: To discuss three methods of thermal energy transfer. Section 4.3: To describe

### DESIGN STANDARDS SECTION 23 60 00

PART 1 - GENERAL 1.01 Work included: A. Piping, tubing and fittings. B. Piping specialties. C. Special duty valves. D. Refrigerants. E. Chillers. F. Refrigerant monitors. 1.02 General requirements: A.

### 1. The Kinetic Theory of Matter states that all matter is composed of atoms and molecules that are in a constant state of constant random motion

Physical Science Period: Name: ANSWER KEY Date: Practice Test for Unit 3: Ch. 3, and some of 15 and 16: Kinetic Theory of Matter, States of matter, and and thermodynamics, and gas laws. 1. The Kinetic

### CLIMATE CONTROL SYSTEM OPERATION, DIAGNOSIS, AND REPAIR

CLIMATE CONTROL SYSTEM OPERATION, DIAGNOSIS, AND REPAIR Welcome to Climate Control System Operation, Diagnosis, and Repair, which is the final training course in the Electrical training sequence. When

### MAXIMUM HEAT LOAD TEMPERATURE TESTING ( Differential Temperature Testing )

MAXIMUM HEAT LOAD TEMPERATURE TESTING ( Differential Temperature Testing ) The Concept Maximum Heat Load Temperature Testing is a powerful air-conditioning diagnostic and evaluation technique. It is also

### Geothermal Alliance of Illinois. TXVs Theory and Fundamentals John Haug Senior Application Engineer Emerson Climate Technologies - Flow Controls

Geothermal Alliance of Illinois TXVs Theory and Fundamentals John Haug Senior Application Engineer Emerson Climate Technologies - Flow Controls Thermal Expansion Valve Topics Anatomy Operation Terms &

### Chapter 18 Temperature, Heat, and the First Law of Thermodynamics. Problems: 8, 11, 13, 17, 21, 27, 29, 37, 39, 41, 47, 51, 57

Chapter 18 Temperature, Heat, and the First Law of Thermodynamics Problems: 8, 11, 13, 17, 21, 27, 29, 37, 39, 41, 47, 51, 57 Thermodynamics study and application of thermal energy temperature quantity

### Heat and Temperature: Front End Evaluation Report. Joshua Gutwill. October 1999

Heat and Temperature: Front End Evaluation Report Joshua Gutwill October 1999 Keywords: 1 Heat and Temperature Front End Evaluation Report October 28, 1999 Goal:

### Multiple Choice For questions 1-10, circle only one answer.

Test Bank - Chapter 1 The questions in the test bank cover the concepts from the lessons in Chapter 1. Select questions from any of the categories that match the content you covered with students. The

### How much do you know about HVAC? Try testing yourself with the following questions and then take a look at the answers on the following page.

Demystifying HVAC Test Your HVAC Knowledge By Ron Prager How much do you know about HVAC? Try testing yourself with the following questions and then take a look at the answers on the following page. 1)

### HOT & COLD. Basic Thermodynamics and Large Building Heating and Cooling

HOT & COLD Basic Thermodynamics and Large Building Heating and Cooling What is Thermodynamics? It s the study of energy conversion using heat and other forms of energy based on temperature, volume, and

### AIR CONDITIONING LIFE EXTENDER ACX10 FIELD INSTALLATION AND PERFORMANCE EVALUATION

AIR CONDITIONING LIFE EXTENDER ACX10 FIELD INSTALLATION AND PERFORMANCE EVALUATION Tony Thorne Manager of Electrical Engineering Index Sensors and Controls, Stanwood, WA 98292 USA ABSTRACT Air conditioning

### Troubleshooting HVAC/R systems using refrigerant superheat and subcooling

Troubleshooting HVAC/R systems using refrigerant superheat and subcooling Application Note Troubleshooting and servicing refrigeration and air conditioning systems can be a challenging process for both

### New Trends in the Field of Automobile Air Conditioning

New Trends in the Field of Automobile Air Conditioning E. Janotkova and M. Pavelek Department of Thermomechanics and Environmental Engineering Brno University of Technology, 61669 Brno, Czech Republic

### Every mathematician knows it is impossible to understand an elementary course in thermodynamics. ~V.I. Arnold

Every mathematician knows it is impossible to understand an elementary course in thermodynamics. ~V.I. Arnold Radiation Radiation: Heat energy transmitted by electromagnetic waves Q t = εσat 4 emissivity

### Name: Class: Date: 10. Some substances, when exposed to visible light, absorb more energy as heat than other substances absorb.

Name: Class: Date: ID: A PS Chapter 13 Review Modified True/False Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true. 1. In all cooling

### Section 15.2 Water Purification

Section 15.2 Water Purification Fresh water is an essential ingredient of modern life. Thought it s often available as the result of natural processes, there are times when it must be extracted from impure

### Flushing and Cleaning the A/C System

Flushing and Cleaning the A/C System Once an AC system has been contaminated or has suffered a failure, the most important part of the AC service to restore the cooling performance to the system = FLUSHING

### It will be available soon as an 8.5 X 11 paperback. For easier navigation through the e book, use the table of contents.

The System Evaluation Manual and Chiller Evaluation Manual have been revised and combined into this new book; the Air Conditioning and Refrigeration System Evaluation Guide. It will be available soon as

### Chemistry 13: States of Matter

Chemistry 13: States of Matter Name: Period: Date: Chemistry Content Standard: Gases and Their Properties The kinetic molecular theory describes the motion of atoms and molecules and explains the properties

### INSTALLATION INSTRUCTIONS HOT GAS BYPASS SYSTEM DESIGN MANUAL

INSTALLATION INSTRUCTIONS HOT GAS BYPASS SYSTEM DESIGN MANUAL MODELS: WA/WL44H WA/WLH WA/WL70*H NOTE: Electrical data presented in this manual supersedes any other data f the above listed models. Bard

### Chapter 10 Temperature and Heat

Chapter 10 Temperature and Heat What are temperature and heat? Are they the same? What causes heat? What Is Temperature? How do we measure temperature? What are we actually measuring? Temperature and Its

### INSTALLATION INSTRUCTIONS Fan Coil Replacement Coil Kit EBX & EBXX

Fan Coil Replacement Coil Kit EBX & EBXX These instructions must be read and understood completely before attempting installation. These instructions covers the installation of replacement coil kit into

### SERVICE BULLETIN AIR CONDITIONER COMPRESSOR FAILURES ALSO SEE BULLETIN #SB3-304AS (SYSTEM CONTAMINATION)

Form #SB4-304AS AirSourceR SERVICE BULLETIN AIR CONDITIONER COMPRESSOR FAILURES ALSO SEE BULLETIN #SB3-304AS (SYSTEM CONTAMINATION) Second only to refrigerant hose leaks, compressors have the highest rate

### Heavy Duty Air Conditioning Service Manual

Heavy Duty Air Conditioning Service Manual Safety Precautions & Warnings Servicing Refrigerant Systems 1. Always wear the proper protective eyewear and clothing before working on any refrigeration system.

### SECTION 5 COMMERCIAL REFRIGERATION UNIT 22 CONDENSERS

SECTION 5 COMMERCIAL REFRIGERATION UNIT 22 CONDENSERS UNIT OBJECTIVES After studying this unit, the reader should be able to explain the purpose of the condenser in a refrigeration system. describe differences

### an ISO 9001: 2008 Registered Company

PERFORMANCE AUTOMOTIVE an ISO 9001: 2008 Registered Company AIR CONDITIONING THEBasics 18865 Goll St San Antonio, TX 78266 PH 210.654.7171 FAX 210.654.3113 1.800.TO.COOL.U (862-6658) www.vintageair.com

### POLICY BULLETIN Tecumseh Compressor Company Compressor Group

to Bulk Milk Coolers and Other System Page 1 of 5 Overall reliability can be enhanced if there exists a complete understanding of the features, system design, installation requirements, processing, charging

### BUT PRECAUTIONS MUST BE TAKEN OR SERIOUS BURNS CAN RESULT.

Cooling System Operation Below is an explanation of this system's operation Radiator The radiator is a device designed to dissipate the heat which the coolant has absorbed from the engine. It is constructed

### Creating Efficient HVAC Systems

Creating Efficient HVAC Systems Heating and Cooling Fundamentals for Commercial Buildings Heating, ventilating, and air conditioning (HVAC) systems account for nearly half of the energy used in a typical

### Ground Source Heat Pumps The Fundamentals. Southington, Connecticut 860 628 4622 John F. Sima III P.E.

Ground Source Heat Pumps The Fundamentals Southington, Connecticut 860 628 4622 John F. Sima III P.E. Winter/Spring 2010 Ground Source Heat Pumps The Fundamentals TOPICS: Heat Pump Terminology Basic Physics

### Chillin Out: Designing an Insulator

SHPE Jr. Chapter May 2015 STEM Activity Instructor Resource Chillin Out: Designing an Insulator Students learn about the three ways heat can be transferred from one object to another. They also learn what

### A discussion of condensate removal systems for clarifier and thickener drives for water and wastewater facilities.

A discussion of condensate removal systems for clarifier and thickener drives for water and wastewater facilities. Richard L. Dornfeld, BSME, P.E. Staff Engineer September 25, 2014 Moisture can be a problem

### Chapter 10: Temperature and Heat

Chapter 10: Temperature and Heat 1. The temperature of a substance is A. proportional to the average kinetic energy of the molecules in a substance. B. equal to the kinetic energy of the fastest moving

### air conditioners how to choose a cooling system

air conditioners how to choose a cooling system taking responsibility As an individual, your efficient use of energy brings benefits such as lower bills, improved comfort levels in your home and a reduced

### Partnerships Implementing Engineering Education Worcester Polytechnic Institute Worcester Public Schools

Partnerships Implementing Engineering Education Worcester Polytechnic Institute Worcester Public Schools Supported by: National Science Foundation Weather: 4.H.3 Weather and Classical Instruments Grade

### Vacuum. How It Relates to Refrigeration And Air Conditioning Service

Vacuum How It Relates to Refrigeration And Air Conditioning Service Moisture In A Refrigeration System Visible Moisture Water Droplets Uncommon, but it can occur Invisible Moisture Water Vapor Found in

### MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Sample Mid-Term 3 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) If you double the frequency of a vibrating object, its period A) is quartered.

### Test Bank - Chapter 3 Multiple Choice

Test Bank - Chapter 3 The questions in the test bank cover the concepts from the lessons in Chapter 3. Select questions from any of the categories that match the content you covered with students. The

### TEMPERATURE QUESTIONS TEACHERS NOTES

TEMPERATURE QUESTIONS TEACHERS NOTES If you think of Additional questions, Ways in which these answers could be improved, Anything else you want to tell me, then Please contact me. Michael de Podesta michael.depodesta@npl.co.uk

### Practical Applications of Freezing by Boiling Process

Practical Applications of Freezing by Boiling Process Kenny Gotlieb, Sasha Mitchell and Daniel Walsh Physics Department, Harvard-Westlake School 37 Coldwater Canyon, N. Hollywood, CA 9164 Introduction

### Air Conditioner Maintenance

Central air conditioning systems are wonderful features of many homes in the US. In hot and humid climates it s hard to imagine living without AC, although this convenience has been common in only the

### AIRAH Refrigeration (in HVAC) Back to Basics. For the First Time

AIRAH Refrigeration (in HVAC) Back to Basics For the First Time Terms of Reference What this session is NOT about Detailed Refrigeration Design Detailed analysis of various Refrigants properties Comparison

### Table Z. Troubleshooting Chart for Air Conditioners. Cause

Troubleshooting Chart for Air Conditioners Type of Unit Complaint Cause With open-type compressor Electric motor will not start Power failure Check circuit for power source Compressor stuck Locate cause

### In the compression-refrigeration loop (air conditioning), which is likely to be warmer? 1. Condenser coil 2. Evaporator coil

In the compression-refrigeration loop (air conditioning), which is likely to be warmer? 1. Condenser coil 2. Evaporator coil Answer: (1) Condenser coil See the video. A.R.E. Building Systems Study Guide

### How Ground/Water Source Heat Pumps Work

How Ground/Water Source s Work Steve Kavanaugh, Professor Emeritus of Mechanical Engineering, University of Alabama Ground Source s (a.k.a. Geothermal s) are becoming more common as the costs of energy

### Water Contamination and Water Removal in Industrial Ammonia Refrigeration Systems

Water Contamination and Water Removal in Industrial Ammonia Refrigeration Systems By Ray Ficker, PE Effects of Water Contamination Water contamination in an industrial ammonia refrigeration system can

### Temperature affects water in the air.

KEY CONCEPT Most clouds form as air rises and cools. BEFORE, you learned Water vapor circulates from Earth to the atmosphere Warm air is less dense than cool air and tends to rise NOW, you will learn How

### HEATER, AIR CONDITIONING AND VENTILATION

55-1 GROUP 55 HEATER, AIR CONDITIONING AND VENTILATION CONTENTS GENERAL DESCRIPTION 55-2 HEATER AND AIR CONDITIONING SYSTEM 55-4 HEATER CONTROL 55-6 A/C-ECU 55-7 A/C COMPRESSOR 55-9 CONDENSER 55-9 DUCT

### 1932 Lexington Houston, Texas 77098-4220 (713) 524-4877. Recommendations for installation of cooling systems

1932 Lexington Houston, Texas 77098-4220 (713) 524-4877 The purpose for this information is to provide a better understanding of the HVAC equipment, components, designs, and installations, of HVAC system

### Geothermal Energy Using Water-Source Heat Pumps

Geothermal Energy Using Water-Source Heat Pumps By VIRSTAR Corporation Geothermal Expertise Since 1978 All information contained herein is the exclusive property of VIRSTAR Corporation, all rights reserved.

### Chapter 2: Forms of Energy

Chapter 2: Forms of Energy Goals of Period 2 Section 2.1: To describe the forms of energy Section 2.2: To illustrate conversions from one form of energy to another Section 2.3: To define the efficiency

### ENGINE COOLING SYSTEM

ENGINE COOLING SYSTEM 1988 Toyota Celica 1987-88 TOYOTA Engine Cooling Systems Celica DESCRIPTION The basic liquid cooling system consists of a radiator, water pump, thermostat, cooling fan, pressure cap,

### Technical Training Associates Presents. Commercial Refrigeration Equipment Servicing Part 1

Technical Training Associates Presents Commercial Refrigeration Equipment Servicing Part 1 By Jim Johnson A Practical Approach To The Fundamentals Of Walk-Ins, Reach-In and, Display Cases: Restaurant,

### PERFORMANCE AIR CONDITIONING AUTOMOTIVE. an ISO 9001: 2008 Registered Company

PERFORMANCE an ISO 9001: 2008 Registered Company AUTOMOTIVE AIR CONDITIONING THE Basics 18865 Goll St San Antonio, TX 78266 PH 210.654.7171 FAX 210.654.3113 800.TO.COOL.U (862-6658) www.vintageair.com

### Building Energy Systems. - HVAC: Heating, Distribution -

* Some of the images used in these slides are taken from the internet for instructional purposes only Building Energy Systems - HVAC: Heating, Distribution - Bryan Eisenhower Associate Director Center

### ASHRAE Boston Chapter Meeting Designing AC Refrigeration Systems Lessons Learned February 11, 2014

ASHRAE Boston Chapter Meeting Designing AC Refrigeration Systems Lessons Learned February 11, 2014 Explanation of the refrigeration cycle. Compressors. Benefits and operating characteristics. -Reciprocating

### Study the following diagrams of the States of Matter. Label the names of the Changes of State between the different states.

Describe the strength of attractive forces between particles. Describe the amount of space between particles. Can the particles in this state be compressed? Do the particles in this state have a definite

### Refrigeration and Airconditioning Prof. M. Ramgopal Department of Mechanical Engineering Indian Institute of Technology, Kharagpur

Refrigeration and Airconditioning Prof. M. Ramgopal Department of Mechanical Engineering Indian Institute of Technology, Kharagpur Lecture No. # 22 Refrigeration System Components: Compressor (Continued)

### Refrigerant Changeover Guidelines R-22 to R-407C. Leading the Industry with Environmentally Responsible Refrigerant Solutions

Refrigerant Changeover Guidelines R-22 to R-407C Leading the Industry with Environmentally Responsible Refrigerant Solutions Copeland does not CFC advocate the wholesale changeover of HCFC HCFC refrigerants

### Table V. Troubleshooting Checklist for Refrigeration Systems. Air or non-condensable gas in system. Inlet water warm.

Table V Troubleshooting Checklist for Refrigeration Systems TROUBLE POSSIBLE CAUSE CORRECTIVE MEASURE High condensing pressure. Low condensing pressure. Air or non-condensable gas in system. Inlet water

Convection, Conduction & Radiation There are three basic ways in which heat is transferred: convection, conduction and radiation. In gases and liquids, heat is usually transferred by convection, in which

### (Walter Glogowski, Chaz Shapiro & Reid Sherman) INTRODUCTION

Convection (Walter Glogowski, Chaz Shapiro & Reid Sherman) INTRODUCTION You know from common experience that when there's a difference in temperature between two places close to each other, the temperatures

### Natural Gas / Propane Emergencies. Probationary Firefighter Academy

Natural Gas / Propane Emergencies Probationary Firefighter Academy Properties of Natural Gas / Propane Natural Gas and Propane are gaseous fossil fuels Natural Gas is primarily Methane(CH 4 ) Propane is

### Energy Efficiency. Energy Efficient Home Cooling:

Energy Efficiency Energy Efficient Home Cooling: Choosing an air conditioning system is an important decision. A poor choice may be costly to purchase and operate and yet fail to provide the desired cooling

### A Teaching Unit for Years 3 6 children

A Teaching Unit for Years 3 6 children 1 SEREAD and ARGO: Concept Overview for Years 3-6 Teaching Programme This is the overview for the first part of the SEREAD programme link with ARGO. The overview

### CONTAMINANT REMOVAL FROM CENTRIFUGAL SYSTEMS

CONTAMINANT REMOVAL FROM CENTRIFUGAL SYSTEMS BULLETIN 240-10-3 June 2004 Supersedes June 1983 Many centrifugal systems get little maintenance. As a result they operate with the refrigerant highly contaminated

### Gas Laws. vacuum. 760 mm. air pressure. mercury

Gas Laws Some chemical reactions take place in the gas phase and others produce products that are gases. We need a way to measure the quantity of compounds in a given volume of gas and relate that to moles.

### Hot Leaks. See how the temperature of liquids changes the way they flow.

P h y s i c s Q u e s t A c t i v i t i e s Activity 2 1 Hot Leaks See how the temperature of liquids changes the way they flow. Safety: This experiment requires using the hot water tap and straight pins.

### Central Air Conditioning Plants

Central Air Conditioning Plants In our department, these plants (Air cooled or water cooled) are commonly available above 10 TR up to 100 TR. These types of plants are more suitable for large installations

### TECHNICAL BULLETIN SEPTEMBER 2015 COLD, HARD FACTS ON A/C REPAIR

TECHNICAL BULLETIN SEPTEMBER 2015 This article was written by Tim Sramcik, contributing editor of Auto Body Repair Network Magazine (ABRN). It was published in the April 2015 edition. COLD, HARD FACTS

### Elements Elements describe the essential outcomes. 1. Prepare to diagnose and repair air conditioning and HVAC system

AURETU004 Application Competency Field Unit Sector Elements Elements describe the essential outcomes. 1. Prepare to diagnose and repair air conditioning and HVAC system 2. Diagnose air conditioning and

### 7. 1.00 atm = 760 torr = 760 mm Hg = 101.325 kpa = 14.70 psi. = 0.446 atm. = 0.993 atm. = 107 kpa 760 torr 1 atm 760 mm Hg = 790.

CHATER 3. The atmosphere is a homogeneous mixture (a solution) of gases.. Solids and liquids have essentially fixed volumes and are not able to be compressed easily. have volumes that depend on their conditions,

### Air Conditioning Clinic

Air Conditioning Clinic Introduction to HVAC Systems One of the Systems Series February 2012 TRG-TRC018-EN Introduction to HVAC Systems One of the Systems Series A publication of Trane Preface Introduction

### Temperature. Temperature

Chapter 8 Temperature Temperature a number that corresponds to the warmth or coldness of an object measured by a thermometer is a per-particle property no upper limit definite limit on lower end Temperature

Dehumidification Basics Why do you want to keep indoor Rh between 30-60%? ASHRAE recommends keeping the relative humidity in a home between 30-60% to limit the effects of many unwanted conditions and harmful

### SWIMMING POOL HEAT PUMP

SWIMMING POOL HEAT PUMP Installation & User Manual Model HP40B HP50B HP65B Hayward Pool Products Canada, Inc. T: 1-888-238-7665 www.haywardpool.ca CONTENT I. Application 4 II. Features 4 III. Technical

### AIR CONDITIONING EFFICIENCY F8 Energy eco-efficiency opportunities in Queensland Foundries

AIR CONDITIONING EFFICIENCY F8 Energy eco-efficiency opportunities in Queensland Foundries Hot tips and cool ideas to save energy and money! Air conditioning units or systems are often used by foundries

### 13.1 The Nature of Gases. What is Kinetic Theory? Kinetic Theory and a Model for Gases. Chapter 13: States of Matter. Principles of Kinetic Theory

Chapter 13: States of Matter The Nature of Gases The Nature of Gases kinetic molecular theory (KMT), gas pressure (pascal, atmosphere, mm Hg), kinetic energy The Nature of Liquids vaporization, evaporation,