Modern Refrigeration and Air Conditioning

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Questions and Answers

HVACR generally falls into the ________ career?

Architecture and Construction

The initial setup of HVACR equipment and systems is _________ work.

Installation

Fixing and performing maintenance on existing systems is _______ work.

Service

The career requiring the highest level of education and licensing is an HVACR ________.

Engineer Signup and view all the answers

To develop a bid, an estimator generally adds together the cost of what?

equipment and materials, labor and time required, permits and inspections Signup and view all the answers

An energy auditor generally performs which tests?

blower door test, duct tightness test, thermal imaging Signup and view all the answers

Building inspectors ensure that a building project adheres to _________.

applicable codes Signup and view all the answers

A career search is enhanced by ________, which is the process of connecting with other individuals within a group or industry.

networking Signup and view all the answers

An application process will usually involve what paperwork?

application form, cover letter, resume Signup and view all the answers

After an interview for a position, send a _________ to the interviewer(s).

thank-you letter Signup and view all the answers

Employers value good work habits. These include:

being dependable, punctual, and responsible Signup and view all the answers

Characteristics of good leadership include:

motivating others, serving as a good role model, and solving problems Signup and view all the answers

Professional behavior includes:

analyzing a situation for a workable solution, maintaining a positive attitude, and working as a team Signup and view all the answers

All persons who intend to install, maintain, service, or repair HVACR equipment should first acquire ______________________.

EPA certification Signup and view all the answers

HVACR state licensing generally requires:

an application fee, HVACR work experience, and passing a licensing exam Signup and view all the answers

The national code that covers workplace safety is __________.

OSHA Signup and view all the answers

A good method of preventing electrical hazards is to __________.

use a lockout/tagout (LOTO) practice Signup and view all the answers

For proper fire extinguisher use, remember the initials _________.

P.A.S.S. Signup and view all the answers

Before dealing with an electrical fire, make sure that the fire extinguisher is rated _________________.

Class C Signup and view all the answers

An elevated body temperature, headache, nausea, weakness, dizziness, fainting, and confusion are signs of _________.

heat-related illness Signup and view all the answers

A sudden uncontrolled release of refrigerant could cause the following:

blindness, frostbite, and skin damage Signup and view all the answers

When storing or transporting refrigerant cylinders, they should be kept __________.

vertical with the valve at the top Signup and view all the answers

Since nitrogen cylinders can be charged to such high internal pressure, a ________ is necessary when using the nitrogen.

pressure regulator Signup and view all the answers

Because many refrigerant vapors are heavier than air, a confined space must have _________.

good ventilation Signup and view all the answers

When cutting or removing asbestos, run a ventilation system with a(n) _________ filter.

HEPA Signup and view all the answers

If an environment requires workers to raise their voices to be heard, _________ protection is likely warranted.

hearing Signup and view all the answers

When working in a very dusty environment, __________ should be used for eye protection.

safety goggles Signup and view all the answers

When working where there is a limited amount of oxygen in the air (less than 19.5%), use a(n) __________ as respiratory protection.

supplied-air respirator Signup and view all the answers

When handling toxic or corrosive liquid chemicals, wear __________ gloves.

rubber or plastic Signup and view all the answers

A ladder being used to access an upper area should extend at least _________ above the step off surface.

3 feet Signup and view all the answers

Which of the following is an example of repair work?

replacing a failed compressor Signup and view all the answers

Replacing a working blower fan with a new fan that is more energy efficient is an example of which type of service work?

upgrade/system addition Signup and view all the answers

Define troubleshooting.

analysis of a problem, labor that corrects a problem and the use of instruments to solve a problem Signup and view all the answers

Why is the procedure given in a troubleshooting chart a good method to use?

it saves time, money and frustration Signup and view all the answers

With whom should a technician first speak when troubleshooting a problem?

the building owner Signup and view all the answers

What is the first step in troubleshooting?

obtain a description of the problem Signup and view all the answers

When you are troubleshooting and servicing a unit, quick and hasty decisions may result in __________.

additional and identical service work required later, necessary callbacks, and the unit being only temporarily fixed Signup and view all the answers

What does the first column in a troubleshooting chart list?

the problem Signup and view all the answers

The way a business interacts with customers is called _________.

customer relations Signup and view all the answers

Why do units with maintenance agreements last longer and have fewer breakdowns?

the units are tuned-up on a regular schedule, units are cleaned on a regular schedule, and written analysis of the system is kept Signup and view all the answers

The two main classifications of energy are __________.

potential and kinetic Signup and view all the answers

The law of conservation of energy states that __________.

energy can be changed from one form to another, energy cannot be created, energy cannot be destroyed Signup and view all the answers

__________ is the rate at which work is performed.

power Signup and view all the answers

Temperatures measured on the __________ scale can be converted to Fahrenheit temperatures by subtracting 460 degrees Fahrenheit.

Rankine Signup and view all the answers

The _________ of a substance is the amount of heat added or released to change the temperature of 1 lb of the substance by 1 degree Fahrenheit or 1 kg of the substance by 1 degree Kelvin.

specific heat capacity Signup and view all the answers

Enthalpy is the _________.

total amount of heat in a substance, calculated from an accepted reference temperature Signup and view all the answers

__________ is the method by which heat is transferred from one substance to another through a circulating medium, such as air or water.

convection Signup and view all the answers

Heat energy can be categorized as latent heat and _______ heat.

sensible Signup and view all the answers

Latent heat is heat added to a substance that ________.

causes the substance to change state Signup and view all the answers

The density of a substance is defined as the mass of the substance _________.

divided by its volume Signup and view all the answers

The weight of a substance is defined as the __________.

force of gravity acting on the substance Signup and view all the answers

If a substance has a specific gravity less than 1.0, it means that the substance is _________.

less dense than water Signup and view all the answers

Objects that float on water have a ________.

specific gravity less than 1 Signup and view all the answers

Relative density is defined as the ratio of the mass of a certain volume of a gas as compared to the mass of an equal volume of hydrogen. Knowing this concept and that density is mass per volume, a heavy gas would then have a relative density ________.

greater than 1 Signup and view all the answers

A ton of refrigeration effect is defined as the __________.

amount of heat energy absorbed when a ton of ice melts during one 24-hour day Signup and view all the answers

A gas is any physical substance that has __________.

no definite volume or shape and expands to fill its container Signup and view all the answers

According to the definition and the formula for pressure, if the area increases, __________.

pressure decreases Signup and view all the answers

According to Pascal's law, if a piston applies pressure to fluid in a sealed cylinder, the pressure will __________.

be applied equally and undiminished to all surfaces of the cylinder Signup and view all the answers

Critical pressure is the __________.

minimum pressure at which a gas at its critical temperature can condense Signup and view all the answers

The __ the pressure on a substance, the _ the temperature needed to bring about a change of physical state.

higher, higher Signup and view all the answers

__________ law states that if volume is held constant, temperature varies directly with pressure.

Gay-Lussac's Signup and view all the answers

__________ law states that in a confined mixture of gases, the pressure of each gas must be added to calculate the total pressure.

Dalton's Signup and view all the answers

According to the combined gas law, if the pressure of a gas is held constant as its temperature is increased, then the volume of the gas __________.

increases Signup and view all the answers

A saturated vapor will condense if the _________.

pressure of the vapor is increased and the temperature is decreased Signup and view all the answers

A cooling effect can be generated through _________.

air exchange, pressure change, and state change Signup and view all the answers

___________ refrigeration is like a dry sponge that has the ability to soak up a lot of water.

low-pressure liquid Signup and view all the answers

___________ refrigeration is like a soaking wet sponge that cannot absorb more water.

high-pressure vapor Signup and view all the answers

From the metering device through the evaporator to the compressor is the ___________ side of the system.

low Signup and view all the answers

From the compressor exhaust through the condenser and liquid line to the metering device is the ________ side of the system.

high Signup and view all the answers

Using suction, a compressor draws in refrigerant by creating ________ in the evaporator.

low pressure Signup and view all the answers

Using the process of compression, a compressor increases refrigerant __________.

pressure and heat content Signup and view all the answers

Commonly used in different HVACR applications, _________ compressors use a back-and-forth or up-and-down motion.

reciprocating Signup and view all the answers

A heat-exchanging device designed to expel or reject heat is a(n) _________.

condenser Signup and view all the answers

A condenser that uses a fan to remove heat more quickly is called a _________ condenser.

forced-air Signup and view all the answers

Heat flow can best be described as ________.

flowing from hot areas to cold areas Signup and view all the answers

A storage tank for liquid refrigerant on the high side of the systems is a(n) __________.

liquid receiver Signup and view all the answers

A refrigeration system with a(n)_________ metering device does NOT use a liquid receiver.

capillary tubes Signup and view all the answers

Into which tank can a technician pump a refrigeration system's entire refrigerant charge to perform service?

the liquid receiver Signup and view all the answers

The high-pressure line between the condenser and metering device is called the _________ line.

liquid Signup and view all the answers

To protect a system from dirt, moisture, metal, and other debris, install a(n) _________.

filter-drier Signup and view all the answers

A heat-exchanging device designed to absorb heat is a(n) ___________.

evaporator Signup and view all the answers

The instantaneous evaporation of liquid refrigeration in an evaporator is called _________.

flash gas Signup and view all the answers

A storage tank that traps liquid refrigerant on the low side of the system is a(n)__________.

accumulator Signup and view all the answers

An accumulator will function best with its inlet positioned __________ the tank.

at the top of Signup and view all the answers

The low-pressure line is sometimes called the _________ line.

suction Signup and view all the answers

What size wrench is used to loosen a 1/8" bolt?

below 1/2" bolt size, the wrench size is 3/16" larger than the bolt size - 2/16" + 3/16" = 5/16" Signup and view all the answers

Which of the following could be used to describe a box wrench?

double-ended, offset, double offset Signup and view all the answers

Which type of wrench can be used to access a bolt head or nut from the side?

open end wrench Signup and view all the answers

When should you push and pull on a wrench?

always pull Signup and view all the answers

Which tool is used to remove a screw with a hexagonal indent in the head?

hex key wrench Signup and view all the answers

Another name for a hex key wrench is a(n) _________.

allen wrench Signup and view all the answers

A(n) _________ wrench is used to open and close service valves.

refrigeration service valve Signup and view all the answers

A _________ is used to drive parts together without damaging them.

mallet Signup and view all the answers

Mainly used for cutting wires, _________ have angled jaws for making nearly flush cuts.

diagonal pliers Signup and view all the answers

Drill bit sizes are specified by the _________ of the hole they create.

diameter Signup and view all the answers

Which of the following are common types of punch?

drift, pin, prick, and center Signup and view all the answers

Which file type has only single-cut teeth?

mill Signup and view all the answers

A hacksaw with _______ teeth per inch is used to cut thin metal, tubing, and hard metal.

32 Signup and view all the answers

When cutting a hole into masonry to install an anchor for an outdoor condensing unit, the best tool to use is a _________.

hammer drill Signup and view all the answers

To quickly remove or tighten fasteners for unit assembly, the best tool to use is a(n) __________.

impact driver Signup and view all the answers

Study Notes

HVACR Career Overview

HVACR careers generally fall under Architecture and Construction.
Initial HVACR work involves equipment and systems installation.
Maintenance and repair of existing systems is categorized as service work.
The highest education and licensing requirements apply to HVACR engineers.

Estimation and Auditing

Estimators develop bids by calculating costs of equipment, materials, labor, and permits.
Energy auditors perform essential tests such as blower door tests, duct tightness tests, and thermal imaging.

Building Codes and Networking

Building inspectors ensure compliance with applicable building codes.
Networking is crucial for career development, involving connections within the industry.

Application and Interviewing

Job application paperwork typically includes an application form, cover letter, and resume.
A thank-you letter should be sent after an interview to express gratitude.

Professionalism and Habits

Employers prioritize good work habits: dependability, punctuality, and responsibility are key.
Leadership qualities include motivating others and problem-solving capabilities.

Safety and Certification

Professional behavior in HVACR includes team collaboration and positive attitude maintenance.
All HVACR professionals should obtain EPA certification before working with equipment.
State licensing often requires work experience, an application fee, and an exam.

Workplace Safety

The national safety code is governed by OSHA.
To prevent electrical hazards, implement lockout/tagout practices.
Use P.A.S.S. to remember how to operate fire extinguishers effectively.

Health Hazards and Risks

Symptoms of heat-related illnesses involve elevated temperature, headache, and dizziness.
Sudden refrigerant release can cause serious injuries like frostbite and skin damage.
Refrigerant cylinders must be stored vertically with the valve at the top.

Environmental Safety Practices

Use pressure regulators on nitrogen cylinders due to high internal pressure risks.
Good ventilation is necessary when working with heavier refrigerant vapors in confined spaces.
HEPA filters are needed when handling asbestos to ensure air quality.

Protective Equipment

Hearing protection is required in environments where voices need to be raised.
Safety goggles must be used in dusty work settings.
Supplied-air respirators are necessary in oxygen-deficient environments.

Tools and Equipment for HVACR

A ladder must extend at least 3 feet above the stepping-off surface for safety.
Replacing a failed compressor is an example of repair work.
Upgrade/system addition involves replacing a working component with a more efficient model.

Troubleshooting Techniques

Troubleshooting involves problem analysis, corrective labor, and instrument use.
Following a troubleshooting chart saves time, money, and reduces frustration.
The building owner should be the first point of contact when troubleshooting.

Energy Fundamentals

Energy classifications include potential and kinetic energy.
The conservation of energy principle states that energy can change forms but cannot be created or destroyed.
Power is defined as the rate at which work is performed.

Thermodynamics and Heat Transfer

Latent heat involves heat addition causing a state change; sensible heat is associated with temperature change.
Convection describes heat transfer through a circulating medium, such as air or water.

Refrigeration System Components

Refrigeration systems consist of a low side (evaporator, compressor) and a high side (condenser).
A compressor increases refrigerant pressure while drawing in low-pressure refrigerant.

Refrigeration Process and Protection

The refrigerant charge can be pumped into a liquid receiver for service.
Filter-driers protect systems from contaminants like dirt and moisture.

Tool Usage

Box wrenches are common, double-ended and can have offsets for access.
Pulling is advised over pushing when using wrenches to prevent injury.
Impact drivers are efficient for fastener assembly and disassembly.

Material and Fastening Techniques

Hammer drills are optimal for cutting holes in masonry for anchor installation.
Understand drill bit sizes as specified by the hole diameter they create.

These notes cover key concepts, terminology, and safety practices in the HVACR field, essential for both students and professionals.

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Modern Refrigeration and Air Conditioning - Review