HVAC FINAL

Three-phase AC voltage is a combination of three alternating voltage waveforms, each displaced ______ electrical degrees apart.

120

A condensing unit must be _____ away from a gas or electric meter.

3 feet

Air velocity of_____fpn in building spaces is considered ideal for comfort.

40

Comfor is typically attained at normal cooling and heating temperatures with a relative humidity of about _____%

50%

When installing a condensing unit on a roof, the unit should be installed at a minimum of _____ above the roof surface to avoid icy build up

6 inches

A _____ is a hand tool used to straighten the edges of thin metal fins that extend from condenser or evaporator coils.

A fin comb

An________ refrigeration systemn includes an absorber, generator, condenser, orifice, and evaporator.

Absorption

_________is the movement of air through distribution systems and building spaces.

Air circulation

_______is the process of removing particles and contaminants, such as gases and odors, from air that circulates through air distribution systems.

Air filtration

The mission of the ________ is to advance the arts and sciences of heating, ventilation, air conditioning. and refrigeration to serve humanity and promote a sustainable world.

American Society of Heating, Refirigerating, and Air-Conditioning Engineers (ASHRAE)

A clamp on _____ is a meter that measures the current in a circuit by measuring the strength of the magnetic field around a single conductor.

Ammeter

A(n) is a device that measures average air velocity or average airflow rate

Anemometer

The NFPA specifies live Circuits _____ boundaries where arc protection is required.

Approach

_______ Iists the major items that make up a control panel along with the sensors and actuators that are mounted in the field.

Bill of materials

A ____ is a circuit containing four diodes that permits both halves of an input AC sine wave to pass.

Bridge rectifier

A_____is the quantity of heat required to raise the temperature of I lb of water |°F.

British thermal unit (BTU)

______ is a hand tool with one fixed and one adjustable jaw used for making precision measurements

Caliper

A _____ is an electrical device that consists of two thin metal plates with an insulating dielectric material separating them

Capacitor

Transient voltages are often caused by lightning or stored voltages being released from

Capacitors

The signal word ______ is a word that indicates a potentially hazardous situation that, if not prevented, may result in minor or moderate injury or damage to equipment.

Caution

______ law is a gas law stating that when the pressure on a gas is constant, the volume of the gas is directly proportional to absolute temperature, and when the volume of a gas is constant, the pressure on the gas is directly proportional to absolute temperature.

Charles law

_________ is the hazardous location category that refers to the generic hazardous material present.

Class

_______ hammers are used to drive nails and to remove nails previously driven into a surface

Claw

A ________is a set of regulations or minimum requirements related to a particular trade or environment

Code

A._______ is a refrigeration system component that creates refrigerant flow

Compressor

A split system consists of an indoor unit, which is typically a furnace, and an outdoor unit, which is the ______ unit

Condensing

A _____ Is a space large enough that a technician can enter and perform assigned work but has limited or restricted means of entry and exit and is not designed for continuous occupancy

Confined space

______ tester is an instrument that tests for a complete path for current to flow.

Continuity

A _____ is a large heavy-duty, relay-like switching device that uses low voltage to energize or de-energize the high-current, nonmotor load connected to it

Contractor

_____ is a method of heat transfer in which heat is moved from one location to another through the circulation

Convention

_________is a defect caused by exposure to aggressive solvents, chemicals, or heat that leaves microscopic cracks within the lenses.

Crazing

___________ micrometer is a micrometer that measures component heights and slot depths

Depth

Common types of HVAC_____ include panel details, wiring details, and bills of materials.

Detail drawing

A _____ is a switch that isolates electrical circuits from a voltage source to allow safe access into an electrical panel for maintenance or repair

Disconnect

________ is the hazardous location category that refers to the probability that a hazardous material is present.

Division

A(n)________ indicates areas or tasks that can pose an electrical hazard to personnel and/or HVAC equipment.

Electrical safety label

The forms of _____ used in refrigeration and HVAC systems include mechanical, electrical, and heat.

Energy

A ____ is the part of a refrigeration system responsible for the absorption of heat from a product or building spaces into the fluid (refrigerant) of the system

Evaporator

A(n)_______leak detector is a stationary leak detector system with sensors and controllers to detect one specific type of refrigerant.

Fixed

A_______ is a hand tool applied to the end of tubing used to flare the end of the tubing

Flaring tool

_______ point is the temperature at which oil vapors ignite without the oil itself burning.

Flash point

Refrigerants should have low ______

Freezing point

Building HVAC systems typically use ______ or boilers to provide heating and air conditioners or chillers to provide cooling

Furnace

A_______ is a designation used to classify gases and dusts.

Group

_______ is the international unit of frequency equal to one cycle per second

Hertz

The manufacturing of class ____ refrigerants was stopped in the United States in 1995 because they cause great damage to the Earth's ozone layer when released into the atmosphere

I

______ is the production of current flow due to a magnetic field on a coil.

Inductance

A_______is a rope or webbing that is attached to a worker and a tie-off device to prevent the worker from hitting the ground or other object during a fall

Lifeline

A______ is a device that performs work.

Load

________ is the process of remnoving the source of electrical power from equipment and installing a lock that prevents the power from being turned on.

Lockout

________ pliers are used for bending and cutting thin wires and positioning small components.

Long nose pliers

The typical types of _____ are the digital, U-tube, and inclined-tube.

Manometer

A_______ file is an all-purpose, single-cut file especially adapted for finish filing

Mill

The purpose of _______ is to convey the safety requirements for persons in the workplace installing electrical conductors, electrical equipment, signaling and communications conductors, communications equipment, and raceways

NFPA 70E

_____ is sine wave distortion from motors and electrical devices that enters a power distribution system directly on the wires/grounds or through the magnetic coupling of adjacent wires

Noise

The ______ is a federal government regulatory agency that requires all employers to provide a safe environment for their employees.

Occupational Safety and Health Administration (OSHA)

______ law expresses the relationship between voltage, current, and resistance in a circuit

Ohms

A ______ shuts off the power supply to a circuit when current flow is excessive

Overcurrent protection device

A ________HVAC unit is a self-contained building cooling unit that has the components contained in one cabinet.

Packaged

A ______ is a type of NPN transistor that has a large, thin base region that is switched ON when exposed to a light source.

Phototransistor

______ can be used with attachments for screwing, grinding, and buffing.

Power drills

Most residential air conditioning systems today are charged with ______ refrigerant

R-410a

A _______is a rule that has been made mandatory by a federal, state, or local government.

Regulation

A _____ is a device that clamps securely to a rope and contains a ring to which a lifeline can be attached.

Rope grab

________ are gloves made of latex rubber and are used to provide maximum insulation from electrical shock.

Rubber insulating gloves

A(n)_____ is a printed document used to relay hazardous material information from the manutacturer, importer, or distributor to the technician.

Safety data sheet

________ is a copper tubing joining method that uses nonferrous filler metal with a melting temperature less than 840°F

Soldering

A______ is a hand tool used to cut internal threads in a predrilled hole or clean threads that have been disfigured by damage or improper operation

Tap

___________is the variation of air temperature in a building space that occurs when warm air rises to the ceiling and cold air drops to the floor.

Temperature stratification

________ is a device that detects heat levels from infrared energy emitted without making direct contact with the target

Thermal imager

A_____ is a permanently installed air-handling system device used to measure air velocity in a duct.

Thermoanemometer

A_______ is a solid-state switching device that switches current ON by a quick pulse of control current

Thyristor

A ____ is a three-terminal semiconductor, switch-like device that controls current according to the amount of voltage applied to the base

Transistor

________is the process of reducing air pollution by introducing enough fresh outdoor air into a building to dilute indoor pollutants.

Ventilation

The _____ signal word is a word that indicates a potentially hazardous situation that, if not prevented, could result in death or serious injury.

Warning

The abbreviations, symbols, and addresses that appear on plans also appear on ______

Wiring diagram

A______ is a hand tool with jaws at one or both ends that is designed to turn bolts, nuts, or pipes.

Wrench

_____ pressure is any pressure above a perfect vacuum (0 psia

absolute

R-717, also know as______________ is radically different from other refrigerants and is used in commercial deep freezers.

ammonia

______ pressure is the force exerted by the weight of the atmosphere (gas molecules) on the earth's surface

atmospheric

A _______ refrigerant is a type of refrigerant that consists of chlorine, fluorine, and carbon.

chlorofluorocarbon

A _____ is an overcurrent protection device with a mechanism that automatically opens a circuit when an overload condition or short circuit occurs

circuit breaker

A _____ is the part of a refrigeration system that rejects heat.

condenser

When a system operates close to the ___________ point ,the compressor must perform more work

critical point

_____ is the amount of electrons flowing through a conductor.

current

______ is the mass of a substance per unit of volume

density

_____ is the energy produced from the flow of electrons through a conductor

electricity

A _____ is an overcurrent protection device with a fusible link that melts and opens a circuit when an overload condition or short circuit occurs

fuse

_____ is the energy of a substance resulting from the internal motion of its molecular structure.

heat

According to the EPA ____ refrigerants pose a small risk of damage to the environment and are not categorized as Class I or Class II refrigerants.

hydrofluorocarbon

____ energy is the energy of work

mechanical

A _______ circuit is a circuit that has two or more components connected so that there is more than one path for current to flow

parallel

_______ point is the lowest temperature at which a liquid, such as gas, can flow.

pour point

A _____ is a substance that moves heat by changing state from a liquid to a gas when absorbing heat and from a gas to a liquid when rejecting heat

refrigerant

The opposition of current flow is called

resistance

_______ heat is the heat applied to or removed from a substance that results in a temperature change

sensible

_______ circuit is a circuit that has two or more components connected so that there is one path for current to flow

series

A ________ transformer has a lower output voltage than input voltage.

step down

_____ is the scientific study of the behavior of heat

thermodynamics

_____ is a condition that occurs when a substance contains harmful components that may cause health problems.

toxicity