Start what?

In open systems, static pressure on the discharge side of a pump is balanced by static pressure on the station side. True/False

False

In the adjustment of individual outlets or terminals, any restriction built up by adjusting the volume control dampers at one outlet may significantly decrease the flow through adjacent outlets. True/False

False

Initial checks and tests for proper and safe operation should be made immediately before start-up. True/False

False

Instruments measuring for duct air pressures, which are relatively low pressures, usually measure in unit inches of mercury. True/False

False

Matter is any substance that occupies space and has no weight. True/False

False

Medium-duty pulleys are rated for 75hp to 150hp. True/False

False

Moist air in a three-component mixture of dry air, water vapor, and smoke. True/False

False

Most manometer scales read ounces of water. True/False

False

Net positive suction head is normally not a consideration in open systems. True/False

False

Pressure below atmospheric pressure is usually referred to as impact pressure. True/False

False

Since mercury weighs 13.6 times as much as water, it will move 13.6 times the distance that water would move at a given pressure. True/False

False

Static pressure values are fairly high pressures and should be measured with the static tube of a Pitot tube and a gauge, such as a digital thermometer. True/False

False

Static pressure varies inversely with density. True/False

False

Test pressure is typically 85% to 100% of operating pressure. True/False

False

The brake horsepower actually required to drive a pump is less than the theoretical water horsepower by an amount equal to the inefficiencies in the pump. True/False

False

The calibration data for an orifice insert without a differential pressure gauge is furnished on the nameplate, which indicates the flow rate in CFM for the pressure drop as measured. True/False

False

The cooling of air usually involves the removal of moisture without a change in DB temperature. True/False

False

The direction and amount of deflection of grills and registers do not have an effect on throw and spread. True/False

False

The liquid in a liquid-in-glass thermometer is usually mercury or lead. True/False

False

The relative humidity of dry air is 100%. True/False

False

The speed of a turning wheel or shaft is usually determined in revolutions per hour. True/False

False

The term "flow coefficient," or "valve constant," is the flow rate in GPM that will cause a pressure a pressure drop of 2.31 PSI, 1 ft. of water, across a valve. True/False

False

The vertical portion of an inclined-vertical manometer gives it the ability to measure higher pressures, such as up to 12 or 15 in.w.g., in a compact instrument. True/False

False

Three basic types of air supply outlets are grilles, slot diffuser outlets, and floor diffusers. True/False

False

To determine chiller capacity, read and record water temperatures entering and leaving a cooling water tower and the dry bulb (DB) and wet bulb (WB) temperatures of the ambient air. True/False

False

Two-position type damper control provides gradual opening and closing of a damper. True/False

False

When a pump is field tested, it is likely that the actual GPM and head will be the same as the design values. True/False

False

When it comes to the rate of heat loss by conduction and convection, aside from the factor of humidity control, human comfort depends entirely on the WB temperature of the air. True/False

False

When using ratios to calculate the combined temperature of 2 mixed air streams, the sum of the 2 ratios must always be equal to 0. True/False

False

With centrifugal fans, nearly all the air velocity occurs at the side of the outlet nearest to the fan shaft. True/False

False

Psychrometrics is the concepts of start, test, and balance with an emphasis on the documentation of how a mechanical system relates to the other systems of a project. True/False

False Commissioning

Heat that results in a change of state, as from solid to liquid or liquid to vapor, with no change in the temperature of the substance is called sensible heat. True/False

False Latent

Evacuating and charging of a chiller should be done according to the standards published by the EPA. True/False

False Manufacturer

A common unit of pressure obtained when force is measured in pounds and area is measured in square inches, the resulting unit being pounds per square foot (PSF). True/False

False PSI

Testing, balancing, and adjusting are the procedures used to enable the proper shut-down and storage of a mechanical system. True/False

False Start-up

The logical sequence of the start-up and operation of a mechanical system is designated by the abbreviation TAB, which stands for testing, adjusting, and balancing. True/False

False TBA

3units in common use for defining the rate of heat flow are BTU per hour (BTUH), BTU per minute (BTUM), and millions of BTU per hour (MBH). True/False

False Thousands

All outlets or terminal units should be numbered beginning with the unit or outlet ___ from the supply fan.

Farthest

The velocity of air is ___ in the center of a duct.

Fastest

___ dampers are safety devices held in the open position by a fusible link, which will melt when it is subjected to enough heat. A. Splitter B. Fire C. Single-zone D. Manual volume

Fire

The advantage of using a(n) ___ thermometer is that it may be used to read the temperature in a remote location, such as inside a refrigerator with its door closed. A. Infrared B. Liquid-in-glass C. Multi-probe D. Flexible capillary

Flexible capillary

Control valves are used to regulate the ___ through terminal units. A. Pressure of liquid B. Flow of liquid C. Pressure of air D. Airflow

Flow of liquid

During ___, the rate of heat transfer increases with the acceleration in the velocity of the flow of the medium. A. Radiation B. Conduction C. Natural convection D. Forced convection

Forced convection

___ losses occur due to changes in air velocity and to air turbulence. A. Frictional B. Flow C. Static pressure D. Dynamic

Frictional

A(n) ___ should always be directly ahead of a gauge, which will permit removal of the gauge.

Gauge cock

Dial thermometers should be checked against a good ___ thermometer at the beginning of each testing project and periodically thereafter.

Glass stem mercury thermometer

A(n) ___ valve is capable of producing throttling actions and may be used for balancing, although it is not recommended.

Globe valve

The most elementary and accurate pressure measuring device is a ___. A. Thermometer B. Differential pressure gauge C. Gauge manifold D. Manometer

Manometer

For air side balance, all controls should be set to call for ___. A. Minimum heating B. Minimum cooling C. Maximum heating D. Maximum cooling

Maximum cooling

The ___ method for measuring and adjusting air terminals recommends beginning at the terminal farthest from the fan and proceeding toward the fan.

Proportional or Ratio

___ is the study of the physical principals governing the behavior of moist air

Psychrometrics

If air is not cooled to a temperature lower than its initial dew point temperature, then only___ is removed. A. Humidity B. Latent heat C. Moisture D. Sensible heat

Sensible heat

A locked rotor amperage (LRA) rating is typically ___ times the FLA rating of a motor. A. 3 to 5 B. 12 to 15 C. 15 to 18 D. 20 to 25

3 to 5

A fan operating with an inlet pressure of -1.5 in. W.C. total pressure and an outlet static pressure of +2.45 in. W.C. will have a pressure plotted on the fan curve at ___ in. W.C. A. 1.16 B. 2.03 C. 3.95 D. 4.78

3.95

With a perfect vacuum at the pump suction, the maximum lift would be a distance of ___ ft if the liquid is water in a normal temperature range. A. 0 B. 14.7 C. 34 D. 78.6

34

If velocity through a given duct fitting is doubled, the dynamic loss will be increased by ___ times.

4

In a hydronic heating system where water flows at a rate of 5 GPM, enters the boiler at 178° F, and leaves at 200°, the heat transfer from the boiler to the system is ___ BTUH. A. 114 B. 8800 C. 55000 D. 125000

55000

A medium pressure system has velocities greater than 2,000 ft/min or static pressure in the duct up through ___ in.w.g. A. 2 B. 6 C. 10 D. 15

6

For greatest accuracy, the airway in which an anemometer is to be placed should be ___ times the diameter of the instrument. A. 2 to 4 B. 4 to 6 C. 6 to 8 D. 8 to 10

6 to 8

For optimum success when using a velocity impact meter, the system water should be maintained between ___ pH to minimize corrosion. A. 1.4 and 3 B. 5.1 and 6.8 C. 7 and 8.6 D. 10 and 12.3

7 and 8.6

If possible, a traverse should be made at least ___ duct diameters downstream from a distance. A. 1-1/2 B. 3-1/2 C. 7-1/2 D. 10-1/2

7-1/2

Most fume hoods are designed to operate between ___ at the proper sash height. A. 5 ft/min and 10 ft/min B. 25 ft/min and 40 ft/min C. 50 ft/min and 85 ft/min D. 90 ft/min and 110 ft/min

90 ft/min

The latent heat in vaporization of water at standard sea level pressure is ___ BTU/LB.

970

___ is heat that causes changes in the temperature of a substance and can be measured with a thermometer. A. Saturated steam B. Kinetic energy C. Sensible heat D. Latent heat

Sensible heat

The difference between the suction and the discharge reading for a pump will be the ___.

Actual shut-off head

___ means setting automatic controls and the adjustment of any other devices that affect the manner in which a system operates.

Adjusting

Final steps for proportional balancing include ___. A. Adjusting the grille deflections and diffuser cones B. Setting all of the room thermostats for maximum cooling C. Comparing the measured flow in each branch with the design CFM D. Measuring the static pressure at multiple locations

Adjusting the grille deflections and diffuser cones

Current is measured with a(n) ___. A. Ammeter B. Ohmmeter C. Wattmeter D. Voltmeter

Ammeter

To the owner, an adequate job of testing, balancing, and adjusting means ___. A. Broken equipment gets repaired B. The equipment has gone through the period of initial operation without being subjected to improper or damaging operating conditions C. Avoiding complaints and call-backs from clients D. Assurance that what was paid for has been received

Assurance that what was paid for has been received

When both ends of a U-tube manometer are open, the liquid is ___. A. Separated B. Higher in the closed leg C. Higher in the open leg D. At the same height in each leg

At the same height in each leg

A straight, horizontal line on a psychrometric chart indicates that the heat added between 2 points is ___. A. From high-temperature water sprays B. Latent heat only C. Sensible heat only D. Both sensible and latent heat

Sensible heat only

It may be desirable to install ___ to reduce the amount of stratification in a duct.

Baffling

___ is the process used to regulate a distribution system, typically an air handling system and water pumping system,so they deliver the air, water, or other medium to all the intended locations and in quantities intended by design. A. Adjusting B. Balancing C. Start-up D. Testing

Balancing

On a graph, the intersection of an HQ or head-capacity curve with a zero capacity line indicates ___. A. Brake horsepower B. Shut-off head C. Static head D. Water horsepower

Shut-off head

A(n) ___ is an instrument used in the field to determine the DB and WB temperatures and, from them, the relative humidity in an air-conditioned space.

Sling psychrometer

Most air cooling and dehumidifying processes are represented as ___ lines on a psychrometric chart.

Sloping

For a given motor load and speed, an increase in voltage will result in a ___. A. Smaller power factor B. Greater power factor C. Smaller current D. Greater current

Smaller current

Soiling of a ceiling due to smudge can be reduced by installing a(n) ___ around the diffuser. A. Grille B. Outlet C. Control vane D. Smudge ring

Smudge ring

Most pressure leaks can be found audibly, although it may be necessary to use ___ to find some leaks. A. Fabric B. Ammonia C. Soap suds D. Dye

Soap suds

"___" is the term used to define the capacity of a substance to absorb heat as compared to that of water.

Specific heat

Humidity ratio is the weight of water vapor per pound of dry air, also known as ___. A. Latent heat B. Wet-bulb temperature C. Specific humidity D. Saturation temperature

Specific humidity

When testing for psychrometrics problems, equipment selections normally are based on ___ air. A. Standard B. Dry C. Atmospheric D. Moist

Standard

___ air is dry air at 70°F with a pressure of 29.92 in. Hg and a weight of .075 lb/cu ft.

Standard

Upon initial ___ of a system, testing should confirm that the equipment is operating properly and safely.

Start-up

Any reduction in excess ___ will save the fan horsepower, reduce operating cost, and tend to reduce system noise.

Static pressure

Some terminal units have self-contained regulators and require a certain minimum ___ at their inlet for them to work.

Static pressure

___ is a measurement of the resistance a duct system presents to the flow of air.

Static pressure

Fan ___ is equal to the rise in total pressure across the fan, diminished by the velocity pressure created by the fan.

Static pressure.

The 2 types of dial thermometers are ___. A. Stem and flexible capillary B. Steam and gauge C. Rod and flexible capillary D. Rod and gauge

Stem and gauge

A ___ is an electric tachometer that uses an electronically controlled flashing light. A. Centrifugal-type tachometer B. Digital photo tachometer C. Stroboscope D. Chronometric tachometer

Stroboscope

___ head existed when the source of supply is above the center line of a pump.

Suction

When using a U-tube manometer, the pressure is the ___ of the readings in the two legs.

Sum

___ pressure is the actual atmospheric pressure r a specific location and time, and it may be needed for accurate results in some cases when testing air flow. A. Vacuum B. Absolute C. Gauge D. Barometric

Barometric

A(n) ____ tube is a metal tube of flattened oval cross+section and is bent into a part circle.

Bourdon

___ Law states that the volume of gas varies inversely with the absolute pressure when the temperature remains constant. A. The combined gas B. Boyle's C. Charle's D. Gay-Lussac's

Boyle's

___ horsepower is the actual horsepower required to drive a fan. A. Static B. Total C. Start-up D. Brake

Brake

Any significant adjustment of air volume in a distribution system should be done by adjusting branch duct splitters or manual volume dampers, or by ___. A. Introducing a humidifier into the system B. Changing the fan speed C. Changing the direction of the air flow D. Introducing a dehumidifier into the system

Changing the fan speed

When coal is burned under a boiler, its ___ energy is transformed into heat energy in the steam.

Chemical

A ___ combines a revolution counter and a stop watch in one instrument. A. Chronometric tachometer B. Stroboscope C. Digital photo tachometer D. Centrifugal-type tachometer

Chronometric tachometer

___ is a well-planned process of verifying and documenting that a project or system can perform as the design intended.

Commisioning

A(n) ___ gauge should be used where exposed to vacuum.

Compound

___ is the transfer of heat by movement of a fluid, such as air or water.

Convection

Before any system can be balanced properly, the ___ must develop enough static pressure for the system, and the air volume handled by it must be adequate for the system. A. Air damper B. Supply fan C. Filter D. Return air fan

Supply fan

The resistance to air flow in a straight, unobstructed duct is caused primarily by ___. A. A low velocity of the air B. A difference in pressure from either end of the duct C. Static pressure D. Surface friction as the air scrubs the duct walls

Surface friction as the air scrubs the duct walls

Inlet ___ pressure is equal to inlet static pressure plus inlet velocity pressure. A. Filter B. Total C. Exhaust D. Box

Total

___ pressure is the sum of static pressure and velocity pressure. A. Discharge B. Air flow C. Total D. Impact

Total

Pumps are rated in volume of fluid pumped, usually in GPM, against a certain pressure of head, called ___.

Total dynamic head

2 forms of convection are natural and forced convection. True/False

True

A 10° temperature rise is different than a temperature of 10° True/False

True

A U-tube manometer could be made from a piece of glass or a clear plastic tubing, a ruler, and some water. True/False

True

A U-tube manometer is inherently 100% accurate. True/False

True

A chronometric tachometer is accurate within .05% True/False

True

A duct system is classified as high pressure when duct velocity is greater than 2,000 ft/min or static pressures in the duct are more than 6 in.w.g. And up to 10 in.w.g. True/False

True

A pump does not suck water into its inlet connection. Instead, atmospheric pressure pushes the liquid up into the pump. True/False

True

A sling psychrometer must be whirled around to produce an air velocity of at least 700 ft/min relative to the thermometer bulbs. True/False

True

A small motor operating with no load will have a very low power factor. True/False

True

A stream discharged adjacent to a ceiling will tend to follow along in contact with the ceiling until its velocity is greatly diminished. True/False

True

A system can be placed in operation after gathering information and documentation on the testing results and inspecting that the installation appears safe to start. True/False

True

A system that requires a chilled water supply of 45°F will not ordinarily be satisfied by the water supply at 50°F, even though the total BTUH rate may be as required. True/False

True

A tachometer must be held so the instrument spindle is in line with the shaft whose speed is being measured. True/False

True

A thermometer well should extend at least halfway across a pipe. True/False

True

A turbine thermometer provides an output signal that varies with the flow rate. True/False

True

A/C equipment can treat moist air by adding or removing sensible heat, adding or removing moisture, or by a combination of changes in both sensible heat and latent heat. True/False

True

Adiabatic saturation is the process of saturating air with moisture without any change in the total heat. True/False

True

An inch of water is a unit used to measure the resistance exerted by a vertical column of water one inch in height. True/False

True

Anemometers measure air velocity directly. True/False

True

Balancing procedures ensure that media, such as air and water, are available at the correct locations and in quantities needed. True/False

True

Before each use, thermometers should be visibly checked for liquid separation. True/False

True

Changes in DB temperature are indicative of changes in sensible heat True/False

True

Every fan operates only along its performance curve. True/False

True

Fans used in heating, ventilating, and A/C work are divided into two general classifications, centrifugal fans and axial flow fans. True/False

True

For reasons of economy or available building space, direct return riser systems may be preferable to reverse returns for each individual building. True/False

True

Gauge pressure, when measured in pounds per square inch, is indicated by the abbreviation PSIG. True/False

True

If a fan serves only one hood and is not at a great distance from the hood, it may be assumed that the airflow measured at or near the fan is equal to the air volume entering the hood. True/False

True

If a thermometer must be removed from a refrigerator, coil housing, etc., to be read, it will cease to be in contact with the air and thus will not give a true reading. True/False

True

If a velocity pressure has been measured, the corresponding velocity can be determined. True/False

True

If moist air is cooled to a temperature below its initial dew point, a portion of the moisture in the air will condense and be separated from the air. True/False

True

If the variation in the face velocity of a grille exceeds 25%, the air flow should be balanced to obtain a more even distribution over the face of the grille. True/False

True

In A/C systems, the design of duct and fan systems is based on volume (in CFM). True/False

True

Individual outlet or inlet volume control dampers and register dampers should not be used for balancing other than to balance flow between individual outlets on a duct run or for touch-up adjustment to local occupant comfort. True/False

True

It is generally agreed that air-handling systems should be tested and balanced before work is done on hydronic, steam, or refrigeration systems. True/False

True

Liquid-in-glass thermometers have the advantage of being inexpensive, easy to carry, and reasonably accurate. True/False

True

Many terminal units or control boxes use a device called a constant volume regulator, the purpose of which is to maintain a constant flow of air in the system regardless of the pressure in the supply duct. True/False

True

No single specific balancing procedure applies to all systems. True/False

True

One way to measure the current flowing through a conductor is to break the conductor and insert a meter in the circuit. True/False

True

Proper hydronic system start-up should minimize the amount of make-up water needed. True/False

True

Schematic layouts should indicate all dampers, regulating devices, terminal units, outlets, and inlets of a system. True/False

True

Sheaves with belt speeds above 6,000 FPM to 6,500 FPM require special balancing. True/False

True

Since cooling capacity usually is more critical than heating capacity, balancing is normally done with dampers set for full cooling. True/False

True

Splinter dampers are used to direct air from a main supply duct into a branch duct. True/False

True

Static pressure is pressure within a duct that tends to burst the duct. True/False

True

Static pressure readings, when referred to fan capacity data, may give incorrect results. True/False

True

The Pitot tube, when used with an appropriate pressure gauge, is the preferred device for measuring the air velocities in a duct. True/False

True

The balancing and adjustment of a system may require adjustment of the blade pitch. True/False

True

The efficiency of a motor determines the power consumed by the motor as compared to the horsepower produced. True/False

True

The final balancing of an air system includes calibrating the operating and safety controls. True/False

True

The rate of flow is directly proportional to the change in temperature and to the area of the surface through which heat will flow. True/False

True

The type of pressure gauge to be used depends on the magnitude of the velocity pressure being measured and the accuracy desired. True/False

True

There are 3 important factors concerning the behavior of gases: their temperature, the pressure being exerted on them, and their volume. True/False

True

Thermometer test wells are used to house thermometer bulbs at locations where the temperature of fluid in a pipe is to be measured. True/False

True

Three-phase motors can be reversed by interchanging any two of the three power leads to the motor. True/False

True

Velocity head in a pump is usually insignificant and can be neglected. True/False

True

Velocity pressure is not read directly but as the difference between total pressure and static pressure. True/False

True

Water horsepower is the theoretical horsepower that would be required is a pump were 100% efficient. True/False

True

When a conversion is performed from Hg. to feet of system fluid, the correct conversion will depend on the density of the fluid. True/False

True

When it is necessary to change one belt in a multi-belt drive, all belts in the drive should be replaced with a matched set. True/False

True

When preparing the start-up process for a hydronic system, outdoor conditions usually determine which hydronic system is started first. True/False

True

When using a Bourdon gauge, normal calibration consists of subjecting the gauge to a known pressure, as applied by a "dead-weight" tester, and resetting the linkage or the pointer to read correctly. True/False

True

When using a digital photo tachometer, the rotating object is marked with a reflecting tape, and the probe is then held 1/4" to 25' from the rotating object. True/False

True

The intensity of heat is usually measured using the Fahrenheit temperature scale in the U.S. True/False

True Because 'Murica

The conversion of the upstream static pressure to the velocity pressure of an orifice is not completely efficient, but there is a loss due to ___.

Turbulence.

The actual balancing procedure of air distribution to be used will depend on the ___. A. Size of the system B. Location of the system C. Type of system D. Capacity of the system

Type of system

___ manometers are most suitable for measuring pressures of several in.w.g. or more.

U-tube

The freezing point of mercury is ___°F.

-40

Absolute zero is equal to ___. A. -57°F or -49°C B. -128° F of -89°C C. -275° F or -171°C D. -460°F or -273°C

-460°F or -273°C

The coefficient of performance is normally in the range of ___. A. .2 to .3 B. .6 to .7 C. 1.0 to 1.1 D. 1.4 to 1.5

.6 to .7

Small- to medium-size equipment usually is supplied with an adjustable pitch motor sheave, which permits adjusting the speed within a range of perhaps ___ without changing sheaves. A. 0.5% tp 1% B. 5% to 10% C. 25% to 30% D. 45% to 50%

25% to 30%

Head is equal to ___ if the pump discharge gauge reads 128 psi and the suction gauge reads 20 psi. A. 64 in.Hg. B. 148 psi C. 250 ft D. 296 ft.w.g.

250 ft

Oil having a specific gravity of about 0.83, as compared to water, will rise a distance of about ___ in. at a pressure of 1in. of water. A. 0.21 B. 0.83 C. 1.2 D. 1.83

1.2

The tension on a belt is about right if it can be depressed about ___ under normal pressure from the thumb. A. 1/4" to 1/3" B. 1/2" to 3/4" C. 1" to 1-1/3" D. 1-1/2" to 2"

1/2" to 3/4"

If a gauge is of a large diameter, such as 8", differential pressures can be read accurately to the order of ___ ft. w.g. A. 1/4 B. 1/2 C. 2/3 D. 1

1/4

After all tests and adjustments of fan speed have been made, if the measured CFM of the supply fan, return air fan, or central exhaust fan varies by more than ___% from the design, the drives of each fan must be adjusted to obtain approximately the required air quantities. A. 10 B. 20 C. 30 D. 40

10

It is normally considered that there is an adequate and practical balance when the air quantities, as measured on the job, are within plus or minus ___% of design volumes. A. 10 B. 15 C. 20 D. 25

10

When performing an initial fan check, voltage should be within plus or minus ___% of the motor nameplate rating, and 3-phase voltages must not vary from one another beyond acceptable limits. A. 3 B. 5 C. 10 D. 15

10

A condenser water system should be designed to produce enough capacity after about ___ years of accumulation of corrosion and scale.

10 years

For traversing square or rectangular duct, the cross-section should be divided into at least ___ equal square areas.

16

___ is a measure of the actual weight of water vapor per unit volume of air.

Absolute humidity

___ pressure is the sum of atmospheric pressure plus gauge pressure. A. Vacuum B. Absolute C. Barometric D. Atmospheric

Absolute

A practical measure of heat is the ___. A. BTU B. Melting point C. Boiling point D. PSIG

BTU

___ remains constant in a duct system regardless of changes in air density, provided the fan operates at constant speed and the duct system remains unchanged.

CFM

Pump ___ is expressed as the flow rate or volume, usually in GPM, that a pump can discharge against a given pressure or head.

Capacity

____ is a result of insufficient available net positive suction head that cause low pressures, such that some of the pumped liquid flashes into vapor and forms bubbles. A. Cavitation B. Static head C. Friction head loss D. Dynamic loss

Cavitation

Because open systems are highly susceptible to ___ with the passing of time, pipe friction values should be greater than those for new pipe. A. Leakage and pipe breaks B. Corrosion and roughening of the pipe C. Buildup on pipe walls D. Fitting expansion

Corrosion and roughening of the pipe

A ___ arrangement is when one of the heat transfer media travels in a path that is at right angles to the path of the other medium. A. Cross-flow B. Counterflow C. Parallel D. T-flow

Cross-flow

On a psychrometric chart, specific volume is measured in ___. A. Pounds per square inch B. Cubic feet per pound C. BTU per pound D. Cubic feet per minute

Cubic feet per pound

A clamp-on ammeter can be clamped around a conductor to measure the ___ through the conductor. A. Voltage B. Current flow C. Capacitance D. Resistance

Current flow

Glass-stem test thermometers of good quality have the temperature scale painter on the stem. True/False

False

If a thermometer well cannot be installed exactly vertical, then it must be installed so the open end is not more than 90° across the pipe. True/False

False

___ control air volume in duct systems by imposing a high static pressure loss as airflow is restricted.

Dampers

During the application of sprays, if the spray water is colder than the dew point of the entering air, the sprays will ___ the air.

Dehumidify

If balancing has been done with a dry cooling coil, the total air flow must be rechecked when the coil is ___ and is therefore wet, as its resistance to air flow will be greater when wet than when dry.

Dehumidifying

The usual purpose of measuring the velocity of air in various parts of an air handling system is to ___. A. Compare temperatures of the air through various parts of the system. B. Determine the volume of the air flowing. C. Direct the desired amount of air to a specific area D. Find where air is being dropped or diverted from the system

Determine the volume of the air flowing

___ is the DB temperature at which the atmospheric air becomes saturated with water vapor. A. Dew point temperature B. Enthalpy C. Humidification D. Sensible heat

Dew point temperature

___ are more rugged and easier to read than glass-stem thermometers, and they are fairly inexpensive.

Dial thermometers

According to the best recommendations, when using a sling psychrometer ___ water should be used to wet the wick, using a medicine dropper to transfer the water from the bottle to the wick.

Distilled

Where banks of filters or coils are large enough to make them accessible, measurements should be made on the ___ side of the filter or coil.

Downstream

A(n) ___ is any localized feeling of coolness or warmth (but generally associated with coolness) due to temperature and rate of movement of a current of air.

Draft

___ air is atmospheric air from which all water vapor, and also all contaminants, such as smoke, etc., have been removed.

Dry

A(n) ___ is performed by sealing off the system or section of a system to be tested, applying pressure with a blower, and measuring the volume of air supplied by the blower.

Duct leakage test

If the pressure inside a duct is greater than the pressure outside the duct, then air will flow into the duct. True/False

False

In a round duct, velocity pressure readings should be taken at the edge of the duct. True/False

False

Hand-held chronometric tachometers with speed ranges contain a centrifugal lay operated mechanism similar to the fly-ball governor on a stationary stem engine or the governor on a gasoline engine. True/False

False

The sum of the areas of all the vena contractas existing at a grille or diffuser is called the ___ area of the grille or diffuser. A. Drop B. Gap C. Operating D. Effective

Effective

Heat is a form of ___.

Energy

____ is the capacity for doing work.

Energy

___ is a measure of the total heat energy of air.

Enthalpy

Friction losses for fittings usually are given in ____. A. Inches of suction lift B. Feet of pressure drop C. Inches of suction head D. Equivalent feet of pipe

Equivalent feet of pipe

The flow of heat from one object or substance to another is referred to as heat ___. A. Loss B. Exchange C. Flow D. Balance

Exchange

The term "___" is particularly applicable to the average velocity of the air entering an intake grille.

Face velocity

A kilowatt (kW) is a unit of power equal to 100 watts. True/False

False

A method of uniting a separated liquid column in a thermometer is to cool the bulb enough to draw all of the liquid out of the bulb. True/False

False

A voltage imbalance of 10% on a motor is considered the maximum by industry standards. True/False

False

Any shortage of the air in a hydronic system results in a corresponding increase in capacity. True/False

False

As a load increases, the power factor is reduced. True/False

False

Balancing may include items such as adjusting grille and diffuser air patterns to eliminate drafts or changing the air volumes to produce more desirable temperatures in some areas. True/False

False

Dial thermometers have a relatively shot time lag. True/False

False

During the operation of a gauge modification using a single standard gauge, the gauge glass is fully tightened into place to prevent damage. True/False

False

Electrical testing instruments with wireless communications contain a very sensitive meter, usually a milliammeter, which can measure current in hundredths of an ampere. True/False

False

Fans are rated on the basis of the amount of velocity pressure they can develop as an indication of the amount of duct resistance they can overcome. True/False

False

Flow hoods are made of aluminum. True/False

False

For testing and balancing purposes, the dynamic loss in a square elbow with properly made turning vanes will be roughly equal to the friction in a duct that is 10 duct diameters in length. True/False

False

A good rule of thumb is, for every 35° increase above 85°, the belt life is reduced by ___.

Half

Input voltage and current measurements on variable frequency drives usually will be affected by ___.

Harmonics

A turbine flow meter determines the fluid flow rate to a(n) ___.

Heat exchanger

A pyrometer is used to measure ___ A. Low temperatures B. High temperatures C. Low pressures D. High pressures

High temperatures

Belts are rated by ___ per belt.

Horsepower

The approximation or estimation of ___ is a valuable indication of the flow or the component or system performance.

Horsepower

The pressure exerted by a liquid due to its own weight is called ___ pressure.

Hydrostatic pressure

Class ___ construction is standard, relatively lightweight fan construction A. I B. II C. III D. IV

I

The larger the area of a duct, the ___ the velocity of the air.

Lower

A(n) ___ is an open tube face directly into an air stream to receive the effects of both static pressure and velocity.

Impact tube

A(n) ___ manometer is a variation of a well-type manometer in which the indicating leg or tube is placed in a sloping position rather than vertically. A. Inclined B. Handheld C. Dry-type D. U-tube

Inclined

The ___ is best suited to measuring fairly low pressures, such as in the range of 0.10 to 1.0 in.w.g. A. Inclined-vertical B. Well-type manometer C. Inclined draft gauge D. Dry-type draft gauge

Inclined draft gauge

___ are used for a non-contact temperature measurement. A. Thermistors B. Pyrometer C. Infrared thermometers D. Flexible capillary thermometers

Infrared thermometers

One factor involved in the measurement of heat is the ___ of heat as indicated by the temperature of the substance. A. Quantity B. Intensity C. Quality D. Weight

Intensity

Initial start-up and balancing usually occurs when a building ___. A. Is empty or only partially occupied B. Has been occupied for one week C. Has been occupied for one month D. Has been occupied for one year

Is empty or only partially occupied

As a chilled water flow rate decreases in a hydronic terminal unit, the coil surface temperature rises, and ___ heat capacity is lost. A. Total B. Specific C. Sensible D. Latent

Latent

Total heat is equal to sensible heat plus ___ heat.

Latent

Operation of a(n) ___ thermometer is based on the principle that materials expand when heated and contract when cooled.

Liquid-in-glass

A duct system is classified as a ___ system when velocity are less than 2,000 ft/min and static pressure in the duct is 2 in.w.g. or less. A. Stagnant flow B. Resistive C. Low pressure D. High pressure

Low pressure

When a Bourdon gauge is used, pressure ranges should be selected so the pressures to be measured fall in the___ of the scale range. A. First half B. Middle two-thirds C. Last third D. Second half

Middle two-thirds

The curved upper surface of a liquid column in a manometer is called the ___.

Miniscus

A common process occurring in A/C systems is the mixing of 2 streams of ___ air.

Moist

Brake horsepower may be estimated by comparing the ___ voltage and current with the actual voltage and current as measured on the job.

Motor nameplate

___ can be arranged for either parallel operation or opposed blade operation.

Multi blade danpers

When balancing ___, check the fan CFM against the cooling coil CFM.

Multi-zone units

The ___ divides pulleys into three standard series: light duty, medium duty, and heavy duty. A. American Society of Heating, Refrigeration, and Air-Conditioning Engineers, Incorporated (ASHRAE) B. Airflow Dynamics Corporation of America C. National Belting Committee (NBC) D. National Industrial Belting Association (NIBA)

National Industrial Belting Association (NIBA)

___ may be considered to be the amount of pressure, in excess of the vapor pressure, required to overcome internal pump losses.

Net positive suction head available

If a bypass or hot-deck damper in an A/C system does not close properly when a need for maximum cooling is required, the supply air will___ may have been intended. A. Be colder than it B. Not be as cold as C. Not circulate as D. Be more humid than

Not be as cold as

The unit of impedance in alternating current circuits is measured in ___.

Ohm

The relationships among voltage, current, and resistance or impedance are given by ___.

Ohm's law

A(n) ___ can be used to check for an open circuit, or circuit continuity.

Ohmmeter

The ___ of a system is the condition of CFM and static pressure at which the system actually operates.

Operating point

A(n) ___ is any opening in the wall of a containing vessel.

Orifice

___ is the theoretical velocity of air as it leaves a fan outlet.

Outlet velocity

A manometer may be equipped with ___, which can seal the mercury within the manometer in the event there is sufficient pressure to raise the mercury up out of the manometer.

Over pressure trap

___ is the pressure in pounds that a fluid is exerting on a surface one square inch in area.

PSI

___ is a change in a measurement reading due to a change in the position of the eye.

Parallax

It is common to find ___ pumps on hydronic loops. A. Standby B. Series configured C. Swing D. Parallel configured

Parallel configured

Maximum suction lift would be theoretically possible if there was a(n) ___ at the pump suction.

Perfect vacuum

The first step in starting a chiller is to ___. A. Flush the chiller with bleach B. Flush the chiller with water C. Place the condenser water system in operation D. Check the cooling fan

Place the condenser water system in operation

Belt tension testers operate on the principle of measuring the force in ___ needed to depress or deflect the belt a given amount.

Pounds

A(n) ___ is simply the ratio of true power and apparent power.

Power factor

The bending of a spring in a dry-type draft gauge is proportional to the ___ to be measured.

Pressure

Flow rates usually are determined by measuring the ___ across a piece of equipment or a balancing device, and then referring to the performance or calibration data to determine the flow rate.

Pressure drop

The ___ in a duct are classified as static, velocity, and total.

Pressures

The ___ fan characteristically has a wheel that is narrow but of a comparatively large diameter.

Radial bladed

___ is a means of energy transfer similar to that produced by light waves and radio waves.

Radiation

Adjustment of the airflow normally would be done by ___ until obtaining a pressure drop reading that corresponds to the desired CFM. A. Resetting a damper in the box B. Inserting a rubber stopper into the Pitot tube C. Replacing the regulator D. Placing a hood over the diffuser

Resetting a damper in the box

System ___ is the sum total of all pressure losses through the ductwork and through filters, coils, dampers, etc. A. Drop B. Resistance C. Flow D. Draw

Resistance

Electrical energy can be converted to heat energy by passing the electricity through a(n) ___.

Resistance heating coil

Whenever there are 2 or more terminal units on a 2-pipe system, the return may be arranged in one or two commonly used ways, the direct return or the ___ return. A. Reverse B. Diverting C. Inverse D. Indirect

Reverse

A(n) ___ consisted of a light windmill or propeller wheel that is connected through a gear train to a set of dials that read the linear feet of air passing through the wheel.

Rotating vane anemometer.

When air holds the maximum amount of water vapor possible at a given temperature and pressure, the air is said to be ___. A. Wet B. Dry C. Unsaturated D. Saturated

Saturated

A(n) ___ is an instrument used to measure the speed at which a shaft or wheel is turning.

Tachometer

For new belt drives, the ___ must be rechecked after initial operating periods, such as after the first 12 hrs and 72 hrs of operation, and adjusted if necessary.

Tension

A(n) ___ is a device or unit, often a box, located where a supply duct or duct branch terminates and the air is introduced into the space to be conditioned.

Terminal unit

___ can provide assurance that equipment can operate safely and without danger of being damaged because of being overloaded.

Testing

Fluid temperature may be roughly determined with a strap-on thermometer strapped to a pipe or by putting___. A. The bulb of a thermometer in contact with a pipe and covering it with putty B. A thermometer bulb directly into the branch main C. The shut-off valve in a wide open position and reading the temperature at the opening D. A strap-on thermometer around the generator

The bulb of a thermometer in contact with a pipe covering it with putty

A multi-purpose pump discharge valve acts as a check valve to prevent ___ when the pump is off and to prevent stray flows between operating and non-operating piping circuits. A. The gravity circulation of hot water B. The forced circulation of coolant C. Improper pump operation D. An increase of internal temperature

The gravity circulation of hot water

Written records of ___ will provide a reference point and a basis for changing a system to meet new conditions.

The initial operation

A(n) ___ is a type of transistor or semiconductor and is a solid-state electronic device.

Thermistor

___ is the distance from a grille or the radius from a ceiling diffuser to a point where motion of the mixed air stream is reduced to a given velocity, called the terminal velocity. A. Throw B. Spread C. Drop D. Outlet

Throw

___ is the velocity at the outermost part of a fan blade relative to the fan housing. A. Tip speed B. Dynamic loss C. Fan performance D. Horsepower

Tip speed

A pump suction pressure less than atmospheric would be read as a(n) ____ in inches of mercury.

Vacuum

The total dynamic head of a pump consisted of ___. A. Velocity head, atmospheric pressure, and dynamic losses B. Static head, atmospheric pressure, and leakage losses C. Velocity head, friction losses, and static head D. Friction losses, dynamic losses, and static head

Velocity head, friction losses, and static head

The coefficient of performance is a number that considers effects of the ___.

Vena contractas

A(n) ____ operates on the same general principle as an orifice, but it is shaped so as to avoid abrupt changes in velocity.

Venturi

Voltage, or electrical potential or pressure difference, is measured in ___ . A. Amperes B. Watts C. Ohms D. Volts

Volts

An air ___ is a chamber containing a system of water sprays through which air is passed. A. Humidifier B. Chiller C. Dehumidifier D. Washer

Washer

When a manometer is used on a hydronic system, ____ from the system will rest on top of the mercury in the manometer. A. Coolant B. Air C. Water D. Lubricating oil

Water

___ in a thermometer well may be undesirable if the test well is made of a type of steel that could rust. A. Lubricating oil B. Air C. Mercury D. Water

Water

Power is measured with a(n) ___.

Wattmeter

One leg of a(n) ___ manometer is a tube but the other leg is an enlarged reservoir or well. A. Flexible tube B. Well-type C. U-tube D. Inclined-vertical

Well-type

___ is the temperature registered by a thermometer whose bulb is covered by a wick that is wetted with water and exposed to a current of rapidly moving air.

Wet bulb temperature

If the maximum RPM of a centrifugal fan is exceeded, the shaft may ___.

Whip

For maximum heating or for maximum cooling with refrigeration, the return air damper should be, ___, and the outside air damper set for minimum outside air. A. Partially open, the relief damper shut B. Wide open, the relief damper partially open C. Partially open, the relief damper fully open D. Wide open, the relief damper shut

Wide open, the relief damper shut