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WorksheetsACR-201 FINAL
Total questions: 78
Worksheet time: 39mins
ASHRAE Standard , “Ventilation for Acceptable Indoor Air Quality,” is the standard generally used to determine acceptable indoor air quality.
55
15
90
62
An electrostatic precipitator is the same as
an extended surface air filter.
a fiberglass media filter.
an electronic air cleaner.
a washable steel air filter.
A colorless, odorless, radioactive gas that can cause lung cancer is:
Smog
Carbon Monoxide
Methane
Radon
The purifier ingredient in an activated charcoal air purifier may be
activated carbon.
coconut shell pellets.
manufactured from coal.
any of the above.
Examples of biological contaminants are:
Mold and mildew
Viruses
Dust mites
All the above
Ion generators ________ particles in an area.
disintegrate
charge
wash
remove odors from
Methods for controlling indoor air contaminants include eliminating the source of contamination, providing adequate ventilation, and adding odorants to eliminate foul smells.
True
False
The relative humidity in heated homes is generally the ________ in the winter season.
highest
lowest
General types of air cleaners include ultraviolet-C light and ion generators as well as:
Volatile filters and mechanical filters
Outdoor filters and indoor filters
Mechanical filters and electronic air cleaners
Electronic air cleaners and humidifiers
The recommended relative humidity for a home is between
50% and 70%.
20% and 40%.
30% and 50%
40% and 60%.
Static electricity is more commonly a problem when the air is ________.
dry
moist
The plenum-mounted humidifier is installed in the ________ plenum.
supply
return
supply or return
True or False: Carbon monoxide is produced by mixing vapors from nitrogen dioxide and sulfur dioxide.
True
False
Fiberglass filter media is generally coated with a special nondrying, nontoxic adhesive on each fiber.
True
False
Some humidifiers have their own water-heating devices.
True
False
When the relative humidity goes above 60%, ___________.
nasal and throat passages dry out
static electricity in the air can cause small electric shocks
bacteria, viruses, fungi and other organisms become more active
furniture joints and floors may loosen and creak
___________ is the process of supplying air by natural or mechanical means to a space.
infiltration
ventilation
decontamination
filtration
A fiber found in older pipe and furnace insulation materials, shingles, textured paints, and floor tiles that is dangerous and may cause lung cancer is ________.
asbestos
lead
formaldehyde
pesticides
________ is a fungus that releases it spores, which can be harmful to humans, into the air and is usually found in areas of high humidity.
Mold
Radon
Dust Mites
Asbestos
Sick building syndrome is a term given to situations when people who spend considerable time in a particular building experience health problems.
True
False
A poisonous, lighter-than-air, colorless, odorless gas that is produced by incomplete combustion is ________.
methane
carbon dioxide (CO2)
nvironmental tobacco smoke (ETS)
carbon monoxide (CO)
Pollutants released from combustion appliances include nitrogen dioxide and sulfur dioxide.
True
False
A type of filter that is capable of capturing particles as small as .3 microns is a ________.
pleated filter
pocket filter
cube filter
HEPA filter
The term used to express the amount of moisture in the air compared to the amount of moisture it can hold at a specific temperature is called __________.
relative humidity
absolute humidity
water vapor
latent heat
Two types of atomizing humidifiers are the spray-nozzle and the evaporative.
True
False
The propeller-type fan is most often used as a(n) ___________.
centrifugal blower
exhaust fan or a condenser fan
blower motor in a residential gas furnace
all of the above
The two types of drive assemblies that are commonly used to turn fans and blowers are __________.
rotary drive and scroll drive
direct drive and rotary drive
belt drive and direct drive
screw drive and rotary drive
A(n) ________ is recommended on all installations to prevent noise transmission through the duct system.
vibration eliminator
electronically commutated motor (ECM)
direct-drive blower assembly
fiberglass plenum
The return duct system distributes air to the terminal units, registers, grilles, or diffusers in the conditioned space.
True
False
Plenum, extended plenum, reducing plenum, or perimeter loop are all types of ________.
ventilation methods
duct materials
duct systems
air balancing methods
A __________ is used to make a duct more rigid, which prevents it from swelling and making noises when the blower starts and stops.
cross-break
takeoff fitting
balancing damper
vibration eliminator
Flexible round duct comes in sizes up to about 24 inches in diameter and 25 feet of length to a box.
True
False
A branch duct should be fastened to the main trunk line with a __________.
flex connector
boot
takeoff fitting
end cap
________ is a very thick, putty-like substance that is applied to the duct connections to help make the system airtight.
Foil tape
Duct insulation
Double-sided tape
Mastic
Two ways that fresh air can enter a structure are infiltration and ventilation.
True
False
Which of the following types of fan is used to move large amounts of air against a low static pressure drop?
Vane axial
Centrifugal
Large
Propeller
The three pressures created by air moving through a duct system are:
Static pressure, atmospheric pressure, and total pressure
Static pressure, friction pressure, and total pressure
Velocity pressure, static pressure, and atmospheric pressure
Velocity pressure, static pressure, and total pressure
Pressure in ductwork is expressed in which of the following?
Inches of water column
Psig
Psia
Inches of Hg
Warm air heats a room better if distributed
low in the room.
high in the room.
behind the furniture.
under the curtains.
Multiple-zone systems often use oversized ducts or a damper to alleviate the problem of excess air when only some zones are calling for conditioning.
True
False
The duct sizes on the air friction chart are expressed in which of the following?
Square
Round
Oval
Rectangular
Turbulence in airflow causes friction drop.
True
False
True or False: Air for cooling circulates better through the conditioned space when it is introduced to the space through floor registers.
True
False
When connecting round metal duct sections, a minimum of ____ self-taping sheet metal screws should be used.
5
4
3
2
The applied voltage (the voltage that the unit will actually be drawing) should be within ____% of the rated voltage of the unit.
3
5
10
7
A disconnect or shutoff switch should be installed within _____ feet of each unit and within sight of the unit.
15
25
10
20
18-4 low-voltage wire is _________.
18-gauge wire with 4 conductors inside
14-gauge wire with a current rating of 4 amps
18-gauge wire, 4 total allowed in ½ inch conduit
4-gauge wire with a current rating of 18 amps
An air conditioner in a climate with average humidity will collect about 3 pints of condensate per hour of operation for each ton of air-conditioning.
True
False
A ________ is located in an auxiliary drain pan and is wired in series with the low voltage power supply.
float switch
pressure switch
delay timer
auxiliary thermostat
Line sets come in standard lengths of ________.
15 feet and 35 feet
25 feet and 50 feet
10 feet and 15 feet
50 feet and 100 feet
Split-system equipment includes all components in one cabinet or housing.
True
False
The _____ is the fitting that connects the duct to the supply register.
starting collar
plenum
takeoff
boot
Round metal duct requires more clearance space than square or rectangular duct.
True
False
The three crafts normally associated with an air-conditioning installation are:
Plumbing, programming, and electrical
Electrical, sheet metal, and programming
Sheet metal, electrical, and mechanical
Sheet metal, plumbing, and carpentry
When insulation on the inside of the duct comes loose it causes
the system to shut off.
high head pressure.
increased airflow.
reduced airflow.
True or False: The flexible duct system is the most economical.
True
False
Most duct insulation is made of .
fiberglass
rubber
PVC
foam
Insulation on duct does not prevent duct from sweating.
True
False
The two different duct configurations for package units are under and over and side by side.
True
False
True or False: A package unit comes from the factory with the charge inside.
True
False
The most popular method for determining the heat gain and heat loss of a residential structure is to use _________.
the square footage of the structure
a Manual J calculation
the geographical location of the structure
the Department of Energy's climate regions
Oversized air-conditioning equipment will cool the space faster, resulting in ________.
higher efficiency
poor dehumidification
poor drainage
greater dehumidification
To determine the temperature differential for cooling equipment (Cooling Design TD), use the formula _____________.
average outdoor ambient temperature – 75°F (standard)
indoor design temperature – outdoor design temperature
75°F(standard) – indoor design temperature
outdoor design temperature – indoor design temperature
As an insulating material is compressed, its R-value will ___________.
multiply by the area that is compressed
go down
remain unchanged
go up
The U-value of a material describes its thermal resistance and the R-value of a material describes its thermal conductivity.
True
False
_______ make up a large portion of the structural envelope and account for a large percentage of the total heat loss of a structure.
Walls
Floors
Windows
Cracks and openings
In general, the rate of heat transfer through a wall can be determined by _________.
U-Vale + TD + Area
R-value × TD × Area
U-value × TD × Area
U-value ÷ TD × Area
A term that is used to describe the area of a wall before any doors or windows are cut into it is __________.
gross wall area
net wall area
door area
window area
The higher the U-value, the easier it is for heat to pass through the material.
True
False
The two important factors that affect the U-value for the below-grade portion of a wall are ___________.
how far below grade the wall is and whether it is an interior or exterior wall
whether it is an interior or exterior wall and the construction material
how far below grade the wall is and the construction material
the number of windows and the number of doors in the wall
An oversized air-conditioning system will
cost more to install and operate.
be more efficient than an undersized air-conditioning system.
be better able to maintain the desired humidity in the conditioned space.
require a smaller air distribution system than an undersized air-conditioning system.
An exterior wall
separates a conditioned interior space from an unconditioned interior space.
separates an interior conditioned space from the outside.
separates one interior conditioned space from another conditioned interior space.
separates an interior unconditioned space from the outside.
A partition wall
separates a conditioned interior space from an unconditioned interior space.
separates an interior conditioned space from the outside.
separates one interior conditioned space from another conditioned interior space.
separates an interior unconditioned space from the outside.
As the temperature differential across a panel increases,
the rate of heat transfer through the panel will increase.
the rate of heat transfer through the panel will decrease.
the rate of heat transfer through the panel will remain unchanged since the temperature
difference does not affect the rate of heat transfer.
The typical indoor design temperature used for heat gain calculations is
65°F.
70°F.
75°F.
80°F.
The typical indoor design temperature used for heat loss calculations is
65°F.
70°F.
75°F.
80°F.
All of the following are taken into account on a heat loss calculation except
exterior walls.
interior walls.
basement floors.
top-floor ceilings.
All of the following are taken into account on a heat gain calculation except
exterior walls.
partition walls.
basement floors.
top-floor ceilings.
