NATE A/C Exam 1 QUESTIONS AND ANSWERS 100% ACCURATE.
Minimum Efficiency Reporting Value - MERV ratings are used to rate the ability of an air
conditioning filter to remove dust from the air as it passes through the filter. MERV is a standard
used to measure the overall efficiency of a filter. Higher MERV ratings mean fewer dust
particles and other airborne contaminants pass through the filter. Filters with a merv rating of 9
to 12 are used in commercial and industrial applications and will stop particles in the 1 to 3
micron range. These filters are a great choice for home owners who want the best dust control
possible. When using filters with Merv 9 ratings and above it is important to clean or replace
them when recommended by the manufacturer because they will have a negative effect on air
flow when they become dirty. This can lead to performance problems and decreased operating
efficiency. The most efficient filters have merv ratings of 13 to 16 and will stop particles as small
as .3 microns. These filters are used in hospitals and other super clean environments.
Zeolite is used with
A: Refrigerant filter-driers
B: HEPA filters
C: Pipe threads
D: Solder - A: Refrigerant filter-driers
Vacuum pressures are measured in
A: Microns
B: Millimeters of mercury
C: Inches of mercury
D: All of the above - D: All of the above
The number 25,400 relates to
A: Microns/inch
B: Btu/ton
C: Cfm/hp
D: Cfm/ton - A: Microns/inch
, The general rule of thumb for airflow is
A: 400 cfm/ton
B: 400 cfm/hp
C: 6 cfm/sq
D: 144 cfm/cu - A: 400 cfm/ton
A double suction riser is used to
A: Help improve refrigerant return
B: Allow the compressor to pump at a greater capacity
C: Decrease suction line resistance
D: Improve oil return as system capacity changes - D: Improve oil return as system capacity
changes
A service technician measures a return air temperature of 80 degrees and a supply air
temperature of 55 degrees. What, if anything, may be wrong with this air residential split system
air conditioning unit?
A: Low on refrigerant charge
B: Low on evaporator airflow
C: Refrigerant overcharge
D: There is probably nothing wrong with the system - B: Low on evaporator airflow
The normal compression ratio for a typical comfort air conditioning application should be in the
range of
A: 1 to 2
B: 1.5 to 2.25
C: 2 to 3
D: 2.75 to 3.75 - D: 2.75 to 3.75
Compression rate = discharge pressure (psia) / suction pressure (psia)
Minimum Efficiency Reporting Value - MERV ratings are used to rate the ability of an air
conditioning filter to remove dust from the air as it passes through the filter. MERV is a standard
used to measure the overall efficiency of a filter. Higher MERV ratings mean fewer dust
particles and other airborne contaminants pass through the filter. Filters with a merv rating of 9
to 12 are used in commercial and industrial applications and will stop particles in the 1 to 3
micron range. These filters are a great choice for home owners who want the best dust control
possible. When using filters with Merv 9 ratings and above it is important to clean or replace
them when recommended by the manufacturer because they will have a negative effect on air
flow when they become dirty. This can lead to performance problems and decreased operating
efficiency. The most efficient filters have merv ratings of 13 to 16 and will stop particles as small
as .3 microns. These filters are used in hospitals and other super clean environments.
Zeolite is used with
A: Refrigerant filter-driers
B: HEPA filters
C: Pipe threads
D: Solder - A: Refrigerant filter-driers
Vacuum pressures are measured in
A: Microns
B: Millimeters of mercury
C: Inches of mercury
D: All of the above - D: All of the above
The number 25,400 relates to
A: Microns/inch
B: Btu/ton
C: Cfm/hp
D: Cfm/ton - A: Microns/inch
, The general rule of thumb for airflow is
A: 400 cfm/ton
B: 400 cfm/hp
C: 6 cfm/sq
D: 144 cfm/cu - A: 400 cfm/ton
A double suction riser is used to
A: Help improve refrigerant return
B: Allow the compressor to pump at a greater capacity
C: Decrease suction line resistance
D: Improve oil return as system capacity changes - D: Improve oil return as system capacity
changes
A service technician measures a return air temperature of 80 degrees and a supply air
temperature of 55 degrees. What, if anything, may be wrong with this air residential split system
air conditioning unit?
A: Low on refrigerant charge
B: Low on evaporator airflow
C: Refrigerant overcharge
D: There is probably nothing wrong with the system - B: Low on evaporator airflow
The normal compression ratio for a typical comfort air conditioning application should be in the
range of
A: 1 to 2
B: 1.5 to 2.25
C: 2 to 3
D: 2.75 to 3.75 - D: 2.75 to 3.75
Compression rate = discharge pressure (psia) / suction pressure (psia)
