Refrigeration and Air Conditioning Mechanic - Exam Information

Self-Assessment
Exam Breakdown
Types of Exam Questions
Mathematical Formulas
Acronyms

Self-Assessment

This tool can be used to reflect on your own experience and knowledge in the trade compared with what is on the exam.

Exam Breakdown

Each Red Seal exam's questions are developed to assess the activities laid out in the Red Seal Occupational Standard. This trade's Red Seal exam has 125 questions^{Footnote *}, which are distributed as follows:

Major Work Activity A – Performs common occupational skills - 13 questions

Task A-1 Performs safety-related functions

3 questions

Task A-2 Uses tools and equipment

5 questions

Task A-3 Organizes work

3 questions

Task A-4 Uses communication and mentoring techniques

2 questions

Major Work Activity B – Performs routine trade activities - 19 questions

Task B-5 Performs work site preparation

5 questions

Task B-6 Performs trade activities

14 questions

Major Work Activity C – Plans installation - 18 questions

Task C-7 Plans installation of HVAC/R systems

11 questions

Task C-8 Plans installation of control systems

7 questions

Major Work Activity D – Performs installation - 26 questions

Task D-9 Installs HVAC/R systems

16 questions

Task D-10 Installs control systems

10 questions

Major Work Activity E – Performs commissioning - 21 questions

Task E-11 Commissions HVAC/R systems

13 questions

Task E-12 Commissions control systems

8 questions

Major Work Activity F – Performs maintenance and service - 28 questions

Task F-13 Maintains HVAC/R systems

8 questions

Task F-14 Services HVAC/R systems

11 questions

Task F-15 Maintains and services control systems

9 questions

Types of Exam Questions

All Red Seal exam questions are written in multiple-choice format. A multiple-choice question consists of question followed by four possible responses (A, B, C, D). Every question has exactly one correct answer and three incorrect options. They are not misleading or trick questions, but the incorrect options are not always obvious.

There are three types of questions that you will see on Red Seal Exams:

Knowledge and Recall
Procedural and Application
Critical Thinking

Knowledge and Recall

This type of question tests your ability to recall and understand definitions, facts and principles.

For this trade, between 20 and 30% of questions that are this type.

Example of a Knowledge and Recall Question:

Which cooling coil is selected for maximum dehumidification?

4 row high velocity.
4 row low velocity.
8 row low velocity.
8 row high velocity.

Answer: C

Procedural and Application

This type of question tests your ability to apply your knowledge of procedures to a situation.

For this trade, between 50 and 60% of questions are this type.

Example of a Procedural and Application Question:

A manual pump down is required. How is the king valve adjusted?

By turning the stem clockwise to front seat.
By turning the stem clockwise to back seat.
By turning the stem counter-clockwise to front seat.
By turning the stem counter-clockwise to back seat.

Answer: A

Critical Thinking

This type of question tests your ability to interpret data, solve problems and arrive at valid conclusions.

For this trade, between 10 and 20% of questions are this type.

Example of a Critical Thinking Question:

There is high suction pressure on a heat pump. What is the cause?

Low refrigerant charge.
Leaking reversing valve.
Leaking liquid line solenoid.
Restricted liquid line filter-drier.

Answer: B

Try more sample questions for this trade and check out the Exam Preparation Guide. It will give you practical insights on what goes into Red Seal exams, and how you can best prepare yourself to do well.

Math Formulas

Formulas [PDF, 212 KB]

The following formulas used in this trade may be needed to answer some questions on its Red Seal exam. They will also be provided with the exam sitting.

Formulas

Measurement unit abbreviations

A: ampere
BTU: British thermal unit
Btuh: British thermal units per hour
BTU/lb: British thermal units per pound
CFM: cubic feet per minute
dBA: A-weighted decibel
°C: degree Celsius
°F: degree Fahrenheit
ft.: foot
ft²: square foot
ft³: cubic foot
fpm: feet per minute
gal.: imperial gallon
h: height
hp: horsepower
hr: hour
Hz: hertz
in.: inch
in²: square inch
K: kelvin
kg: kilogram
kPa: kilopascal
kPaG: kilopascal gauge
l: length
L: litre
lb.: pound
m: metre
m²: square metre
m³: cubic metre
mA: milliampere
mm: millimetre
mV: millivolt
oz.: ounce
psi: pounds per square inch
psia: pounds per square inch absolute
psig: pounds per square inch gauge
rpm: revolutions per minute
s: second
t: imperial ton
USG: United States gallon
USGPM: United States gallons per minute
V: volt
VA: volt-ampere
VAC: volts alternating current
VDC: volts direct current
w: width
W: watt
w.c.: water column

Conversion factors

Conversion factors
To convert	To	Multiply by
°C	°F	1.8 and add 32
ft²	in²	144
ft³	USG	7.48
kg	lb.	2.205
kPa	lbf/ft²	20.88
kPa	lbf/in² (psi)	0.1450
L	USG	0.2200
L/min	USGPM	0.2641
L/s	gpm	13.20
m	ft.	3.281
m²	ft²	10.76
m³	ft³	35.31
mm	in.	0.03937

Constants

π: 3.1416
1 USG: 8.33 lb.
12 000 Btuh: 1 t
BTU per 1 000 W (single phase): 3.414
BTU per 1 000 W (three phase): 1.73
Pressure head conversion unit: 0.433 psi/ft.
Specific heat of air: 1.08
Standard for air at sea level: 4.5

Values

α: coefficient of expansion
Area (a): space occupied by a 2 - dimensional figure
B: base
c: specific heat capacity
d: diameter
∆E: energy change — i.e. change in energy of a system at constant volume
∆H: enthalpy change — i.e. change in energy of a system at constant pressure (BTU/lb).
∆P: difference in pressure
∆psig: difference in pounds per square inch gauge
∆T: difference in temperature
∆U: internal energy change
dens.: density
M: mass
NRE: net refrigeration effect
OA: outdoor air
P: pressure
q: velocity pressure (dynamic pressure)
Q: quantity of heat
r: radius
R: thermal resistance
RA: return air
R-value: resistance to conductive flow of heat
SA: total supply air
THR: total heat of rejection
U: thermal transmittance
U-factor: overall heat transfer coefficient
Velocity (v): speed of motion in a given direction

General formulas

General formulas
Descriptions	Full	Abbreviated
Btuh	4.5 × cubic feet per minute × enthalpy change	$4.5 \times CFM \times ∆ H$
Btuh	500 × United States gallons per minute × temperature difference in degrees Farenheit	$500 \times USGPM \times ∆ ˚ F$
Btuh	U - factor × area in square feet × temperature difference in degrees Farenheit	$U \times a in {ft}^{2} \times ∆ ˚ F$
CFM	velocity in feet per minute × area in square feet	$v in fpm \times a in {ft}^{2}$
Coefficient of performance (COP)	$\frac{total heat of rejection}{net refrigeration effect}$	$\frac{THR}{NRE}$
Diameter	diameter 1 × revolutions per minute 1 = diameter 2 × revolutions per minute 2	$d_{1} \times {rpm}_{1} = d_{2} \times {rpm}_{2}$
Enthalpy change	internal energy change + (pressure × volume difference)	$∆ U + (P ∆ V)$
Expansion	length × temperature difference × coefficient of expansion	$l \times ∆ T \times α$
Force	pressure × area	$P \times a$
gpm	$\frac{British thermal units}{pounds per gallon \times temperature difference}$	$\frac{BTU}{(lb. / gal.) \times ∆ T}$
gpm	$\frac{total British thermal units per hour}{temperature difference × mass × specific heat capacity}$	$\frac{total Btuh}{∆ T \times M \times c}$
Grade	$\frac{drop or rise}{run}$	$\frac{drop or rise}{run}$
Outdoor supply air volume (%)	$\frac{outdoor air %}{100} = \frac{outdoor air in cubic feet per minute}{Total in cubic feet per minute}$	$\frac{OA %}{100}$
Pressure	height × density	$h \times dens.$
psia	pounds per square inch gauge + 14.7	$psig + 14.7$
psig	pounds per square inch absolute − 14.7	$psia - 14.7$
Quantity of heat	cubic feet per minute × 1.08 × temperature difference	$CFM \times 1.08 \times ∆ T$
Q (Btuh)	United States gallons per minute × 500 × temperature difference in degrees Farenheit	$USGPM \times 500 \times ∆ ° F$
Q·CFM	$\frac{volts \times amperes \times 3.414}{1.08 \times temperature difference}$	$\frac{V \times A \times 3.414}{1.08 \times ∆ T}$
R- value	1/U- factor	$1 / U$
Temperature difference	$\frac{British thermal units per hour}{500 \times gallons per minute}$	$\frac{Btuh}{500 \times gpm}$
Total supply air	outdoor air % + return air % = 100 % total supply of air	$OA % + RA % = SA$
U-factor	1/R - value	$1 / R$
U-factor	watts per square metre per kelvin	$W / m^{2} K$
Velocity	4 005 × square root of velocity pressure	$4 005 \times \sqrt{q}$

Total thermal formulas

Total thermal formulas
Descriptions	Full	Abbreviated
Btuh	gallons per minute × area × temp. diff.	$gpm \times A \times ∆ T$
Btuh	gallons per minute × cubic feet per minute × total change in energy	$gpm \times CFM \times ∆ E$
Btuh	4.5 × cubic feet per minute × total change in enthalpy	$4.5 \times CFM \times ∆ H$
gpm	$\frac{British thermal units per hour}{500 \times temp. diff. of water}$	$\frac{Btuh}{500 \times ∆ T of water}$

Area formulas

Area formulas
Descriptions	Full	Abbreviated
Circle	$π \times {radius}^{2}$	$π r^{2}$
Cylinder (open top)	$(π \times {radius}^{2}) + (π \times diameter \times height)$	$π r^{2} + π d h$
Cylinder (totally enclosed)	$(2 \times π \times {radius}^{2}) + (π \times diameter \times height)$	$2 π r^{2} + π d h$
Rectangle	length × width	$l \times w$
Rectangle box (open top)	$(length \times width) + 2 (width \times height) + 2 (length \times height)$	$(l \times w) + 2 (w \times h) + 2 (l \times h)$
Rectangle box (totally enclosed)	$2 (length \times width) + 2 (width \times height) + 2 (length \times height)$	$2 (L \times w) + 2 (w \times h) + 2 (L \times h)$
Sphere	$4 \times π \times {radius}^{2}$	$4 π r^{2}$
Triangle	$\frac{base \times height}{2}$	$\frac{B \times h}{2}$

Volume formulas

Volume formulas
Descriptions	Full	Abbreviated
Cylinder	$π \times {radius}^{2} \times height$	$π r^{2} h$
Cuboid	$length \times width \times height$	$l \times w \times h$
Sphere	$\frac{4 \times π \times {radius}^{3}}{3}$	$\frac{4 π r^{3}}{3}$

Acronyms

Acronyms [PDF, 77 KB]

The following acronyms used in this trade may be on its Red Seal exam. They will also be provided with the exam sitting.

A: ampere
AB: alkylbenzene
AC: alternating current
A/C: air conditioning / air conditioner
AHJ: authority having jurisdiction
ANT.: anticipator
ASHRAE: American Society of Heating, Refrigerating and Air-Conditioning Engineers
BTU: British thermal unit
Btuh: British thermal units per hour
BTU/lb: British thermal units per pound
C.E.C.: Canadian Electrical Code
CFH: cubic feet per hour
CFM: cubic feet per minute
cm: centimetre
COP: coefficient of performance
CPR: crankcase pressure regulator
CRAC: computer room air conditioning
CSA: Canadian Standards Association
CSIR: capacitor start / induction run rotor
dBA: A-weighted decibel
°C: degree Celsius
°F: degree Fahrenheit
DHUM: dehumidifier
DIP: dual in-line package
DPDT: double-pole, double-throw
DTFD: defrost terminate fan delay
DX: direct expansion
ECM: electronic control module
EEV: electronic expansion valve
EPR: evaporator pressure regulator
ERV: energy recovery ventilation
EXV: electric expansion valve
FLA: full load amperage
fpm: feet per minute
ft.: foot
GFCI: ground fault circuit interrupter
GND: ground
Hg: mercury
hp: horsepower
HRV: heat recovery ventilator
Hz: hertz
HVAC: heating, ventilation and air conditioning
HVAC/R: heating, ventilation, air conditioning and refrigeration
ID: inside diameter
IMDG: International Maritime Dangerous Goods
in²: square inch
inHg: inches of mercury
inHg vac: inches of mercury vacuum
IR: infrared
ISO: International Organization for Standardization
kPaG: kilopascal gauge
JOHSC: Joint Occupational Health and Safety Committee
lb.: pound
LED: light-emitting diode
LLSV: liquid line solenoid valve
LOTO: lock-out and tag-out
LPS: low pressure switch
LR: long radius
µm: micron
mm: millimetre
MO: mineral oil
NC: normally closed
NO: normally open
NTC: negative temperature coefficient
OAT: outside air temperature
OD: outside diameter
OFC: oil failure control
OFM: outdoor fan motor
OHS: Occupational Health and Safety
ORD: open on rise of differential
ORI: open on rise of inlet
ORO: open on rise of outlet
P/E: pressure enthalpy
POE: polyolester
PPE: personal protective equipment
PSC: permanent split capacitor
psi: pounds per square inch
psia: pounds per square inch absolute
psig: pounds per square inch gauge
P/T: pressure temperature
PTAC: packaged terminal air conditioner
PTC: positive temperature coefficient
R / °R: Rankin scale
R.H.: relative humidity
rpm: revolutions per minute
RTU: rooftop unit
SCBA: self-contained breathing apparatus
SDS: safety data sheet
SPDT: single-pole, double-throw
SPST: single-pole, single-throw
SST: saturated suction temperature
t: imperial ton
TDG: transportation of dangerous goods
TDR: time delay relay
TEV: thermostatic expansion valve
TXV: thermostatic expansion valve
USG: United States gallons
USGPM: United States gallons per minute
UV: ultraviolet
V: volt
VA: volt-ampere
VAC: volts alternating current
VAV: variable air volume
VDC: volt direct current
VFD: variable frequency drive
VRF: variable refrigerant flow
W: watt
w.c.: water column
WHMIS: Workplace Hazardous Information Management System

For more information about exam preparation materials contact your provincial/territorial apprenticeship office.