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Colorado HVAC - Mechanical Contractor Licensing EXAM
QUESTIONS AND CORRECT VERIFIED SOLUTIONS LATEST
UPDATE THIS YEAR – JUST RELEASED
Colorado HVAC / Mechanical Contractor Licensing Exams
10-Line Exam Coverage in Points Form
1. Licensing & Regulations – Colorado jurisdiction is local (cities/counties) but DORA
oversees state-level mechanical licensing ; applicants must be licensed in the county/city
where work is performed ; passing score is 75% on PSI state exam ; exam fee is $65 ; EPA
608 Universal certification is required federally ; consequences of unlicensed work
include Class 2 misdemeanor charges (up to 120 days jail, $750 fines) ; and county
licenses typically require annual renewal with 8 hours CE per year .
2. Mechanical Code & Permits – Primary purpose of a mechanical permit is to ensure
compliance with adopted codes (IMC) ; IMC definition of "duct" as a passageway for air
movement in HVAC systems ; existing systems being altered must be brought up to
current code where affected by the alteration ; minimum clearance for equipment is
specified by manufacturer ; and boilers must be installed with manufacturer-specified
clearances for service and safety .
3. Refrigeration Principles – Primary purpose of HVAC is to control indoor temperature,
humidity, and air quality ; most critical refrigerant property for heat transfer is low
boiling point (evaporates and condenses easily) ; R-410A is most common modern
refrigerant ; evaporator coil removes moisture by cooling air below dew point ; and
superheat is heat added to refrigerant vapor after evaporation (ensures fully vaporized
state) .
4. System Components & Operation – Compressor functions to pressurize refrigerant
vapor ; condenser coil releases heat to outside air ; expansion valve regulates refrigerant
flow into evaporator ; thermostat controls system temperature setpoints ; blower motor
circulates air through ducts ; and heat exchanger transfers heat between fluids .
5. Boilers & Hydronic Systems – Low-water cutoff shuts down boiler if water level drops
too low ; pressure relief valves prevent over-pressurization ; hydronic systems must be
pressure tested after filling before operation ; flushing removes debris, oil, and
contaminants ; and minimum clearance to combustibles for hydronic boilers is 6 inches
unless manufacturer specifies otherwise .
6. Gas Piping & Venting – Black steel pipe is standard for natural gas distribution inside
buildings ; gas shutoff valves must be accessible and located within 6 feet of appliance ;
flexible gas connectors cannot pass through floors, walls, or ceilings ; gas piping must be
pressure tested at 1.5× design pressure then soap-solution tested ; gas meters must be
at least 12 inches above finished grade ; and propane tanks must be at least 20 feet from
building openings .
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7. Ductwork & Airflow – Duct sizing is based primarily on airflow requirements (CFM) ;
proper sealing of seams improves energy efficiency and indoor air quality ; ducts in
unconditioned spaces require minimum R-6 to R-8 insulation ; pressure drop in gas pipe
for 500-ft run limited to 1 in wg ; and airflow is measured with an anemometer .
8. Safety & OSHA Requirements – OSHA training is mandatory for all workers exposed to
workplace hazards ; confined space entry permits must authorize entry and specify
hazards, precautions, and rescue plans ; SDS information must be available on site for all
hazardous chemicals ; general liability insurance is required (typically $1M-$2M
aggregate) ; and workers' compensation is required when applicable .
9. Equipment & Installation – Minimum clearance around furnace for service is
manufacturer-specified ; rooftop equipment must be anchored against wind and seismic
forces ; equipment in mechanical rooms must have clearances for maintenance and
proper airflow ; direct-vent furnace terminations must be at least 6 feet above roof ; and
high-efficiency furnaces require proper vent sizing .
10. Efficiency & Environmental Compliance – SEER measures cooling efficiency over a
typical cooling season ; EER measures steady-state cooling performance at specific load ;
ODP is critical for environmental compliance in refrigerant selection ; nitrogen is used for
leak detection (inert, non-contaminating) ; and R-410A is preferred over ozone-depleting
R-22 .
250 MCQ Questions with Rationales
Question 1
Which Colorado agency oversees state-level mechanical contractor licensing?
A) Colorado Department of Public Health and Environment
B) Colorado Division of Professions and Occupations (DORA)
C) Colorado Department of Transportation
D) Colorado Public Utilities Commission
Correct Answer: B
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Rationale: The Colorado Division of Professions and Occupations (DORA) administers state-level
licensing for mechanical contractors, including HVAC trades . However, licensing is primarily
managed at the county and municipal level, and contractors must be licensed in the specific
jurisdiction where they perform work .
Question 2
What is the passing score required for the Colorado HVAC/Mechanical contractor exam
administered by PSI?
A) 65%
B) 70%
C) 72%
D) 75%
Correct Answer: D
Rationale: The Colorado HVAC Contractor License requires passing a written trade exam
administered by PSI Exams with a minimum score of 75% . The exam fee is $65 and covers HVAC
systems, refrigerant handling, local codes, and safety regulations.
Question 3
What is the primary purpose of an HVAC system according to standard industry definitions?
A) To generate electricity for the building
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B) To control indoor temperature, humidity, and air quality
C) To supply water to plumbing fixtures
D) To provide structural support for the building
Correct Answer: B
Rationale: HVAC systems are designed to regulate indoor environmental comfort by controlling
temperature, humidity, and air quality . While HVAC components may have secondary
functions, the primary purpose is maintaining comfortable and healthy indoor conditions.
Question 4
Which refrigerant is most commonly used in modern HVAC systems in the United States?
A) R-22
B) R-12
C) R-410A
D) R-502
Correct Answer: C
Rationale: R-410A is widely used in modern HVAC systems due to its efficiency and
environmental compliance . It has zero ozone depletion potential (ODP) and has largely replaced
R-22, which is being phased out due to its ozone-depleting properties.
Colorado HVAC - Mechanical Contractor Licensing EXAM
QUESTIONS AND CORRECT VERIFIED SOLUTIONS LATEST
UPDATE THIS YEAR – JUST RELEASED
Colorado HVAC / Mechanical Contractor Licensing Exams
10-Line Exam Coverage in Points Form
1. Licensing & Regulations – Colorado jurisdiction is local (cities/counties) but DORA
oversees state-level mechanical licensing ; applicants must be licensed in the county/city
where work is performed ; passing score is 75% on PSI state exam ; exam fee is $65 ; EPA
608 Universal certification is required federally ; consequences of unlicensed work
include Class 2 misdemeanor charges (up to 120 days jail, $750 fines) ; and county
licenses typically require annual renewal with 8 hours CE per year .
2. Mechanical Code & Permits – Primary purpose of a mechanical permit is to ensure
compliance with adopted codes (IMC) ; IMC definition of "duct" as a passageway for air
movement in HVAC systems ; existing systems being altered must be brought up to
current code where affected by the alteration ; minimum clearance for equipment is
specified by manufacturer ; and boilers must be installed with manufacturer-specified
clearances for service and safety .
3. Refrigeration Principles – Primary purpose of HVAC is to control indoor temperature,
humidity, and air quality ; most critical refrigerant property for heat transfer is low
boiling point (evaporates and condenses easily) ; R-410A is most common modern
refrigerant ; evaporator coil removes moisture by cooling air below dew point ; and
superheat is heat added to refrigerant vapor after evaporation (ensures fully vaporized
state) .
4. System Components & Operation – Compressor functions to pressurize refrigerant
vapor ; condenser coil releases heat to outside air ; expansion valve regulates refrigerant
flow into evaporator ; thermostat controls system temperature setpoints ; blower motor
circulates air through ducts ; and heat exchanger transfers heat between fluids .
5. Boilers & Hydronic Systems – Low-water cutoff shuts down boiler if water level drops
too low ; pressure relief valves prevent over-pressurization ; hydronic systems must be
pressure tested after filling before operation ; flushing removes debris, oil, and
contaminants ; and minimum clearance to combustibles for hydronic boilers is 6 inches
unless manufacturer specifies otherwise .
6. Gas Piping & Venting – Black steel pipe is standard for natural gas distribution inside
buildings ; gas shutoff valves must be accessible and located within 6 feet of appliance ;
flexible gas connectors cannot pass through floors, walls, or ceilings ; gas piping must be
pressure tested at 1.5× design pressure then soap-solution tested ; gas meters must be
at least 12 inches above finished grade ; and propane tanks must be at least 20 feet from
building openings .
, Page 2 of 134
7. Ductwork & Airflow – Duct sizing is based primarily on airflow requirements (CFM) ;
proper sealing of seams improves energy efficiency and indoor air quality ; ducts in
unconditioned spaces require minimum R-6 to R-8 insulation ; pressure drop in gas pipe
for 500-ft run limited to 1 in wg ; and airflow is measured with an anemometer .
8. Safety & OSHA Requirements – OSHA training is mandatory for all workers exposed to
workplace hazards ; confined space entry permits must authorize entry and specify
hazards, precautions, and rescue plans ; SDS information must be available on site for all
hazardous chemicals ; general liability insurance is required (typically $1M-$2M
aggregate) ; and workers' compensation is required when applicable .
9. Equipment & Installation – Minimum clearance around furnace for service is
manufacturer-specified ; rooftop equipment must be anchored against wind and seismic
forces ; equipment in mechanical rooms must have clearances for maintenance and
proper airflow ; direct-vent furnace terminations must be at least 6 feet above roof ; and
high-efficiency furnaces require proper vent sizing .
10. Efficiency & Environmental Compliance – SEER measures cooling efficiency over a
typical cooling season ; EER measures steady-state cooling performance at specific load ;
ODP is critical for environmental compliance in refrigerant selection ; nitrogen is used for
leak detection (inert, non-contaminating) ; and R-410A is preferred over ozone-depleting
R-22 .
250 MCQ Questions with Rationales
Question 1
Which Colorado agency oversees state-level mechanical contractor licensing?
A) Colorado Department of Public Health and Environment
B) Colorado Division of Professions and Occupations (DORA)
C) Colorado Department of Transportation
D) Colorado Public Utilities Commission
Correct Answer: B
, Page 3 of 134
Rationale: The Colorado Division of Professions and Occupations (DORA) administers state-level
licensing for mechanical contractors, including HVAC trades . However, licensing is primarily
managed at the county and municipal level, and contractors must be licensed in the specific
jurisdiction where they perform work .
Question 2
What is the passing score required for the Colorado HVAC/Mechanical contractor exam
administered by PSI?
A) 65%
B) 70%
C) 72%
D) 75%
Correct Answer: D
Rationale: The Colorado HVAC Contractor License requires passing a written trade exam
administered by PSI Exams with a minimum score of 75% . The exam fee is $65 and covers HVAC
systems, refrigerant handling, local codes, and safety regulations.
Question 3
What is the primary purpose of an HVAC system according to standard industry definitions?
A) To generate electricity for the building
, Page 4 of 134
B) To control indoor temperature, humidity, and air quality
C) To supply water to plumbing fixtures
D) To provide structural support for the building
Correct Answer: B
Rationale: HVAC systems are designed to regulate indoor environmental comfort by controlling
temperature, humidity, and air quality . While HVAC components may have secondary
functions, the primary purpose is maintaining comfortable and healthy indoor conditions.
Question 4
Which refrigerant is most commonly used in modern HVAC systems in the United States?
A) R-22
B) R-12
C) R-410A
D) R-502
Correct Answer: C
Rationale: R-410A is widely used in modern HVAC systems due to its efficiency and
environmental compliance . It has zero ozone depletion potential (ODP) and has largely replaced
R-22, which is being phased out due to its ozone-depleting properties.
