2024 Edition

HVAC Certification Test

HVAC Certification typically leads to professional growth and more money. The free HVAC Certification Practice Test below was written by HVAC Excellence. It will give you an idea of the types of questions and sections on your actual exam. It is applicable to HVAC technicians and students in all 50 states.

Even if a state does not require a license to work in the field of HVACR, many technicians get certified through a professional organization. Certification ensures prospective employers and customers that a technician is knowledgeable, trained and professional.

For more comprehensive practice, check out the HVAC Practice Exam Kit - it has 300 questions with fully explained answers.

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Principles of Electrical and Refrigeration Theory

1.	There are two capacitors wired in parallel, one rated at 25 mfd and one rated at 5 mfd. What is capacitance?
		a. 125 mfd
		b. 30 mfd
		c. 20 mfd
		d. 4.17 mfd
When capacitors are wired in parallel, the formula used for combining the capacitors is C₁ + C₃ = C_t : 25 + 5 = 30 Incorrect answer. Please choose another answer.

2.	An electronically commutated motor (ECM) is designed to ________.
		a. maintain a constant velocity
		b. have high starting torque
		c. operates at lower static pressure than axial fan motors
		d. provide proper air flow under various conditions
ECM motors are designed to maintain the proper air flow based on the static pressure to a predetermined limit set by the manufacturer. Incorrect answer. Please choose another answer.

3.	If the conductor in an AC circuit is wound into a coil, the resulting EMF opposes the supply voltage. What is this opposition called?
		a. capacitive reactance
		b. conductance
		c. inductive reactance
		d. influence
Inductive reactance is a phenomena that takes place in an alternating current circuit involving a coil of wire and the reversing magnetic fields which will create a voltage in the opposite direction. This counter EMF will act like resistance to the applied voltage. Incorrect answer. Please choose another answer.

Air Conditioning

4.	A refrigerant releases heat when __________.
		a. it is compressed
		b. it evaporates
		c. it condenses
		d. it vaporizes
When refrigerant gas is compressed, the pressure and temperature rapidly increases above saturation temperature. The gas enters the condenser which will cause the gas to de-superheat, change state (Vapor to liquid) and finally become subcooled. During this whole process the heat is being released by sensible and latent processes. Incorrect answer. Please choose another answer.

5.	When testing the efficiency of a (15 seer or lower) air cooled condenser, the refrigerant condensing temperature should be no more than ____ higher than the entering air temperature.
		a. approximately 20 deg F
		b. approximately 30 deg F
		c. approximately 80 deg F
		d. approximately 100 deg F
The saturated or condensing temperature of the refrigerant should not exceed 20^oF above the outdoor ambient. This is referred to as Condenser TD difference between refrigerant condensing and ambient air. It is also referred to as CTOA condensing temperature over ambient. The higher the efficiency, the closer the saturated refrigerant condensing temperature is to the air temperature. Incorrect answer. Please choose another answer.

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6.	What is the minimum vertical drop from the outlet of the condensate drain pan to the inlet of the P trap when the evaporator is ahead of the blower?
		a. 9 inches
		b. 7 inches
		c. 5 inches
		d. 3 inches
The water level in the trap must be low enough that a pressure higher than the static pressure of the air-handler would be required to make it flow back into the drain pan. The higher the air-handle static pressure, the more vertical drop is required. Incorrect answer. Please choose another answer.

Commercial Air Conditioning

7.	How should metallic vibration eliminators be installed on a system which uses a reciprocating compressor?
		a. Perpendicular to the compressor crankshaft.
		b. Parallel to the compressor crankshaft.
		c. Vertical and in the suction line only.
		d. Vertical and in the discharge line only.
The primary function of a vibration eliminator is to absorb compressor vibration and stop the transition of vibration into the piping and components of the air-conditioning system. By isolating the compressors vibration, the risk of damage to piping and the connecting components are reduced. Vibration eliminators should be installed perpendicular to the direction of vibration (parallel with the compressor crankshaft). Incorrect answer. Please choose another answer.

8.	When is the installation of a "P" trap mandatory in a drain line?
		a. When the evaporator coil is located after a heat exchanger.
		b. When the evaporator coil is located on the positive side of the blower.
		c. When the evaporator is an 'A' type coil.
		d. When the evaporator coil is located on the negative side of the blower.
Due to the negative pressure, without a P-trap air will be sucked through the drain and will block the flow of condensate. Incorrect answer. Please choose another answer.

9.	Why do multiple compressor systems have a balance line?
		a. To maintain equal loads on all compressors during operation.
		b. To maintain equal oil levels on all compressors.
		c. To compensate for different pressures.
		d. To compensate for evaporator pressure drop.
When multiple compressors are used in conjunction with each other it is important to keep the oil level the same in all the compressors. Incorrect answer. Please choose another answer.

Commercial Refrigeration

10.	The automatic expansion valve (AEV) maintains a constant ______ in the evaporator.
		a. temperature
		b. superheat
		c. liquid level
		d. pressure
The automatic expansion valve is designed to maintain a constant pressure in the evaporator. This valve can only be used when the evaporator load does not change very much. When the valve responds to higher load demands, it functions opposite to TEV valve, it will temporally cause the valve to close as demand increases. Incorrect answer. Please choose another answer.

11.	A refrigeration system used to cool another refrigeration system is called a _______.
		a. piggy-back system
		b. cascade system
		c. twin system
		d. parallel system
Cascade systems are an arrangement of two or more refrigeration systems that are used in series to achieve ultra-low temperatures. The evaporator cools the condenser of the other system. Incorrect answer. Please choose another answer.

12.	If a low pressure control has been adjusted to cut in at 30 psig, in order to have a 10 psig cut out, the differential setting of the control must be:
		a. 55 Psig.
		b. 35 Psig
		c. 25 Psia
		d. 20 Psig
The difference between cut in and cut out is known as differential setting. In this problem, cut in is 30 psig and cut out is 10, therefore 30 minus 10 equals 20 psig. Incorrect answer. Please choose another answer.

Heat Pump Service

13.	What is the heat pump industry standard for maximum duration for defrost?
		a. As long as it takes to get the ice off the coil.
		b. A maximum of 10 minutes.
		c. 15 minutes if the temperature is below 28°F.
		d. A maximum of 30 minutes.
The standard is 10 minutes; if any longer, the compression ratio would increase and possibly damage the compressor. Incorrect answer. Please choose another answer.

14.	During the heating cycle the indoor coil becomes __________.
		a. a condenser
		b. an evaporator
		c. a receiver
		d. an accumulator
During the heating cycle the indoor coil is the condenser. The heat rejected by the coil is used for heating the structure. Incorrect answer. Please choose another answer.

15.	During the heating mode, the refrigerant in the outdoor coil is under ________.
		a. low pressure
		b. high pressure
		c. atmospheric pressure
		d. a vacuum
In the heating mode the outdoor coil is the evaporator and therefore, under low pressure. Incorrect answer. Please choose another answer.

Heat Pump Installation

16.	Good field practice requires insulating the condensate line for at least the first ____ feet of the run from the indoor unit installed in a hot attic.
		a. 5
		b. 10
		c. 15
		d. 20
Many southern codes state that the condensate line must be insulated for the first 10 feet to prevent sweating, which could create a moisture problem. Incorrect answer. Please choose another answer.

17.	The vapor line on split system heat pumps between the outdoor and indoor units should be:
		a. uninsulated.
		b. insulated using 1/4 inch insulation.
		c. insulated using 3/8 inch insulation.
		d. insulated using 1/2 inch insulation.
Manufacturers recommend a minimum of 1/2 insulation be used on the vapor line which is the suction line in cooling and the hot gas line in heating. Incorrect answer. Please choose another answer.

18.	To maintain efficiency, what type of control is wired in the system to prevent the auxiliary heat from coming on until needed?
		a. A bypass electric heat relay
		b. A 15 minute time delay on the 2nd stage
		c. An outdoor thermostat set above the balance point
		d. An outdoor thermostat set below the balance point
Outdoor thermostats are used to control the auxiliary heat from coming on too early. There are situations that could cause the auxiliary heat to come on prematurely such as having the heat off all day where the temperature is well below the thermostat set point, but the outdoor temperature is such that the heat pump itself could supply the heat needed without addition auxiliary heat. Incorrect answer. Please choose another answer.

Gas, Oil and Combustion

19.	What is the first step in the heating sequence of operation when using a non-communicating control?
		a. Main burner ignition
		b. Pilot flame ignition
		c. Pressure switch closes
		d. Thermostat calls for heat
The first step in the heating sequence of operation is the thermostat calls for heat. Nothing else happens until the thermostat calls for heat. Incorrect answer. Please choose another answer.

20.	The specific heat of air is:
		a. 0.12 BTU/lb.
		b. 0.24 BTU/lb.
		c. 0.48 BTU/lb.
		d. 0.98 BTU/lb.
Specific heat is the quantity of heat required to change 1 pound of a particular substance 1°F. Every substance has a different specific heat, i.e. the specific heat of water is 1. The specific heat of air is .24. Incorrect answer. Please choose another answer.

21.	What is the approximate manifold gas pressure for a propane furnace?
		a. 0.25 PSI
		b. 7 Inches of water column
		c. 11 inches of water column
		d. 1 PSI
Most manufacturers specify 11 to 13 inches of water column gas pressure as the pressure setting for propane fuelled residential furnaces. Incorrect answer. Please choose another answer.

Electric Heat

22.	A thermostat used on an electric heat furnace will ________.
		a. be a two stage thermostat.
		b. open on a rise / close on rise.
		c. open on a drop / close on rise.
		d. open on rise / close on a drop.
Heating stats work off the principle of open circuit on temperature rise and closed circuit on temperature fall. Incorrect answer. Please choose another answer.

23.	What is a major cause of electrical heat element failure?
		a. Low airflow
		b. Low voltage
		c. High air velocity
		d. Open fusible link
Low air flow will cause the elements to overheat and trip the overloads or fuses. Without proper airflow across the heater elements the furnace will fail. Incorrect answer. Please choose another answer.

24.	Circuit protection of _________ amps is used for each 5 kW of heat.
		a. 15
		b. 30
		c. 60
		d. 100
A 30 amp breaker is used for each 5 kW of heat and 60 amps is used on 10 kW. Incorrect answer. Please choose another answer.

Residential Heat Load Calculation

25.	Which of the following is the reciprocal of "U" value?
		a. R value
		b. T factor
		c. K factor
		d. R=X factor
The inverse of U Value is the R value. Incorrect answer. Please choose another answer.

26.	Which of the following is considered an infiltration load?
		a. Outdoor air leaking in.
		b. Heat from appliances.
		c. Heat lost through non-porous building materials.
		d. Heat gain from the number of occupants.
Infiltration is the unintentional leakage of outside air into a building, typically through cracks in the building envelope and through window and doors. Infiltration is often referred to as air leakage. Incorrect answer. Please choose another answer.

27.	Elevation changes greater than a few hundred feet can _________.
		a. cause no significant change in design conditions
		b. significantly change the design conditions
		c. decrease the heating load in some instances
		d. usually cause a decrease in cooling and heating loads
Elevation changes can significantly change the design conditions based on temperature change, wind speed or other environmental conditions. Incorrect answer. Please choose another answer.

Universal R-410A Safety and Training

28.	Which of the following is true about Polyalkylene Glycol (PAG) Oils?
		a. They are non-toxic if inhaled.
		b. They are extremely hygroscopic.
		c. They perform well in aluminum-on-steel applications.
		d. All of the above.
PAG oils have poor aluminum on steel lubricating abilities. PAG oils can be harmful if inhaled in certain concentrations. PAG oils attract and retain moisture making them very hygroscopic. Incorrect answer. Please choose another answer.

29.	Technicians handling liquid refrigerant should wear gloves and ___________.
		a. steel-toe boots
		b. self contained breathing apparatus (SCUBA)
		c. hearing protection
		d. approved eye protection
It is important that technicians receive proper safety training and become familiar with OSHA policies and other federal and state regulations as well as company policies. Incorrect answer. Please choose another answer.

30.	The receiver bypass:
		a. prevents subcooled liquid from sitting in the receiver and losing its sub-cooling.
		b. prevents superheated liquid from sitting in the receiver and losing its superheat.
		c. prevents subcooled vapor from sitting in the receiver and losing its sub-cooling.
		d. prevents subcooled liquid from sitting in the receiver and losing its superheat.
A receiver bypass is often used to bypass sub-cooled refrigerant around the receiver and route it directly to the liquid line. This method will help refrigerant from losing its sub-cooling while being stored in the receiver. Incorrect answer. Please choose another answer.

Green Awareness

31.	Which of the following is a source of sustainable energy?
		a. Nuclear
		b. Coal
		c. Natural gas
		d. Ethanol
Sustainable energy are sources of energy that will not be depleted in the time frame relevant to the human race, such as nuclear, wind, solar, geo-thermal and tides. Incorrect answer. Please choose another answer.

32.	What is the cost of electricity based on?
		a. Electricity consumed by the watt meter.
		b. Voltage used over a period of time.
		c. Wattage used over a period of time
		d. Electrons used over a period of time.
The cost of electricity is based on wattage usage in a given time period, usually one month. Incorrect answer. Please choose another answer.

33.	How much of all the available water on the planet is fresh water?
		a. 2.5%
		b. 24%
		c. 67%
		d. 75%
Of all the water available on our planet less than 2.5% is fresh water, three quarters of which is frozen or otherwise not attainable. Only 0.3 percent is available for use in the form of rivers and lakes, most of which are polluted in some way, requiring treatment before drinking. Incorrect answer. Please choose another answer.

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Written by:
HVAC Excellence

The Leading HVAC Authority

The questions are based on industry standards and offer a comprehensive coverage of the fundamental subject matter found on most HVACR certification exams.

The HVACR Practice Test Kit provides:

assessment of broad based HVACR knowledge
practice in the various specialty areas
a good opportunity for practicing test taking skills and learning the subject matter

Summary of Typical HVACR Certification Exams:

What: HVACR exams are part of the certification process for HVACR technicians which identifies the scope and level of a technician's competency in core and specialty areas.

Who: HVACR professionals who wish to become certified in various HVACR specialties

Where: HVACR certification exams are typically administered at various testing centers, schools and other locations throughout the United States.

When: There are various times throughout the year so check with the exam provider for information.

Why: Certification programs improve technical competency and safety allowing technicians to demonstrate competency and earn more money.

Type: Multiple choice, in both computer-based and paper/pencil formats.

Time: Time varies. The average time is 2 hours.

Language: English

Cost: Depending on the subject and organization, it typically costs between $25 - $150 per actual certification exam.

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