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NATE_CORE NEC 2023

NATE Core Practice Test 6

This practice test covers the comfort factors from the NATE Core exam blueprint. You will see questions on temperature, humidity, air movement, air cleanliness, and noise level, how they combine to create comfortable indoor conditions, and sensible heat, sensible heat ratio, and air-change calculations.

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NATE Core

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Frequently Asked Questions

Yes — completely free with no signup required. Every question includes a full explanation of the correct answer.

Two: the NATE Core exam plus at least one specialty exam (for example AC Service, Heat Pump Service, or Air Distribution Service). You can take them on the same day or separately.

The Core exam has 50 questions and each installation or service specialty exam has 100 questions. You need 70% on each to pass — 35 of 50 on Core and 70 of 100 on a specialty. Check natex.org for the current format before you book.

NATE certification lasts two years. To renew, you submit 16 hours of continuing education or retake the specialty exam before your certification expires.

No. These are independent practice tests written to match the published NATE exam topics. They are not official NATE exam questions.

Exam Tip: When a question describes a comfort complaint, ask yourself which factor besides temperature could be the real cause: humidity, airflow, air cleanliness, or noise.

30

Questions

30 min

Time

70%

Pass

Timer starts immediately. Progress is auto-saved.

NATE Core Practice Test 6 — Question List

Question 1: Besides temperature, which of these also affects how comfortable a room feels?

Outdoor barometric pressure
Humidity level
The brand of thermostat
The size of the furniture

Question 2: What indoor relative humidity range does the U.S. EPA recommend to limit mold growth while keeping occupants comfortable?

Ideally 30 to 50 percent, and below 60 percent
10 to 20 percent
60 to 80 percent
Above 70 percent during the cooling season

Question 3: How does air filtration contribute to occupant comfort?

It has no connection to comfort
It changes the room's temperature directly
It reduces electrical voltage in the home
It removes dust and particles, improving air cleanliness

Question 4: Why can a noisy HVAC system reduce occupant comfort, even if the temperature is correct?

Excess noise can be distracting and unpleasant, even in a properly heated or cooled room
Noise changes the humidity level
Noise always raises the room temperature
Noise has no effect on comfort at all

Question 5: Why is controlling indoor humidity important for comfort, not just temperature?

Humidity has no effect on how a temperature feels
High or low humidity can make the same temperature feel more or less comfortable
Humidity only matters in commercial buildings
Humidity control replaces the need for a thermostat

Question 6: A room feels "stuffy" even though the thermostat shows the correct temperature. What comfort factor is most likely the problem?

Electrical voltage
Refrigerant pressure
Poor air movement (circulation)
Insulation R-value

Question 7: Occupants complain that a room feels drafty and uncomfortable, even though the temperature reading is correct. What comfort factor should be checked first?

The size of the electrical panel
The refrigerant charge
The brand of the compressor
Air movement, which may be too strong or poorly directed

Question 8: An air conditioner is oversized for a humid home. The thermostat is satisfied quickly, but the house feels clammy. Why?

Oversized units remove too much moisture and overdry the air
The larger compressor raises the dew point of the indoor air
Short run times do not give the coil enough time to remove moisture (latent load)
Oversized units run longer cycles, which raises indoor humidity

Question 9: A thermostat is set to 72 degrees F and holds that temperature accurately, but occupants still feel uncomfortable and clammy. What is a likely cause?

The thermostat is broken
The humidity level is too high
The refrigerant charge is too low
The air filter is too clean

Question 10: What is one reason clean air filtration matters for occupant comfort and well-being?

It changes the electrical voltage of the home
It automatically lowers humidity
It reduces dust, allergens, and particles that can irritate occupants
It reduces the size of the ductwork needed

Question 11: Air leaves a coil 20°F cooler than it entered, at 1,000 CFM. About how much sensible heat is the coil removing?

About 20,000 BTU/h
About 1,080 BTU/h
About 54,000 BTU/h
About 21,600 BTU/h

Question 12: What term describes the uncomfortable feeling caused by air moving too quickly across a person's skin?

Draft
Condensation
Latent heat
Conduction

Question 13: During winter, a home's air feels very dry, causing static shocks and dry skin, even though the temperature is comfortable. What comfort factor needs attention?

Air filtration only
Humidity, which is likely too low
Noise level
Refrigerant pressure

Question 14: Why should an HVAC technician think about more than just temperature when trying to solve a customer's comfort complaint?

Temperature is the only factor technicians are trained to fix
Customers never complain about anything besides temperature
The real cause of discomfort might be humidity, airflow, air quality, or noise, not just the temperature setting
Other comfort factors are not part of an HVAC technician's job

Question 15: A customer complains about a rattling noise coming from the ductwork whenever the system runs. Which comfort factor does this affect?

Temperature
Humidity
Air cleanliness
Noise level

Question 16: What is the goal when it comes to air movement for occupant comfort?

Air should circulate enough to avoid stuffiness, without creating an uncomfortable draft
Air movement should always be completely stopped
Air movement should always be as strong as possible
Air movement has no ideal range; any amount is fine

Question 17: A cooling load is 30,000 BTU/h total, of which 24,000 BTU/h is sensible. What is the sensible heat ratio (SHR)?

0.20
0.80
1.25
0.24

Question 18: A dirty, clogged air filter is restricting airflow through a system. How can this affect occupant comfort?

It always improves air quality
It has no impact on comfort since it only affects the filter itself
Reduced airflow can lead to uneven temperatures and poor air circulation in the space
It automatically lowers humidity

Question 19: Besides discomfort, what other issue can result from indoor humidity that stays too high for a long time?

Reduced refrigerant pressure
Lower electrical voltage
Higher R-value insulation
Mold or mildew growth

Question 20: A technician arrives at a home where the temperature is correct, but the customer is still unhappy. What is the best next step?

Check other comfort factors, such as humidity, airflow, air cleanliness, and noise
Assume the thermostat is defective and replace it immediately
Tell the customer nothing more can be done since the temperature is correct
Turn off the system completely

Question 21: A home feels dusty and occupants notice more allergy symptoms than usual. Which comfort factor is likely affected?

Temperature only
Air cleanliness (filtration)
Refrigerant pressure
Electrical voltage

Question 22: Which statement about indoor relative humidity and comfort is accurate?

Relative humidity has no connection to how comfortable a space feels
Only very high humidity affects comfort; very low humidity never does
Both very high and very low relative humidity can make a space feel less comfortable
Only very low humidity affects comfort; very high humidity never does

Question 23: A 12,000 cubic foot home receives 200 CFM of outdoor ventilation air. How many air changes per hour (ACH) does this provide?

0.1 ACH
2.0 ACH
60 ACH
1.0 ACH

Question 24: A bedroom feels warmer than the rest of the house, even though the thermostat reading elsewhere is normal. What comfort factor should be checked in that room?

Airflow, such as a blocked or closed vent reducing circulation to that room
The brand of the mattress
The outdoor unit's refrigerant charge
The electrical voltage in that outlet

Question 25: A loud outdoor unit disturbs a customer sitting on their patio nearby. Which comfort factor is being affected?

Air cleanliness
Noise level
Humidity
Refrigerant charge only

Question 26: An occupant sitting beside a large single-pane window in winter feels cold, even though the thermostat reads 72°F. What is most responsible?

Radiant heat loss from the body to the cold window surface
High relative humidity near the glass
Too much supply airflow from the nearest register
A thermostat that reads about 10°F too low

Question 27: What is the general purpose of an HVAC air filter in a home comfort system?

To reduce the electrical voltage used by the system
To measure the temperature of the air
To increase the humidity in the home
To trap dust and particles before air recirculates through the home

Question 28: A customer reports the home feels both muggy and stuffy at the same time. What two comfort factors are most likely both a problem?

Humidity (too high) and air movement (too little circulation)
Noise level and R-value
Refrigerant type and voltage
Insulation and foundation type

Question 29: Why might installing an overly restrictive air filter without checking system compatibility actually reduce comfort?

Filters never affect airflow in any way
A very restrictive filter can reduce airflow through the system, leading to weaker circulation and uneven temperatures
Restrictive filters always improve humidity control automatically
Filters have no relationship to airflow

Question 30: Supply registers in a humid basement are sweating. The register surface is 55°F, and the room's dew point is 60°F. Why?

The register surface is below the room air's dew point, so moisture condenses on it
The register is above the dew point, so it absorbs moisture from the air
Condensation only forms when the whole room reaches 100% relative humidity
The supply air is carrying liquid water off the coil

EXAM CARD NATE_CORE

Questions30

Time limit30 min

Pass score70%

Code editionNEC 2023

DifficultyIntermediate

Last reviewedJun 2026

Timer starts immediately. Progress is auto-saved.

Source: NEC 2026 (NFPA 70)