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NV HVAC Contractor practice questions

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Question 1Nevada contractor licensing law and Board regulations (NRS 624)

Under NRS 624, which entity issues a contractor's license in Nevada?

  1. The Nevada State Contractors Board Correct answer.
  2. The county building department where the contractor's office is located
  3. The Nevada Labor Commissioner
  4. The Nevada Department of Business and Industry, Division of Insurance

Explanation

NRS 624 creates the Nevada State Contractors Board and vests it with authority to examine applicants, issue licenses, and discipline licensees. County building departments issue permits but cannot confer state contractor licensure. The Labor Commissioner and the Division of Insurance regulate other matters entirely.

Question 2Nevada contractor licensing law and Board regulations (NRS 624)

A person advertises and bids on a kitchen remodel in Las Vegas without holding a Nevada contractor's license. Under NRS 624, this conduct is best characterized as:

  1. A misdemeanor first offense that may be treated as a felony on repeat violations Correct answer.
  2. Permissible if the person holds a license in another state
  3. Lawful if the contract price stays under $1,000
  4. A civil matter only, enforceable solely by the homeowner

Explanation

NRS 624 makes it unlawful to act as a contractor without a license, and violations carry criminal exposure that escalates with repeat offenses. A first violation is generally a misdemeanor, while subsequent violations can be charged as felonies. Out-of-state licensure does not authorize work in Nevada, and the Board may act regardless of whether a homeowner complains.

Question 3Nevada contractor licensing law and Board regulations (NRS 624)

For an initial contractor's license application, NRS 624 requires the qualifying party to demonstrate a minimum amount of experience in the classification applied for. What is that minimum?

  1. Six years of experience
  2. One year of experience
  3. Four years of experience Correct answer.
  4. Two years of experience

Explanation

NRS 624 requires the qualifying party to show at least four years of experience, gained within a specified recent period, in the work of the classification sought. Experience must be documented and verifiable, such as through payroll records or signed statements from employers or clients. Shorter periods do not satisfy the statutory threshold.

Question 4Nevada contractor licensing law and Board regulations (NRS 624)

A licensed Nevada contractor wants to add a new classification to an existing license. Which statement best describes the Board's requirement?

  1. The contractor must file a new application and meet the experience and examination requirements for that classification Correct answer.
  2. The contractor may simply begin performing the added work and notify the Board at renewal
  3. The contractor may add any classification by paying a fee, with no examination
  4. The contractor must first surrender the existing license and wait one year before reapplying

Explanation

Adding a classification requires an application for that classification and demonstration that the qualifying party meets its experience and examination standards. The Board must approve the addition before the contractor may lawfully perform the added scope of work. Performing unclassified work before approval exposes the licensee to discipline.

Question 5Nevada contractor licensing law and Board regulations (NRS 624)

Which individual is responsible for the day-to-day supervision and technical direction of a licensed Nevada contracting business?

  1. The qualifying party named on the license Correct answer.
  2. The company's registered agent
  3. The surety company that issued the license bond
  4. The Board's executive officer

Explanation

The qualifying party is the individual who satisfies the experience and examination requirements and who must exercise direct supervision over the licensee's construction work. If that person leaves the business, the license is affected and the licensee must report the change and obtain a replacement. The registered agent handles legal service of process, not construction supervision.

Question 6Nevada contractor licensing law and Board regulations (NRS 624)

A Nevada contractor's qualifying party resigns from the company. What is the licensee's obligation under NRS 624 and Board regulations?

  1. The licensee may continue operating indefinitely if it hires a licensed subcontractor
  2. No action is required as long as the license has not yet expired
  3. The licensee must immediately transfer the license to the new supervisor
  4. The licensee must notify the Board and secure a replacement qualifying party within the time allowed by the Board Correct answer.

Explanation

Because the qualifying party is essential to lawful licensure, the licensee must promptly report the dissociation and obtain a qualified replacement within the period the Board allows. Failure to do so can result in suspension or other discipline. Subcontracting work does not cure the loss of the qualifying party.

Question 7Nevada contractor licensing law and Board regulations (NRS 624)

Under NRS 624, a contractor's license bond primarily serves which purpose?

  1. It insures the contractor's equipment against theft
  2. It guarantees the contractor will never be disciplined by the Board
  3. It replaces the need for general liability insurance
  4. It provides a source of recovery for persons harmed by the contractor's failure to perform or pay certain obligations Correct answer.

Explanation

The license bond is a financial assurance that allows claimants to recover for specified defaults, such as failure to perform or failure to pay certain obligations connected to the licensed work. It is not a substitute for liability insurance, which covers third-party injury and property damage. The bond does not shield a licensee from Board discipline.

Question 8Nevada contractor licensing law and Board regulations (NRS 624)

A homeowner submits a complaint to the Nevada State Contractors Board alleging defective work. Which statement accurately describes the Board's authority?

  1. The Board may only refer the matter to the county building department
  2. The Board may act only if the homeowner first wins a court judgment
  3. The Board may award the homeowner compensatory damages in a civil judgment
  4. The Board may investigate and impose discipline, including fines, suspension, or revocation Correct answer.

Explanation

The Board has authority to investigate complaints of violations of NRS 624 and to impose discipline on licensees, including administrative fines, suspension, or revocation. The Board is not a court and does not enter civil money judgments for damages. A prior court judgment is not a prerequisite to its investigation.

Question 9Nevada contractor licensing law and Board regulations (NRS 624)

Which of the following is a ground for disciplinary action against a Nevada contractor's license under NRS 624?

  1. Using a written contract instead of a verbal agreement
  2. Charging a price the homeowner later considers too high
  3. Declining a project because the parties could not agree on terms
  4. Failing to complete a project while abandoning the work and failing to account for payments received Correct answer.

Explanation

NRS 624 lists conduct such as abandonment of a project without justification, failure to account for money paid, and diversion of funds as grounds for discipline. Merely charging a price a customer dislikes, or declining a project, is not a statutory violation. Using a written contract is generally the preferred practice.

Question 10Nevada contractor licensing law and Board regulations (NRS 624)

A licensed Nevada contractor diverts money a homeowner paid for a specific project and uses it to cover unrelated business expenses, leaving the project unfinished. This conduct is best described as:

  1. Permissible commingling because the money is business revenue
  2. A bookkeeping error that the Board does not address
  3. Lawful as long as the contractor eventually finishes the project
  4. Diversion of construction funds, which is a statutory violation and may support discipline Correct answer.

Explanation

NRS 624 addresses diversion of construction funds, treating payments received for a project as committed to that project's costs. Using those funds for unrelated purposes can constitute a violation and support disciplinary action. Later completion does not necessarily erase the violation, and the Board does treat such conduct.

Question 11Nevada contractor licensing law and Board regulations (NRS 624)

Under NRS 624, a contractor's written contract with a residential owner must generally include which element?

  1. The contractor's personal Social Security number
  2. The surety's internal underwriting file
  3. A waiver of the owner's right to file a Board complaint
  4. The contractor's license number Correct answer.

Explanation

Nevada requires that certain contracts include the contractor's license number so the owner can verify licensure and identify the responsible licensee. Personal identifiers such as a Social Security number are not contract requirements. A contract cannot validly waive the owner's right to complain to the Board.

Question 12Nevada contractor licensing law and Board regulations (NRS 624)

For work on a residential property, NRS 624 gives an owner a limited right to cancel a home improvement contract. Within what period may the owner generally cancel after signing?

  1. Ten calendar days
  2. Three business days Correct answer.
  3. Thirty calendar days
  4. One calendar day

Explanation

Nevada law provides a three-business-day right to cancel certain home improvement contracts, allowing the owner to rescind within that window. The right is tied to specific notice requirements in the contract. Longer periods such as ten or thirty days do not reflect the statutory cancellation window.

Question 13Nevada contractor licensing law and Board regulations (NRS 624)

A Nevada contractor is cited for a violation and the Board imposes an administrative fine. Which statement about the fine is accurate?

  1. The fine can only be imposed by a district court
  2. The fine is paid to the homeowner as damages
  3. The fine is a civil penalty payable to the Board and is separate from any restitution ordered Correct answer.
  4. The fine may be avoided by simply renewing the license

Explanation

Administrative fines are civil penalties imposed by the Board and are distinct from restitution that may be ordered to reimburse an injured party. Paying a fine does not resolve restitution obligations. The Board, not only a court, may impose such penalties.

Question 14Nevada contractor licensing law and Board regulations (NRS 624)

Which statement best describes the role of the Nevada State Contractors Board's executive officer in disciplinary proceedings?

  1. The executive officer personally decides the outcome of every complaint without a hearing
  2. The executive officer serves as the contractor's legal counsel during hearings
  3. The executive officer has no role in the agency's functions
  4. The executive officer administers the agency and its operations, while disciplinary decisions are made through the Board's established hearing process Correct answer.

Explanation

The executive officer manages the agency's day-to-day operations, but discipline is imposed through the Board's hearing process, which gives the licensee notice and an opportunity to respond. The officer does not unilaterally decide cases or represent licensees. Saying the officer has no role misstates the position entirely.

Question 15Nevada contractor licensing law and Board regulations (NRS 624)

A contractor licensed in Nevada wants to operate under a different business name. What must the contractor do?

  1. Notify the Board and obtain approval of the name change consistent with Board requirements Correct answer.
  2. File a new license application and pay a full initial license fee
  3. Wait until the next license renewal to disclose the change
  4. Nothing, because the license attaches to the individual regardless of the business name

Explanation

A change in business name must be reported to the Board and approved so that the license accurately reflects the licensed entity. Operating under an undisclosed name can create confusion about licensure and expose the licensee to discipline. A full new application is not the mechanism for a name change.

Question 16Nevada contractor licensing law and Board regulations (NRS 624)

Under NRS 624, which of the following best describes when a Nevada contractor's license must be renewed?

  1. Every two years, with renewal tied to the license expiration date set by the Board Correct answer.
  2. Only when the contractor changes classifications
  3. Every year on the anniversary of the original issuance
  4. Every five years

Explanation

Nevada contractor licenses are renewed on a two-year cycle, and the Board sets expiration dates and renewal procedures. Renewal is not triggered by classification changes or by the anniversary of issuance each year. Failing to renew timely can result in license expiration and loss of authority to contract.

Question 17Nevada contractor licensing law and Board regulations (NRS 624)

A contractor allows its license to expire and continues to bid and perform work. What is the legal consequence?

  1. The contractor's prior license remains valid until the Board sends a notice
  2. The contractor is treated as unlicensed and subject to the penalties for unlicensed contracting Correct answer.
  3. The contractor has a 90-day grace period to keep working
  4. The contractor may continue working because the license is merely lapsed

Explanation

Once a license expires, the holder no longer has authority to act as a contractor, and continued work is unlicensed contracting subject to penalties. There is no automatic grace period that authorizes continued work. The absence of a Board notice does not extend the license's validity.

Question 18Nevada contractor licensing law and Board regulations (NRS 624)

Which statement about the Nevada State Contractors Board's investigative authority is most accurate?

  1. The Board may investigate only projects valued over $50,000
  2. The Board may investigate complaints from homeowners, other licensees, or on its own initiative Correct answer.
  3. The Board may investigate only complaints submitted by licensed contractors
  4. The Board may investigate only after a criminal conviction

Explanation

The Board's investigative authority is broad and is not limited to complaints from a particular class of persons or to a dollar threshold. It may act on homeowner complaints, licensee complaints, or its own initiative. A criminal conviction is not a prerequisite to investigation.

Question 19Nevada contractor licensing law and Board regulations (NRS 624)

A Nevada contractor's license is suspended by the Board. Which statement is correct?

  1. The contractor may transfer the license to a family member to keep operating
  2. The suspension automatically becomes a permanent revocation
  3. The contractor must cease contracting activity during the suspension unless the Board orders otherwise Correct answer.
  4. The contractor may continue working while the suspension is on appeal

Explanation

A suspension removes the authority to act as a contractor for its duration, so the licensee must stop contracting unless the Board provides otherwise. A suspension is not automatically a permanent revocation, and licenses cannot be transferred to relatives to continue operations. Continuing to work while suspended compounds the violation.

Question 20Nevada contractor licensing law and Board regulations (NRS 624)

Under NRS 624, a contractor is required to maintain workers' compensation coverage for employees. What is the consequence of failing to maintain required coverage?

  1. The contractor's bond automatically pays all employee injury claims
  2. The contractor receives a warning only, with no effect on the license
  3. No consequence, because coverage is optional for licensed contractors
  4. The license may be suspended or disciplined, and the contractor may not lawfully operate without required coverage Correct answer.

Explanation

Nevada requires contractors to maintain workers' compensation coverage for their employees, and failure to do so can result in license suspension or other discipline. The requirement is not optional. The license bond is not a substitute for workers' compensation insurance.

Question 21Nevada contractor licensing law and Board regulations (NRS 624)

Which situation most clearly constitutes unlicensed contracting under NRS 624?

  1. A licensed contractor attends a pre-bid meeting for a public project
  2. A licensed contractor hires a licensed subcontractor for electrical work
  3. A licensed contractor submits a bid for a project in a different county
  4. An unlicensed handyman advertises and performs a bathroom remodel for compensation Correct answer.

Explanation

Acting as a contractor, including advertising and performing construction work for compensation, requires a Nevada license. Bidding across county lines and hiring licensed subcontractors are ordinary activities of licensed contractors. Attending a pre-bid meeting does not itself constitute contracting.

Question 22Nevada contractor licensing law and Board regulations (NRS 624)

A licensed Nevada contractor is convicted of a felony involving fraud in connection with a construction project. How does this affect the license?

  1. The conviction is irrelevant because it occurred outside a Board hearing
  2. The contractor may keep the license if the victim is repaid
  3. The license is automatically renewed because the conviction is unrelated to licensing
  4. The conviction may constitute grounds for disciplinary action, including suspension or revocation Correct answer.

Explanation

NRS 624 identifies certain criminal convictions, particularly those involving fraud or dishonesty connected to contracting, as grounds for discipline. The Board may suspend or revoke the license after following its procedures. Repaying a victim does not automatically restore the license.

Question 23Nevada contractor licensing law and Board regulations (NRS 624)

A contractor licensed in Nevada enters into a contract that requires arbitration of all disputes. Which statement best reflects the Board's position?

  1. The Board must enforce the arbitration award as its own decision
  2. An arbitration clause prevents the homeowner from filing a Board complaint
  3. An arbitration clause does not strip the Board of its authority to investigate and discipline licensees Correct answer.
  4. Arbitration clauses are prohibited in all Nevada construction contracts

Explanation

The Board's regulatory and disciplinary authority is independent of private dispute-resolution agreements between the parties. An arbitration clause may govern civil claims but does not bar a complaint to the Board. Arbitration clauses are generally enforceable, and the Board does not adopt awards as its own decisions.

Question 24Nevada contractor licensing law and Board regulations (NRS 624)

Under NRS 624, which of the following is required for a contractor to lawfully engage in the business of contracting in Nevada?

  1. A business license from every city in which the contractor bids
  2. A federal contractor registration number
  3. Membership in a statewide trade association
  4. A valid license issued by the Board for the work to be performed Correct answer.

Explanation

The core requirement is a valid license issued by the Board covering the classification of work to be performed. Trade association membership and federal registration are not licensing prerequisites. Local business licenses may be required for operating within a jurisdiction, but they do not substitute for state licensure and are not required in every city where a bid is submitted.

Question 25Nevada contractor licensing law and Board regulations (NRS 624)

A contractor's license lists a qualifying party who has no actual involvement in the business's construction operations; the contractor uses the individual's name only to satisfy licensing requirements. This arrangement is best described as:

  1. A violation because the qualifying party must actually supervise and be responsible for the work Correct answer.
  2. Lawful if the contractor pays the individual a consulting fee
  3. Permissible because the Board does not review supervision
  4. Acceptable if the individual signs the license application

Explanation

The qualifying party must genuinely supervise and be responsible for the licensee's construction work; serving only as a name on the license defeats the statutory purpose. This practice can support discipline for the licensee and the individual. Payment arrangements or signatures do not cure the lack of actual supervision.

Question 26Nevada contractor licensing law and Board regulations (NRS 624)

Under NRS 624, a Nevada contractor's license is issued to a business entity. Which statement best describes the role of the qualifying party for that license?

  1. The qualifying party may be any licensed contractor who agrees to lend their license number for a fee.
  2. The qualifying party must be a licensed architect or engineer employed by the Board.
  3. The qualifying party must be an owner, officer, or employee who actively supervises the contracting work and whose qualifications support the license. Correct answer.
  4. The qualifying party must be a silent investor with no daily involvement in construction operations.

Explanation

NRS 624 requires a qualifying party to be a bona fide owner, officer, or employee who is actively engaged in the business and supervises the contracting work. The qualifying party's experience and qualifications are the basis for the license, so the person cannot be a passive figurehead or an unrelated license holder.

Question 27Nevada contractor licensing law and Board regulations (NRS 624)

A Nevada contractor licensed in the specialty classification of fencing wants to bid on a project that includes installing an automatic gate operator and low-voltage wiring. How should the contractor proceed under NRS 624?

  1. Ask the general contractor to sign a waiver of the specialty classification requirement.
  2. Bid the entire project because the gate is incidental to the fence installation.
  3. Perform all work and disclose the electrical scope to the Board after completion.
  4. Perform only the fencing scope and either subcontract the electrical portions to a properly licensed contractor or obtain the appropriate classification. Correct answer.

Explanation

A Nevada contractor may perform only work within the scope of the classifications shown on its license. Electrical and low-voltage work generally requires the appropriate classification or a licensed subcontractor, and a private waiver cannot authorize work outside a license.

Question 28Nevada contractor licensing law and Board regulations (NRS 624)

A Nevada contractor receives a notice from the Board alleging a violation and requesting a response. Which statement best describes the contractor's obligation during the Board's investigation?

  1. The contractor should cooperate and provide the requested records, because failure to do so can itself be a ground for discipline. Correct answer.
  2. The contractor may ignore the request because the Board must prove its case without the contractor's help.
  3. The contractor may respond only through the Attorney General's office.
  4. The contractor must respond only after the Board files a formal disciplinary complaint.

Explanation

NRS 624 gives the Board authority to investigate complaints and examine records, and a licensee's failure to cooperate or produce requested records can be treated as a violation supporting discipline. Cooperation during the investigative stage is expected even before a formal complaint is filed.

Question 29Nevada contractor licensing law and Board regulations (NRS 624)

A Nevada contractor's license is placed on probation with conditions by the Board after a disciplinary hearing. Which statement best describes the effect of that probation?

  1. The contractor may continue contracting but must comply with the conditions and may face further discipline for violations. Correct answer.
  2. The contractor's license is automatically cancelled and cannot be reinstated.
  3. The contractor may operate without any restrictions because probation is not a disciplinary action.
  4. The contractor must transfer the license to another qualifying party to remain active.

Explanation

Probation allows a licensee to continue operating subject to conditions imposed by the Board, and a violation of those conditions can lead to additional discipline. It is a disciplinary outcome, not a cancellation, and does not require transferring the license.

Question 30HVAC systems and equipment

In a residential split system operating in cooling mode, what is the function of the metering device at the indoor coil?

  1. It stores liquid refrigerant during the off cycle
  2. It raises refrigerant pressure so the condenser can reject heat
  3. It reduces refrigerant pressure and temperature before the evaporator Correct answer.
  4. It removes moisture from the refrigerant before the compressor

Explanation

The metering device throttles high-pressure liquid refrigerant into the low-pressure side, dropping both pressure and temperature so the coil can absorb heat from indoor air. The compressor, not the metering device, creates the pressure difference. Moisture removal is a function of the air side, and receiver/storage is a separate component.

Question 31HVAC systems and equipment

A technician measures a temperature split across the evaporator of a central air conditioner. Which measurement set correctly yields the split?

  1. Return air dry-bulb minus supply air dry-bulb Correct answer.
  2. Outdoor dry-bulb minus return air dry-bulb
  3. Supply air wet-bulb minus outdoor dry-bulb
  4. Supply air dry-bulb minus liquid line temperature

Explanation

The evaporator temperature split is the difference between return air and supply air dry-bulb temperatures measured at the equipment. It indicates how much sensible heat the coil removed. Comparing indoor and outdoor temperatures or including refrigerant line temperatures does not measure coil performance.

Question 32HVAC systems and equipment

What is the primary purpose of the accumulator in a heat pump or air conditioning system?

  1. To separate oil from refrigerant vapor
  2. To hold refrigerant charge during pump-down
  3. To prevent liquid refrigerant from reaching the compressor Correct answer.
  4. To store subcooled liquid for the metering device

Explanation

An accumulator is installed on the suction line to trap any liquid refrigerant and allow it to boil off before entering the compressor. Slugging liquid damages compressor valves and dilutes lubricating oil. Receivers store liquid on the high side, which is a different function.

Question 33HVAC systems and equipment

Which refrigerant is classified as A1 by ASHRAE Standard 34?

  1. R-290 (propane)
  2. R-410A Correct answer.
  3. R-32
  4. R-717 (ammonia)

Explanation

ASHRAE 34 classifies R-410A as A1, meaning low toxicity and no flame propagation. R-32 is A2L, R-290 is A3, and ammonia is B2L. The letter denotes toxicity and the number denotes flammability.

Question 34HVAC systems and equipment

A furnace has a cracked heat exchanger confirmed by visual inspection. What is the correct action?

  1. Increase combustion air and return the unit to service
  2. Adjust the manifold pressure and monitor for spillage
  3. Red-tag the unit and shut off the gas until the exchanger is replaced Correct answer.
  4. Seal the crack with high-temperature furnace cement

Explanation

A cracked heat exchanger can allow flue gases including carbon monoxide into the supply air, so the appliance must be taken out of service. Field repair of a cracked exchanger is not permitted and cannot restore the integrity of the component. Only replacement of the exchanger or the appliance is acceptable.

Question 35HVAC systems and equipment

In a ducted system, what does external static pressure represent?

  1. The pressure difference across the compressor
  2. The velocity pressure inside the return drop
  3. The refrigerant pressure at the suction service valve
  4. The resistance of the ductwork and accessories to airflow Correct answer.

Explanation

External static pressure is the sum of supply and return duct resistance measured at the air handler, excluding the coil and cabinet. It is used with the fan performance table to determine delivered airflow. It is an air-side measurement and has nothing to do with refrigerant pressures.

Question 36HVAC systems and equipment

Which component changes a heat pump from cooling to heating operation?

  1. The accumulator
  2. The expansion valve
  3. The crankcase heater
  4. The reversing valve Correct answer.

Explanation

The reversing valve redirects refrigerant flow so the indoor coil becomes the condenser and the outdoor coil becomes the evaporator. The metering device, accumulator, and crankcase heater perform the same function in either mode. Only the reversing valve changes the direction of refrigerant travel.

Question 37HVAC systems and equipment

A technician is brazing copper refrigerant lines. Which practice is required to protect the system?

  1. Cap both ends of the line before applying heat
  2. Purge with dry nitrogen while brazing Correct answer.
  3. Wet the fittings with refrigerant oil before heating
  4. Flow oxygen through the line to displace air

Explanation

A low-pressure dry nitrogen purge prevents oxidation inside the tubing, which would otherwise form scale that contaminates the metering device and compressor. Oxygen must never be used because it supports combustion and accelerates oxidation. Capping the line traps air and worsens the problem.

Question 38HVAC systems and equipment

A technician measures 45 psig suction pressure on an R-410A system with a 75°F indoor return. Which condition is most consistent with these readings?

  1. Low refrigerant charge Correct answer.
  2. Restricted liquid line
  3. Overcharged system
  4. Failed condenser fan motor

Explanation

R-410A at 45 psig corresponds to roughly 15°F saturation, well below the expected evaporating temperature for a 75°F return. Low suction pressure with a warm space usually indicates an undercharge or restricted metering device. A restriction would also show high superheat and low subcooling, but the low charge is the primary suspect given the low suction.

Question 39HVAC systems and equipment

What does superheat measure at the evaporator outlet?

  1. The temperature difference between liquid and vapor lines
  2. The pressure drop across the metering device
  3. The amount of liquid refrigerant below saturation
  4. The temperature of refrigerant vapor above its saturation temperature Correct answer.

Explanation

Superheat is the difference between the actual suction line temperature and the saturation temperature corresponding to suction pressure. It confirms that all refrigerant has boiled off before reaching the compressor. Subcooling is the analogous measurement on the liquid side.

Question 40HVAC systems and equipment

A technician is charging an R-410A system in cooling mode using the subcooling method. Which measurement set is required?

  1. Suction pressure and compressor current draw
  2. Suction line temperature and outdoor ambient temperature
  3. Liquid line temperature and liquid line saturation temperature Correct answer.
  4. Return air wet-bulb and supply air dry-bulb

Explanation

Subcooling is found by subtracting the liquid line temperature from the saturation temperature derived from the liquid line pressure. This method is standard for systems with a TXV. Suction-side measurements are used for superheat charging on fixed-orifice systems.

Question 41HVAC systems and equipment

What is the purpose of a heat anticipator in a conventional thermostat?

  1. To end the heating cycle slightly before the setpoint is reached Correct answer.
  2. To lock out the compressor during defrost
  3. To delay the blower start after the burner lights
  4. To limit the maximum supply air temperature

Explanation

The heat anticipator adds a small amount of heat inside the thermostat to open the contacts early, reducing overshoot of the room temperature. It adjusts the cycling rate and comfort rather than protecting equipment. Blower delay and defrost lockout are separate controls.

Question 42HVAC systems and equipment

A heat pump in heating mode is frosting heavily on the outdoor coil. Which sequence describes a normal defrost cycle?

  1. The compressor stops and the auxiliary heat runs until frost melts
  2. The indoor blower stops and the outdoor coil is bypassed
  3. The reversing valve shifts to cooling, the outdoor fan stops, and the outdoor coil is heated Correct answer.
  4. The outdoor fan speeds up and the reversing valve stays in heating

Explanation

During defrost the reversing valve temporarily switches the system to cooling so hot discharge gas flows through the outdoor coil, while the outdoor fan is stopped to speed melting. Auxiliary heat is energized to temper supply air. The compressor continues to run.

Question 43HVAC systems and equipment

A technician finds a 0.8 in. w.c. total external static pressure on a system rated for 0.5 in. w.c. What is the most likely consequence?

  1. Lower compressor amperage and longer life
  2. Reduced airflow and possible coil freezing Correct answer.
  3. Increased airflow and higher capacity
  4. Reduced refrigerant charge requirement

Explanation

Excess external static pressure means the duct system is too restrictive, so the blower delivers less airflow than design. Low airflow reduces heat transfer, causing low suction pressure and possible evaporator icing. It also raises compressor stress rather than reducing it.

Question 44HVAC systems and equipment

Which condition indicates a restricted liquid line filter-drier?

  1. Equal temperatures on both sides of the drier
  2. A temperature rise across the filter-drier
  3. High suction pressure and low head pressure
  4. A temperature drop across the filter-drier Correct answer.

Explanation

A partial restriction causes a pressure drop, which produces a measurable temperature drop across the filter-drier. Normal operation should show little or no temperature difference. A restriction also tends to raise subcooling upstream and lower suction pressure.

Question 45HVAC systems and equipment

What is the function of a TXV bulb charged with the same refrigerant as the system?

  1. It senses outdoor ambient and resets the compressor
  2. It senses room temperature and cycles the blower
  3. It senses liquid line pressure and opens the bypass
  4. It senses suction line temperature and modulates refrigerant flow Correct answer.

Explanation

The TXV bulb is clamped to the suction line and charged with refrigerant, so its pressure changes with suction line temperature. That pressure acts on the diaphragm to modulate the valve opening and hold superheat near the setting. It does not control the compressor or blower.

Question 46HVAC systems and equipment

A technician is sizing a gas furnace vent connector. Which factor most directly governs the allowable diameter and rise?

  1. The indoor blower horsepower
  2. The thermostat heat anticipator setting
  3. The appliance category, input rating, and vent height Correct answer.
  4. The refrigerant charge of the matching coil

Explanation

Vent sizing depends on the appliance category, input Btu/h, connector rise, and total vent height, as given in the manufacturer's tables and the mechanical code. Blower horsepower, refrigerant charge, and thermostat settings do not affect vent capacity.

Question 47HVAC systems and equipment

What is the purpose of a condensate trap on a draw-through air handler?

  1. To filter debris from the condensate before it reaches the drain
  2. To measure the volume of condensate produced
  3. To maintain a water seal that overcomes the negative pressure in the drain pan Correct answer.
  4. To prevent refrigerant from entering the drain line

Explanation

A draw-through coil operates under negative pressure, which would hold water in the pan or draw air into the drain. A properly sized trap creates a water seal that allows drainage while blocking air. It is not a filter or a measuring device.

Question 48HVAC systems and equipment

A technician measures 12°F subcooling on a TXV system with a 10°F target. Which action is appropriate?

  1. Recover a small amount of refrigerant and recheck Correct answer.
  2. Adjust the TXV superheat setting without checking charge
  3. Replace the compressor
  4. Add refrigerant until subcooling reaches 20°F

Explanation

Subcooling above target on a TXV system indicates excess charge, so refrigerant should be recovered in small increments and the reading rechecked after stabilization. Adding charge increases subcooling further. The TXV superheat adjustment is not the charge correction.

Question 49HVAC systems and equipment

Which refrigerant has a GWP of approximately 675 and is classified A2L?

  1. R-134a
  2. R-410A
  3. R-22
  4. R-32 Correct answer.

Explanation

R-32 has a GWP near 675 and is classified A2L, which is why it is used in many newer residential systems. R-410A has a much higher GWP near 2,088, R-134a is about 1,430, and R-22 is about 1,810. Only R-32 matches both the GWP and safety classification given.

Question 50HVAC systems and equipment

A two-stage furnace is operating on low fire with a manifold pressure that reads below the manufacturer's low-fire specification. Which is the most likely cause?

  1. An overcharged refrigerant circuit
  2. A miswired heat anticipator
  3. A failed indoor blower capacitor
  4. A partially clogged burner orifice or low inlet gas pressure Correct answer.

Explanation

Low manifold pressure on a specific firing stage points to a gas supply or orifice problem, such as low inlet pressure or a blocked orifice. Blower and refrigerant faults do not change manifold pressure. The anticipator affects cycling only.