Virginia Refrigeration Contracting Qualified Individual Examination

Under 18VAC50-22-30, Virginia Refrigeration Contracting (REF) is intended for contractors who repair or install which group of equipment?

• AFurnaces, boilers, and occupied-space air-conditioning systems
• BGas piping, water heaters, and plumbing fixtures
• CElectrical services, panelboards, and comfort-cooling ductwork
• DCoolers, refrigerated casework, ice-making machines, drinking fountains, cold-room equipm…

Which functions does the Virginia REF specialty expressly not provide?

• AElectrical, plumbing, gas fitting, or HVAC functions
• BRemoval of existing refrigerated casework
• CRepair of a hermetic walk-in cooler condensing unit
• DInstallation of a commercial ice-making machine

Which Virginia contractor classification also provides the refrigeration function covered by REF?

• AGas fitting contracting (GFC) only
• BHVAC contracting (HVA)
• CElectrical contracting (ELE) only
• DPlumbing contracting (PLB) only

A firm holds only the REF specialty. A building owner asks the firm to replace a rooftop unit that cools occupied office space. What is the correct scope decision?

• AREF covers the job because any cooling coil is refrigeration
• BREF covers the job if the rooftop unit uses a hermetic compressor
• CThe job is comfort HVAC and is outside REF; an HVA classification is required
• DREF covers the job if no new gas piping is installed

Which project is within the intended REF specialty?

• AInstalling a supermarket refrigerated display case and its hermetic condensing unit
• BInstalling a gas-fired furnace for a store sales floor
• CInstalling supply and return ductwork for occupied-space cooling
• DInstalling a hydronic boiler and process heating piping

A REF-only contractor is asked to install new natural-gas piping to a kitchen appliance while on site replacing a reach-in cooler. What must the contractor do?

• ARun the gas piping because it is incidental to refrigeration
• BRun the gas piping if the pipe is smaller than 1 inch
• CRun the gas piping if a permit is pulled under the cooler job
• DDecline the gas piping; REF provides no gas-fitting functions

A new walk-in cooler condensing unit needs a new 240-volt dedicated circuit from the building panel. The firm holds only REF. What is required?

• AThe REF firm may install the new circuit because the unit is refrigeration equipment
• BAn electrical contractor must provide the electrical work; REF does not include electrica…
• CThe REF firm may install the circuit if it uses existing conduit
• DThe REF firm may install the circuit if the breaker is 30 amperes or less

Which statement about drinking-fountain work is consistent with the Virginia REF definition?

• ADrinking fountains are plumbing-only and never REF
• BOnly the bubbler valve is REF; the refrigeration chassis is HVAC
• CRepair or installation of drinking-fountain refrigeration equipment is intended REF work
• DDrinking fountains are REF only when they also heat occupied space

Installing a commercial cube ice machine in a restaurant kitchen is:

• AIntended REF work as ice-making machine refrigeration
• BComfort HVAC because the machine rejects heat to the kitchen
• CPlumbing-only work because it uses potable water
• DOutside every Virginia specialty unless the firm also holds HVA and PLB

A grocery store wants an obsolete walk-in cooler refrigeration package removed and hauled away, with no replacement installed. Does REF cover the work?

• ANo, because REF covers installation only
• BNo, because removal is a demolition classification only
• CNo, unless the store also buys a new unit from the same firm
• DYes. REF includes removal of refrigeration equipment

A firm already holds the HVA classification. It is awarded a contract to install a walk-in freezer and refrigerated case line. Must the firm also obtain the REF specialty?

• AYes. Only REF may touch walk-in freezers
• BNo. The HVA classification also provides the refrigeration function
• CYes, unless the freezer uses a hermetic compressor
• DNo, but only if the cases cool occupied aisle air rather than product

Which job is HVA work and not REF work?

• AReplacing a reach-in meat-case evaporator
• BCharging a drinking-fountain refrigeration circuit after a leak repair
• CInstalling a boiler and process piping that heat occupied space
• DSetting a self-contained floral cooler

In the vapor-compression refrigeration cycle, which four components appear in every basic hermetic system?

• ABoiler, expansion tank, circulator, and radiator
• BEvaporator, compressor, condenser, and metering device
• CFurnace, evaporator coil, supply fan, and flue
• DCooling tower, steam trap, condensate pump, and economizer

Where in the cycle does liquid refrigerant absorb heat from the box or product and change to vapor?

• ACompressor discharge muffler
• BLiquid receiver
• CEvaporator
• DCondenser

What is the condenser’s job in a refrigeration circuit?

• ALower liquid pressure to evaporator pressure
• BStore oil for the compressor crankcase
• CAbsorb heat from the product load
• DReject heat so high-pressure vapor condenses to liquid

What does the compressor do to refrigerant vapor?

• AIt only meters liquid into the evaporator
• BIt raises the vapor’s pressure and temperature so the condenser can reject heat
• CIt converts liquid directly to a low-pressure mixture
• DIt dries and filters liquid in the liquid line

Why must a metering device drop refrigerant pressure before the evaporator?

• ASo remaining liquid can boil at the low evaporator saturation temperature
• BSo the compressor can pump liquid instead of vapor
• CSo condenser pressure falls below atmospheric pressure
• DSo oil is forced out of the crankcase heater

Where is a liquid-line filter-drier installed on a typical hermetic refrigeration package?

• AIn the suction line immediately after the evaporator
• BIn the discharge line before the oil separator
• CIn the liquid line, after the condenser or receiver and before the metering device
• DAcross the compressor start capacitor

A liquid-line sight glass is primarily used to:

• AMeasure evaporator superheat directly in degrees
• BShow whether a solid liquid column is present and, on many driers, indicate moisture
• CControl condenser-fan cycling by pressure
• DRelieve noncondensable gases automatically

What is the purpose of a liquid receiver on a TXV refrigeration system?

• ATo store extra high-pressure liquid after the condenser so the TXV always has liquid avai…
• BTo keep liquid out of the compressor crankcase during the off cycle
• CTo measure microns during deep vacuum
• DTo superheat suction vapor before it enters the compressor

A suction-line accumulator is installed to:

• ARaise condenser pressure during low ambient
• BStore oil for the metering device
• CProtect the compressor from liquid refrigerant slugging
• DDry liquid before it reaches a TXV

What distinguishes a hermetic compressor of the type named in the REF specialty?

• AThe motor and compressor are sealed inside a welded shell that is not field-torn down
• BThe motor is open to the equipment room and drives the compressor through a shaft seal
• CThe compressor has no moving parts and uses only a boiler
• DThe compressor can be unbolted and the valves serviced like a semi-hermetic unit

One refrigeration ton equals 12,000 Btu/h. What is the cooling capacity of a 3-ton condensing unit?

• A3,000 Btu/h
• B12,000 Btu/h
• C24,000 Btu/h
• D36,000 Btu/h

Why must a condenser reject more heat than the evaporator absorbs from the box?

• ABecause the metering device adds electrical heat to the liquid
• BBecause the condenser must also reject the heat of compression added by the compressor
• CBecause receivers generate additional refrigeration effect
• DBecause suction-line insulation adds heat that the evaporator never sees

On a pump-down system, what happens when the liquid-line solenoid closes at the end of a cycle?

• AThe compressor continues to run until most refrigerant is stored in the high side, then a…
• BThe compressor is locked off immediately with a full low-side charge
• CThe TXV is forced wide open to flood the compressor
• DThe condenser fan reverses to defrost the evaporator

An evaporator-pressure regulator (EPR) on a multi-evaporator rack is used to:

• AKeep a warmer evaporator from being pulled down to a colder companion coil’s pressure
• BRaise compressor discharge pressure in winter
• CMeter oil into the TXV equalizer
• DConvert a capillary tube into a TXV

Where is an oil separator installed when used on a refrigeration condensing unit?

• AIn the liquid line after the receiver
• BIn the compressor discharge line before the condenser
• CIn the condensate drain of a walk-in coil
• DIn the TXV equalizer tube

What is flash gas at a metering device?

• AAir leaking into the suction line through a shaft seal
• BThe portion of liquid that vaporizes in the device so the remaining liquid is cooled to e…
• COil foam leaving the crankcase heater
• DSteam produced by a comfort-heating boiler

Section 608 of the Clean Air Act requires technician certification for people who:

• AOnly sell ice machines without opening the refrigerant circuit
• BOnly carry a Virginia REF contractor license, with no federal credential needed to handle…
• CMaintain, service, repair, or dispose of equipment that could release refrigerants
• DOnly design walk-in boxes and never touch refrigerant

EPA Section 608 Type I certification is the type that covers:

• AOnly motor-vehicle air conditioners
• BSmall appliances
• COnly low-pressure centrifugal chillers
• DOnly industrial ammonia plants

For Section 608 purposes, a small appliance is one that contains:

• AAny charge if the compressor is hermetic
• BMore than 50 pounds of refrigerant
• CFive pounds or less of refrigerant
• DOnly ammonia, regardless of charge

What does an EPA Section 608 Universal certification authorize a technician to service, from a certification-type standpoint?

• AOnly Type I small appliances
• BMotor-vehicle air conditioners instead of stationary equipment
• CSmall appliances, high-pressure appliances, and low-pressure appliances (Types I, II, and…
• DOnly refrigerants with zero ozone-depletion potential

Under Section 608, knowingly venting ozone-depleting refrigerants or most substitute refrigerants to the atmosphere is:

• ARequired whenever a recovery cylinder is full
• BAllowed if the job is only a small drinking fountain
• CProhibited, except for limited releases such as de minimis losses during good-faith recov…
• DAllowed if the refrigerant has no odor

In EPA refrigerant-handling language, what does reclaim mean?

• ARemove refrigerant from a system and store it in any unlabeled drum
• BReprocess recovered refrigerant to at least AHRI 700 virgin-product specifications at a r…
• CRun recovered refrigerant through a filter-drier and immediately put it back into a diffe…
• DVent noncondensables and return the remaining vapor to the same system

When recovering refrigerant from a small appliance, which method satisfies EPA recovery requirements?

• AOpening the process tube and letting the charge boil to atmosphere
• BEvacuating the small appliance to 4 inches of mercury vacuum
• CRunning the compressor with the high-side service valve front-seated and no recovery mach…
• DAdding compressed air to push leftover refrigerant out the suction line

A supermarket parallel rack holds well over five pounds of high-pressure HFC refrigerant. Which Section 608 type is required to service that appliance?

• AType I only
• BSection 609 only
• CType III only
• DType II, or Universal which includes Type II

EPA Section 608 Type III certification is required to service:

• ALow-pressure appliances
• BOnly self-contained ice machines
• COnly drinking fountains
• DOnly R-290 charge-limited plug-in cases

Who may purchase refrigerant for use in stationary refrigeration appliances?

• AAny person with a Virginia driver’s license
• BOnly a Class A contractor, regardless of 608 status
• CA technician (or employing contractor) holding the appropriate Section 608 certification
• DAnyone who owns a recovery machine, certified or not

A technician is tempted to top off an R-134a fountain with leftover R-404A because both are HFC blends or components. What is the correct action?

• AMix them. All HFCs are interchangeable
• BMix them if the pressures look similar on a compound gauge
• CDo not mix refrigerants. Recover the existing charge and recharge only the refrigerant sp…
• DMix them if the oil is mineral oil

Why must copper and brass piping be kept out of an anhydrous-ammonia (R-717) circuit?

• AAmmonia is compatible with copper and brass, so the statement is false
• BAmmonia attacks copper and copper alloys; steel piping is the usual material
• CAmmonia can be used with copper if the oil is POE
• DBrass is required; copper is optional

R-290 (propane) used in some self-contained cases and ice machines is classified as:

• AA3, a flammable hydrocarbon used only in limited charges
• BB2L toxic ammonia
• CA1 and nonflammable in any quantity
• DA steam-heating fluid, not a refrigerant

Why must polyolester (POE) oil containers be kept sealed until use?

• APOE oil is not hygroscopic and needs no special handling
• BPOE oil evaporates into a flammable A3 refrigerant if left open
• CPOE oil is strongly hygroscopic and absorbs moisture that can form acid and damage a herm…
• DPOE oil freezes at room temperature if the can is closed

A typical medium-temperature walk-in cooler used for packaged food is designed to hold about:

• A−20°F to −10°F
• B0°F to −10°F
• C35°F to 38°F
• D65°F to 75°F occupied-space comfort temperature

A typical walk-in freezer used for frozen food is designed to hold about:

• A35°F to 40°F
• B0°F or slightly below
• C55°F wine-storage temperature only
• D72°F occupied-room temperature

Why can many medium-temperature walk-in coolers use off-cycle defrost, while freezers usually need electric or hot-gas defrost?

• ACooler coils rise above freezing during the off cycle and shed frost; freezer coils stay…
• BFreezer coils never frost
• COff-cycle defrost requires a gas furnace, which coolers already have
• DElectric defrost is illegal on freezers

Night covers or strip curtains on display cases and walk-in doorways are used mainly to:

• AIncrease infiltration so the coil stays wet
• BReplace the need for a condensing unit
• CConvert the case into occupied-space air conditioning
• DReduce warm, moist air infiltration and therefore reduce box load and frost