Scroll compressors are becoming popular because they can handle liquid floodback without compressor damage.

The best method of leak checking is when the refrigeration system is ____.

Refrigerated air driers are normally self-contained refrigeration systems that may be air cooled or water cooled.

The approach of a cooling tower is the ____.

An open case is more efficient than a closed case.

The pressure-limiting TXV ____.

A normally operating water-cooled condenser is operating with a 10°F differential between water in and water out. If scale forms on the water tubes and the entering water is 85°F, which of the following is possible?

A direct expansion-type evaporator is also called a ___

High head pressures from low ambients can cause insufficient refrigerant flow rates through metering devices, which in turn can starve evaporators.

The household refrigerator fresh-food compartment is a good example of ____ refrigeration.

Because of the low refrigerant flow rate through the compressor and the system being undercharged, the 100% saturated vapor point in the condenser will be very low in the condenser, causing low condenser subcooling.

The refrigerant in a condenser in a refrigeration system ____.

The purpose of an external equalizer in a TXV is to ____.

____ is the best method of checking to see when a refrigerant coil has a proper level of refrigerant.

Since many new replacement refrigerants are being used throughout the industry, a technician should rely on system temperatures to ease the troubleshooting process.

Dirty condenser coils are often the cause for inefficient condensers.

the most popular secondary fluid currently used in refridgeration systems is

Which of the following can be used to maintain the head pressure of a system with an air-cooled condenser?

A micron gauge is used to measure ____.

In a kitchen, ____ condensing units may be easier to maintain.

CO2, ammonia, propane, butane, and isobutane are all natural refrigerants.

When the load on the evaporator increases, the TXV ____.

The solid-state controlled step-motor valve has a temperature sensor, or thermistor, as one of its inputs.

When the evaporative condenser is used in cold climates, freeze protection must be provided in winter.

One of the disadvantages of the secondary-fluid refrigeration systems is ____.

In a water-cooled condenser, a regulating valve is used to control the ____.

If the spring pressure of a water regulating valve is increased, the system head pressure will also increase.

The cross liquid charge bulb at the TXV contains fluid that ____.

To check the performance of a dry-type evaporator, the service technician would first make sure that the refrigerant coil is operating with enough liquid inside.

After repairing a system that has had an electrical motor failure (compressor burnout), it is good field practice to re-use the recovered refrigerant in that system.

For maximum efficiency, individual ice machine models have different programs called algorithms stored in their ____.

In a wastewater system, the water entering the condenser is 85°F and the water leaving the condenser is 105°F. Which of the following statements is a logical explanation for the above conditions?

AXVs are usually found on smaller equipment with somewhat constant evaporator loads.

In a wastewater cooled system, the difference between the condensing temperature of the refrigerant and the leaving water temperature is approximately ____.

The TXV sensing bulb is mounted ____.

An air-cooled condenser that is operating in a climate that has four distinct seasons must ____.

One good feature of an electronic charging scale is that it counts upward as refrigerant is removed, to tell the technician how much refrigerant was used.

The process of removing heat from a place where it is not wanted and transferring that heat to a place where it makes little or no difference is known as ____.

If 22 oz. of refrigerant are to be added to a refrigeration system and the supply cylinder weighs 24 lb. 12 oz. before any is added, what will be the supply cylinder weight after the system has been charged?

Balanced port TXVs are used to ____ ambient temperatures.

In a wastewater system, the water entering the condenser is 85°F and the water leaving the condenser is 90°F. Which of the following statements is a logical explanation for the above conditions?

Self-contained equipment normally plugs into either a 120-V or 230-V electrical outlet.

When adding refrigerant in liquid form into the high-side of the system, the system motor/compressor assembly is running.

If an R-12 refrigeration system has its air-cooled condensing unit on a roof with an ambient air temperature of 100°F and the condenser outlet temperature (refrigerant) is 115°F, with how much subcooling is the condenser operating?

A typical superheat for an evaporator operating under normal conditions would be ____.

When charging a refrigeration system with a near-azeotropic mixture, what must be done to prevent liquid from entering the system?

A thermostatic expansion valve's capacity will drop if the pressure drop across the valve increases.

The three-way heat reclaim valves in most heat reclaim systems are ____ operated.

Hard starting may also occur in a low ambient condition, causing low head pressures.

With the entering air to the condenser above 70°F, the temperature difference between the outdoor air and the condensing temperature on standard units will be ____.

When adding refrigerant in vapor form to an operating refrigeration system, the refrigerant must be added to the low-pressure side of the system.

Low-temperature food storage applications generally start at ____.

If the compression ratio of a system with a reciprocating compressor decreases, the amount of refrigerant pumped by the compressor ____.

Using a restrictor, liquid refrigerant can be charged into the low-side of the system with the system operating.

The screw compressor is used primarily in ____.

The shell-and-tube condenser is cleaned ____.

Low density vapors entering the compressor will mean low refrigerant flow through the compressor.

Refrigerant in liquid form is normally put into the system through the ____.

When the system pressures are lower than the pressure in the refrigerant tank, such as when the system has just been evacuated or if the system is out of refrigerant, refrigerant can be added to both the high and low pressure sides of the system.

The refrigerated cabinet temperature of a high-temperature refrigeration unit ranges from ____.

A manufacturer's charging chart may be used when available to determine the correct charge for a system.

When charging liquid refrigerant from a single valve supply cylinder, the cylinder is placed ____.

In a water-cooled condensing unit/cooling tower combination, the temperature difference of the water through the condenser will be approximately ____.

The discus valve design is more efficient than a flapper valve design because ____.

The clearance volume of a compressor cylinder is the ____.

The quickest method to charge a system is to charge only vapor.

The process of ice making usually occurs in which temperature range?

Moisture in a liquid state must be ____ before it can be removed with a vacuum pump.

If a thermostatic expansion valve's thermal bulb came loose from the suction line at the outlet of the evaporator, which of the following could result?

A refrigeration system designed for the storage of flowers or candy is considered a ____ type.

An air-cooled R-12 refrigeration system is operating normally with a suction pressure of 25 psig and a head pressure of 136 psig. Which of the following represents a possible set of operating pressures if the condenser fan motor burns out?

In a high-temperature refrigeration unit, the boiling point of the refrigerant in the coil is normally ____ lower than the cabinet temperature.

When moisture is present in a refrigeration system, it will react with the refrigerant and the oil to form ____.

The sight glass on a semihermetic compressor is used to allow light to enter the crankcase to keep the oil warm.

The capacity (tonnage) of the heat exchanger can vary with its height and depth.

One big problem designers face when designing air-cooled refrigeration and air-conditioning equipment is the changing ambient of the changing seasons.

Low suction pressures, iced coils, short cycling, and inefficient cooling, can also result from low head pressures.

If 30 oz. of refrigerant are to be added to a refrigeration system and the supply cylinder weighs 26 lb. 4 oz. before any is added, what will the supply cylinder weigh after the system has been charged?

The higher the rpm of a compressor, the higher the pumping efficiency.

Glide is the range of temperatures/pressures in which a blended refrigerant will condense.

Rotary compressors have pistons that rotate inside the cylinders.

The refrigeration evaporator is a component that absorbs heat from the conditioned space into the refrigeration system.

Every central split cooling system manufactured in the USA today must have a Seasonal Energy Efficiency Ratio (SEER) of at least 10.

Noncondensable gases ____.

The rotary screw compressor uses an open motor instead of the hermetic design.

Knock-down walk-in coolers are constructed of interlocking panels from ____ thick.

Most ice makers use a hot gas harvest or defrost to melt an ice sheet off the evaporator.

The desired water flow through a condenser connected to a recirculating water system is approximately 3 gallons per minute per ton of refrigeration.

A graduated cylinder charging device is a device that ____.

Carbon dioxide (CO2) is one of the newest refrigerants.

If the tank is a reusable tank, there are no check valves and system refrigerant can enter the tank as long as the system pressure is higher than the pressure in the tank.

Because a scroll compressor’s has fewer moving parts, it operates much quieter than other compressor designs and technologies.

Refrigerated compressed air driers typically run ____% of the time.

The primary advantage of parallel compressor systems is their ____.

Charging a refrigeration system refers to ____.

A water regulating valve helps to maintain a system's head pressure by modulating the flow of refrigerant through the condenser.

Most of the heat energy in the suction vapor entering the compressor is ____.

High-temperature refrigeration applications will normally provide box temperatures of ____.

Often, parallel compressor systems employ a satellite or booster compressor.

What can be used to maintain the head pressure of a system with a water-cooled condenser?