HVAC Unit 3

The evaporating pressure of R-22 is 75 psig and the evaporator outlet pressure is 58 F. What is the evaporator superheat? A. 13 F B. 45 F C. 58 F D. 132 F

A. 13 F

Saturated R-410A at a pressure of 95psig will change at a temp of.. A. 29 F B. 95 F C. 118 F D. 295 F

A. 29 F

The three processes commonly used to describe refrigerant handling are? A. Recovering, recycling, and reclaiming B. Recovering, removing, and replacing C. Removing, recycling, and replacing D. Removing, recycling, and reclaiming

A. Recovering, recycling, and reclaiming

If the evaporator outlet temp on an R-410A system is 50 F and the evaporator superheat is 10 F, what is the evaporating pressure of the refrigerant in this system? A. 143 psig B. 118 psig C. 84 psig D. 62 psig

B. 118 psig

The condensing pressure is 417.4 psig for an R-410A and the condenser pressure temp is 108 F. How much sub cooling is there in the condenser? A. 7 F B. 12 F C. 21 F D. 42 F

B. 12 F

The color coding for in R-22 refrigerant cylinder is A. White B. Green C. Orange D. Brown

B. Green

One of the challenges of plotting an R - 407C system on a pressure/enthalpy chart is that the refrigerant... A. is a single compound refrigerant with one pressure for each temperature B. Has a significant temperature glide C. Is a binary blend of R- 32 and R- 125, making it unstable. D. Is easily mistaken for R- 134A and R- 410A

B. Has a significant temperature glide

A refrigeration system that maintains a space at a temperature between 35 degree F and 40 degree F would be classified as what type of system? A. High Temp B. Medium Temp C. Low Temp D. Ultra-Low Temp

B. Medium Temp

The term that is used to quantify the amount of heat absorbed in the evaporator is.. A. Total heat of rejection B. Net refrigeration effect C. Heat of compressor D. Adiabatic expansion

B. Net refrigeration effect

When the air-conditioning system operates in a vacuum, which of the following is true? A. Air will leak out of the system B. Refrigerant will leak out of the system C. Air will be pulled into the system D. Refrigerant will be pulled into the system

B. Refrigerant will leak out of the system

Of the following compressors, which is a residential compressor that is forgiving when it comes to having liquid entering it? A. The reciprocating compressor B. The scroll compressor C. The rotary compressor D. The screw compressor

B. The scroll compressor

The state of the refrigerant at the outlet of the evaporator is approximately.. A. 50% liquid and 50% vapor B. 75% liquid and 25% vapor C. 100% superheated vapor D. 100% sub cooled vapor

C. 100% superheated vapor

A refrigeration system that is intended to provide comfort cooling would be classified as what type of system? A. High Temp B. Medium Temp C. Low Temp D.Ultra-Low Temp

C. Low Temp

The expansion device is responsible for.. A. Controlling the operation of the compressor B. Controlling the sub cooling C. Metering refrigerant flow into the evaporator D. Storing the refrigerant for future use

C. Metering refrigerant flow into the evaporator

The color coding for an R-404A refrigerant cylinder is A. White B. Green C. Orange D. Brown

C. Orange

The thumbprint shaped region on the pressure/enthalpy chart is called the.. A. Saturation curve B. Saturation cycle C. Super heated curve D. Superheated region

C. Super heated curve

The three regions on a pressure/enthalpy chart are.. A. High pressure, low pressure, critical pressure B. Super heated vapor, super heated liquid, depressurized liquid C. Super heated diaper, Sub cooled liquid, saturated D. High pressure liquid, low pressure gas, low pressure liquid

C. Super heated diaper, Sub cooled liquid, saturated

The basic refrigeration cycle can be best described as a.. A. Non-repeating, vapor compression cycle B. Non-repeating, vapor combustion cycle C. repeating, vapor compression cycle D. repeating, vapor combustion cycle

C. repeating, vapor compression cycle

A properly operating compressor should have _______ and its inlet ______ at its outlet A. 100% vapor, 100% vapor B. 100% liquid, 100% liquid C. 100% vapor, 100% liquid D. 100% liquid, 100% vapor

D. 100% liquid, 100% vapor

The state of the refrigerant at the inlet of the evaporator is approximately.. A. 50% liquid and 50% vapor B. 75% liquid and 25% vapor C. 100% superheated vapor D. 100% sub cooled vapor

D. 100% sub cooled vapor

The state of the refrigerant at the outlet of the condenser should be... A. 50% liquid and 50% vapor B. 75% liquid and 25% vapor C. 100% superheated vapor D. 100% sub cooled vapor

D. 100% sub cooled vapor

One ton of refrigeration is equivalent of moving heat at a rate of.. A. 1200 Btu/min B. 12,000 Btu/min C. 1200 Btu/Hr D. 12,000 Btu/Hr

D. 12,000 Btu/Hr

If the evaporating pressure was 76 psig for R-22 and the compressor inlet temp was 65 F, what would be the total superheat entering the compressor? A. 11 F B. 21 F C. 10 F D. 20 F

D. 20 F

Which of the following statements is true with regards to reciprocating and Rotary compressors? A. Rotary and reciprocating compressors with similar capacities are similarly sized B. Both rotary and reciprocating compressors are equipped with suction and discharge valves C. Both rotary and reciprocating compressors can be opened for service D. Four compressors with similar capacities rotary compressors are smaller than reciprocating compressors

D. Four compressors with similar capacities rotary compressors are smaller than reciprocating compressors

Of the following refrigerants which has the lowest global warming potential (GWP) A. R- 410A B. R- 134a C. R- 407C D. R-1234yf

D. R-1234yf