HVAC EPA 608 Certification Study Guide.pdf file:///C:/Users/HP/Desktop/TYPA%20NEW/HVAC%20EPA%2060
HVAC EPA 608 Certification Study Guide
1. Are there drop-in replacements for R-12 systems? Why or why not?
ANS No because the new refrigerants are incompatible with the oils and lubricants used inR-12
systems.
2. What type of oil is used in R-134a and what oils will it mix with?
ANS Ester basedoils and they do not mix with other oils
3. What type of lubricant is used with HCFCs?
ANS Alkylbenzene lubricant
4. What is difference b/w ternary blend a azeotropic blend?
ANS Ternary blendsare three-part mixtures whereas azeotropic blends are blends of two or
more compounds that act like a single compound.
5. What is the trait of a hygroscopic lubricant?
ANS It absorbs (takes on) moisture
6. What is temperature glide and what type of blend won't have it?
ANS Temp.blendis the difference between the dew point and the bubble point
7. Dew Point
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,HVAC EPA 608 Certification Study Guide.pdf file:///C:/Users/HP/Desktop/TYPA%20NEW/HVAC%20EPA%2060
ANS Occurs when saturation temp in evaporator causes refrigerant tochange from liquid to
vapor
8. Bubble Point
ANS Occurs when saturation temp in condenser changes refrigerantfrom vapor to liquid
9. Will the gases in a ternary blend leak at the same rate?Why or why not?
ANS Nobecause different refrigerants in blend have different vapor pressures, causing themto
leak at uneven rates
10. Refrigeration Process
ANS transfer of heat from one place to another
11. Evaporator
ANS Absorbs heat into system from space to be cooled. Absorption ofheat causes refrigerant to
boil. Upon leaving, refrigerant changed to low pressure,low temperature vapor
12. Compressor
ANS Takes low pressure, low temp vapor and changes it to a high-temp, high-pressure,
superheated vapor and delivers it to the condenser
13. Condenser
ANS Rejects heat from system and changes refrigerant from high-temp,high-pressure vapor into
high-pressure, high-temp liquid
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,HVAC EPA 608 Certification Study Guide.pdf file:///C:/Users/HP/Desktop/TYPA%20NEW/HVAC%20EPA%2060
14. Metering Device
ANS reduces pressure of refrigerant and changes the high-pres-sure, high-temp liquid into
low pressure, low temp liquid.
15. Compound Gauge
ANS Typically blue and measures low pressure (psig) and vac-uum (inHg).
16. High Pressure Gauge
ANS Red and measures high side (discharge) pressure. 0 to500 psi
17. What does a compressor compress?
ANS Vapor
18. Why will refrigerant migrate to the crankcase in a compressor?
ANS Becauseof the vapor pressure difference between refrigerant and oil
19. What color is the high pressure gauge?
ANS Red
20. What color is the low pressure gauge?
ANS Blue
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HVAC EPA 608 Certification Study Guide
1. Are there drop-in replacements for R-12 systems? Why or why not?
ANS No because the new refrigerants are incompatible with the oils and lubricants used inR-12
systems.
2. What type of oil is used in R-134a and what oils will it mix with?
ANS Ester basedoils and they do not mix with other oils
3. What type of lubricant is used with HCFCs?
ANS Alkylbenzene lubricant
4. What is difference b/w ternary blend a azeotropic blend?
ANS Ternary blendsare three-part mixtures whereas azeotropic blends are blends of two or
more compounds that act like a single compound.
5. What is the trait of a hygroscopic lubricant?
ANS It absorbs (takes on) moisture
6. What is temperature glide and what type of blend won't have it?
ANS Temp.blendis the difference between the dew point and the bubble point
7. Dew Point
1/8
1 of 22 8/8/2024, 3:05
,HVAC EPA 608 Certification Study Guide.pdf file:///C:/Users/HP/Desktop/TYPA%20NEW/HVAC%20EPA%2060
ANS Occurs when saturation temp in evaporator causes refrigerant tochange from liquid to
vapor
8. Bubble Point
ANS Occurs when saturation temp in condenser changes refrigerantfrom vapor to liquid
9. Will the gases in a ternary blend leak at the same rate?Why or why not?
ANS Nobecause different refrigerants in blend have different vapor pressures, causing themto
leak at uneven rates
10. Refrigeration Process
ANS transfer of heat from one place to another
11. Evaporator
ANS Absorbs heat into system from space to be cooled. Absorption ofheat causes refrigerant to
boil. Upon leaving, refrigerant changed to low pressure,low temperature vapor
12. Compressor
ANS Takes low pressure, low temp vapor and changes it to a high-temp, high-pressure,
superheated vapor and delivers it to the condenser
13. Condenser
ANS Rejects heat from system and changes refrigerant from high-temp,high-pressure vapor into
high-pressure, high-temp liquid
2/8
2 of 22 8/8/2024, 3:05
,HVAC EPA 608 Certification Study Guide.pdf file:///C:/Users/HP/Desktop/TYPA%20NEW/HVAC%20EPA%2060
14. Metering Device
ANS reduces pressure of refrigerant and changes the high-pres-sure, high-temp liquid into
low pressure, low temp liquid.
15. Compound Gauge
ANS Typically blue and measures low pressure (psig) and vac-uum (inHg).
16. High Pressure Gauge
ANS Red and measures high side (discharge) pressure. 0 to500 psi
17. What does a compressor compress?
ANS Vapor
18. Why will refrigerant migrate to the crankcase in a compressor?
ANS Becauseof the vapor pressure difference between refrigerant and oil
19. What color is the high pressure gauge?
ANS Red
20. What color is the low pressure gauge?
ANS Blue
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