Are there drop-in replacements for R-12 systems? Why or why not?
No because the new refrigerants are incompatible with the oils and lubricants used in
... [Show More] R-12 systems.
What type of oil is used in R-134a and what oils will it mix with?
Ester based oils and they do not mix with other oils
What type of lubricant is used with HCFCs?
Alkylbenzene lubricant
What is difference b/w ternary blend a azeotropic blend?
Ternary blends are three-part mixtures whereas azeotropic blends are blends of two or more compounds that act like a single compound.
What is the trait of a hygroscopic lubricant?
It absorbs (takes on) moisture
What is temperature glide and what type of blend won't have it?
Temp. blend is the difference between the dew point and the bubble point
Dew Point
Occurs when saturation temp in evaporator causes refrigerant to change from liquid to vapor
Bubble Point
Occurs when saturation temp in condenser changes refrigerant from vapor to liquid
Will the gases in a ternary blend leak at the same rate? Why or why not?
No because different refrigerants in blend have different vapor pressures, causing them to leak at uneven rates
Refrigeration Process
transfer of heat from one place to another
Evaporator
Absorbs heat into system from space to be cooled. Absorption of heat causes refrigerant to boil. Upon leaving, refrigerant changed to low pressure, low temperature vapor
Compressor
Takes low pressure, low temp vapor and changes it to a high-temp, high-pressure, superheated vapor and delivers it to the condenser
Condenser
Rejects heat from system and changes refrigerant from high-temp, high-pressure vapor into high-pressure, high-temp liquid
Metering Device
reduces pressure of refrigerant and changes the high-pressure, high-temp liquid into low pressure, low temp liquid.
Compound Gauge
Typically blue and measures low pressure (psig) and vacuum (inHg).
High Pressure Gauge
Red and measures high side (discharge) pressure. 0 to 500 psi
What does a compressor compress?
Vapor
Why will refrigerant migrate to the crankcase in a compressor?
Because of the vapor pressure difference between refrigerant and oil
What color is the high pressure gauge?
Red
What color is the low pressure gauge?
Blue
What needs to happen if oil has been contaminated by burnout?
Triple evacuate system, install permanent filter-drier, conduct deep vacuum before recharging
What are three Rs of refrigeration?
Recover, recycle, reclaim
Recover
to remove any refrigerant in any condition from system and store in external container without necessarily testing or processing in any way
Recycle
To clean refrigerant for immediate reuse by separating oil from refrigerant and removing moisture and acidity from refrigerant by use of products like filter driers
Reclaim
To process refrigerant to level of new product specifications as determines by chemical analysis
What standards must refrigerant recovery equipment meet and what components must all Type I and Type II refrigerant systems have?
EPA-approved equipment testing organization. Service aperture or process stub
System-Dependent Devices
Capture refrigerant with assistance of compressor and/or pressure of refrigerant in appliances from which refrigerant is being recovered
Self-contained Devices
Have independent means to draw refrigerant out of appliances [Show Less]