FCC HVAC Study Guide Questions And Answers

FCC HVAC Study Guide Questions And Answers what is the name of EPA's program that identifies refrigerants with lower overall risks to human health and the environment? - ANSWER- the Significant New Alternatives Policy(SNAP) Program. what is a lawful use of HCFC-22? - ANSWER- Charging any new system designed for R-407c. how does cooling occur in a direct expansion vapor compression refrigeration system? - ANSWER- when the liquid refrigerant is vaporized. which process applies to cleaning refrigerant for immediate reuse by oil separation and single or multiple passes through devices like replaceable core filter driers which reduce moisture and acidity? - ANSWER- recycling what should the technician review when working with any solvents chemicals or refrigerants? - ANSWER- safety data sheets (SDS). in general which elastomers for use in seals and gaskets are NOT compatible with HFO refrigerants? - ANSWER- none new household refrigerators may NOT be factory charged with? - ANSWER- R-600a a standard vacuum pump designed for evacuation and dehydration can... - ANSWERbe used alone as a system dependent recovery device. which condition requires accessing both the high and low side of the system for refrigerant recovery. - ANSWER- when the compressor does not run. after installation of a field piped split system the unit should first be pressurized with... - ANSWER- nitrogen and leak checked. which leak repair category does the EPA define as the refrigeration appliances used in the retail food cold storage warehouse sectors? - ANSWER- industrial process refrigeration (IPR) when recovery is first started at what phase is the refrigerant removed to save recovery time? - ANSWER- the liquid phase how can you speed up the removal of the refrigerant charge from a system? - ANSWER- cooling the recovery cylinder to lower its pressure. your recovery/recycling device has R-22 in it and you need to recover a R-410A unit. what must be done? - ANSWER- remove the R-22 from the recovery unit and change the filter. what is the primary water source for a water cooled recovery units condescending coil. - ANSWER- the local municipal water supply. what steps should be taken before using a recovery unit to remove a charge? - ANSWER- the oil should be changed and the recovery cylinder evacuated. what statement about recycling and recovery equipment is FALSE? - ANSWERpurchase of recovery or recycling equipment must be reported to the EPA. what repair will always be seen as a major repair under the EPA's regulations? - ANSWER- replacement of an evaporator coil. when is it against EPA regulations to use a system dependent recovery devices. - ANSWER- When the compressor is operational. Refrigerant cannot be recovered without isolating a parallel compressor system because of... - ANSWER- an open equalization connection. pressure relief valves can only be installed... - ANSWER- vertically if an owner of a appliance with 50 pounds of a ozone depleting refrigerant charge is required to retrofit or retire an appliance that has exceeded the threshold leak rate how many months do they have if the replacement appliance uses a refrigerant exempt from the venting prohibition? - ANSWER- 18 months. starting in 2019 what is the leak rate threshold for comfort cooling appliances with a full charge of 50 or more pounds? - ANSWER- 10% a typical setting for the high pressure cut out control on a recovery unit used for evacuating the refrigerant from a low pressure chiller is... - ANSWER- 10 psig why should the oil be removed from a low pressure system at 130 degrees Fahrenheit? - ANSWER- less refrigerant will be contained in the oil at the higher temperature. what is a typical advantage of a water cooled recovery unit? - ANSWER- faster recovery of large amounts of refrigerant. where is the lowest access point on a low pressure centrifugal air conditioning appliance? - ANSWER- the evaporator charging valve. how long must a technician evacuating refrigerant from appliances with a full charge of more than 5 pounds and less than 50 pounds that are being disposed of keep records of the event? - ANSWER- 3 years where is refrigerant added to a centrifugal machine? - ANSWER- the evaporator charging valve. which type of refrigerant typically has the lowest global warming potential? - ANSWERHFO's how do the global warming potentials of isobutane propane and R-441A compare to the GWP's? - ANSWER- they are significantly lower. what are the characteristics of HFO's? - ANSWER- non-ozone depleting and have a low global warming potential. why are some HFO refrigerants classified as A2L? - ANSWER- they are less flammable than hydrocarbon refrigerants but most are still mildly flammable. what type of lubricants are HFO refrigerants miscible in? - ANSWER- POE lubricants. what does ozone in the stratosphere above the earth consist of? - ANSWER- molecules containing 3 oxygen atoms? what are the characteristics of HCFC's and CFC's make them more likely to reach the stratosphere than most other compounds containing chlorine? - ANSWER- they do not dissolve in water or easily break down in the atmosphere