R Q Unit 9 - 1341 - 6/30/17

Explain what is meant by non- pressurized recovery container, and briefly explain which applications it is used for.

A non- pressurized recovery container has no rigid walls. An example would be a refrigerant bag that expands from refrigerant pressure. Non- pressurized containers must be used in a passive type of recovery.

Briefly describe the two types of piercing valves used in the industry , and list some advantages and disadvantages of both.

A piercing valve drives a sharp pin through the system's tubing. When the pin is retracted , access is gained to the system. Piercing valves can either a clamp-on or solder -on type. The clamp -on piercing valves are used where temporary system access is needed, as in a recovery and charging process. All clamp -on type piercing valves should be removed when service is finished because their soft rubber gasket can rot over time and causes leaks. It is a good idea to leak check these valves before piercing the system's tubing. Piercing valves are not recommended for use on steel tubing . Solder-on piercing valves are used for permanent access to a system. Once the valve is soldered on the system 's tubing , leak check the assembly before piercing the tubing. This can be done by pressurizing the assembly .

what is a quick- couple or quick- connect and where are they used ?

A quick- couple is a low- loss fitting that can either manually closed off or automatically closed off when it is removed from a pressurized refrigeration system or recovery device. It is used on gauge manifold sets and recovery machines. Any recovery equipment manufactured after November 15, 1993, must have low-loss fittings on the system.

The standard that a refrigerant must meet after it has been reclaimed and before it can be sold to another owner is ______________.

ARI 700

Explain the difference between active and passive recovery methods.

Active refrigerant recovery is the method used by technicians the majority of the time. Refrigerant is removed by means of a certified self-contained recovery machine. Passive recovery or system - dependent recovery is the use of the internal pressure of the system and/ or the system's compressor to aid in the refrigeration recovery process.

Describe the difference between an azeotropic refrigerant blend and a near- azeotropic or zeotropic refrigerant blend.

Azeotropes have negligible temperature glide and fractionation in refrigeration and air-conditioning temperature ranges. Zeotropes have noticeable temperature glide and fractionation in these ranges.

Describe the difference between CFCs, HCFCs, HFCs and Hcs.

CFCs contain chlorine , have longer lives, greatly deplete the ozone layer, and are more stable. HCFCs contain chlorine, have shorter lives, deplete the ozone layer much less than CFCs and are less stable than CFCs. HFCs contain no chlorine and do not deplete the ozone layer. Hcs have no chlorine and do not deplete the ozone layer. HCs are flammable. All are global warming chemicals.

To recycle refrigerant means to ________________________.

Clean the refrigerant by oil separation and single or multiple passes through devices such as replaceable core filter driers,which reduce moisture, acidity, and particulate matter.

What is the name of the federal agency that must approve containers into which refrigerant may be transferred ?

Department of Transportation

Describe the difference between a direct and an indirect global warming potential.

Direct global warming potentials measure chemicals like CFCs, HCFCs, and HCFs that are emitted directly into the atmosphere. Indirect global warming potentials measures the inefficiencies of refrigeration and air- conditioning equipment and how much extra energy they are generating because of this inefficiency. These added inefficiencies cause more carbon dioxide to be introduced into the atmosphere , which greatly increases global warming.

Only CFcs and HCFCs contribute to global warming : a. T b. F

False

Explain what a global warming potential (GWP ) is ___________________.

Global Warming Potentials (GWPs ) is an index that measures the direct effects of global warming.

Describe the difference between good and bad ozone.

Good ozone is in the stratosphere and protects the earth from harmful ultraviolet radiation. Bad ozone is in the troposphere and is a pollutant.

Which refrigerants have a 0 ODP ? a. HFCs b. HCFCs c. CFCs d. booth A and B

HFCs

CFcs are more harmful to the stratospheric ozone layer than HCFC s because they __________________________.

Have a less HFCs d stable hydrogen bond, have longer lives, and reach the stratosphere where stratospheric ozone resides.

Are federal excise taxes on reclaimed refrigerants the same as those for new refrigerants ?

No, recycled and reclaimed refrigerants are exempt from the excise tax.

Brief describe an oil- less refrigerant recovery unit.

Oil- less recovery unit operate under the principle that enough residual oil vapor comes back to the recovery unit's compressor from the system under recovery to provide proper lubrication of the recovery compressor's moving parts. The recovery unit's compressor crankcase carries no reservoir of oil and is referred to as " oil -less ". This allows the recovery system to be more versatile and prevents cross contamination of oil within the refrigeration systems on which it is used. Oil- less recovery systems, which have very few moving parts, can be used on most types of refrigerant and oil systems.

To reclaim refrigerant means to __________________________.

Process refrigerant to new product specifications by mean that may include distillation. It will require chemical analysis of the refrigerant to determine that appropriate product specifications are met. This term usually implies the use of processes or procedures available only at a reprocessing or manufacturing facility.

Name two HFC -based refrigerant blends that are being used to retrofit R-22 air - conditioning systems today.

R- 407C and R- 438A

Why are their more safety precautions for R-410A than with other popular refrigerants like R-22 and R - 404A ?

R-404A systems operate at much higher pressures (60 % higher ) in air- conditioning applications than a conventional R-22 system. Gauge manifold sets, hoses, recovery equipment, and recovery storage cylinders all have to be designed to handle the higher pressures of R-410A . Different gauge line connections are used for the two refrigerants, preventing the technician from making a mistake. In fact, the gauge and manifold set for R-410A is required to range up to 800 psig on the high side and 250 psig on the low side, with a 550 psig low side retard. All R- 410A hoses must have a service rating of 800 psig. Even filter driers for R- 410A must be rated and capable of handling the higher pressures.

To recover refrigerant means to ____________________.

Remove refrigerant in any condition from a system and store it in an external container without necessarily testing or processing it in any way.

What agency of the federal government is charged with implementing the United States Clean Air Act Amendments of 1990 ?

The Environmental Protection Agency

What is the name of the conference that was held in Canada in 1987 to attempt to solve problems with refrigerants released into the atmosphere ?

The Montreal Protocol

What is the difference between the oxygen we breathe and the ozone located in the earth's atmosphere ?

The ozone molecules we breathe contain 2 atoms of oxygen, written O2 ; ozone molecules contain 3 atoms of oxygen . written O3.

HFCs do not damage the ozone layer but still contribute to global warming. a. T b.F

True

Explain the process of ozone depletion resulting from the breaking up of a CFC molecule in the stratosphere.

Ultraviolet radiation in the stratosphere separates the chlorine atom from the CFC molecule. This chlorine atom then bonds with an ozone molecule to form oxygen and chlorine monoxide.

The three most popular synthetic oils in the refrigeration and air-conditioning industry are ______________________, ________________________. and _________________________.

alkybenzenes, gycols , esters

An increase in the natural greenhouse effect that leads to heating of the earth is called _______________________.

global warming

Describe the difference between global warming and ozone depletion.

global warming is a process caused the atmospheric absorption of infrared heat energy radiated from the earth's surface. Global warming occurs in the troposphere. Ozone depletion is the depletion of the ozone molecule in the stratosphere, which protects the earth from harmful ultraviolet radiation.

what measurements or index takes into consideration both the indirect and direct global warming effects of refrigerants ? a. total equivalent warming impact ( TEWI ) b. greenhouse warming number c. global warming number d. greenhouse effect number

total equivalent warming impact (TEWI)