2R410a Training R410 Refrigerant… Why and When? Basic Refrigeration CycleImportance of AirflowSuperheat and SubcoolingInstallationTroubleshootingThis class is being offered to train the technician in the proper handling and necessary precautions to take in order to effectively install equipment utilizing R-410A refrigerant. The material that will be presented today includes the following: (READ THE SLIDE)
3AMANA’S WEB SITE Go to WWW.GOODMANMFG.COM Go to bottom left of the screen hit on PARTNER LINKUser Name…….goodmanPassword………dealerGo to the top of the screen hit on …… INFO FINDERType in the Model NumberSelect the type of Literature you are looking for
4R410a Training R410 Refrigerant… Why and When? Basic Refrigeration CycleImportance of AirflowSuperheat and SubcoolingInstallationTroubleshooting
6What is it? Why and when will it be coming? R410a RefrigerantWhat is it?Why and when will it be coming?
7Definitions of Refrigerants A refrigerant is a fluid used for heat transfer in a refrigeration system.Most refrigerants absorb heat during evaporation at low temperature and low pressure and reject heat during condensation at a higher temperature and higher pressure.In order to insure that the technician is able to understand the overall implications of the switch from R-22 to R-410A, we will be covering some rather basic topics. The first of these will be (READ THE SLIDE)
8CFC, HCFC,HFC CFCs (chlorofluorocarbons) These have a high ozone‑depleting potential (ODP) contributing to the breakdown of the ozone layer, are banned by the Montreal Protocol (an international agreement to protect the earth's ozone layer) and is no longer being manufactured in the European Community (e.g.R11, R12 and R114.)HCFCs (hydrochlorofluorocarbons)These have limited ODP are classified under the Montreal Protocol as transitional substances and are due to be phased out early this century. Examples are R22, R123 and R124.HFCs (hydrofluorocarbons)These contain no chlorine and therefore have zero ODP and as such are not controlled by the Montreal Protocol. It is however, controlled under the authority of the Federal Clean Air Act which prohibits venting it to the atmosphere. Examples are R410a, R134a and R152a. R134a can be substituted for R12, requiring replacement of some serviceable' components.We also need to cover just exactly what kind of refrigerants we are dealing with. (READ THE SLIDE)
9Montreal Protocol/US Phase-Out R-22 Phase-Out Timeline$2/lb$10/lb$20/lb% 1996 CAP65%35%10%%No New Equip. EUNo New Equip. US5010019992004201020152020EU Phase-OutMontreal Protocol/US Phase-OutR-22 CostAs the blue line in the graph shows, production for R-22 refrigerant was reduced in 2004 to 65% of the 1996 production cap. You can also see from the green line that there is a corresponding increase in the cost of R-22 refrigerant. In 2010, the production will be 35% of the 1996 cap. This time frame also corresponds to the year that production of R-22 equipment will cease and the production of strictly R-410A equipment will begin. Once again you will notice an increase in the cost of R-22 refrigerant. In 2020, the amount of R-22 that will be produced will be less than one half of one percent until 2030 when production will cease completely.Production of new equipment is banned in Europe in 2004 and 2010 in USProduction of R-22 ends in Europe in 2010 and 2030 in USEurope driving accelerated phase-out datesAll dates could be accelerated
10Why R-410a? R-22 Alternatives R-134a R-407c R-410a R-417b Propane Carbon DioxideSeveral replacements for R-22 have been investigated by the refrigerant producers and equipment manufacturers. The three generally considered are R-134A, R-407C, and R-410A. As you are already aware, R134-A is in place at this time but for the most part has become the replacement for R-12. R-407C is primarily being used in very large equipment. R-410A has become the refrigerant of choice for the replacement of R-22. Greenpeace has lobbied for the use of Propane as a refrigerant, but U.S. manufacturers have ruled this out as a safety concern. Japanese car manufactures are developing CO2 systems for possible use in automotive applications.R-134A is a pure refrigerant, not a blend like the other alternatives.This refrigerant has proven to be a near drop in for R-12 in automotive and some refrigeration applications. As a pure refrigerant, R-134A does not suffer from a condition known as fractionation. Fractionation can occur in some blends and allow one component to escape at a different rate than the others.
11R-410A Facts Ozone friendly- No Chlorine Replacement for R-22, NOT a drop in!Higher Pressure Range-50 to 75% higher than R-22Requires Special LubricantsOther facts to keep in mind about R-410A are as follows: (READ THE SLIDE)
12R-410A It’s a Blended Refrigerant. 50% R-32 and 50% R-125. This blend is a near-azeotrope, not a true azeotrope like R-502.A true azeotrope is a mixture that maintains its composition through both the liquid and vapor phase.(READ THE SLIDE)
13The Future Refrigerant R-410A Azeotrope/Near AzeotropeTemperature GlideFractionationThere are some rather interesting properties that should be discussed about R-410A. These are as follows: (READ THE SLIDE)
14R-410AFor a near-azeotrope, the individual refrigerants evaporate or condense at different temperatures.The differences between these saturation temperature points with mixed refrigerants is called: “TEMPERATURE GLIDE”When temperature glide is high the refrigerants can separate during evaporation or condensation.This changes the composition of the resulting vapor and liquid.This separation is called: “FRACTIONATION”(READ THE SLIDE)
15R-410AAnother significant difference between R-410A and R-22 is its saturation pressure range.R-410A has a higher pressure range curve than R-22.Remember, R-410A is a near azeotrope that is subject to some fractionation. At any specific temperature it has a higher vapor pressure than R-22 when saturated.(READ THE SLIDE) An example of this could be:85 degrees ambient temperature, the High pressure would be around 200 PSI and Low pressure would be around 75 PSI85 degrees ambient temperature, the High pressure would be around 315PSI and the Low pressure would be around 125 PSI
16“Saturation Temperature” – can be defined as the temperature of a liquid, vapor, or a solid, where as any heat is added or removed, a change of state takes place.A change of state requires a large amount of energy.Water is an example of how the saturation property of a material, can transfer a large amount of heat.Refrigerants use the same principles as water. For any given pressure, refrigerants have a corresponding saturation temperature.As the pressure is lowered, the saturation temperature is lowered. If the pressure is raised, the saturation temperature is raised.(READ THE SLIDE) Remember when you are discussing water, it takes just one BTU to change the temperature of a pound of water one degree F. This temperature can be felt or measured until you reach the saturation or boiling point of the water. At that point, it takes 970 BTU’s to change the water to a vapor. During this time, there will be no change at all in the temperature of the water.
17Metering DevicesMetering devices regulate how much liquid refrigerant enters the evaporator .Commonly used metering devices are, small thin copper tubes referred to as “capillary tubes”, thermally controlled diaphragm valves called “TXV’s” (thermostatic expansion valves) and single opening “orifices”.The metering device regulates the amount of refrigerant going into the evaporator causing the pressure to be lowered. Small amounts of refrigerant flash or boil off causing the refrigerant temperature to be lowered.Now we have a low pressure, cooler liquid refrigerant entering the evaporator coil (pressure goes down – so saturation temperature goes down).(READ THE SLIDE) Understand that Goodman and Amana no longer use Capillary Tube metering devices.
18Thermal expansion Valves A very common type of metering device is called a TXV (Thermostatic Expansion Valve). This valve has the capability of controlling the refrigerant flow. If the load on the evaporator changes, the valve can respond to the change and increase or decrease the flow accordingly.The TXV has a sensing bulb attached to the outlet of the evaporator. This bulb senses the superheat from the suction line temperature as it leaves the evaporator and sends a signal to the TXV allowing it to adjust the flow rate. This is important because, if not all of the refrigerant in the evaporator changes state into a gas, there could be liquid refrigerant returning to the compressor. This can be fatal to the compressor. Liquid cannot be compressed. When a compressor tries to compress a liquid, mechanical failure can occur. The compressor can suffer broken valves and washed out bearings. This is caused by” liquid slugging”.Normally TXV's are set to maintain around 10 deg. F of superheat. That means that the gas returning to the compressor is at least 10 deg. F away from the risk of having any liquid return.(READ THE SLIDE)
19Components that needed Redesigning for R-410A CompressorCondenser CoilFilter DrierExpansion DeviceEvaporatorPressure Switches(READ THE SLIDE) As you can see, there is absolutely no part of the refrigeration system that comes into contact with the refrigerant itself that is not affected by the increased pressures. It is critical that all parts that are used for the R-410A system are designed to handle the increase in the working pressures.
20Pressure Switches Pressure Switches have to be at higher settings Low Pressure R-410A = 50psiHigh Pressure R-410A = 610psi(READ THE SLIDE)
21Line Sets New Line Sets are always recommended, but required if: The previous system had a compressor burn out.The existing line set has oil return traps.The existing line set has been open to the atmosphere for an extended time.The existing line set is larger than or smaller than the recommended line size for the Goodman® R-410A system.The existing line set is damaged, corroded, or shows signs of abrasion/fatigue.(READ THE SLIDE) It is important for the technician to understand that there are three problems that will be addressed here. The first is the need to eliminate as much contamination as possible, second to insure that the structural integrity of the piping is strong enough to handle the increased pressures and third is to insure the proper flow characteristics in the system. The reason for this will become more clear as we progress through this program.
29Special Tools Required Differences in Saturation Pressures between R-22 and R-410A affects many of the tools the Technician must use when Charging and Servicing an R410A system.Some of the tools used on R-22 systems may be unacceptable for use on R410a systems.(READ THE SLIDE)
30Manifold Gauge SetStandard Gauges and hoses cannot be used safely with R410A.The High Side gauge should have a range of zero to 800psi.The Low Side gauge should have a range from 30 inches vacuum to 250psi.The Low Side gauge should also have a 500psi retardation feature. This slows the movement of the gauge needle at higher pressures.(READ THE SLIDE) Safety is a concern without the use of proper gauges and hoses.
31Manifold Gauge SetThis set of gauges will work on R-410A systems however, notice that there is no saturation temperature scale on these. It would be better if the technician used gauges with the saturation temperature scale on the gauge itself.
32Refrigerant HosesThe 600psi rating of standard hoses is NOT adequate for R410A.Hoses need to be rated for a 800psi working pressure, with a 4000psi bursting rating.A 5 to 1 safety margin is necessary to prevent dangerous hose ruptures.(READ THE SLIDE) Technicians should periodically check their hoses for leaks. With the higher pressures involved, a hose coming apart might get pretty exciting for the unsuspecting tech. The other reason for checking is to insure that there are no leaks when you are pulling a vacuum or charging the system.
33Vacuum PumpsPumps used with CFC and HCFC charged systems may also be used on R410A systems as long as the pump is capable of attaining a vacuum of level of at least 250 Microns.(READ THE SLIDE) It should also be noted that in order for the vacuum pump to pull into the range required for a proper evacuation, the pump must be properly maintained and the oil changed as required.
34Leak DetectorsLeak detectors should be checked to see that they are designed to properly detect R410A.The detector should have adjustable sensitivity to allow leaks to be pinpointed in areas where background vapor might cause false readings.(READ THE SLIDE)
35R-410AThe temperature glide of R-410A is very low, thus it acts very much like a single refrigerant.Fractionation is very low.R-410A does not significantly separate in the system and the composition of the refrigerant has very minor changes if a leak occurs.But the fact that some fractionation occurs, means that charging techniques must be adjusted.(READ THE SLIDE) What this means is that although R-410A will not fractionate much, you still need to charge by drawing liquid refrigerant from the refrigerant bottle and either throttle or use a commercial type metering device to flash off the refrigerant before it enters the refrigeration system.
36CylindersMost R-410A cylinders have an internal dip tube which allows the feeding of liquid when the cylinder is in an upright position. They must be inverted for for vapor flow.Color is rose (pink).The cylinder has to have minimum cylinder pressure requirement of 400 psig rating (DOT 4B400 or DOT 4BW400)(READ THE SLIDE) Make sure that you understand the note at the bottom of this slide. Technicians may want to exercise care in the storage of these tanks on your trucks. It could get quite exciting far a while if one of these tanks lets go due to over pressurization.NOTE: Avoid storing R-410A where temperatures will exceed 120° F.
37LubricationThe chemistry of R-410A makes it incompatible with mineral based lubricants.Mineral oils typically used with R-22 has relativity low Miscibility with R-410A.Miscibility is the ability of an oil to dissolve uniformly in refrigerant in either the liquid or vapor state.(READ THE SLIDE)
38LubricationThe preferred lubricants are the Polyolester or ester based oils.Commonly known as POE oils.POE oils are miscible with any mineral oil traces that might be in the system.While miscible, it is very important to remove as much mineral oil, particulates, and moisture from existing line sets as possible.(READ THE SLIDE) Make sure you understand that the oils will mix somewhat. It is the R-410A that will not mix with the mineral oil.
39Lubrication The POE oils are more Hygroscopic than mineral oils. This means that they absorb moisture very rapidly.Exposure to the atmosphere must be limited.The oil will re-hydrate and become acidic.Keep the system closed.Now here is where the real problem lies. (READ THE SLIDE) This moisture can be absorbed in minutes, not hours or days. As we go through this you will see how important it is for you to exercise extra care in how you install this equipment to prevent any moisture intrusion.
40LubricationAny moisture absorbed by POE oil cannot be removed with a vacuum pump-only a new drier will work!Break a recovery vacuum with Nitrogen!Keep all systems closed until any component replacements are ready for installation.(READ THE SLIDE) On really bad contaminations, multiple drier changes could be required. Once a system is contaminated, the technician should remove the drier that has been installed inside the system at the factory and hard pipe that segment back in. Move the drier to the outside of the unit so that it may be changed readily and will allow for system pump down, using the condenser. Also, it is recommended that a liquid line sight glass with moisture indicator be installed on any R-410A system. Other things the technician might consider is leaving plugs in the equipment until you are ready to insert the refrigeration piping and braze it. Refrigeration lines should be kept sealed or brazed shut until actually being installed in the equipment. A little precaution goes a long way in preventing serious problems with these systems.
41Brazing Should be using at least 2% silver alloy. Always wear glasses and gloves.Always purge with nitrogen when brazing.Protect the service valves with wet rags or heat sink material.Scale will get you with POE oils.(READ THE SLIDE) POE’s are an excellent solvent will strip old copper and scale. This also the reason that you should replace the refrigerant lines on systems that have experienced a burn out. The residue will be cleaned out and deposited somewhere, possible a place you would prefer not to have it. It is recommended also that you braze refrigerant lines as opposed to soldering them. Remember, you are dealing with significantly higher pressures in this equipment
42Recovery Yes, you still have to recover the refrigerant. R-410A does not readily biodegrade, care should be taken to avoid any releases to the environment.The recovery machines used for R-410A must be designed to prevent cross contamination between oils and refrigerants..Use machines certified for use with R-410A.(READ THE SLIDE)
43RecoveryThe preferred type of recovery machine is an oil-less compressor model with a pump down feature for removal of all refrigerant from the machine after each use.If an oil bearing compressor model is used, the machine should be restricted to R-410A refrigerant. The machine must use ester based oil.(READ THE SLIDE)
44Charging While Machine Is Running Charge through the suction side of the system.Use a commercial-type metering device in manifold hose to allow liquid to vaporize.Follow your typical sub-cooling or superheat procedures to arrive at the correct charge.(READ THE SLIDE)
45If The Entire System Is Still In a Positive Pressure Condition, A small leak in an R-410A system can cause:All of the system’s oil to vaporize.All of the system’s oil to be contaminated.Little difference in refrigerant compositionMajor changes in refrigerant composition.“C” IS CORRECT
46The high pressure gauge on an R-410A manifold gauge set typically has a pressure range of: 30 to 250 psig.0 to 500 psig.0 to 800 psig.0 to 1200 psig.“C” IS CORRECT
47The cylinder color for a disposable container of R-410A is: MaroonGreenBlueRose“D” IS CORRECT
48Which of the following is a characteristic of POE oil: POE has higher wax content than mineral oil.POE oil will not mix with mineral oil.POE oil is available in only one grade.POE oil is hygroscopic.“D” IS CORRECT
49To remove moisture from POE oil requires the use of a(n): High capacity vacuum pump.Low volume vacuum pump.Liquid line filter drier.Oil separator.“C” IS CORRECT
50The preferred method of charging a Running R-410A system is: Liquid charging through the low pressure valve.Liquid charging through the high pressure valve.Vapor charging through the low pressure valve.Vapor charging through the high pressure valve.“A” IS CORRECT
51Which of the following recovery machine features will help prevent cross contamination between different types of refrigerants and oils?An oil-less compressor and pump down capabilities.A scroll compressor and an internal drier.A piston style compressor and internal oil separator.A built in sight glass and moisture indicator.“A” IS CORRECT
52Under which of the following circumstances may an R-22 expansion valve be used with R-410A? The R-22 expansion valve has an adjustable superheat control.The system capacity is less than 48,000 btu’s.The evaporator coil is rated for R-410A.Under no circumstances.“D” IS CORRECT
53R-410A is combustible if it is mixed with: Oil under a vacuum.Oil under pressure.Pressurized air.Pressurized nitrogen.“C” IS CORRECT