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Goodman ® Brand R-410A Training

Goodman ® Brand R-410A Training. R410a Training . R410 Refrigerant… Why and When? Basic Refrigeration Cycle Importance of Airflow Superheat and Subcooling Installation Troubleshooting. R410a Refrigerant. What is it? Why and when will it be coming?. Definitions of Refrigerants

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Goodman ® Brand R-410A Training

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  1. Goodman® Brand R-410A Training

  2. R410a Training • R410 Refrigerant… Why and When? • Basic Refrigeration Cycle • Importance of Airflow • Superheat and Subcooling • Installation • Troubleshooting

  3. R410a Refrigerant What is it? Why and when will it be coming?

  4. Definitions 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.

  5. CFC, HCFC,HFC CFCs (chlorofluorocarbons) These have a high ozone‑depleting potential (ODP) contributing to the breakdown of the ozone layer, are banned bythe 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 theMontreal 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.

  6. % $20/lb 100 R-22 Cost Montreal Protocol/US Phase-Out 65% % 1996 CAP $10/lb 50 35% EU Phase-Out 10% $2/lb 0 1999 2004 2010 2015 2020 No New Equip. US No New Equip. EU R-22 Phase-Out Timeline • Production of new equipment is banned in Europe in 2004 and 2010 in US • Production of R-22 ends in Europe in 2010 and 2030 in US • Europe driving accelerated phase-out dates • All dates could be accelerated

  7. Why R-410a? • R-22 Alternatives • R-134a • R-407c • R-410a • R-417b • Propane • Carbon Dioxide

  8. R-410A Facts • Ozone friendly- No Chlorine • Replacement for R-22, NOT a drop in! • Higher Pressure Range-50 to 75% higher than R-22 • Requires Special Lubricants

  9. R-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.

  10. The Future Refrigerant R-410A • Azeotrope/Near Azeotrope • Temperature Glide • Fractionation

  11. R-410A • For 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”

  12. R-410A • Another 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.

  13. “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.

  14. Metering Devices • Metering 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).

  15. Thermal 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.

  16. Components that needed Redesigning for R-410A • Compressor • Condenser Coil • Filter Drier • Expansion Device • Evaporator • Pressure Switches

  17. Pressure Switches • Pressure Switches have to be at higher settings • Low Pressure R-410A = 50psi • High Pressure R-410A = 610psi

  18. Line 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.

  19. Special 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.

  20. Manifold Gauge Set • Standard 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.

  21. Refrigerant Hoses • The 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.

  22. Vacuum Pumps • Pumps 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.

  23. Leak Detectors • Leak 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.

  24. R-410A • The 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.

  25. Cylinders • Most 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) NOTE: Avoid storing R-410A where temperatures will exceed 120° F.

  26. Lubrication • The 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.

  27. Lubrication • The 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.

  28. Lubrication • 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.

  29. Lubrication • Any 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.

  30. Brazing • 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.

  31. Recovery • 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.

  32. Recovery • The 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.

  33. Charging 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.

  34. Thank you!

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