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2015 KULTHORN KIRBY Low GWP Refrigerant Interaction Lesson
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Transcript of 2015 KULTHORN KIRBY Low GWP Refrigerant Interaction Lesson
LOW GWP REFRIGERANTS These ‘alternative’ refrigerants possess different characteristics that affect their
suitability to be used, according to environmental, safety, cost and efficiency constraints but are considered as lower
GWP options.
Global Warming Potential (GWP)
HCFCs are gases or liquids
which evaporate easily
HCFCnon-toxic
(not poison-not bad)
HCFCs – HydroChloroFluoroCarbonHydrogen, Chlorine, Fluorine, and Carbon
Hydrocarbon
non-toxichigh
flammability miscible
miscibleFlammable liquids that are water miscible may have decreased flash
points when mixed with water.
Hydrocarbon (HC) R290 Propane is used in Commercial and Process Refrigeration
as a substitute for R22. Although Propane is non-toxic its mixture with air in certain proportions is explosive, trace levels of an odorant could be added to help identify a leak but most
odorants are too reactive for refrigeration systems. R1270 Propylene is a colorless, flammable, non-toxic gas and is part of the group of liquefied gases. It is used in high temperature
chilling applications as a substitute for R22 and R502. Like Propane, Propylene is flammable so inventory must be small to
reduce hazard. Like R290 and R1270, R600a Isobutane is a colourless, easily liquefied flammable gas. It is commonly used in refrigeration
applications, such as domestic refrigerators, drinks dispensers.
Hydrocarbon (HC)
substitute(replacement)
explosive(hazard)
(hazardous)
odorant(smell)
odorantsodorant (plural odorants). Any substance that has a distinctive (strong) smell.
Ammonia
Incompatible
(can’t work together)
Copper(metal with very high thermal and electrical
conductivity)
drop-in(REPLACEMENT)
Ammonia (NH3) R-717 Ammonia, or azane, is a
compound of nitrogen and hydrogen with the formula
NH3. It is a colorless gas with a characteristic pungent smell.
LOW GWP REFRIGERANTS
ammonia toxic low-flammability
Ammonia (NH3) R-717 Ammonia has been highly effective in industrial refrigeration plants for over 130 years. It is deemed environmentally friendly, economical and energy efficient. Its boiling point of -330C makes it possible to have refrigeration temperatures below -200C without reduced pressure. It is a colorless gas, slightly flammable and in some mixtures with air can be explosive. Ammonia can endure moderate water levels and is ideal for large scale chilling. It must not be used with copper, brass or
bronze and has a tendency for seal shrinkage.
DROP-IN ALTERNATIVES FOR R-12 REFRIGERANT?Though a number of alternative refrigerants are marketed as "drop-in" replacements for R-12, there is really no such thing as a true drop-in replacement. The reason why is because Federal law prohibits the topping off A/C systems with ANY refrigerant that is chemically different from what is already in the system, unless all of the old refrigerant is first removed so the system can be converted to the alternative refrigerant.There are, however, a number of alternative refrigerants that can be used in older vehicles with R-12 A/C systems, and most have been reviewed and approved by the EPA for retrofitting older R-12 A/C systems. Approved refrigerants must meet the EPA's SNAP (Significant New Alternatives Policy) criteria for environmental acceptability and usage.NOTE: The SNAP rules prohibit the use of flammable refrigerants (propane, butane and similar hydrocarbons) in mobile A/C systems because of their hazardous nature, and the SNAP rules prohibit the use of any other refrigerants that contain ozone-damaging CFCs. for more information about flammable refrigerants.
LOW GWP REFRIGERANTS
non-toxic non-flammable high operating pressure
Carbon Dioxide (CO2) R-744 CO2 has been used as a refrigerant since 1850 and is
now regaining popularity due to its low environmental impact. It has excellent thermodynamic properties including a high cooling capacity and is therefore
suitable for a large range of applications. Its ability to be in direct food contact makes it suitable for soft drinks chilling and ice-cream. It is non-flammable and non-
toxic. Moisture can cause corrosion in the steel pipework and ice formation. Ice can block small
capillary tubing which can lead to eventual system failure. R744 is also ideal as a secondary refrigerant. The refrigerant operates at extremely high pressure in the trans-critical state and efficiency is reduced when
operating in higher ambient temperatures.
Carbon Dioxide (CO2) R-744
moisture corrosive capillary tubing
Hydrofluoro Olefin (HFO) HFO-1234yf looks likely to become the refrigerant of
choice for automotive air conditioning in Europe. However it is yet to become commercially available outside of automotive and only sample quantities are
available for lubricant evaluation in stationary refrigeration and air conditioning.
HFO-1234ze is more commercially available as a foam blowing agent and testing is underway with refrigerant
suppliers, lubricant suppliers and OEM compressor manufacturers for evaluation in some industrial and
other refrigeration applications. Both of these HFO refrigerants are considered
mildly flammable. .
R-32 – Difluoromethane
non-toxic non-flammable candidate(solution)
R-32 - Difluoromethane R-32 has a GWP of 675 and ODP of 0. It is mildly flammable but not toxic. It is more
environmentally acceptable than other HFCs retaining the properties of the many
common HFCs which can offer less disruption and cost for wholesale
compressor and system changes that might be necessary for some non-HFC
refrigerants.
R-32 , also called Difluoromethane or HFC-32.
R-32 , also called Difluoromethane or HFC-32 , is an organic compound of
the dihalogenoalkane variety. It is based on methane, except that two of
the four hydrogen atoms have been replaced by fluorine atoms. Hence the formula is CH2F2 instead of CH4 for
normal methane.
January 2014 saw the revised EU Regulation of F-Gases following
publication of a draft proposal by the European Commission at the end of 2012. The much anticipated regulation changes
aim to strengthen the existing F-Gas Regulation and to 'encourage' the industry to move towards a HFC free market and
use of low GWP (Global Warming Potential) refrigerants.
An HFC free market and use of low GWP (Global Warming Potential) refrigerants.
Low GWP Refrigerant Interaction
(GWP-Global Warming Potential)
Prepared by
Ajarn CharlieMay 2015