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