"Assessment of HCFCs and Environmentally Acceptable Alternatives"  

May 2010

• HFC-32 has been given an "ASHRAE A2 flammability" rating with a relatively low flame speed. There would be limited technical challenges in replacing R-410A with HFC-32. Products using HFC-32 have not yet been commercialised but development is taking place, particularly in China.  
• HFC-32, which can be more efficient than R-410A is likely to be used as an alternative to HCFC-22 and the higher GWP R-410A in many applications. HFC-32 systems are expected to be lower cost than the current R-410A systems
• Use of HFC-1234yf in chillers is expected.
• HFC-1234yf is flammable, (A2L)
• With a GWP of 4, the low toxicity substance HFC-1234yf qualifies for use in the EU under the EC F-Gas Directive.
• HFC-1234yf and a proprietary blend composed of HFC-1234zf or ze with two other HFCs are among those most prominently discussed p9
• Blends of HFC-1234yf with other HFC refrigerants can be applied as low-GWP alternatives to R-410A and R-407C. Systems using these blends are expected to be at a much higher cost than existing R-410A and R-407C systems.
• Chillers with R-407C require larger, more expensive heat exchangers to achieve competitive performance. The temperature glide makes R-407C unsuitable for use in larger chillers, which employ flooded evaporators.
• HC-290 (propane) is used in chillers in industrial applications. HC-290 and another hydrocarbon, HC-1270, are used in a limited number of small (<300 kW) air-cooled chiller installations in Europe
• HC-290 (propane) is the hydrocarbon refrigerant most likely to be applied in air conditioning applications. It has performance characteristics very close to those of HCFC-22. The most significant issue is its Class 3 (higher) flammability rating. P63
• Hydrocarbon refrigerants are expected to see increased usage in low charge packaged applications (less than 1 kg of refrigerant).
• Because of the relatively low liquid density of HCs, compared to most fluorinated refrigerants, approximately two to three times the cooling capacity is achievable with the same charge size.

In domestic refrigeration, about 63 % of newly produced refrigerators employ HFC-134a refrigerant. About 36 % employ hydrocarbon refrigerants mainly Isobutane (HC-600a).

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For car and light truck AC: R-744, HFC-152a and HFC-1234yf... have GWPs below the European MAC Directive threshold of 150.

Table 8-1: HCFCs and low-GWP alternatives p65

<!--[if !vml]--><!--[endif]-->"Scoping Study on HCFC Alternatives Under High Ambient Temperature Conditions"  

May 2010

The performance (capacity and efficiency) of R- 410A air-conditioners falls off more rapidly than HCFC-22 systems at high ambient temperatures p10 

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R-410A and R-407C both have lower critical temperatures than HCFC R-22. This occurs because HFC-125 (a component of both R-407C and R-410A) has a comparatively low critical point temperature of 66.0°C (150°F). Refrigerants having a low critical point temperature will exhibit a steeper decline in capacity with increased ambient (outdoor) temperatures.

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There are many regions globally where outdoor design conditions are high enough to result in condenser temperatures near or above the critical temperature of HFC-125.

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Table 2-4 compares the degradation in capacity as the condensing temperature is increased. The results show that R-410A shows the largest degradation (10 %) at 65C

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For an R-410A unit, the cost of increasing the capacity by 10 percent will increase the cost of the unit approximately 3 %.

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The primary global replacement for commercial refrigeration is R-404A, a blend of HFC refrigerants. Two of the three components of this blend are HFC-125 and HFC-143a, both having relatively low critical temperatures

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Table 1-1: Properties of the different refrigerants dealt with in this report p5

Also Just Announced

Honeywell and DuPont Form JV To Manufacture HFO-1234yf 

- The product meets European Union regulatory requirements for lower GWP refrigerants for automobile AC systems

 - Will begin supplying the refrigerant in the fourth quarter of 2011