R-448A: Pros, Cons, & Comparisons to Other Refrigerants

Posted by Super Radiator Coils on Oct 14, 2022 8:41:47 AM

Our refrigerant focus series consists of deep dives into the history, properties, suitable applications and pros and cons of some of today’s common refrigerants. This installment will focus on R-448A.

History of R-448A as a Refrigerant

R-448A was developed between 2010 and 2015, the result of a collaborative effort among Honeywell, the University of Maryland, and Oak Ridge National Laboratory’s Building Technologies Research & Integration Center.

The stated goal of this research was to develop next-gen refrigerants, the performance of which would allow for a 50% reduction in energy consumption of the equipment in which it was used. Specifically, this work sought to synthesize a refrigerant to replace R-22, R-404A, and R-507 in low-to-medium temperature applications, such as supermarket refrigeration.

Properties of R-448A

R-448A is a low-toxicity, non-flammable blended refrigerant, classified by ASHRAE into safety group A1. It's is a 5-part zeotropic blend, made using a combination of hydrofluorocarbon and hydrofluoroolefin constituents at the concentrations outlined below.

  • R-32 (26%)
  • R-125 (26%)
  • R-134a (21%)
  • R-1234ze (7%)
  • R-1234yf (20%)

The table below shows R-448A’s properties compared to the properties of the refrigerants it is intended to replace.

 

R-448A R-404A R-22

Formula

R-32 (26%)

R-125 (26%)

R-134a (21%)

R-1234ze (7%)

R-1234yf (20%)

R-125 (44%)

R-143A (52%)

R-134A (4%)

CHCLF2

Molecular weight (g/mol)

86.3

97.6

86.47

Boiling Temp ˚F (˚C)

-43.27 (-45.9)

-51 (-46.2)

-41.4 (-40.8)

Critical Temp ˚F (˚C)

182.6 (83.7)

161.7 (72)

205 (96.1)

Critical pressure, PSI (Bar)

675.9 (46.6)

541 (37.7)

723.7 (49.9)

Global Warming Potential

~1320

3922

~1810

Ozone Depletion Percentage

0

0

0.05

ASHRAE Safety Group

A1

A1

A1

 

Performance Comparison of R-448A vs. R-404 & R-22

For a performance comparison, we’ve run a theoretical 6” x 70” 8-row copper-aluminum evaporator through our coil selection software, Enterprise. The coil’s airside and tube-side requirements are below and the coil’s rating is below that. 

Inputs

Airside

Tube-side

Airflow

4,000 SCFM

Refrigerant suction temp

35 ˚F

Target capacity

140,000 Btu/Hr.

Degrees superheat

6 ˚F

Entering air temp (dry bulb)

85 ˚F

Liquid temp

100 ˚F

Leaving air temp (dry blub)

55 ˚F

 

 

Air pressure

14.696 PSIA

 

 

 

Performance Comparison: R-448A vs. R-404A

 

R-448A

R-404A

Difference (%)

Difference (abs.)

Coil capacity

145,558 Btu/hr.

140,680 Btu/hr.

3.3%

4,878 Btu/hr.

Leaving air temp.

51.6°F

52.7°F

-2.6%

1.1°F

Refrigerant inlet temperature

33.7°F

42.7°F

-27%

9°F

Refrigerant pressure drop

7.694 PSI/coil

13.419 PSI/coil

-74%

5.725 PSI/coil

Refrigerant mass flow

2,179 lb./hr.

3,228 lb./hr.

-48%

1,049 lb./hr.

Circuit loading

12,130 Btu/hr.

11,723 Btu/hr.

3.3%

407 Btu/hr.

 

Performance Comparison: R-448A vs. R-22

 

R-448A

R-22

Difference (%)

Difference (abs.)

Coil capacity

145,558 Btu/hr.

144,347 Btu/hr.

0.8%

1,211 Btu/hr.

Leaving air temp.

51.6°F

51.9°F

0.6%

0.3°F

Refrigerant inlet temperature

33.7°F

40.1°F

19%

6.4°F

Refrigerant pressure drop

7.694 PSI/coil

6.905 PSI/coil

-10.2%

0.789 PSI/coil

Refrigerant mass flow

2,179 lb./hr.

2,082 lb./hr.

-4.4%

97 lb./hr.

Circuit loading

12,130 Btu/hr.

12,029 Btu/hr.

-0.8%

101 Btu/hr.

 

Pros & Cons of R-448A

R-448A: Pros

The chief benefit of R-448A is its lessened environmental impact relative to the refrigerants it was designed to replace. It’s non-ozone depleting and has a global warming potential of 1320, which is 37% less than R-22 and 197% less than R-404.

And, while R-448A’s performance compares similarly to R-22, that refrigerant has been nearly totally phased out. And when compared to the less-regulated R-404A, R-448A resulted in a per-coil capacity increase of just over 3%. R-448A also demonstrated a significantly lower (74%) pressure drop in our hypothetical application.

R-448A: Cons

One minor drawback of R-448A is that, due to it being a zeotropic mixture, it does have a temperature glide of between 5 and 8˚F – a variable that merits attention when designing equipment.

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